A PROJECT REPORT ON ROAD CONSTRUCTION

IN

CIVIL ENGINEERING

(2010-2011)

2

SUMMER TRAINING REPORT

SUBMITTE BY:

RAMESH KUMAR

0622073407

B.TECH. IIIRD YEAR

(CIVIL ENGINEERING)

CHECKED BY:

3

……………………………… …………………………… …………………………… INTERNAL EXAMINER EXTERNAL

EXAMINAR PROJECT INCHARGE

PREFACE

As a part of course curriculum of b. tech we were asked to undergo 6 weeks summer training in any organization so as to give exposure to practical with various activities taking place in the organization.

I have put my sincere efforts to accomplish my objective within the stipulated time. Despite all limitation, obstructions, hurdle and hindrances, I have toiled and worked to my optimum potential to achieve desired goals. I put the best of my efforts and have also tried to be justice with available. If any where something is found unacceptable or unnecessary to the theme; you are welcome with your valuable suggestions.

Thanking you

Yours Sincerely

Ramesh Kumar

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ACKNOWLEDGEMENT

To matter what accomplishment we achieve somebody helps me. Forevery accomplishment we need the cooperation and help of others. Asknowledge advances by steps not by leaps so, ability advances byencouragement and guidance. Although you have ability and knowledgebut it is worthless unless and until you can develop it if somebodyencourages you.

While developing the project, I have learnt a lot. Firstly I got theexposure to the industry. We got to learn the work culture of a company.This will be an unforgetful experience. While developing this project, alot of difficulties were faced by me. But it was the help of some specialpeople that I have gained much confidence and developed the project

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quite well. Hereby, I shall like to thank all the employees of MCD tocoordinate with me and provide me the information needed to completethe analysis part of this project. I shall like to thank everyone who inanyway helped me in this project.

My heartiest thanks to Mr. KAMAL SINGH who helped me in providing the required infrastructure, good work culture, make me learn a lot of new things, guiding me throughout the project and for providing me such a golden opportunity to experience the work culture before actually working for a company.At last I am greatly thankful to the lectures of CH. B. P GOVT. ENGINEERING COLLEGE JAFFARPUR NEW DELHI whose inspiration &teaching are strong tool for completion of this training.

RAMESH KUMAR

INDEX

S.NO

TOPIC PAGE

1 ABOUT MCD 8

2 TYPES OF ROAD 103 HISTORY OF ROAD TRANSPORT 14

1. EARLY ROAD 14

2. HARAPPAN ROAD 14

4 MACADM 165 THE AMERICAN ROAD -1823-FIRST MACADAM 18

6 ASPHALT CONCRETE 257 CONSTRUCTION AGGREGATE 308 ROAD -SURFACE 33

6

9 CONCRETE 3510 ENVIRONMENTAL CONCERNS 5111 CONCRETE HANDLING /SAFETY PRECAUTION

53

12 GRAVEL ROAD59

13 ROAD DESIGN AND CONSTUCTION PROCEDURE62

PRELIMINARY SURVEYS 62

CNSTUCTION SURVEYS 65

CONSTRUCTION 67

MAINTENANCE 72

14 SOIL TREATMENT 76

15 TESTS 0N MATERIAL 84

(1).TEST ON AGGREGATEAGGREGATE IMPACT VALUE

84

(2).AGGREGATE CRUSHING VALUE 88

(3).SLUMP TEST 92

(4).COMPACTION FACTOR TEST

94

(5).SPECIFIC GRAVITY OF FINE AND COARSE AGGREGATES 96

(6)FLAKINESS INDEX AND ELONGATION INDEX OF COARSE AGGREGATE

100

(7).DETERMINATION OF LOS ANGLES ABRASION VALUE 104

(8).WATER ABSORPTION TEST

109

(9).TEST ON BITUMEN PENETRATION TEST

113

(10) DETERMINING SOFTINING POINT 117

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0F BITUMEN

(11) DETERMINING BITUMEN CONTENT 120

(12) DETERMINING SPECIFICGRAVITY OF BITUMEN

122

(13)DETERMINIG FLASH AND FIRE POINT BITUMEN 124

16 NAME OF WORK .1 127

1.COAST ESTIMATION

2.GOOGLE EARTH VIEW OF SITE OF WORK.1

3.ROUTE MAP OF CNSTRUCTION SITE OF WORK.1

17 NAME OF WORK.2 133

18 NAME OF WORK .3 135

ABOUT MCD

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The Municipal Corporation of Delhi is among the largest municipal bodies in the world providing civic services to more than estimated population of 13.78 million citizens in the capital city. It is next only to Tokyo in terms of area. Within its jurisdiction are some of the most densely populated areas in the world. It has also the unique distinction of providing civic services to rural and urban villages, Resettlement Colonies, regularised unauthorised colonies, JJ Squatter Settlements, slum 'basties, private 'katras' etc. MCD came into existance on the 7th of April, 1958 under and Act of Parliament. Since then, the Municipal Body has always been alive in its constitution and functioning to the growing needs of citizens. The Amendment of 1993 in the Act brought about fundemental changes in composition, functions, governance and administration of the Corporation. The entire MCD area is divided into 12 Zones.The Citizens' representatives in the corporation, namely councillors are always approachable for removal of grievances.

Municipal Corporation of Delhi : Services

 

It also works for the betterment of slums and squatter localities. The department functions separately from the state government so that it becomes easy for people to avail the facilities of every department depending upon their requirements. For their convenience, the Delhi Municipal Corporation/Nagar Nigam has divided the city into twelve different zones and their offices are located in every specific zone. 

It has also opened many recreational centers where one can take training of vocational courses where they give professional training so that one can open their own business as well. Under the act of 1957, the corporation also levies taxes including property tax, which is on residential as well as commercial properties and house tax, which is on residential property throughout the city. 

With improvement in the services in every sector and resource management, the Municipal Corporation of Delhi MCD has not only

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successfully accomplished but has also undertaken many challenging projects as well. Indiahousing.com appreciates the efforts of Municipal Corporation of Delhi India and provides you with their website as well as site address for further detailed information:

Types of road

Types of roads

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Various Types of road are in use around the world. Roads range in size from private driveways, to the two-lane highway, to high capacity dual carriageway routes, such as Freeways, Expressways, and High-quality dual carriageways.

The names associated with a particular type of road vary around the world, and

many names are partially equivalent but not exactly equivalent to each other. As a

result, the name given to a road in one country could apply to a different type of

road in another country. Details for each are covered in the specific articles about

each Type of road.

Road materials

Roads are constructed from many materials.

The material used depends on local conditions and other factors such as

1. The amount of traffic the road is designed for

2. And the weight of

the vehicles

allowed to use the

road.

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Some of the materials used to build roads and surface Pavement

(material) includes:

Asphalt concrete

Brick

Chipseal

Cobblestone

Concrete

Corduroy road

Gravel road

Ice road

Macadam

Plank road

Portland cement

Tarmac

Composite pavements

Whitetopping

Asphalt overlay over concrete

Descriptive road terms

Some terms used to describe roads cover characteristics of the road and can be

used on many types of roads. These terms include:

Grade separated interchange

Dual carriageway = divided highway

Toll road = turnpike

Low capacity

Low capacity roads are generally low speed local roads serving a

particular village, town, neighborhood, or city. They provide access to and from

roads designed with higher capacities and for higher speeds. They often also serve

the broadest variety of road users such

as pedestrians, automobiles, motorcycles, trucks, animals, wagons, and carriages.

This category includes:

Alley

Arterial road

Avenue

Backroad

Boulevard

Collector road

Court

Cul-de-sac

Dirt road

Driveway

Frontage road

Lane

Road

Single carriageway

Street

Winter road

High speed roads

Most countries have major roads of medium capacity that

connect cities, places, other routes, or other significant

points of interest. They may have multiple lanes of traffic,

a median or central reservation between lanes of

opposing traffic, and partial access control

(ramps and grade separation). Often they are restricted to

motorized vehicles that can maintain high speeds.

However, they can also be as simple as a two-lane

shoulderless road.

These roads go by names like:

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2+1 road

2+2 road

Farm to Market Road

Highway

Motorway

Parkway

High speed restricted access roads

Most high capacity roads are built to a higher standard

than general purpose roads. In order to provide for higher

traffic volumes, access is restricted to certain categories

of motorized vehicles and limited to a certain number of

access points where grade separations and ramps enable

through traffic to proceed without interruption. These high

capacity routes are almost always divided.

Autobahn

Auto-estrada

Autopista

Autostrada

Autostrasse

Expressway

Freeway

High-quality dual carriageway (HQDC)

Interstate Highway

Limited-access highways

Super two

Multi Modal

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Multi-modal roads: a newer concept which can include a

shared dedicated lane for:

High occupancy vehicle-HOV

Carpool lane - carpool

Bus

Lightrail tracks.

Bike paths (adjacent)

Example:

Transportation Expansion Project (Denver) — T-REX

History of road transport

The history of road transport started with the development of tracks by humans

and their beasts of burden.

Early roads

The first forms of road transport were horses, oxen or even humans carrying goods

over tracks that often followed game trails, such as the Natchez Trace.[1] In

the Stone Age humans did not need constructed tracks in open country. The first

improved trails would have been at fords, mountain passes and through swamps.[2] The first improvements would have consisted largely of clearing trees and big

stones from the path. As commerce increased, the tracks were often flattened or

widened to accommodate human and animal traffic. Some of these dirt tracks were

developed into fairly extensive networks,

allowing communications, tradeand governance over wide areas. The Incan

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Empire in South America and the Iroquois Confederation in North America, neither

of which had the wheel, are examples of effective use of such paths.

Harappan roads

Street paving has been found from the first human settlements around 4000 BC in

cities of the Indus Valley Civilization on theIndian subcontinent, such

as Harrapa and Mohenjo-daro.

Wheeled transport

Wheels appear to have been developed in ancient Sumer in Mesopotamia around

5000 BC, perhaps originally for the making of pottery. Their original transport use

may have been as attachments to travois or sleds to reduce resistance. It has been

argued that logs were used as rollers under sleds prior to the development of

wheels, but there is no archeological evidence for this. [6]Most early wheels appear to

have been attached to fixed axles, which would have required regular lubrication by

animal fats or vegetable oils or separation by leather to be effective. [7] The first

simple two-wheel carts, apparently developed from travois, appear to have been

used in Mesopotamia and northern Iran in about 3000 BC and two-

wheel chariots appeared in about 2800 BC. They were hauled by onagers, related

to donkeys.[7]

Early tar-paved roads

In the medieval Islamic world, many roads were built throughout the Arab Empire.

The most sophisticated roads were those of theBaghdad, Iraq, which were paved

with tar in the 8th century. Tar was derived from petroleum, accessed from oil

fields in the region, through the chemical process of destructive distillation.[11]

New construction methods in the 18th and 19th centuries

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As states developed and became richer, especially with the Renaissance, new roads

and bridges began to be built, often based on Roman designs. Although there were

attempts to rediscover Roman methods, there was little useful innovation in road

building before the 18th century.

Toll roads

England and Wales

As traffic levels increased in England, roads deteriorated. Toll roads were built

by Turnpike Trusts, especially between 1730-1770. It has been claimed that as a

result the time taken between London, to York, Manchester or Exeter was cut by

two-thirds between 1720 and 1780.[13] Blind Jack Metcalf (1717–1810) built about

300 km (180 miles) of turnpike road between 1753 and 1810, mainly

in Lancashire, Derbyshire, Cheshire and Yorkshire. He understood the importance of

good drainage and surfaced his roads with "a compact layer of small, broken stones

with sharp edges", rather than the naturally rounded stones traditionally used in

European road building. British turnpike builders began to realise the importance of

selecting clean stones for surfacing, and excluding vegetable material and clay to

make better lasting roads.

United States of America

Highways in the USA circa 1825

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Turnpikes were also later built in the United States. They were usually built by

private companies under a government franchise. They typically paralleled or

replaced routes already with some volume of commerce, hoping the improved road

would divert enough traffic to make the enterprise profitable. Plank roads were

particularly attractive as they greatly reduced rolling resistance and mitigated the

problem of getting mired in mud. Another improvement, better grading to lessen

the steepness of the worst stretches, allowed draft animals to haul heavier loads.

McAdam

John Loudon McAdam (1756–1836), another Scottish engineer, designed the first

modern roads. He developed an inexpensive paving material of soil and stone

aggregate (known as macadam), and he embanked roads a few feet higher than the

surrounding terrain to cause water to drain away from the surface. He had noticed

in his observations that coaches with narrow, iron-tyred wheels and moving at

relatively high speed were causing significant damage to roads, but that areas of

small broken stones were most resistant to damage, while the areas that had large

surface stones degraded fastest. His solution was to create roads with three layers

of stones laid on a crowned subgrade with side ditches for drainage. The first two

layers consisted of angular hand-broken aggregate, maximum size

3 inches (75 mm), to a total depth of about 8 inches (200 mm). The third layer was

about 2 inches (50 mm) thick with a maximum aggregate size of 1 inch (25 mm).

Each layer would be compacted with a heavy roller, causing the angular stones to

lock together with their neighbours. It is possible that his initial decision not to use

the heavy layer of base stones used by Telford in his subgrade reflected lack of

suitable stones, but McAdam quickly saw they were not necessary. In practice, his

roads proved to be twice as strong as Telford's roads.[22] He also insisted on raising

the roads to ensure good drainage and flat crowned surfaces, rather than ridges

built into the road to encourage drainage.[23]

McAdam was adamantly opposed to the filling of the voids between his small cut

stones with smaller material, possibly as a reaction against the use of poor

materials, including soil and vegetable matter, on roads in the past. Nevertheless, in

practice road builders began to introduce filler materials such as smaller stones,

sand and clay, and it was observed that these roads were stronger as a result.

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Macadam roads were being built widely in the United States and Australia in the

1820s and in Europe in the 1830s and 1840s.[24]

Development of modern paved roads

Various systems had been developed over centuries to reduce washaways, bogging

and dust in cities, including cobblestones and wooden paving. Tar-bound macadam

(tarmac) was applied to macadam roads towards the end of the 19th century in

cities such as Paris. In the early 20th century tarmac and concrete paving were

extended into the countryside.

Incidentally, bicyclists were among the early campaigners on what was called

the Good Roads Movement. Bicycling was an extremely popular recreation among

the middle and upper classes in the late 19th century and was more fun on paved

roads.

1823 - First American Macadam Road

19

\

20

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The first macadam surface in the United States was laid on the "Boonsborough Turnpike Road" between Hagerstown and Boonsboro, Maryland. By 1822, this section was the last unimproved gap in the great road leading from Baltimore on the Chesapeake Bay to Wheeling on the Ohio River. Stagecoaches using the road in winter needed 5 to 7 hours of travel to cover 10 miles.

Historic Pennsylvania Ave. was first paved with asphalt in 1876. In this photo, taken in 1907, crews repave with the equipment of the time.

Desirable qualities in pavements include durability, smoothness, quietness, ease of cleaning, and a nonslippery surface. The requirements conflict to a degree, so no one material is ideal in all respects. The foundation of a pavement must be crowned, or slightly arched, for rapid shedding of water; it must be strong enough to withstand heavy dynamic loads, but capable of responding to temperature changes. It has been estimated that some 27,000 tons of water fall annually on one mile of road.

In 1919, the Washington-Richmond Road near Dumfries, Va., about 30 miles (48 km) south of Washington, D.C., claimed this car. Mud was a serious problem before asphalt paving.

The deplorable conditions of the nations roads became a great public concern in the late nineteenth century with the invention of the bicycle and later the motor car. In the early 1890's bicycle clubs in the United States pushed hard for road improvements. These efforts brought about the "National League for Good Roads" in 1892. Continued dissatisfaction with the conditions of the nations roads resulted in the creation of the "Office of Road Inquiry" by Congress in 1893.

Thomas Telford, who was born in Eskdale, Scotland, in 1757, perfected the method of

Materials used in road construction

Asphalt concrete

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Asphalt concrete.

As shown in this cross-section, many older roadways are smoothed by applying a

thin layer of asphalt concreteto the existing portland cement concrete.

A layer of asphalt concrete. In road construction, a base layer of crushed rock is

usually laid down first to increase durability (see photo below)

23

Machine laying asphalt concrete, fed from a dump truck.

Asphalt concrete is a composite material commonly used for construction

ofpavement, highways and parking lots. It consists of asphalt (used as a binder) and

mineral aggregate mixed together, then laid down in layers and compacted.

The terms "asphalt (or asphaltic) concrete", "bituminous asphalt concrete" and the

abbreviation "AC" are typically used only in engineering and construction

documents and literature. Asphalt concrete pavements are often called just

"asphalt" by laypersons who tend to associate the term concrete with Portland

cement concreteonly. The engineering definition of concrete is any composite

material composed of mineral aggregate glued together with a binder, whether that

binder is Portland cement, asphalt or even epoxy. Informally, asphalt concrete is

also referred to as "blacktop

Mixture formulations

Mixing of asphalt and aggregate is accomplished in one of several ways:

Hot mix asphalt concrete (commonly abbreviated as HMAC or HMA) is

produced by heating the asphalt binder to decrease its viscosity, and drying the

aggregate to remove moisture from it prior to mixing. Mixing is generally

performed with the aggregate at about 300 °F (roughly 150 °C) for virgin asphalt

and 330 °F (166 °C) for polymer modified asphalt, and the asphalt cement at

200 °F (95 °C). Paving and compaction must be performed while the asphalt is

sufficiently hot. In many countries paving is restricted to summer months

because in winter the compacted base will cool the asphalt too much before it is

packed to the optimal air content. HMAC is the form of asphalt concrete most

commonly used on highly trafficked pavements such as those on

majorhighways, racetracks and airfields.

Warm mix asphalt concrete (commonly abbreviated as WMA or WAM) is

produced by adding either zeolites, waxes, or asphalt emulsions to the mix. This

allows significantly lower mixing and laying temperatures and results in lower

consumption of fossil fuels, thus releasing less carbon dioxide, aerosols and

vapours. Not only are working conditions improved, but the lower laying-

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temperature also leads to more rapid availability of the surface for use, which is

important for construction sites with critical time schedules. The usage of these

additives in hot mixed asphalt (above) may afford easier compaction and allow

cold weather paving or longer hauls.

Cold mix asphalt concrete is produced by emulsifying the asphalt in water

with (essentially) soap prior to mixing with the aggregate. While in its emulsified

state the asphalt is less viscous and the mixture is easy to work and compact.

The emulsion will break after enough water evaporates and the cold mix will,

ideally, take on the properties of cold HMAC. Cold mix is commonly used as a

patching material and on lesser trafficked service roads.

Cut-back asphalt concrete is produced by dissolving the binder in kerosene or

another lighter fraction of petroleum prior to mixing with the aggregate. While in

its dissolved state the asphalt is less viscous and the mix is easy to work and

compact. After the mix is laid down the lighter fraction evaporates.

Mastic asphalt concrete or sheet asphalt is produced by heating hard grade

blown bitumen (oxidation) in a green cooker (mixer) until it has become a

viscous liquid after which the aggregate mix is then added.

The bitumen aggregate mixture is cooked (matured) for around 6-8 hours

and once it is ready the mastic asphalt mixer is transported to the work site

where experienced layers empty the mixer and either machine or hand lay

the mastic asphalt contents on to the road. Mastic asphalt concrete is

generally laid to a thickness of around 3⁄4–1 3⁄16 inches (20-30 mm) for footpath

and road applications and around 3⁄8 of an inch (10 mm) for flooring or roof

applications.

In addition to the asphalt and aggregate, additives, such as polymers, and

antistripping agents may be added to improve the properties of the final

product.

Natural asphalt concrete can be produced from bituminous rock,

found in some parts of the world, where porous sedimentary rock near

the surface has been impregnated with upwelling bitumen.

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A landing strip, one of the uses of asphalt concrete

Asphalt concrete is often touted as being 100% recyclable. Several in-place

recycling techniques have been developed to rejuvenate oxidized binders

and remove cracking, although the recycled material is generally not very

water-tight or smooth and should be overlaid with a new layer of asphalt

concrete. Asphalt concrete that is removed from a pavement is usually

stockpiled for later use as a base course material. This reclaimed material,

commonly known by the acronym 'RAP' for recycled or reclaimed asphalt

pavement, is crushed to a consistent gradation and added to the HMA

mixing process. Very little asphalt concrete is actually disposed of

in landfills. Sometimes waste materials, such as rubber from old tires, are

added to asphalt concrete as is the case with rubberized asphalt, but there

is a concern that the hybrid material may not be recyclable.

Asphalt damaged by cryoturbation, or freezing of groundwater.

Asphalt deterioration can include alligator cracks, potholes, upheaval,

raveling, rutting, shoving, stripping, and grade depressions. In cold

26

climates, freezing of the groundwater underneath can crack asphalt even in

one winter (by cryoturbation). Filling the cracks with bitumen can

temporarily fix the cracks, but only proper construction, i.e. allowing water

to drain away from under the road, can slow this process.

Asphalt concrete pavements—especially those at airfields—are sometimes

called tarmac for historical reasons, although they do not contain tar and

are not constructed using the macadamprocess.

Performance characteristics

Asphalt concrete has different performance characteristics in terms of surface

durability, tire wear, braking efficiency and roadway noise. The appropriate asphalt

performance characteristic is obtained by the traffic level amount in categories

A,B,C,D,E, and friction coarse (FC-5). Asphalt concrete generates less roadway noise

than Portland cement concrete surfacing, and is typically less noisy than chip

seal surfaces. Tire noise effects are amplified at higher operating speeds. The sound

energy is generated through rolling friction converting kinetic energy to sound

waves. The idea that highway design could be influenced by acoustical engineering

considerations including selection of surface paving types arose in the very early

1970s.

Construction aggregate

27

Limestone quarry.

10 mm graded crushed rock or aggregate, for use in concrete. Called "blue metal"

in Australia.

20 mm graded aggregate.

28

Construction aggregate, or simply "aggregate", is a broad category of coarse

particulatematerial used in construction, including sand, gravel, crushed stone, slag,

recycled concrete and geosynthetic aggregates. Aggregates are a component

of composite materials such as concreteand asphalt concrete; the aggregate serves

as reinforcement to add strength to the overall composite material. Due to the

relatively high hydraulic conductivity value as compared to most soils, aggregates

are widely used in drainage applications such as foundation and french drains,

septic drain fields, retaining wall drains, and road side edge drains. Aggregates are

also used as base material under foundations, roads, and railroads. To put it

another way, aggregates are used as a stable foundation or road/rail base with

predictable, uniform properties (e.g. to help prevent differential settling under the

road or building), or as a low-cost extender that binds with more expensive cement

or asphalt to form concrete.

The American Society for Testing and Materials publishes an exhaustive listing of

specifications for various construction aggregate products, which, by their individual

design, are suitable for specific construction purposes. These products include

specific types of coarse and fine aggregate designed for such uses as additives to

asphalt and concrete mixes, as well as other construction uses. State transportation

departments further refine aggregate material specifications in order to tailor

aggregate use to the needs and available supply in their particular locations.

Sources for these basic materials can be grouped into three main areas: Mining of

mineral aggregate deposits, including sand, gravel, and stone; use of waste slag

from the manufacture of iron and steel; and recycling of concrete, which is itself

chiefly manufactured from mineral aggregates. In addition, there are some (minor)

materials that are used as specialty lightweight aggregates: clay, pumice, perlite,

and vermiculite

Modern production

The advent of modern blasting methods enabled the development of quarries,

which are now used throughout the world, wherever competent bedrock deposits of

aggregate quality exist. In many places, good limestone, granite, marble or other

29

quality stone bedrock deposits do not exist. In these areas, natural sand and gravel

are mined for use as aggregate. Where neither stone, nor sand and gravel, are

available, construction demand is usually satisfied by shipping in aggregate by

rail, barge or truck. Additionally, demand for aggregates can be partially satisfied

through the use of slag and recycled concrete. However, the available tonnages and

lesser quality of these materials prevent them from being a viable replacement for

mined aggregates on a large scale.

Over 1 million tons annually are mined from this quarry near San Francisco.[1]

Large stone quarry and sand and gravel operations exist near virtually all

population centers. These are capital-intensive operations, utilizing large earth-

moving equipment, belt conveyors, and machines specifically designed

for crushing and separating various sizes of aggregate, to create distinct product

stockpiles.

According to the USGS, 2006 U.S. crushed stone production was 1.72 billion tonnes

valued at $13.8 billion (compared to 1.69 billion tonnes valued at $12.1 billion in

2005), of which limestone was 1,080 million tonnes valued at $8.19 billion from

1,896 quarries, granite was 268 million tonnes valued at $2.59 billion from 378

quarries, traprock was 148 million tonnes valued at $1.04 billion from 355 quarries,

and the balance other kinds of stone from 729 quarries. Limestone and granite are

also produced in large amounts as dimension stone. The great majority of the

crushed stone moved by heavy truck from the quarry/plant to the first point of sale

or use. According to theUSGS, 2006 U.S. sand and gravel production was 1.32 billion

tonnes valued at $8.54 billion (compared to 1.27 billion tonnes valued at $7.46

billion in 2005), of which 264 million tonnes valued at $1.92 billion was used as

30

concrete aggregates. The great majority of this was again moved by truck, instead

of by electric train.

Currently, total U.S. aggregate demand by final market sector was 30%-35% for

non-residential building (offices, hotels, stores, manufacturing plants, government

and institutional buildings, and others), 25% for highways, and 25% for housing. [2]

Road surface  

A road in the process of being resurfaced

Road surface (British English) or pavement (American English) is the durable

surface material laid down on an area intended to sustain vehicular or foot traffic. In

the pastcobblestones and granite setts were extensively used, but these surfaces

have mostly been replaced by asphalt or concrete. Such surfaces are

31

frequently marked to guide traffic. Today,permeable paving methods are beginning

to be used for low-impact roadways and walkways.

Metalling

The term road metal refers to the broken stone or cinders used in the repair or

construction of roads or railways,[1] and is derived from theLatin metallum, which

means both "mine" and "quarry".[2] Metalling is known to have been used

extensively in the construction of roads by soldiers of the Roman

Empire (see Roman road) but a limestone-surfaced road, thought to date back to

the Bronze Age, has been found in Britain.[3] Metalling has had two distinct usages in

road surfacing. The term originally referred to the process of creating a gravel

roadway. The route of the roadway would first be dug down several feet and,

depending on local conditions, French drains may or may not have been added.

Next, large stones were placed and compacted, followed by successive layers of

smaller stones, until the road surface was composed of small stones compacted into

a hard, durable surface. "Road metal" later became the name of stone chippings

mixed with tar to form the road surfacing material tarmac. A road of such material

is called a "metalled road" in Britain, a "paved road" in the USA, or a "sealed road"

in Australia.

Asphalt

32

Closeup of asphalt on a driveway

Asphalt (specifically, asphalt concrete) has been widely used since 1920–1930. The

viscous nature of the bitumen binder allows asphalt concrete to sustain

significant plastic deformation, although fatigue from repeated loading over time is

the most common failure mechanism. Most asphalt surfaces are built on a gravel

base, which is generally at least as thick as the asphalt layer, although some 'full

depth' asphalt surfaces are built directly on the native subgrade. In areas with very

soft or expansive subgrades such as clay or peat, thick gravel bases or stabilization

of the subgrade with Portland cement or lime may be required. Polypropylene and

polyester materials have also been used for this purpose[5] and in some countries,

a foundation ofpolystyrene blocks has used, which has the added advantage of

providing a frost proof base.[6] The actual material used in paving is termed HMA

(Hot Mix Asphalt), and it is usually applied using afree floating screed.

An asphalt concrete surface will generally be constructed for high volume primary

highways having an Average Annual Daily Traffic load higher than 1200 vehicles per

day.[7] Advantages of asphalt roadways include relatively low noise, relatively low

cost compared with other paving methods, and perceived ease of repair.

Disadvantages include less durability than other paving methods, less tensile

strength than concrete, the tendency to become slick and soft in hot weather and a

certain amount of hydrocarbon pollution to soil and groundwater or waterways.

In the 1960s, rubberized asphalt was used for the first time, mixing crumb rubber

from used tires with asphalt. In addition to using tires that would otherwise fill

landfills and present a fire hazard, rubberized asphalt is more durable and provides

a 7–12 decibel noise reduction over conventional asphalt. However, application of

rubberized asphalt is more temperature-sensitive, and in many locations can only

be applied at certain times of the year.

Concrete

33

Concrete surfaces (specifically, Portland cement concrete) are created using a

concrete mix of Portland cement, gravel, sand and water. The material is applied in

a freshly-mixed slurry, and worked mechanically to compact the interior and force

some of the thinner cement slurry to the surface to produce a smoother, denser

surface free from honeycombing. The water allows the mix to combine molecularly

in a chemical action called hydration.

Concrete surfaces have been refined into three common types: jointed plain (JPCP),

jointed reinforced (JRCP) and continuously reinforced (CRCP). The one item that

distinguishes each type is the jointing system used to control crack development.

Jointed Plain Concrete Pavements (JPCP) contain enough joints to control the

location of all the expected natural cracks. The concrete cracks at the joints and not

elsewhere in the slabs. Jointed plain pavements do not contain any steel

reinforcement. However, there may be smooth steel bars at transverse joints and

deformed steel bars at longitudinal joints. The spacing between transverse joints is

typically about 15 feet for slabs 7–12 inches thick. Today, a majority of the U.S.

state agencies build jointed plain pavements.

Jointed Reinforced Concrete Pavements (JRCP) contain steel mesh reinforcement

(sometimes called distributed steel). In jointed reinforced concrete pavements,

designers increase the joint spacing purposely, and include reinforcing steel to hold

together intermediate cracks in each slab. The spacing between transverse joints is

typically 30 feet or more. In the past, some agencies used a spacing as great as 100

feet. During construction of the interstate system, most agencies in the Eastern and

Midwestern U.S. built jointed-reinforced pavement. Today only a handful of agencies

employ this design, and its use is generally not recommended as JPCP and CRCP

offer better performance and are easier to repair.

Continuously Reinforced Concrete Pavements (CRCP) do not require any transverse

contraction joints. Transverse cracks are expected in the slab, usually at intervals of

3–5 ft. CRCP pavements are designed with enough steel, 0.6–0.7% by cross-

sectional area, so that cracks are held together tightly. Determining an appropriate

spacing between the cracks is part of the design process for this type of pavement.

Continuously reinforced designs generally cost more than jointed reinforced or

jointed plain designs initially due to increased quantities of steel. However, they can

demonstrate superior long-term performance and cost-effectiveness. A number of

agencies choose to use CRCP designs in their heavy urban traffic corridors.

34

One advantage of cement concrete roadways is that they are typically stronger and

more durable than asphalt roadways. They also can easily be grooved to provide a

durable skid-resistant surface. Disadvantages are that they typically have a higher

initial cost and are perceived to be more difficult to repair.

The first street in the United States to be paved with concrete was Court Avenue

in Bellefontaine, Ohio, but the record for first mile of concrete pavement to be laid

in the United States is claimed by Michigan.

Composite surfaces

Composite surfaces combine Portland cement concrete and asphalt. They are

usually used to rehabilitate existing roadways rather than in new construction.

Asphalt overlays are sometimes laid over distressed concrete to restore a smooth

wearing surface. A disadvantage of this method is that the joints between the

underlying concrete slabs usually cause cracks, called reflective cracks in the

asphalt.

Whitetopping uses Portland cement concrete to resurface a distressed asphalt road.

Surface deterioration

35

Deteriorating asphalt.

As pavement systems primarily fail due to fatigue (in a manner similar to metals),

the damage done to pavement increases with the fourth power of the axle load of

the vehicles traveling on it. Civil Engineersconsider truck axle load, current and

projected truck traffic volume, supporting soil properties (can be measured using

the CBR) and sub-grade drainage in design. Passenger cars are considered to have

no practical effect on a pavement's service life, from a fatigue perspective.

Other failure modes include ageing and surface abrasion. As years go by, the binder

in a bituminous wearing course gets stiffer and less flexible. When it gets "old"

enough, the surface will start losing aggregates, and macrotexture depth increases

dramatically. If no maintenance action is done quickly on the wearing course

potholing will take place. If the road is stil structually sound, a bituminous surface

treatment, such as a chipseal or surface dressing can prolong the life of the road at

low cost. In areas with cold climate, studded tires may be allowed on passenger

cars. In Sweden and Finland, studded passenger car tires account for a very large

share of pavement rutting.

Several design methods have been developed to determine the thickness and

composition of road surfaces required to carry predicted traffic loads for a given

period of time. Pavement design methods are continuously evolving. Among these

are the Shell Pavement design method, and the American Association of State

Highway and Transportation Officials (AASHTO) 1993 "Guide for Design of Pavement

Structures". A new mechanistic-empirical design guide has been under development

by NCHRP (Called Superpave Technology) since 1998. A new design guide called

Mechanistic Empirical Pavement Design Guide (MEPDG) was developed and is about

to be adopted by AASHTO.

According to the AASHO Road Test, heavily loaded trucks can do more than 10,000

times the damage done by a normal passenger car. Taxrates for trucks are higher

than those for cars in most countries for this reason, though they are not levied in

proportion to the damage done.[18]

The physical properties of a stretch of pavement can be tested using a falling

weight deflectometer.

36

Further research by University College London into pavements has led to the

development of an indoor, 80-sq-metre artificial pavement at a research centre

called Pedestrian Accessibility and Movement Environment Laboratory (PAMELA). It

is used to simulate everyday scenarios, from different pavement users to varying

pavement conditions.[19] There also exists a research facility near Auburn University,

the NCAT Pavement Test Track, that is used to test experimental asphalt

pavements for durability.

ConcreteHistory

Concrete has been used for construction in various ancient civilizations.[4] An

analysis of ancient Egyptian pyramids has shown that concrete was employed in

their construction.[5]

During the Roman Empire, Roman concrete (or opus caementicium) was made

fromquicklime, pozzolana, and an aggregate of pumice. Its widespread use in

many Roman structures, a key event in the history of architecture termed

the Roman Architectural Revolution, freed Roman construction from the restrictions

of stone and brick material and allowed for revolutionary new designs both in terms

of structural complexity and dimension.[6]

Modern tests show that opus caementicium had as much compressive strength as

modern Portland-cement concrete (ca. 200 kg/cm2).[8] However, due to the absence

ofsteel reinforcement, its tensile strength was far lower and its mode of application

was also different:

Modern structural concrete differs from Roman concrete in two important details.

First, its mix consistency is fluid and homogeneous, allowing it to be poured into

forms rather than requiring hand-layering together with the placement of

aggregate, which, in Roman practice, often consisted of rubble. Second, integral

reinforcing steel gives modern concrete assemblies great strength in tension,

whereas Roman concrete could depend only upon the strength of the concrete

bonding to resist tension.[9]

37

Additives

Concrete additives have been used since Roman and Egyptian times, when it was

discovered that adding volcanic ash to the mix allowed it to set under water.

Similarly, the Romans knew that adding horse hair made concrete less liable to

crack while it hardened, and adding blood made it more frost-resistant.[11]

Recently, the use of recycled materials as concrete ingredients has been gaining

popularity because of increasingly stringent environmental legislation. The most

conspicuous of these is fly ash, a by-product of coal-fired power plants. This

significantly reduces the amount of quarrying and landfill space required, and, as it

acts as a cement replacement, reduces the amount of cement required.

In modern times, researchers have experimented with the addition of other

materials to create concrete with improved properties, such as higher strength or

electrical conductivity. Marconite is one example.

Cement and sand ready to be mixed.

Composition

There are many types of concrete available, created by varying the proportions of

the main ingredients below. By varying the proportions of materials, or by

substitution for the cemetitious and aggregate phases, the finished product can be

tailored to its application with varying strength, density, or chemical and thermal

resistance properties.

38

The mix design depends on the type of structure being built, how the concrete will

be mixed and delivered, and how it will be placed to form this structure.

Cement

Portland cement is the most common type of cement in general usage. It is a basic

ingredient of concrete, mortar, and plaster. English masonry worker Joseph

Aspdin patented Portland cement in 1824; it was named because of its similarity in

colour to Portland limestone, quarried from the English Isle of Portland and used

extensively in London architecture. It consists of a mixture of oxides

of calcium, silicon and aluminium. Portland cement and similar materials are made

by heating limestone (a source of calcium) with clay, and grinding this product

(calledclinker) with a source of sulfate (most commonly gypsum).

Water

Combining water with a cementitious material forms a cement paste by the process

of hydration. The cement paste glues the aggregate together, fills voids within it,

and allows it to flow more freely.

Less water in the cement paste will yield a stronger, more durable concrete; more

water will give an freer-flowing concrete with a higherslump.[12]

Impure water used to make concrete can cause problems when setting or in causing

premature failure of the structure.

Hydration involves many different reactions, often occurring at the same time. As

the reactions proceed, the products of the cement hydration process gradually bond

together the individual sand and gravel particles, and other components of the

concrete, to form a solid mass.

Reaction:

Cement chemist notation: C3S + H → C-S-H + CH

Standard notation: Ca3SiO5 + H2O → (CaO)·(SiO2)·(H2O)(gel) + Ca(OH)2

Balanced: 2Ca3SiO5 + 7H2O → 3(CaO)·2(SiO2)·4(H2O)(gel) + 3Ca(OH)2

39

Aggregates

Fine and coarse aggregates make up the bulk of a concrete

mixture. Sand, natural gravel and crushed stone are mainly used for

this purpose. Recycled aggregates (from construction, demolition and

excavation waste) are increasingly used as partial replacements of

natural aggregates, while a number of manufactured aggregates,

including air-cooled blast furnace slag and bottom ash are also

permitted.

Decorative stones such as quartzite, small river stones or crushed

glass are sometimes added to the surface of concrete for a decorative

"exposed aggregate" finish, popular among landscape designers.

Distribution of aggregates after compaction is inhomogeneous due to

the influence of vibration. As a result, gradients of strength may be

significant .

Installing rebar in a floor slab during a concrete pour.

Reinforcement

Concrete is strong in compression, as the aggregate efficiently carries

the compression load. However, it is weak in tension as the cement

holding the aggregate in place can crack, allowing the structure to

40

fail. Reinforced concrete solves these problems by adding eithersteel

reinforcing bars, steel fibers, glass fiber, or plastic fiber to carry tensile

loads.

Chemical admixtures

Chemical admixtures are materials in the form of powder or fluids that

are added to the concrete to give it certain characteristics not

obtainable with plain concrete mixes. In normal use, admixture

dosages are less than 5% by mass of cement, and are added to the

concrete at the time of batching/mixing.The common types of

admixtures] are as follows.

Accelerators  speed up the hydration (hardening) of the concrete.

Typical materials used are CaCl2 and NaCl. However, use of

chlorides may cause corrosion in steel reinforcing and is prohibited

in some countries.

Retarders  slow the hydration of concrete, and are used in large or

difficult pours where partial setting before the pour is complete is

undesirable. Typical polyol retarders are sugar, sucrose, sodium

gluconate, glucose, citric acid, and tartaric acid.

Air entrainments  add and entrain tiny air bubbles in the concrete,

which will reduce damage during freeze-thaw cycles thereby

increasing the concrete's durability. However, entrained air is a

trade-off with strength, as each 1% of air may result in 5% decrease

in compressive strength.

Plasticizers /superplasticizers (water-reducing admixtures) increase

the workability of plastic or "fresh" concrete, allowing it be placed

more easily, with less consolidating effort. Typical plasticizers are

liginsulfate, polyol type. Alternatively, plasticizers can be used to

reduce the water content of a concrete (and have been called water

reducers due to this application) while maintaining workability.

Such treatment improves its strength and durability characteristics.

Superplasticizers (high-range water-reducing admixtures) are a

41

class of plasticizers that have fewer deleterious effects when used

to significantly increase workability. Representative

superplasticizers are sulfonated naphthalene formaldehyde

condensate, sulfonated melamine, formaldehy condensate, and

acetone formaldehyde condensate. More advanced

superplasticizers are polycarboxylate types.

Pigments  can be used to change the color of concrete, for

aesthetics.

Corrosion inhibitors  are used to minimize the corrosion of steel and

steel bars in concrete.

Bonding agents are used to create a bond between old and new

concrete.

Pumping aids improve pumpability, thicken the paste, and reduce

separation and bleeding.

Mineral admixtures and blended cements

There are inorganic materials that also have pozzolanic or latent

hydraulic properties. These very fine-grained materials are added to

the concrete mix to improve the properties of concrete (mineral

admixtures),[13] or as a replacement for Portland cement (blended

cements).[15]

Fly ash : A by product of coal fired electric generating plants, it is

used to partially replace Portland cement (by up to 60% by mass).

The properties of fly ash depend on the type of coal burnt. In

general, silicious fly ash is pozzolanic, while calcareous fly ash has

latent hydraulic properties.[16]

Ground granulated blast furnace slag  (GGBFS or GGBS): A by-

product of steel production is used to partially replace Portland

cement (by up to 80% by mass). It has latent hydraulic properties.[17]

42

Silica fume : A by-product of the production of silicon

and ferrosilicon alloys. Silica fume is similar to fly ash, but has a

particle size 100 times smaller. This results in a higher surface to

volume ratio and a much faster pozzolanic reaction. Silica fume is

used to increase strength and durability of concrete, but generally

requires the use of superplasticizers for workability.

High reactivity Metakaolin (HRM): Metakaolin produces concrete

with strength and durability similar to concrete made with silica

fume. While silica fume is usually dark gray or black in color, high

reactivity metakaolin is usually bright white in color, making it the

preferred choice for architectural concrete where appearance is

important.

Concrete production

Concrete plant facility (background) with concrete delivery trucks.

The processes used vary dramatically, from hand tools to heavy

industry, but result in the concrete being placed where it cures into a

final form. Wide range of technological factors may occur during

production of concrete elements and their influence to basic

characteristics may vary (article of Maksym Bulavytskyi (Ukraine) at

www.concreteresearch.org)

When initially mixed together, Portland cement and water rapidly form

a gel, formed of tangled chains of interlocking crystals. These continue

43

to react over time, with the initially fluid gel often aiding in placement

by improving workability. As the concrete sets, the chains of crystals

join up, and form a rigid structure, gluing the aggregate particles in

place. During curing, more of the cement reacts with the residual

water (hydration).

This curing process develops physical and chemical properties. Among

other qualities,mechanical strength, low moisture permeability, and

chemical and volumetric stability.

Cement being mixed with sand and water to form concrete.

Mixing concrete

Thorough mixing is essential for the production of uniform, high quality

concrete. Therefore, equipment and methods should be capable of

effectively mixing concrete materials containing the largest specified

aggregate to produce uniform mixtures of the lowest slump practical

for the work.

Separate paste mixing has shown that the mixing of cement and water

into a paste before combining these materials with aggregates can

increase the compressive strength of the resulting concrete. The paste

is generally mixed in a high-speed, shear-type mixer at a w/cm (water

to cement ratio) of 0.30 to 0.45 by mass. The cement paste premix

44

may include admixtures such as accelerators or retarders,

plasticizers, pigments, orsilica fume. The latter is added to fill the gaps

between the cement particles. This reduces the particle distance and

leads to a higher final compressive strength and a higher water

impermeability. The premixed paste is then blended

with aggregates and any remaining batch water, and final mixing is

completed in conventional concrete mixing equipment.

High-energy mixed concrete (HEM concrete) is produced by means of

high-speed mixing of cement, water and sand with net specific

energy consumption at least 5 kilojoules per kilogram of the mix. It is

then added to aplasticizer admixture and mixed after that with

aggregates in conventional concrete mixer. This paste can be used

itself or foamed (expanded) for lightweight concrete.[22] Sand

effectively dissipates energy in this mixing process. HEM concrete fast

hardens in ordinary and low temperature conditions, and possesses

increased volume of gel, drastically reducing capillarity in solid and

porous materials. It is recommended for precast concrete in order to

reduce quantity of cement, as well as for concrete roof and siding tiles,

paving stones and lightweight concrete block production.

Pouring a concrete floor for a commercial building, slab-on-ground.

45

Concrete pump.

A concrete slab ponded while curing.

Workability

Workability is the ability of a fresh (plastic) concrete mix to fill the

form/mold properly with the desired work (vibration) and without

reducing the concrete's quality. Workability depends on water

content, aggregate (shape and size distribution), cementitious content

and age (level of hydration), and can be modified by adding chemical

admixtures. Raising the water content or adding chemical admixtures

will increase concrete workability. Excessive water will lead to

increased bleeding (surface water) and/or segregation of aggregates

(when the cement and aggregates start to separate), with the resulting

concrete having reduced quality. The use of an aggregate with an

undesirable gradation can result in a very harsh mix design with a very

46

low slump, which cannot be readily made more workable by addition of

reasonable amounts of water.

Workability can be measured by the concrete slump test, a simplistic

measure of the plasticity of a fresh batch of concrete following

the ASTM C 143 or EN 12350-2 test standards. Slump is normally

measured by filling an "Abrams cone" with a sample from a fresh batch

of concrete. The cone is placed with the wide end down onto a level,

non-absorptive surface. It is then filled in three layers of equal volume,

with each layer being tamped with a steel rod in order to consolidate

the layer. When the cone is carefully lifted off, the enclosed material

will slump a certain amount due to gravity. A relatively dry sample will

slump very little, having a slump value of one or two inches (25 or

50 mm). A relatively wet concrete sample may slump as much as eight

inches.

Slump can be increased by adding chemical admixtures such as mid-

range or high-range water reducing agents (super-plasticizers) without

changing the water-cement ratio. It is bad practice to add water on-site

that exceeds the water-cement ratio of the mix design, however in a

properly designed mixture it is important to reasonably achieve the

specified slump prior to placement as design factors such as air

content, internal water for hydration/strength gain, etc. are dependent

on placement at design slump values.

High-flow concrete, like self-consolidating concrete, is tested by other

flow-measuring methods. One of these methods includes placing the

cone on the narrow end and observing how the mix flows through the

cone while it is gradually lifted.

After mixing, concrete is a fluid and can be pumped to where it is

needed.

Concrete mixture placement

47

Concrete mixture placement

Concrete compaction

Concrete compaction

Curing

it may continue to strengthen for In all but the least critical

applications, care needs to be taken to properly cure concrete, and

achieve best strength and hardness. This happens after the concrete

has been placed. Cement requires a moist, controlled environment to

gain strength and harden fully. The cement paste hardens over time,

initially setting and becoming rigid though very weak, and gaining in

strength in the days and weeks following. In around 3 weeks, over 90%

of the final strength is typically reached, though decades.[23]

Hydration and hardening of concrete during the first three days is

critical. Abnormally fast drying and shrinkage due to factors such as

48

evaporation from wind during placement may lead to increased tensile

stresses at a time when it has not yet gained significant strength,

resulting in greater shrinkage cracking. The early strength of the

concrete can be increased by keeping it damp for a longer period

during the curing process. Minimizing stress prior to curing minimizes

cracking. High early-strength concrete is designed to hydrate faster,

often by increased use of cement that increases shrinkage and

cracking. Strength of concrete changes (increases) up to three years. It

depends on cross-section dimension of elements and conditions of

structure exploitation. Resulting strength distribution in vertical

elements researched and presented at the article "Concrete

Inhomogeneity of Vertical Cast-In-Place Elements In Skeleton-Type

Buildings"

During this period concrete needs to be in conditions with a controlled

temperature and humid atmosphere. In practice, this is achieved by

spraying or ponding the concrete surface with water, thereby

protecting concrete mass from ill effects of ambient conditions. The

pictures to the right show two of many ways to achieve this, ponding –

submerging setting concrete in water, and wrapping in plastic to

contain the water in the mix.

Properly curing concrete leads to increased strength and lower

permeability, and avoids cracking where the surface dries out

prematurely. Care must also be taken to avoid freezing, or overheating

due to the exothermic setting of cement (the Hoover Dam used pipes

carrying coolant during setting to avoid damaging overheating).

Improper curing can cause scaling, reduced strength, poor abrasion

resistance and cracking.

Properties

Concrete has relatively high compressive strength, but significantly

lower tensile strength, and as such is usually reinforced with materials

that are strong in tension (often steel). The elasticity of concrete is

49

relatively constant at low stress levels but starts decreasing at higher

stress levels as matrix cracking develops. Concrete has a very

low coefficient of thermal expansion, and as it matures concrete

shrinks. All concrete structures will crack to some extent, due to

shrinkage and tension. Concrete that is subjected to long-duration

forces is prone tocreep.

Tests can be made to ensure the properties of concrete correspond to

specifications for the application.

Environmental concerns

Worldwide CO2 emissions and global change

The cement industry is one of two primary producers of carbon

dioxide (CO2), creating up to 5% of worldwide emissions of this

gas, of which 50% is from the chemical process, and 40% from

burning fuel.The embodied carbon dioxide (ECO2) of one tonne of

concrete varies with mix design and is in the range of 75 – 175 kg

CO2/tonne concrete.The CO2 emission from the concrete

production is directly proportional to the cement content used in

the concrete mix. Indeed, 900 kg of CO2 are emitted for the

fabrication of every ton of cement. Cement manufacture

contributes greenhouse gases both directly through the production

of carbon dioxide when calcium carbonate is thermally

decomposed, producing lime and carbon dioxide,[27] and also

through the use of energy, particularly from the combustion

of fossil fuels. However, some companies have recognized the

problem and are envisaging solutions to counter their

CO2 emissions. The principle of carbon capture and

50

storage consists of directly capturing the CO2 at the outlet of the

cement kiln in order to transport it and to store the captured

CO2 in an adequate and deep geological formation.

Surface runoff

Surface runoff, when water runs off impervious surfaces, such as

non-porous concrete, can cause heavy soil erosion. Urban

runoff tends to pick up gasoline, motor oil, heavy metals, trash and

other pollutants from sidewalks, roadways and parking lots.[28]

[29] The impervious cover in a typical city sewer system prevents

groundwater percolation five times than that of a typical woodland

of the same size.[30] A 2008 report by the United States National

Research Council identified urban runoff as a leading source

of water quality problems.

Urban heat

Both concrete and asphalt are the primary contributors to what is

known as the urban heat island effect.

Using light-colored concrete has proven effective in reflecting up

to 50% more light than asphalt and reducing ambient

temperature. A lowalbedo value, characteristic of black asphalt,

absorbs a large percentage of solar heat and contributes to the

warming of cities. By paving with light colored concrete, in

addition to replacing asphalt with light-colored concrete,

communities can lower their average temperature.

Concrete dust

Building demolition, and natural disasters such as earthquakes

often release a large amount of concrete dust into the local

51

atmosphere. Concrete dust was concluded to be the major source

of dangerous air pollution following the Great Hanshin earthquake.

Health concerns

The presence of some substances in concrete, including useful and

unwanted additives, can cause health concerns.

Natural radioactiveelements (K, U and Th) can be present in

various concentration in concrete dwellings, depending on the

source of the raw materials used.Toxic substances may also be

added to the mixture for making concrete by unscrupulous

makers. Dust from rubble or broken concrete upon demolition or

crumbling may cause serious health concerns depending also on

what had been incorporated in the concrete.

Concrete handling/safety precautions

Handling of wet concrete must always be done with proper

protective equipment. Contact with wet concrete can cause skin

burns due to the caustic nature of the mixture of cement and

water.

52

Secondary efflorescence: Water seeping through the concrete,

often in cracks, having dissolved components of cement

stone.Osteoporosis of concrete often happens in parking garages,

as road salt comes off cars to the concrete floor as a saline

solution in the winter.

Damage modes

Concrete degradation

Concrete spalling caused by the corrosion ofreinforcement

bars after that carbonation of cement decreased the pH below the

passivation threshold for steel.

53

Concrete can be damaged by many processes such as, e.g., the

expansion of corrosion products of the steel reinforcement bars,

freezing of trapped water, fire or radiant heat, aggregate

expansion, sea water effects, bacterial corrosion, leaching, erosion

by fast-flowing water, physical damage and chemical damage

(from carbonation, chlorides, sulfates and distillate water).

Manufacturers of cement and concrete admixtures must keep on

top of microbiological contamination in raw materials,

intermediates and final products to prevent product spoilage. One

method of keeping controlling contamination is through 2nd

Generation ATP test.

Concrete repair

Concrete pavement preservation (CPP) and concrete pavement

restoration (CPR) are techniques used to manage the rate of

pavement deterioration on concrete streets, highways and

airports. Without changing concrete grade, this non-overlay

method is used to repair isolated areas of distress. CPP and

CPRtechniques include slab stabilization, full- and partial-depth

repair, dowel bar retrofit, cross stitching longitudinal cracks or

joints, diamond grinding and joint and crack resealing. CPR

methods, developed over the last 40 years, are utilized in lieu of

short-lived asphalt overlays and bituminous patches to repair

roads. These methods are often less expensivethan an asphalt

overlay but last three times longer and provide a greener solution.

CPR techniques can be used to address specific problems or bring

a pavement back to its original quality. When repairing a road,

design data, construction data, traffic data, environmental data,

previous CPR activities and pavement condition, must all be taken

into account. Pavements repaired using CPR methods usually last

15 years. The methods are described below.

54

Slab stabilization  restores support to concrete slabs by filling

small voids that develop underneath the concrete slab at joints,

cracks or the pavement edge.

Full-depth repairs fixes cracked slabs and joint deterioration by

removing at least a portion of the existing slab and replacing it

with new concrete.

Partial-depth repairs corrects surface distress and joint-crack

deterioration in the upper third of the concrete slab. Placing a

partial-depth repair involves removing the deteriorated

concrete, cleaning the patch area and placing new concrete.

Dowel bar retrofit  consists of cutting slots in the pavement

across the joint or crack, cleaning the slots, placing the dowel

bars and backfilling the slots with new concrete. Dowel bar

retrofits link slabs together at transverse cracks and joints so

that the load is evenly distributed across the crack or joint.

Cross-stitching longitudinal cracks or joints repairs low-severity

longitudinal cracks. This method adds reinforcing steel to hold

the crack together tightly.

Diamond grinding , by removing faulting, slab warping, studded

tire wear and unevenness resulting from patches, diamond

grinding, creates a smooth, uniform pavement profile. Diamond

grinding reduces road noise by providing a longitudinal texture,

which is quieter than transverse textures. The longitudinal

texture also enhances surface texture and skid resistance in

polished pavements.

Joint and crack sealing  minimizes the infiltration of surface

water and incompressible material into the joint system.

Minimizing water entering the joint reduces sub-grade

softening, slows pumping and erosion of the sub-base fines,

and may limit dowel-bar corrosion caused by de-icing

chemicals.

Concrete pumping

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The world record for vertical concrete pumping was achieved in

India by Schwing Stetter in August 2009.Concrete was pumped to

a height of 715m for the construction of the Parbati hydro-electric

power project in the Indian state of Himachal Pradesh.

Continuous pours

The world record for largest continuously poured concrete raft was

achieved in August, 2007 in Abu Dhabi by contracting firm, Al

Habtoor-CCC Joint Venture. The pour (a part of the foundation for

the Abu Dhabi's Landmark Tower) was 16,000 cubic meters of

concrete poured within a two day period.[42] The previous record

(close to 10,500 cubic meters) was held by Dubai Contracting

Company and achieved March 23, 2007.[43]

The world record for largest continuously poured concrete floor

was completed November 8, 1997 in Louisville, Kentucky by

design-build firm, EXXCEL Project Management. The monolithic

placement consisted of 225,000 square feet of concrete placed

within a 30 hour period, finished to a flatness tolerance of FF 54.60

and a levelness tolerance of FL 43.83. This surpassed the previous

record by 50% in total volume and 7.5% in total area.[44][45]

Building with concrete

Concrete is the safest, most durable and sustainable building

material. It provides superior fire resistance, gains strength over

time and has an extremely long service life. Concrete is the most

widely used construction material in the world with annual

consumption estimated at between 21 and 31 billion tonnes.

Concrete construction minimizes the long-term costs of a building

or infrastructure project.

Environmentally sustainable

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With its 100-year service life, concrete conserves resources by

reducing the need for reconstruction. Its ingredients are cement

and readily available natural materials: water, aggregate (sand

and gravel or crushed stone). Concrete does not require any

CO2 absorbing trees to be cut down. The land required to extract

the materials needed to make concrete is only a fraction of that

used to harvest forests for lumber.

The Baths of Caracalla, Rome, Italy, in 2003.

Concrete absorbs CO2 throughout its lifetime through carbonation,

helping reduce its carbon footprint. A recent study [46] indicates

that in countries with the most favorable recycling practices, it is

realistic to assume that approximately 86% of the concrete is

carbonated after 100 years. During this time, the concrete will

absorb approximately 57% of the CO2 emitted during the original

calcination. About 50% of the CO2 is absorbed within a short time

after concrete is crushed during recycling operations.

Concrete consists of between 7% and 15% cement, its only

energy-intensive ingredient. A study [47] comparing the

CO2 emissions of several different building materials for

construction of residential and commercial buildings found that

concrete accounted for 147 kg of CO2 per 1000 kg used, metals

accounted for 3000 kg of CO2 and wood accounted for 127 kg of

CO2. The quantity of CO2 generated during the cement

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manufacturing process can be reduced by changing the raw

materials used in its manufacture.

A new environmentally friendly blend of cement known as

Portland-limestone cement (PLC) is gaining ground all over the

world. It contains up to 15% limestone, rather than the 5% in

regular Portland cement and results in 10% less CO2 emissions

from production with no impact on product performance. Concrete

made with PLC performs similarly to concrete made with regular

cement and thus PLC-based concrete can be widely used as a

replacement. In Europe, PLC-based concrete has replaced about

40% of general use concrete. In Canada, PLC will be included in

the National Building Code in 2010. The approval of PLC is still

under consideration in the United States.

Energy efficiency

Energy requirements for transportation of concrete are low

because it is produced locally from local resources, typically

manufactured within 100 kilometers of the job site. Once in place,

concrete offers significant energy efficiency over the lifetime of a

building .[48] Concrete walls leak air far less than those made of

wood-frames. Air leakage accounts for a large percentage of

energy loss from a home. The thermal mass properties of concrete

increase the efficiency of both residential and commercial

buildings. By storing and releasing the energy needed for heating

or cooling, concrete's thermal mass delivers year-round benefits

by reducing temperature swings inside and minimizing heating

and cooling costs. While insulation reduces energy loss through

the building envelope, thermal mass uses walls to store and

release energy. Modern concrete wall systems use both insulation

and thermal mass to create an energy-efficient building. Insulating

Concrete Forms (ICFs) are hollow blocks or panels made of either

insulating foam or rastra that are stacked to form the shape of the

walls of a building and then filled with reinforced concrete to

create the structure.

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Models of Porsche automobiles, made out of concrete, part of an

exhibition, "Best of Austria," in the Lentos Museum in Linz,

Austria in 2009.

Gravel road

A gravel road, as often found in ruralareas and lesser-developed nations.

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A close-up of gravel road in Terre Haute, Indiana.

A gravel road is a type of unpaved road surfaced with gravel that has been

brought to the site from a quarry or stream bed. They are common in less-

developed nations, and also in the rural areas of developed nations such

as Canada and the United States. In New Zealand, they are known as 'metal roads'.[1] They may be referred to as 'dirt roads' in common speech, but that term is used

more for unimproved roads with no surface material added. If well constructed and

maintained, a gravel road is an all-weather road.

The gravel used consists of irregular stones mixed with a varying amount

of sand, silt, and clay, which can act as a binder. A gravel road is quite different

from a 'gravel drive', popular as privatedriveways in the United Kingdom. This uses

clean gravel consisting of uniform, rounded stones and small pebbles.

Characteristics

Construction

Compared to sealed roads, which require large machinery to work and

pour concrete or to lay and smooth a bitumen-based surface, gravel roads are easy

and cheap to build. However, compared to dirt roads, all-weather gravel highways

are quite expensive to build, as they requirefront loaders, dump

trucks, graders and roadrollers to provide a base course of hard-packed earth or

other material, sometimesmacadamised, covered with one or more different layers

of gravel. Graders are also used to produce a more extreme camber compared to a

paved road to aid drainage, as well as construct drainage ditches

and embankments in low-lying areas. Cellular confinement systems can be used to

prevent the washboarding effect.

.Maintenance

Gravel roads require much more frequent maintenance than paved roads,

especially after wet periods and when accommodating increased traffic. Wheel

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motion shoves material to the outside (as well as in-between travelled lanes),

leading to rutting, reduced water-runoff, and eventual road destruction if

unchecked. As long as the process is interrupted early enough, simple re-grading is

sufficient, with material being pushed back into shape.

Another problem with gravel roads is washboarding — the formation of

corrugations across the surface at right angles to the direction of travel. They can

become severe enough to cause vibration in vehicles so that bolts loosen or cracks

form in components. Grading removes the corrugations, and reconstruction with

careful choice of good quality gravel can help prevent them re-forming. Additionally,

installing acellular confinement system will prevent the washboard-like corrugations

from occurring.

Gravel roads are often found in cold climates because they are less vulnerable to

freeze / thaw damage than asphalt roads and also because the inferior surface of

gravel is not an issue if the road is covered by snow and ice for extended periods.

Driving

Although well-constructed and graded gravel roads are suitable for speeds of 100

km/h (60 mph), driving on them requires far more attention to variations of the

surface and it is easier to lose control than on a paved road. In addition to potholes,

ruts and loose stony or sandy ridges at the edges or in the middle of the road,

problems associated with driving on gravel roads include:

sharper and larger stones cutting and puncturing tires, or being thrown up by

the wheels and damaging the underside, especially puncturing the fuel tank of

unmodified cars

stones skipping up hitting the car body, lights or windshields when two vehicles

pass

dust thrown up from a passing vehicle reducing visibility

'washboard' corrugations cause loss of control or damage to vehicles

skidding on mud after rain

in higher rainfall areas, the increased camber required to drain water, and open

drainage ditches at the sides of the road, often cause vehicles with a high centre

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of gravity, such as trucks and off-road vehicles, to overturn if they do not keep

close to the crown of the road.

Tire wear increases by 40%-50% on Gravel Roads

Excess dust permeates door-opening rubber moulding breaking the seal

Lost binder in the form of road dust, when mixed with rain, will wear away the

painted surfaces of vehicles

ROAD DESIGN AND CONSTRUCTION PROCEDURE

ROAD AND BRIDGE RECONSTRUCTION IMPROVEMENTS ARE PRIORITIZED BASE ON PUBLIC INPUT, PUBLIC HEARINGS, ENGINEERING JUDGMENT AND AVAILABILITY OF FUNDING SOURCES. ONCE A PROJECT HAS BEEN APPROVED AND SCHEDULED ON THE COUNTY'S FIVE YEAR CONSTRUCTION PROGRAM THE COUNTY ENGINEER IS DIRECTED TO BEGIN PRELIMINARY SURVEYS USED FOR DESIGN. THE FOLLOWING IS A RECAP OF THIS PROCEDURE:

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PRELIMINARY SURVEYS

1. PRELIMINARY MAPPING SURVEY

MAP THE ENTIRE AREA WHERE THE NEW ROAD CONSTRUCTION WILL TAKEPLACE TO ENABLE ESTABLISHMENT OF THE NEW HIGHWAY LOCATION.

BENCH MARKS EVERY 1000 FEET OVER THE ENTIRE PROJECT

1. BENCH MARKS

ESTABLISH LENGTH, REFERENCED TO SEA LEVEL ELEVATION.

2. ALIGNMENT

ESTABLISH THE NEW ALIGNMENT OF THE HIGHWAY ON THE ENTIRE LENGTH OF THE PROJECT, INCLUDING PUBLIC ROAD CONNECTIONS.

(1) ASURE AND ESTABLISH SURVEY POINTS EVERY 100 FEET.

(2) SET REFERENCE POINTS TO PRESERVE THE NEW ROAD

ALIGNMENT (APPROXIMATELY 30 PER MILE).

3. PROPERTY CORNERS

LOCATE ALL EXISTING PROPERTY CORNERS ADJACENT TO THE NEW HIGHWAYAND REFERENCE THEM TO THE NEW CENTERLINE.

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4. TOPOGRAPHY

REFERENCE ALL PHYSICAL LAND FEATURES TO THE NEW HIGHWAYCENTERLINE (BUILDINGS, FENCES, TREES, DRIVEWAYS, ROAD CONNECTIONS,WETLAND, LAKES, RIVERS, UTILITY POLES, CABLES, PEDESTALS, CULVERTS, ETC.) TO A POINT 100 FEET (MINIMUM) ON EACH SIDE OF THE NEW HIGHWAY CENTERLINE.

5. CROSS SECTIONS

ESTABLISH SEA LEVEL ELEVATIONS OF THE EXISTING GROUND SURFACEEVERY 30 - 50 FEET TO A POINT 100 FEET ON EACH SIDE OF THE NEW HIGHWAY CENTERLINE OVER THE ENTIRE PROJECT LENGTH, (APPROXIMATELY 115 CROSS SECTIONS PER MILE).

6. SOILS SURVEY

SOIL BORINGS ARE TAKEN WITH A DRILL RIG AND BY HAND AUGER TO A POINT 100 FEET ON EACH SIDE OF THE NEW HIGHWAY CENTERLINE, ( A MINIMUM OF 25 BORINGS PER MILE), AND THE SOILS CLASSIFIED.

7. SWAMP SOUNDINGS

THE DEPTH OF THE MUCK AND PEAT MATERIAL IS MEASURED IN ALL

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WETLANDS AND RIVERS WITHIN 100 FEET OF THE NEW HIGHWAY CENTERLINE. (APPROXIMATELY 30 SOUNDINGS PER ACRE).

8. RIGHT OF WAY ACQUISITION

THE RIGHT OF WAY AND SLOPE EASEMENT LIMITS OF THE NEW HIGHWAYINCLUDING PROPERTY LINES, ARE STAKED EVERY 100 FEET (MINIMUM) ON EACH SIDE OF THE HIGHWAY FOR APPRAISAL OF THE PROPERTY AND RIGHT OF WAY NEGOTIATIONS.

9. ADDITIONAL SURVEYS

HIGHWAY AND BRIDGE CONSTRUCTION PROJECTS WHICH AFFECT WETLANDS, LAKES AND RIVERS REQUIRE ADDITIONAL SURVEYS AND ATTENTION TO DETERMINE THE TOTAL IMPACT TO THE AREA. THIS DATA IS NEEDED TO OBTAIN PERMITS FROM THE MINNESOTA DEPARTMENT OF NATURAL RESOURCES AND THE U.S. ARMY CORPS OF ENGINEERS AND ALSO FOR NOTIFYING THE OTHER AGENCIES THAT MAY BE INVOLVED WITH THE PROPOSED CONSTRUCTION (MINNESOTA POLLUTION CONTROL AGENCY, STATE HISTORIC PRESERVATION OFFICER, ETC.) ALONG WITH PERMITS THERE MAY BE REPORTS REQUIRED TO BE WRITTEN DESCRIBING CERTAIN ENVIRONMENTAL ISSUES WHICH AT THE MINIMUM TAKE 60 DAYS FOR REVIEW.

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CONSTRUCTION SURVEYS

1. PRIOR TO CONSTRUCTION OPERATIONS

(1) RE-ESTABLISH THE NEW HIGHWAY CENTERLINE (SET

SURVEY POINTS EVERY 100 FEET ON THE NEW CENTERLINE). (2) SET STAKES TO MARK THE LIMITS OF TREE AND BRUSH REMOVAL AT THERIGHT OF WAY LIMITS (APPROXIMATELY 150 STAKES PER MILE).

1. AFTER COMPLETION OF THE TREES AND BRUSH REMOVAL

(1) RE-ESTABLISH THE NEW HIGHWAY CENTERLINE, (THE CENTERLINEESTABLISHED IN STEP NO. 1 IS PARTIALLY DESTROYED DURING THE TREE AND BRUSH REMOVAL OPERATIONS).

(2) SET CONSTRUCTION STAKES:

A. CENTERLINE REFERENCE STAKES ARE SET EVERY 100 FEET ON EACH SIDEOF THE NEW HIGHWAY BEYOND THE CONSTRUCTION LIMITS TO ENABLE THECONTRACTOR TO LOCATE THE NEW HIGHWAY CENTERLINE, SHOULDER ANDDITCH BOTTOM ELEVATION.

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B. SLOPE STAKES ARE ALSO SET EVERY 100 FEET (MINIMUM) ON EACHSIDE OF THE NEW HIGHWAY CENTERLINE WHICH ESTABLISH THE CUT OR FILLPOINT OF THE NEW CONSTRUCTION.

C. STAKES ARE SET AT ALL NEW CROSS CULVERTS WHICH INDICATE THELOCATION AND ELEVATION OF THE INLET AND OUTLET OF THE CULVERT.

D. ADDITIONAL STAKES ARE SET IN VARIOUS AREAS FOR CURB AND GUTTERAND STORM SEWER CONSTRUCTION AND OTHER SPECIAL CONSTRUCTIONITEMS.

3. WHEN THE EARTHWORK PORTION OF THE CONSTRUCTION IS NEAR COMPLETION

STAKES (BLUE TOPS) ARE SET ON THE NEW HIGHWAY CENTERLINE AND SHOULDER LINE EVERY100 FEET (MINIMUM) AND DRIVEN TO THE ELEVATION INDICATED IN THE CONSTRUCTION PLANS.

THE "BLUE TOPS" ARE THEN USED BY THE CONTRACTOR TO PERFORM THE FINAL FINISH TO THE NEW HIGHWAY PRIOR TO CONSTRUCTING THE AGGREGATE BASE AND BITUMINOUS SURFACE MATERIALS.WHEN THE FINISH

4. EROSION CONTROL

ING OF THE SLOPES AND DITCH BOTTOMS AND REPLACEMENT OF THE TOPSOIL ARE COMPLETE, SODDING STAKES ARE SET FOR THE CONTRACTOR TO PLACE SOD ON VARIOUS AREAS OF THE SHOULDERS AND DITCH BOTTOMS TO PREVENT EROSION. STAKES ARE ALSO SET FOR OTHER EROSION CONTROL MATERIALS SUCH AS STRAW MULCH, ROCK RIPRAP, ETC.

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5. WHEN THE PROJECT IS COMPLETE

FINAL MEASUREMENTS ARE TAKEN ON THE CONTRACT ITEMS TO DETERMINE A OVERRUN OR UNDERRUN OF QUANTITY, SUCH AS BORROW PITS, CONCRETE ITEMS, SOD, SEEDING, ETC. TO ARRIVE AT FINAL PAYMENT FOR THE CONTRACTOR.

IF THE MANY TRIPS AND TIME ELEMENT INVOLVED WITH A NEW PROJECT FROM START TO FINISH IS MUCH LONGER THEN SEEMS REASONABLE, THEN I HOPE THIS ARTICLE WILL BE HELPFUL IN UNDERSTANDING THE HIGHWAYDEPARTMENT'S ASSIGNED RESPONSIBILITIES TO RECONSTRUCT A ROAD OR BRIDGE.

Construction

A road being torn up.

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Surveyor at work with a leveling instrument.

Asphalt layer and roller

Sub-base layer composed of cement-based material being applied during construction of

the M8 motorway in Ireland.

Road construction requires the creation of a continuous right-of-way, overcoming geographic obstacles and having grades low enough to permit vehicle or foot travel. and may be required to meet standards set by law or official guidelines.The process is often begun with the removal of earth and rock by digging or blasting, construction of embankments, bridges andtunnels, and removal of vegetation (this may involve deforestation) and followed by the laying of pavement material. A variety of road building equipment is employed in road building.

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After design, approval, planning, legal and environmentalconsiderations have been addressed alignment of the road is set out by a surveyor.The Radiiand gradient are designed and staked out to best suit the natural ground levels and minimize the amount of cut and fill.Great care is taken to preserve reference Benchmarks 

Roadways are designed and built for primary use by vehicular and pedestrian traffic. Storm drainage and environmental considerations are a major concern. Erosion and sediment controls are constructed to prevent detrimental effects. Drainage lines are laid with sealed joints in the road easement with runoff coefficients and characteristics adequate for the land zoning and storm water system. Drainage systems must be capable of carrying the ultimate design flow from the upstream catchment with approval for the outfall from the appropriate authority to a watercourse,creek, river or the sea for drainage discharge.

A Borrow pit (source for obtaining fill, gravel, and rock) and a water source should be located near or in reasonable distance to the road construction site. Approval from local authorities may be required to draw water or for working (crushing and screening) of materials for construction needs. The top soil and vegetation is removed from the borrow pit and stockpiled for subsequentrehabilitation of the extraction area. Side slopes in the excavation area not steeper than one vertical to two horizontal for safety reasons

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Road construction on Marquette Avenue in Minneapolis, Minnesota, United States

Old road surfaces, fences, and buildings may need to be removed before construction can begin. Trees in the road construction area may be marked for retention. These protected trees should not have the topsoil within the area of the tree's drip line removed and the area should be kept clear of construction material and equipment. Compensation or replacement may be required if a protected tree is damaged. Much of the vegetation may be mulched and put aside for use during reinstatement. The topsoil is usually stripped and stockpiled nearby for rehabilitation of newly constructed embankments along the road. Stumps and roots are removed and holes filled as required before the earthwork begins. Final rehabilitation after road construction is completed will include seeding, planting, watering and other activities to reinstate the area to be consistent with the untouched surrounding areas.)

Processes during earthwork include excavation, removal of material to spoil, filling, compacting, construction and trimming. If rock or other unsuitable material is discovered it is removed, moisture content is managed and replaced with standard fill compacted to 90% relative compaction. Generally blasting of rock is discouraged in the road bed. When a depression must be filled to come up to the road grade the native bed is compacted after the topsoil has been removed. The fill is made by the "compacted layer method" where a layer of fill is spread then compacted to specifications, the process is repeated until the desired grade is reached.

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Typical pavement strata for a heavily traveled road

General fill material should be free of organics, meet minimum California bearing ratio (CBR) results and have a low plasticity index. The lower fill generally comprises sand or a sand-rich mixture with fine gravel, which acts as an inhibitor to the growth of plants or other vegetable matter. The compacted fill also serves as lower-stratum drainage. Select second fill (sieved) should be composed of gravel, decomposed rock or broken rock below a specified Particle sizeand be free of large lumps of clay. Sand clay fill may also be used. The road bed must be "proof rolled" after each layer of fill is compacted. If a roller passes over an area without creating visible deformation or spring the section is deemed to comply.

The completed road way is finished by paving or left with a gravel or other natural surface. The type of road surface is dependent on economic factors and expected usage. Safety improvements likeTraffic signs, Crash barriers, Raised pavement markers, and other forms of Road surface markingare installed.

According to a May 2009 report by the American Association of State Highway and Transportation Officials (AASHTO) and TRIP—a national

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transportation research organization—driving on rough roads costs the average American motorist approximately $400 a year in extra vehicle operating costs. Drivers living in urban areas with populations more than 250,000 are paying upwards of $750 more annually because of accelerated vehicle deterioration, increased maintenance, additional fuel consumption, and tire wear caused by poor road conditions.

When a single carriageway road is converted into dual carriageway by building a second separate carriageway alongside the first, it is usually referred to as duplication, twinning or doubling. The original carriageway is changed from two-way to become one-way, while the new carriageway is one-way in the opposite direction. In the same way as converting railway lines from single track to double track, the new carriageway is not always constructed directly alongside the existing carriageway.

Maintenance

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Like all structures, roads deteriorate over time. Deterioration is primarily due to accumulated damage from vehicles, however environmental effects such as frost heaves, thermal cracking and oxidation often contribute.[25] According to a series of experiments carried out in the late 1950s, called the AASHO Road Test, it was empirically determined that the effective damage done to the road is roughly proportional to the 4th power of axle weight.[26] A typical tractor-trailer weighing 80,000 pounds (36.287 t) with 8,000 pounds (3.6287 t) on the steer axle and 36,000 pounds (16.329 t) on both of the tandem axle groups is expected to do 7,800 times more damage than apassenger vehicle with 2,000 pounds (0.907 t) on each axle. Potholes on roads are caused by rain damage and vehicle braking or related construction works.

Pavements are designed for an expected service life or design life. In some UK countries the standard design life is 40 years for new bitumen and concrete pavement. Maintenance is considered in the whole life cost of the road with service at 10, 20 and 30 year milestones.[27]Roads can be and are designed for a variety of lives (8-, 15-, 30-, and 60-year designs). When pavement lasts longer than its intended life, it may have been overbuilt, and the original costs may have been too high. When a pavement fails before its intended design life, the owner may have excessive repair and rehabilitation costs. Many concrete pavements built since the 1950s have significantly outlived their intended design lives.[28] Some roads like Chicago, Illinois's "Wacker Drive", a major two-level viaduct in downtown area are being rebuilt with a designed service life of 100 years.[29]

Virtually all roads require some form of maintenance before they come to the end of their service life. Pro-active agencies continually monitor road conditions and apply preventive maintenance treatments as needed to prolong the lifespan of their roads. Technically advanced agencies monitior the road network surface condition with sophisticated equipment such as laser/inertial Profilometers. These measurements include road curvature, cross slope, unevenness, roughness, rutting and texture (roads). This data is fed into a pavement management system, which recommends the best maintenance or construction treatment to correct the damage that has occurred.

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Maintenance treatments for asphalt concrete generally include crack sealing, surface rejuvenating, fog sealing, micro-milling and surface treatments. Thin surfacing preserves, protects and improves the functional condition of the road while reducing the need for routing maintenance, leading to extended service life without increasing structural capacity.

Failure to maintain roads properly can create significant costs to society, in a 2009 report released by the American Association of State Highway and Transportation Officials (USA) about 50% of the roads in the USA are in bad condition with urban areas worse. The report estimates that urban drivers pay an average of $746/year on vehicle repairs while the average US motorist pays about $335/year. In contrast, the average motorist pays about $171/year in road maintenance taxes (based on 600 gallons/year and $0.285/gallon tax).

Slab Stabilization

Distress and serviceability loss on concrete roads can be caused by loss of support due to voids beneath the concrete pavement slabs. The voids usually occur near cracks or joints due to surface water infiltration. The most common causes of voids are pumping, consolidation, subgrade failure and bridge approach failure. Slab stabilization is a non-destructive method of solving this problem and is usually employed with other Concrete Pavement Restoration (CPR) methods including patching and diamond grinding. The technique restores support to concrete slabs by filing small voids that develop underneath the concrete slab at joints, cracks or the pavement edge. The process consists of pumping a cementitous grout or polyurethane mixture through holes drilled through the slab. The grout can fill small voids beneath the slab and/or sub-base. The grout also displaces free water and helps keep water from saturating and weakening support under the joints and slab edge after stabilization is complete. The three steps for this method after finding the voids are locating and drilling holes, grout injection and post-testing the stabilized slabs.

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Slab stabilization does not correct depressions, increase the design structural capacity, stop erosion or eliminate faulting. It does, however, restore the slab support, therefore, decreasing deflections under the load. Stabilization should only be performed at joints and cracks where loss of support exists. Visual inspection is the simplest manner to find voids. Signs that repair is needed are transverse joint faulting, corner breaks and shoulder drop off and lines at or near joints and cracks. Deflection testing is another common procedure utilized to locate voids. It is recommended to do this testing at night as during cooler temperatures, joints open, aggregate interlock diminishes and load deflections are at their highest.

Another testing method is ground penetrating radar. It pulses electromagnetic wave technology into the pavement and then ceases the transmission during which the transmitter-receiver detects signals that are deflected from the pavement. Yet another method is the epoxy/core test, which confirms void presence by visual and mechanical methods. It consists of drilling a 25 to 50 millimeter hole through the pavement and into the sub-base with a dry-bit roto-hammer. Next, a two-part epoxy is poured into the hole that is dyed for visual clarity. Once the epoxy is hardened, the technicians drill through the hole. If a void is present, the epoxy will stick to the core and provide physical evidence.

Common stabilization materials are pozzolan-cement grout and polyurethane. The requirements for slab stabilization are strength and the ability to flow into or expand to fill small voids. Colloidal mixing equipment is necessary to use the pozzolan-cement grouts. The contractor should place the grout using a positive-displacement injection pump or a non-pulsing progressive cavity pump. A drill is also necessary but it must produce a clean hole with no surface spalling or breakouts. The injection devices must include a grout packer that is capable of sealing a hole. The injection device must also have a return hose or a fast-control reverse switch in case workers detect slab movement on the uplift gauge. The uplift beam helps to monitor the slab deflection and has to have sensitive dial gauges.

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Joint Sealing

Also called joint and crack repair, this method’s purpose is to minimize infiltration of surface water and incompressible material into the joint system. Joint sealants are also used to reduce dowel bar corrosion in Concrete Pavement Restoration (CPR) techniques. Successful resealing consists of old sealant removal, shaping and cleaning the reservoir, installing the backer rod and installing the sealant. Sawing, manual removal, plowing and cutting are methods used to remove the old sealant. Saws are used to shape the reservoir. When cleaning the reservoir, no dust, dirt or traces of old sealant should remain. Thus, it is recommended to water wash, sand-blast and then air blow to remove any sand, dirt or dust. The backer rod installation requires a double-wheeled, steel roller to insert the rod to the desired depth. After inserting the backer rod, the sealant is placed into the joint. There are various materials to choose for this method including hot pour bituminous liquid, silicone and preformed compression seals.

SOIL TREATMENT

BACKFILLING, CONSOLIDATION & COMPACTION

Preparationo The ground over which the filling has to be done should be

cleaned off all grass, loose stones, rubbish of all kinds etc. If there is water in the area, it should be pumped or bailed out.

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o If the plinth depth doesn’t exceed 45cm above ground level and if the exposed ground is B.C. soil , then remove the BC soil completely to avoid uneven settlement of the flooring.

o Select the refilling material from the excavated stuff and stock it separately for reuse.

o Estimate the quantity of refilling in the plinth and in pits. Judge the quantity of material available.

o Place the order for any further refilling material required. o Engage laborers for refilling. o Keep all tools for refilling and  compaction ready.

Filling, consolidation & compaction

o The sides of  concrete and masonry in foundation trenches or in the column pits should be filled with suitable excavated material. Filling should be done in layers, and compacted with steel rammer or with wooden logs.

o The approved excavated material, which has been stocked, shall be cleaned of all rubbish, large size stone, vegetation etc.

o Filling should be done in layers each layer being of 15cm to 20cm.

o Each layer is watered and compacted with heavy rammers of wooden logs or steel.

o If the area of refilling is large then either electric operated or fuel operated compactors are used to compact the filling material.

o The process of filling in plinth, watering and compaction shall be carried out till the required level is reached so as to form a thoroughly compacted base.

o While compacting due care is taken to protect the foundation columns, plinth walls, etc., which are already constructed.

o If the depth of filling exceeds more than 1m then for economy purpose building rabbit may be allowed as a filling material for further depth, the procedure being the same.

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o Under no circumstances black cotton soil shall be used for filling in plinth and footing pits.

COMPACTION OF SOILS

Compaction means pressing of soil particles close to each other by

mechanical methods. Air during compaction  is expelled from the

void space in the soil mass and therefore the mass density is

increased. Compaction is done to improve the engineering

properties of the soil. Compaction of soil is required for

the construction  of earth dams , canal embankments, highways,

runways and many other structures .

STANDARD PROCTOR TEST

To assess the amount of compaction and water content required

in the field, compaction tests are done on the same soil in the

laboratory. The test provides a relationship between the water

content and the dry density. The water content at which the

maximum dry density is attained is obtained from the relationship

provided by the tests. Proctor used a standard mould of 4 inches

internal diameter and an effective height of 4.6 inches with a

79

capacity of 1/30 cubic foot. The mould had a detachable base

plate and a removable collar of 2 inches height at its top. The soil

is compacted in the mould in 3 layers, each layer was given 25

blows of 5.5 pounds rammer filling through a height of 12 inches.

IS: 2720 part VII recommends essentially the same specification

as in Standard Proctor test, some minor modifications. The mould

recommended is of 100mm diameter, 127.3 mm height and

1000ml capacity. The rammer recommended is of 2.6 kg mass

with a free drop of 310mm and a face diameter of 50mm. The soil

is compacted in three layers. The mould is fixed to the detachable

base plate. The collar is of 60mm height.

Procedure

About 3kg of air dried soil is taken for the test. It is mixed with 8%

water content and filled in the mould in three layers and giving 25

blows to each layer. The volume of the mould and mass of the

compacted soil is taken. The bulk density is calculated from the

observations. A representative sample is placed in the oven for

determination of water content. The dry density id found out from

the bulk density and water content. The same procedure is

repeated by increasing the water content.Presentation of results

Compaction curve

80

A compaction curve is plotted between the water content as

abscissa and the corresponding dry density as ordinate. It is

observed that the dry density initially increases with an increase

in water content till the maximum density is attained. With further

increase in water content the dry density decreases. The water

content corresponding to maximum dry density is known as the

optimum water content (O.W.C) or the optimum moisture content

(O.M.C).

At a water content more than the optimum, the additional water

reduces the dry density as it occupies the space that might have

been occupied by the solid particles.

For a given water content, theoretical maximum density is

obtained corresponding to the condition when there are no air

voids (degree of saturation is 100%). The theoretical maximum

density is also known as saturated dry density. The line indicating

theoretical maximum density can be plotted along with the

compaction curve. It is known as the zero air void line.

81

MODIFIED PROCTOR TEST

The modified Proctor test was developed to represent heavier

compaction than that in the standard Proctor test. The test is

used to simulate field conditions where heavy rollers are used.

The test was standardized by American association of State

Highway Officials and is, therefore also known as modified AASHO

test.

In this, the mould used is same as that in the Std Proctor test.

However, the rammer used is much heavier and has a greater

drop than that in the Std Proctor test. Its mass is 4.89 kg and the

free drop is 450mm. The soil is compacted in five equal layers,

each layer is given 25 blows. The compactive effort in modified

Proctor test is 4.56 times greater than in the Std Proctor test. The

rest of the procedure is same

FACTORS AFFECTING COMPACTIONo Water Content

At low water content, the soil is stiff and offers more resistance to

compaction. As the water content is increased, the soil particles

get lubricated. The soil mass becomes more workable and the

particles have closer packing. The dry density of the soil increases

with an increase in the water content till the O.M.C is reached.o Amount of compaction

The increase in compactive effort will increase the dry density at

lower water content to a certain extent.o Type of soil

The dry density achieved depends upon the type of soil. The

O.M.C and dry density for different soils are differento Method of compaction

The dry density achieved depends on the method of compaction

82

EFFECT OF COMPACTION ON PROPERTIES OF SOILS

1. Soil Structure

Soils compacted at a water content less than the optimum

generally have a flocculated structure . Soils compacted at water

content more than the optimum usually have a dispersed

structure.

2. Permeability

The permeability of a soil depends upon the size of voids. The

permeability of a soil decreases with an increase in water content

on the dry side of optimum water content.

3. Swelling

4. Pore water pressure

5. Shrinkage

6. Compressibility

7. Stress-strain relationship

8. Shear strength

METHODS OF COMPACTION USED IN THE FIELD

Several methods are used in the field for compaction of soils. The

choice of method will depend upon the soil type, the maximum

dry density required and economic consideration. The commonly

used methods are

1. Tampers

2. Rollers

83

3. Vibratory compactors

The compaction depends upon the following factorso Contact pressure o Number of passes o Layer thickness o Speed of roller

Types of rollerso Smooth-wheel rollers o Pneumatic tyred rollers o Sheep foot rollers

COMPACTION CONTROL

Compaction control is done by measuring the dry density and the

water content of compacted soil in the fieldo Dry density

The dry density is measured by core cutter method and sand

replacement methodo Water content

For the measurement of water content, oven drying method, sand

bath method, calcium carbide method etc are used. Proctor

needle is also used for this.

COMPRESSIBILITY AND CONSOLIDATION OF SOILS

When a soil mass is subjected to a compressive force, its volume

decreases. The property of the soil due to which a decrease in

84

volume occurs under compressive force is known as the

compressibility of soil . The compression of  soil can occur due to 1. Compression of solid particles and water in the voids 2. Compression and expulsion of air in the voids 3. Expulsion of water in the voids

The compression of saturated soil under a steady static pressure

is known as consolidation . It is entirely due to expulsion of water

from the voids

INITIAL, PRIMARY AND SECONDARY CONSOLIDATION

o Initial  Consolidation

When a load is applied to a partially saturated soil, a decrease in

volume occurs due to expulsion and compression of air in the

voids. A small decrease in volume occurs due to compression of

solid particles. The reduction in volume of the soil just after the

application of the load is known as initial consolidation  or initial

compression. For saturated soils, the initial consolidation is mainly

due to compression of solid particles.

o Primary Consolidation

After initial consolidation, further reduction in volume occurs due

to expulsion of water from the voids. When a saturated soil is

subjected to a pressure, initially all the applied pressure is taken

up by water as an excess pore water pressure. A hydraulic

gradient will develop and the water starts flowing out and a

decrease in volume occurs. This reduction in volume is called as

the primary consolidation of soilo secondary Consolidation

85

The reduction in volume continues at a very slow rate even after

the excess hydrostatic pressure developed by the applied

pressure is fully dissipated and the primary consolidation is

complete. The additional reduction in the volume is called as the

secondary consolidation.

TESTS ON MATERIALS USED:

(1) TESTS ON AGGREGATE

AGGREGATE IMPACT VALUE

DETERMINATION OF  AGGREGATE IMPACT VALUE

AIM:

(i) to determine the impact value of the road aggregates ;

(ii) to assess their suitability in road construction   on the basis of

impact value.

 

APPARATUS:

The apparatus as per IS: 2386 (Part IV) – 1963 consists of:

86

(i) A testing machine weighing 45 to 60 kg and having a metal

base with a painted lower surface of not less than 30 cm in

diameter. It is supported on level and plane   concrete   floor of

minimum 45 cm thickness. The machine should also have

provisions for fixing its base.

(ii) A cylindrical steel cup of internal diameter 102 mm, depth 50

mm and minimum

thickness 6.3 mm. .

(iii) A metal hammer or tup weighing 13.5 to 14.0 kg the lower

end being cylindrical in shape, 50 mm long, 100.0 mm in

diameter, with a 2 mm chamfer at the lower edge and case

hardened. The hammer should slide freely between vertical

guides and be concentric with the cup. Free fall of hammer should

be within 380±5 mm.

(iv) A cylindrical metal measure having internal diameter 75 mm

and depth 50 mm

for measuring   aggregates .

(v) Tamping rod 10 mm in diameter and 230 mm long, rounded at

one end.

(vi) A balance of capacity not less than 500g, readable and

accurate upto 0.1 g.

 

THEORY:

The property of a material to resist impact is known as toughness.

Due to movement of vehicles on the road the aggregates are

subjected to impact resulting in their breaking down into smaller

pieces. The aggregates should therefore have sufficient

toughness to resist their disintegration due to impact. This

characteristic is measured by impact value test.

The   aggregate   impact value is a measure of resistance to sudden

87

impact or shock, which may differ from its resistance to gradually

applied compressive load.

 

PROCEDURE:

The test sample consists of aggregates sized 10.0 mm 12.5 mm.

Aggregates may be dried by heating at 100-110° C for a period of

4 hours and cooled.

(i) Sieve the material through 12.5 mm and 10.0mm IS sieves.

The aggregates

passing through 12.5mm sieve and retained on 10.0mm sieve

comprises the test

material.

(ii) Pour the aggregates to fill about just 1/3 rd depth of

measuring cylinder.

(iii) Compact the material by giving 25 gentle blows with the

rounded end of the

tamping rod.

(iv) Add two more layers in similar manner, so that cylinder is full.

(v) Strike off the surplus aggregates.

(vi) Determine the net weight of the aggregates to the nearest

gram(W).

(vii) Bring the impact machine to rest without wedging or packing

up on the level plate, block or floor, so that it is rigid and the

hammer guide columns are vertical.

(viii) Fix the cup firmly in position on the base of machine and

place whole of the test

sample in it and compact by giving 25 gentle strokes with

tamping rod.

(ix) Raise the hammer until its lower face is 380 mm above the

surface of aggregate sample in the cup and allow it to fall freely

88

on the aggregate sample. Give 15 such blows at an interval of not

less than one second between successive falls.

(x) Remove the crushed aggregate from the cup and sieve it

through 2.36 mm IS sieves until no further significant amount

passes in one minute. Weigh the fraction passing the sieve to an

accuracy of 1 gm. Also, weigh the fraction retained in the sieve.

Compute the aggregate impact value. The mean of two

observations, rounded to nearest whole number is reported as the

Aggregate Impact Value.

 

OBSERVATIONS

Total weight of dry sample ( W1  gm)

Weight of portion passing 2.36 mm sieve (W2  gm)

Aggregate Impact Value (percent) = W2  / W 1  X 100

Mean   = 14.5%

 

RESULT:

Aggregate Impact Value = 14.5 % ( bituminous macadam)

19 % (cement concrete )

 

RECOMMENDED VALUES

Classification of aggregates using Aggregate Impact Value is as

given

below:

89

Aggregate Impact Value Classification

<20% Exceptionally Strong

10 – 20% Strong

20-30% Satisfactory for road surfacing

>35% Weak for road surfacing

 

Specified limits of percent aggregate impact value for

different   types   of road   construction   by Indian Roads Congress is

given below.

AGGREGATE CRUSHING VALUE

AIM

To determine the aggregate crushing value of coarse  aggregate .

”The aggregate crushing value gives a relative measure of the

resistance of an aggregate crushing under gradually applied

compressive load . With aggregate crushing value 30 or higher’

the result may be anomalous and in such cases the ten percent

fines value should be determined instead.

 

APPARATUS

(I) A steel cylinder 15 cm diameter with plunger and base plate .

90

(II) A straight metal tamping rod 16mm diameter and 45 to 60cm

long rounded at one end.

(III) A balance of capacity 3 kg readable and accurate to one

gram.

(IV) IS sieves of sizes 12.5mm, 10mm and 2.36mm

(V) A compression testing machine.

(VI) Cylindrical metal measure of sufficient rigidity to retain its

from under rough

usage and of 11.5cm diameter and 18cm height.

(VII) Dial gauge

SAMPLING

91

Coarse aggregate passing 12.5mm IS sieve and retained on

a10mm. IS sieve and heated at 100 to 110°C for 4 hours and

cooled to room temperature.

The quantity of aggregate shall be such that the depth of material

in the cylinder , after tamping as described below shall be 10 cm.

The appropriate quantity may be found conveniently by filling the

cylinder.

Measure in three layers of approximately equal depth ,each layer

being tamped 25 times with the tamping rod and finally leveled

off using the tamping rod as straight edge,care being taken in the

case of weaker materials not to break the particles.the weight of

the material comprising the test sample shall be determined

(weight A) and the same weight of sample shall be taken for the

repeat test.

 

PROCEDURE

((i)Put the cylinder in position on the base plate and weigh it (W)

(ii)Put the sample in 3 layers ,each layer being subjected to 25

strokes using the tamping rod ,care being taken in the case of

weak materials not to break the particles and weigh it (W1)

(iii)Level the surface of aggregate carefully and insert the plunger

so that it rests horizontally on the surface ,care being taken to

ensure that the plunger does not jam in the cylinder.

(iv)Place the cylinder with plunger on the loading platform of the

compression testing machine.

92

(v)Apply load at a uniform rate so that a total load of 40T is

applied in 10 minutes .

(vi)Release the load and remove the material from the cylinder.

(vii)Sieve the material with 2.36mm IS sieve, care being taken to

avoid loss of fines .

(viii)Weigh the fraction passing through the IS sieve (W2)

 

CALCULATIONS

The ratio of weight of fines formed to the weight of total sample in

each test shall be expressed as a percentage , the result being

recorded to the first decimal place.

W2

Aggregate crushing value = (W2x100) / (W1-W)

W2 =Weight of fraction passing through the appropriate sieve

W1-W =Weight of surface dry sample.

The mean of two result to nearest whole number is the aggregate

crushing value.

 

RESULT

The aggregate crushing value of the given sample= 21%(cement

concrete)

93

SLUMP TEST

AIM

To study the workability (determine the consistency) of

prepared concrete either in the laboratory or laboratory or during

the progress of work in the field and to check the uniformity

of concrete from batch to batch.

APPARATUS

Mould for slump test, non porous base plate, measuring scale,

temping rod. The mould for the test is in the form of the frustum

94

of a cone having height 30 cm, bottom diameter 20 cm and top

diameter 10 cm. The tamping rod is of steel 16 mm diameter and

60cm long and rounded at one end.

SAMPLING

A concrete mix (M15 or other) by weight with suitable

water/ cement ratio is prepaid in the laboratory similar to that

explained in 5.9 and required for casting 6 cubes after conducting

Slump test.

PROCEDURE

i. Clean the internal surface of the mould and apply oil.

ii. Place the mould on a smooth horizontal non- porous base plate.

iii. Fill the mould wit5h the prepared concrete mix in 4

approximately equal layers.

iv. Tamp each layer with 25 strokes of the rounded end of the

tamping rod in a uniform manner over the cross section of the

mould. For the subsequent layers, the tamping should penetrate

into the underlying layer.

v. Remove the excess concrete and level the surface with a

trowel.

vi. Clean away the mortar or water leaked out between the mould

and the base plate.

vii. Raise the mould from the concrete immediately and slowly in

vertical direction.

viii. Measure the slump as the difference between the height of

the mould and that of height point of the specimen being tested.

NOTE

95

The above operation should be carried out at a place free from

Vibrations or shock and within a period of 2 minutes after

sampling.

SLUMP

The slump (Vertical settlement) measured shall be recorded in

terms of millimeters of subsidence of the specimen during the

test.

RESULT

Slump for the given sample= 50mm

COMPACTION FACTOR TEST

AIM

96

To study the workability of concrete

APPARATUS

Compaction factor apparatus’ trowels, hand scoop (15.2 cm long),

a rod of steel or other suitable material (1.6 cm diameter, 61 cm

long rounded at one end ) and a balance.

SAMPLING

Concrete mix (M15) is prepared as per mix design  in the

laboratory

PROCEDURE

(I)Place the concrete sample gently in the upper hopper to its

brim using the hand scoop and level it.

(ii) Cover the cylinder

(iii) Open the trap door at the bottom of the upper hopper so

that concrete fall in to the lower hopper .Push

the concrete sticking on its sides gently with the road.

(iv) Open the trap door of the lower hopper and allow

the concrete to fall in to the cylinder below

(v) Cut of the excess of concrete above the top level of cylinder

using trowels and level it. (vi) Clean the outside of the cylinder.

(vii) Weight the cylinder with concrete to the nearest 10 g. This

weight is known as the weight of partially compacted concrete

(wi).

97

(viii) Empty the cylinder and then refill it with the same concrete

mix in layers approximately 5cm deep, each layer being heavily

rammed to obtain full compaction .

(ix) Level the top surface.

(x) Weigh the cylinder with fully compacted. This weight is known

as the weight of fully compacted concrete (w2).

(xi) Find the weight of empty cylinder (W).

NOTE

The test is sufficiently sensitive to enable difference in work

ability arising from the initial process in the hydration

of cement to be measured. Each test, there for should be carried

out at a constant time interval after the mixing is completed, if

strictly comparable results are to be obtained. Convenient time

for releasing the concrete from the upper hopper has been found

to be two minutes after the completion of mixing.

CALCULATION1. The compaction factor is defined as the ratio of the weight of

partially compacted concrete to the weight of fully compacted concrete. It shall normally to be stated to the nearest second decimal place.

1. Compaction Factor= (W1-W2 / W2-W)

RESULT

Compaction factor of the concrete = 0.8

98

SPECIFIC GRAVITY OF FINE AND CORSE AGGREGATES

AIM

To determine the specific gravity of given sample of fine and

coarse aggregates .

 

SPECIFIC GRAVITTY OF COARSE AGGREGATE .

Apparatus

1. A balance or scale of capacity not less than 3 kg, readable and accurate to 0.5 g and of such a type and shape as to permit the basket containing the sample to be suspended from the beam and the weighed in water.

2. A well ventilated oven thermostatically controlled to maintain a temperature of 100oC to 110oC.

3. A wire basket of not more than 6.3 mm mesh or a perforated container of convenient size.

4. A stout water tight container of convenient size. 5. Two dry soft absorbent cloths each not less than 75×45 cm 6. A shallow tray of area no less than 650 cm2 7. An air tight container of capacity similar to that of the basket.

 Procedure

(I) Take 2 kg of aggregate . Sample larger than 10mm

(ii)Wash the sample thoroughly to remove finer particle and dust.

99

(iii) Place the sample in a wire basket and immerse it in distilled

water at a temperature between 22oC and 32oC with a cover of

at least 5 cm of water above the top of the basket.

(iv) Remove the entrapped air by lifting the basket containing the

sample 25 mm above the base of the tank and allowing it to drop

per second, care being taken to see that the sample is completely

immersed in water during the operation.

(v) With the sample in water at a temper of 220C-32oC (W).

(vi) Remove the basket and aggregate from water and allow To

drain for a few minutes.

(vii) Empty the aggregate from the basket to a shallow tray.

(viii) Immerse the empty basket in water jolt 25 times and than

the weight in water (w2).

(ix) Place the aggregates in oven at a temperature of 100oC to

110oC for 24+- 0.5 hours.

(x) Remove it from the oven and cool it and find the weight. (w2)

Calculations

Apparent Specific Gravity = (Weight of a substance/ wt of an

equal vol of water)

= W3/(W3- (w1-w2))

Result

S specific gravity of given coarse aggregate= ……

2.65………………..

100

SPECIFIC GRAVITY OF FINE AGGREGATE

Apparatus

1.A balance of capacity not less than 3kg ,readable and accurate

to 0.5 gm and of such a type as to permit the weighing of the

vessel containing the aggregate and water .

2.A well ventilated oven to maintain a temperature of 100ºC to

110ºC

3.Pyconometer of about 1 littre capacity having a metal conical

screw top with a 6mm hole at its apex . The screw top shall be

water tight .

4.a means supplying a current warm air .

5.A tray of area not less than 32cm².

6.An air tight container large enough to take the sample.

7.Filter papers and funnel.

101

 

Procedure

(I) Take about 500g of sample and place it in the pycnometer.

(II) Pour distilled water into it until it is full.

(III) Eliminate the entrapped air by rotating the pycnometer on its

side ,the hole in the apex of the cone being covered with a finger.

(IV) Wipe out the outer surface of pycnometer and weigh it (W)

(V) Transfer the contents of the pycnometer into a tray , care

being taken to ensure that all the aggregate is transferred .

(VI) Refill the pycnometer with distilled water to the same level .

(VII) Find out the weight (W1)

(VIII) drink water from the sample through a filter paper .

(IX) Place the sample in oven in a tray at a temperature of 100ºC

to 110º C for 24±0.5 hours ,during which period ,it is stirred

occasionally to facilitate drying .

(X) Cool the sample and weigh it (W2)

Calculation

Apparent specific gravity = (weight of dry sample/weight of equal

volume of water )

= W2/(W2- (W-W2))

Result

Specific gravity of fine aggregate =…2.60………………..

102

Flakiness index and Elongation Index of Coarse   Aggregates

AIM:

of an aggregate is the percentage by weight of particles whose greatest dimension (length) is greater than nine-fifths (1.8times) their mean dimension. This test is not applicable for sizes smaller than 6.3mm.

 i.      to determine the elongation index of the

given aggregates

ii.     to determine the flakiness index of the given

aggregates

APPARATUS:

The apparatus for the shape tests consists of the

following:

(i)   A standard thickness gauge         (ii)  A standard length gauge    

(iii) IS sieves of sizes 63, 50 40, 31.5, 25, 20, 16, 12.5,10 and 6.3mm

(iv)  A balance of capacity 5kg, readable and accurate up to 1 gm.

103

THEORY:

The particle shape of aggregates is determined by the percentages of flaky and elongated particles contained in it. For base course and constructionof bituminous and cement concrete types, the presence of flaky and elongated particles are considered undesirable as these cause inherent weakness with possibilities of breaking down under heavy loads. Thus, evaluation of shape of the particles, particularly with reference to flakiness and elongation is necessary.The Flakiness index of aggregates is the percentage by weight of particles whose least dimension (thickness) is less than three- fifths (0.6times) of their mean dimension. This test is not applicable to sizes smaller than 6.3mm.

The Elongation index

PROCEDURE:   

(i)  Sieve the sample through the IS sieves (as specified in the table).(ii) Take a minimum of 200 pieces of each fraction to be tested and weigh them.

       (iii) In order to separate the flaky materials, gauge each

fraction for thickness on a thickness gauge. The width of

the slot used should be of the dimensions specified in

column (4) of the table for the appropriate size of the

material.

(iv)  Weigh the flaky material passing the gauge to an

accuracy of at least 0.1 per cent of the test sample.

         (v)    In order to separate the elongated materials, gauge

each fraction for length on a length gauge. The width of

the slot used should be of the dimensions specified in

104

column (6) of the table for the appropriate size of the

material.

         (vi)  Weigh the elongated material retained on the gauge to

an accuracy of at least 0.1 per cent of the test sample.

OBSERVATIONS TABLE:

Size of aggregates

Weight

of 

fraction 

consisti

ng 

of at

least

200

pieces,g

Thickne

ss

gauge

size,

mm

Weight of

aggregat

es in

each

fraction

passing

thickness

gauge,m

m

Lengt

h

gaug

e

size,

mm

Weight of

aggregat

es in

each

fraction

retained

on length

gauge,m

m

Passin

g

throug

h IS

Sieve,

mm

Retaine

d on IS

Sieve,

mm

1 2 3 4 5 6 7

63 50 W1 23.90 X1 - -

50 40 W2 27.00 X2 81.00 Y1

40 31.5 W3 19.50 X3 58.00 Y2

31.5 25 W4 16.95 X4 - -

105

25 20 W5 13.50 X5 40.5 Y3

20 16 W6 10.80 X6 32.4 Y4

16 12.5 W7 8.55 X7 25.5 Y5

12.5 10 W8 6.75 X8 20.2 Y6

10 6.3 W9 4.89 X9 14.7 Y7

Total W =   X =   Y =

 

 OBSERVATIONS:

           Flakiness Index     =    (X1+ X2+…..) / (W1 + W2 + ….) X 100

            Elongation Index   =     (Y1 + Y2 + …) / (W1 + W2 + ….) X

100    

RESULT:

i)   Flakiness Index     =   13% (bituminous macadam)

ii)  Elongation Index   = 12.5% (bituminous macadam)

RECOMMENDED VALUE:

               The shape tests give only a rough idea of the

relative shapes of aggregates. Flaky and elongated

particles should be avoided in pavement construction,

particularly in surface course. If such particles are present

in appreciable proportions, the strength of pavement layer

would be adversely affected due to possibility of breaking

under loads. Workability is reduced for cement concrete.

106

IRC recommendations for maximum limits of flakiness

index are as given.

 

 

DETERMINATION OF LOS ANGELES ABRASION VALUE

AIM:

(i)  to determine the Los Angeles abrasion value.

(ii) to find the suitability of aggregates for use in

road construction.

 

APPARATUS:

The apparatus as per IS: 2386 (Part IV) – 1963 consists of:

107

(i) Los Angeles Machine: It consists of a hollow steel cylinder,

closed at both the ends with an internal diameter of 700 mm and

length 500 mm and capable of rotating about its horizontal axis. A

removable steel shaft projecting radially 88 mm into cylinder and

extending full length (i.e.500 mm) is mounted firmly on the

interior of cylinder. The shelf is placed at a distance 1250 mm

minimum from the opening in the direction of rotation.

(ii) Abrasive charge: Cast iron or steel balls, approximately 48mm

in diameter and each weighing between 390 to 445g; six to

twelve balls are required.

(iii) Sieve: 1.70, 2.36,4.75,6.3,10,12.5,20,25,40,50,63,80 mm IS

Sieves.

(iv) Balance of capacity 5kg or 10kg

(v) Drying oven

(vi)  Miscellaneous like tray

THEORY:

The aggregate used in surface course of the highway pavements

are subjected to wearing due to movement of traffic. When

vehicles move on the road, the soil particles present between the

pneumatic tyres and road surface cause abrasion of

road aggregates. The steel reamed wheels of animal driven

vehicles also cause considerable abrasion of the road surface.

Therefore, the roadaggregates should be hard enough to resist

abrasion. Resistance to abrasion of aggregate is determined in

laboratory by Los Angeles test machine. The principle of Los

108

Angeles abrasion test is to produce abrasive action by use of

standard steel balls which when mixed with aggregates and

rotated in a drum for specific number of revolutions also causes

impact on aggregates. The percentage wear of the aggregates

due to rubbing with steel balls is determined and is known as Los

Angeles Abrasion Value.

 

PROCEDURE:

The test sample consists of clean aggregates dried in oven at

105° – 110°C. The sample should conform to any of the gradings

shown in table 1.

(i) Select the grading to be used in the test such that it

conforms to the grading to be used inconstruction, to

the maximum extent possible.

(ii) Take 5 kg of sample for gradings A, B, C & D and 10 kg

for gradings E, F & G.

(iii)

(iv) Choose the abrasive charge as per Table 2 depending

on grading of aggregates.

(v) Place the aggregates and abrasive charge on the

cylinder and fix the cover.

(vi) Rotate the machine at a speed of 30 – 33 revolutions

per minute. The number of revolutions is 500 for

gradings A, B, C & D and 1000 for gradings E, F & G.

The machine should be balanced and driven such that

there is uniform peripheral speed.

109

(vi) The machine is stopped after the desired number of

revolutions and material is discharged to a tray.

(vii) The entire stone dust is sieved on 1.70 mm IS sieve.

(viii) The material coarser than 1.7mm size is weighed

correct to one gram.

OBSERVATIONS:

Original weight of aggregate sample = W1 g

Weight of aggregate sample retained = W2 g

Weight passing 1.7mm IS sieve = W1 - W2 g

Abrasion Value = (W1 - W2 ) / W1 X 100

 

RESULT:

Los Angeles Abrasion Value =39 % (bituminous macadam)

= 19 % (bituminous concrete

surface course)

 

RECOMMENDED VALUE:

Los Angeles test is commonly used to evaluate the hardness of

aggregates. The test has more acceptability because the

resistance to abrasion and impact is determined simultaneously.

Depending upon the value, the suitability of aggregates for

110

different road constructions can be judged as per IRC

specifications as given:

 

Sl

NoType of pavement

Aggregate impact value

not more than

1. Wearing Course 30

a) Bituminous surface dressing

b) Penetration macadam

c) Bituminous carpet concrete

d) Cement concrete

2.Bitumen bound macadam

base course35

3.WBM base course with

bitumen surfacing40

111

4 Cement concrete base course 45

WATER ABSORPTION TEST

AIM:

To determine the water absorption ofaggregates

112

 

APPARATUS:

The apparatus consists of the following

(a) A balance of capacity about 3kg, to weigh accurate 0.5g, and

of such a type and shape as to permit weighing of the sample

container when suspended in water.

(b) A thermostatically controlled oven to maintain temperature at

100- 110° C.

(c) A wire basket of not more than 6.3 mm mesh or a perforated

container of convenient size with thin wire hangers for suspending

it from the balance.

(d) A container for filling water and suspending the basket

(e) An air tight container of capacity similar to that of the basket

(f) A shallow tray and two absorbent clothes, each not less than

75x45cm.

 

THEORY:

The specific gravity of an aggregate is considered to be a

measure of strength or quality of the material. Stones having low

specific gravity are generally weaker than those with higher

specific gravity values.

 

PROCEDURE:

(i) About 2 kg of 

113

(ii) aggregate  sample is washed thoroughly to remove

fines, drained and placed in wire basket and immersed

in distilled water at a temperature between 22- 32º C

and a cover of at least 5cm of water above the top of

basket.

(iii) Immediately after immersion the entrapped air is

removed from the sample by lifting the basket

containing it 25 mm above the base of the tank and

allowing it to drop at the rate of about one drop per

second. The basket and aggregate should remain

completely immersed in water for a period of 24 hour

afterwards.

(iv) The basket and the sample are weighed while

suspended in water at a temperature of 22° – 32°C. The

weight while suspended in water is noted =W1g.

(v) The basket and aggregates are removed from water

and allowed to drain for a few minutes, after which

the aggregates are transferred to the dry absorbent

clothes. The empty basket is then returned to the tank

of water jolted 25 times and weighed in water=W2g. .

(vi) The aggregates placed on the absorbent

clothes are surface dried till no further moisture could

be removed by this cloth. Then the aggregates are

transferred to the second dry cloth spread in single

layer and allowed to dry for at least 10 minutes until

114

the aggregates are completely surface dry. The surface

dried aggregate is then weighed =W3 g

(vii) The aggregate is placed in a shallow tray and kept

in an oven maintained at a temperature of 110° C for

24 hrs. It is then removed from the oven, cooled in an

air tight container and weighted=W4 g.

 

(1) Specific gravity = (dry weight of the aggregate

/Weight of equal volume of water)

(2) Apparent specific gravity = (dry weight of the

aggregate/Weight of equal volume of water excluding

air voids in aggregate)

 

OBSERVATIONS:

Weight of saturated aggregate suspended in water with basket =

W1 g

Weight of basket suspended in water = W2 g

Weight of saturated aggregate in water = W1 – W2 g

Weight of saturated surface dry aggregate in air = W3 g

Weight of water equal to the volume of the aggregate = W3–(W1–

W2)g

Weight of oven dry aggregate = W4 g

(1) Specific gravity = W3 / (W3– (W1– W2))

(2) Apparent specific gravity = W4 / (W4– (W1– W2))

(3) Water Absorption = ((W3 – W4) / W4) X 100

 

115

RESULT:

Water Absorption =0.49%

 

RECOMMENDED VALUE:

The size of the aggregate and whether it has been artificially

heated should be indicated. ISI specifies three methods of testing

for the determination of the specific gravity of aggregates,

according to the size of the aggregates. The three size ranges

used are aggregates larger than 10 mm, 40 mm and smaller than

10 mm. The specific gravity of aggregates normally used in

road constructionranges from about 2.5 to 3.0 with an average of

about 2.68. Though high specific gravity is considered as an

indication of high strength, it is not possible to judge the

suitability of a sample road aggregate without finding the

mechanical properties such as aggregate crushing, impact and

abrasion values. Water absorption shall not be more than 0.6 per

unit by weight.

116

(2) TESTS ON BITUMEN

PENETRATION TEST

AIM:

(i) To determine the consistency of bituminous material

(ii) To assess the suitability of bitumen for use under different

climatic conditions and various types of construction.

APPARATUS:

(i) Container: A flat bottomed cylindrical metallic dish 55 mm in

diameter and 35 mm in depth is required. If the penetration is of

the order of 225 or more, dish of 70mm diameter and 45mm

depth is required.

(ii) Needle: A straight, highly polished, cylindrical hard steel rod.

(iii)Water bath: Water bath maintained at 25° ± 0.1 °C, containing

not less than 10 litres of water, the sample being immersed to a

depth not less than 100 mm from top& supported on perforated

shelf not less than 50 mm from bottom of the bath.

117

(iv)Transfer dish or tray: Should provide support to the container

& should not rock it. It should be of such capacity as to

completely immerse container during test.

(v) Penetration apparatus: Should be such that it allows needle to

penetrate without much friction& is accurately calibrated to give

results in one tenth of a millimeter.

(vi)Thermometer: Range 0- 44 °C and in readable upto 0.20 C.

(vii)Time measuring device: With an accuracy of l second.

THEORY:

Penetration value is a measure of hardness or consistency of

bituminous material. It is the vertical distance traversed or

penetrated by the point of a standard needle in to the bituminous

material under specific conditions of load, time and temperature.

This distance is measured in one tenths of a millimeter. This test

is used for evaluating consistency of bitumen. It is not regarded

118

as suitable for use in connection with the testing of road tar

because of the high surface tension exhibited by these materials.

PROCEDURE:

(i) Preparation of test specimen: Soften the material to a pouring

consistency at a temperature not more than 60°C for tars and

90°C for bitumen above the approximate softening point and stir

it thoroughly until it is homogeneous and is free from air bubbles

and water. Pour the melt into the container to a depth at least

10mm in excess of the expected penetration. Protect the sample

from dust and allow it to cool in an atmosphere at a temperature

between 15° to 30° C for one hour. Then place it along with the

transfer dish in the water bath at 25° ± 0.1 °C, unless otherwise

stated.

(ii) Fill the transfer dish with water from the water bath to depth

sufficient to cover the container completely, place the sample in it

and put it upon the stand of the penetration apparatus.

(iii) Clean the needle with benzene, dry it and load with the

weight. The total moving load required is 100 ± 0.25 gms,

including the weight of the needle, carrier and super-imposed

weights.

(iv) Adjust the needle to make contact with the surface of the

sample. This may be done by placing the needlepoint in contact

with its image reflected by the surface of the bituminous material.

(i) Make the pointer of the dial to read zero or note the initial dial

reading.

119

(ii) Release the needle for exactly five seconds.

(vi) Adjust the penetration machine to measure the distance

penetrated.

(vii)Make at least 3 readings at points on the surface of the

sample not less than 10 mm apart and not less than l0mm from

the side of the dish. After each test return the sample and

transfer dish to the water bath and wash the needle clean with

benzene and dry it. In case of material of penetration greater than

225, three determinations on each of the two identical test

specimens using a separate needle for each determination should

be made, leaving the needle in the sample on completion of each

determination to avoid disturbance of the specimen.

PRECAUTIONS:

(i) There should be no movement of the container while needle

penetrates into sample.

(ii) The sample should be free from any extraneous matter.

(iii)The needle should be cleaned with benzene and dried before

penetration.

OBSERVATIONS

Actual test temperature = 35 °C

RESULT:

33.5mm (bituminous macadam)

120

RECOMMENDED VALUE:

Penetration test is a commonly adopted test on bitumen to grade

the material in terms of its hardness. A 80/100 grade bitumen

indicates that its penetration value lies between 80 &

100.Grading of bitumen helps to assess its suitability in different

climatic conditions and types ofconstruction. For bituminous

macadam and penetration macadam, IRC suggests bitumen

grades 30/40, 60/70, 80/100. In warmer regions, lower

penetration grades are preferred to avoid softening whereas

higher penetration grades like 180/200 are used in colder regions

to prevent the occurrence of excessive brittleness. High

penetration grade is used in spray application works.

DETERMINING SOFTENING POINT OF BITUMEN

This test is done to determine the softening point of asphaltic bitumen and fluxed native asphalt, road tar, coal tar pitch and blown type bitumen as per IS: 1205 – 1978. The principle behind this test is that softening point is the temperature at which the substance attains a particular degree of softening under specified condition of the test.The apparatus required for this test :-

i) Ring and ball apparatus

121

ii) Thermometer – Low Range : -2 to 80oC, Graduation 0.2oC – High Range : 30 to 200oC, Graduation 0.5oC

PREPARATION OF SAMPLE

i) The sample should be just sufficient to fill the ring. The excess sample should be cut off by a knife.ii) Heat the material between 75 and 100oC. Stir it to remove air

bubbles and water, and filter it through IS Sieve 30, if necessary.iii) Heat the rings and apply glycerine. Fill the material in it and cool it for 30 minutes.

iv) Remove excess material with the help of a warmed, sharp knife.

Procedure to determine Softening Point Of Bitumen

A) Materials of softening point below 80o C:

122

i) Assemble the apparatus with the rings, thermometer and ball guides in position.

ii) Fill the beaker with boiled distilled water at a temperature 5.0 ± 0.5oC per minute.

iii) With the help of a stirrer, stir the liquid and apply heat to the beaker at a temperature of 5.0 ± 0.5oC per minute.

iv) Apply heat until the material softens and allow the ball to pass through the ring.

v) Record the temperature at which the ball touches the bottom, which is nothing but the softening point of that material.

B) Materials of softening point above 80oC:

The procedure is the same as described above. The only difference is that instead of water, glycerine is used and the starting temperature of the test is 35oC.Record the temperature at which the ball touches the bottom.

RESULTS

softening point below 80 o   C: 50 degree celsius

123

DETERMINING BITUMEN CONTENT

BITUMEN CONTENT

This test is done to determine the bitumen content as per ASTM 2172. The apparatus needed to determine bitumen content are –

i) Centrifuge extractor

124

ii) Miscellaneous – bowl, filter paper, balance and commercial benzene.

A sample of 500g is taken.

Procedure to determine bitumen content

i) If the mixture is not soft enough to separate with a trowel,place 1000g of it in a large pan and warm upto 100oC to separate the particles of the mixture uniformly.ii) Place the sample (Weight ‘A’) in the centrifuge extractor. Cover the sample with benzene, put the filter paper on it with the cover plate tightly fitted on the bowl.

iii) Start the centrifuge extractor, revolving slowly and gradually increase the speed until the solvent ceases to flow from the outlet.

iv) Allow the centrifuge extractor to stop. Add 200ml benzene and repeat the procedure.

125

v) Repeat the procedure at least thrice, so that the extract is clear and not darker than the light straw colour and record the volume of total extract in the graduated vessel.

vi) Remove the filter paper from the bowl and dry in the oven at 110 + 5oC. After 24hours, take the weight of the extracted sample (Weight ‘B’). [(A-B)/B]×100 %

Repeat the test thrice and average the results.

RESULTS Bitumen content = 7.86%

DETERMINING SPECIFIC GRAVITY OF BITUMEN

126

This test is done to determine the specific gravity of semi-solid bitumen road tars, creosote and anthracene oil as per IS: 1202 – 1978. The principle is that it is the ratio of mass of a given volume of bitumen to the mass of an equal volume of water, both taken at a recorded/specified temperature.The apparatus needed to determine specific gravity of bitumen is

i) Specific gravity bottles of 50ml capacityii) Water bathiii) Bath thermometer – Range 0 to 44oC, Graduation 0.2oCTake the sample (half the volume of the specific gravity bottles).

Procedure to determine specific gravity of bitumen 

i) Clean, dry and weigh the specific gravity bottle along with the stopper (Weight ‘A’).ii) Fill the specific gravity bottle with freshly boiled distilled water and insert the stopper firmly. Keep it in the water bath having a temperature of 27.0 + 1oC for not less than half an hour and weigh it (Weight ‘B’).

127

iii) Weigh the specific gravity bottle about half-filled with the material (Weight ‘C’).

iv) Weigh the specific gravity bottle about half-filled with the material and the other half with distilled water (Weight ‘D’).

v) Weigh the specific gravity bottle completely filled with the material (Weight ‘E’).

i) Specific gravity (Solids and semi-solids) = (C-A )/[ ( B-A) - (D-C)]ii) Specific gravity (Liquids) = (E-A)/(B-A)The average of the two results should be reported.

RESULTS Specific gravity of bitumen = 0.99

DETERMINING FLASH AND FIRE POINT OF BITUMEN

128

This test is done to determine the flash point and the fire point of asphaltic bitumen and fluxed native asphalt, cutback bitumen and blown type bitumen as per IS: 1209 – 1978. The principle behind this test is given below :

Flash Point – The flash point of a material is the lowest temperature at which the application of test flame causes the vapours from the material to momentarily catch fire in the form of a flash under specified conditions of the test.

Fire Point – The fire point is the lowest temperature at which the application of test flame causes the material to ignite and burn at least for 5 seconds under specified conditions of the test.The apparatus required for this test isi) Pensky-Martens apparatusii) Thermometer- Low Range : - 7 to 110oC, Graduation 0.5oCHigh Range : 90 to 370oC, Graduation 2oCThe sample should be just sufficient to fill the cup upto the mark given on it.

129

Procedure to determine the Flash And Fire Point Of Bitumen

A) FLASH POINT

i) Soften the bitumen between 75 and 100oC. Stir it thoroughly to remove air bubbles and water.ii) Fill the cup with the material to be tested upto the filling mark. Place it on the bath. Fix the open clip. Insert the thermometer of high or low range as per requirement and also the stirrer, to stir it.

iii) Light the test flame, adjust it. Supply heat at such a rate that the temperature increase, recorded by the thermometer is neither less than 5oC nor more than 6oC per minute.iv) Open flash point is taken as that temperature when a flash first appears at any point on the surface of the material in the cup. Take care that the bluish halo that sometimes surrounds the test flame is not confused with the true flash. Discontinue the stirring during the application of the testflame.v) Flash point should be taken as the temperature read on the thermometer at the time the flash occurs.

B) FIRE POINT

i) After flash point, heating should be continued at such a rate that the increase in temperature recorded by the thermometer is neither less than 5oC nor more than 6oC per minute.ii) The test flame should be lighted and adjusted so that it is of the size of a bead 4mm in dia.

RESULTS

130

The min. Flash point of test is 177.5 degree Celsius

i) The flash point should be taken as the temperature read on the thermometer at the time of the flame application that causes a distinct flash in the interior of the cup.ii) The fire point should be taken as the temperature read on the thermometer at which the application of test flame causes the material to ignite and burn for at least 5 seconds.

131

NAME OF WORK 1 :

NEW LOAD OF 2500 KW ON HT SYSTEM OF SUPPLY UNDER MLHT CAT IN F/O ADDL. DIRECTOR , ISMANDH KHERA DABOUR VILL. AREA IN C-133 SH : RESTORATION OF ROAD CUT MADE BY BSES IN KHERA DABOUR VILL AREA IN C-133 NGZ.

FTC NO. : 09/066/66/1076/039/11/C-133/DN-2/03/11/88

TENDER AMOUNT: 499797 UNIT/ESTIMATED RATE: 499797 CONTRACTUAL AMOUNT: 499797/- TIME OF COMPLETION: 2 MONTHS HEAD OF ACCOUNT : 66-1076 TENDER NO.: 654 NIT NO: UNIT RATE

132

COST ESTIMATION:

S. No DSR/AppItems

Item Unit Quantity Rate Amount

1 2.6.1 Earth work in excavation by mechanical means (Hydraulic excavator)/manual means over areas (exceeding 30 cm in depth, 1.5 m in width as well as 10 sqm on plan) including disposal of excavated earth, lead up to 50 m and lift upto 1.5m ; disposed earth to be levelled and nearly dressed ; All kind of soil.

cum 252.00 95.00 23910.00

2 16.3.2 Supplying and stacking at site 63 mm to 45mm size stone aggregate

cum 94.50 890.00 84105.00

3 16.3.3 Supplying and stacking at site 53mm to 22.4mm size stone aggregate

cum 94.50 899.0 84955.50

133

4 16.5.2 Laying water bond macadam sub –base with brick aggregate and blinding material earth etc. including screening ,sorting and spreading to template and consolidation with light power road-roller etc complete (payment for brick aggregate and moorum etc to be made separately) over burnt (jhama) brick aggregate 90mm to 45mm

cum 189.00 178.00 33642.00

5 16.38s Supplying and stacking at site ; red bajri

cum 5.04 1050.00 5292.00

6 16.39 Supplying and stacking at site ; good earth

cum 5.04 173.00 871.92

7 16.30.1 Providing and applying tack coat using hot straight run bitumen of grade 80/100 including heating the bitumen, spraying the bitumen with mechanically operated spray unit fitted on bitumen boiler , cleaning and preparing the existing road surface as per specification ; on W.B.M .@0.75 kg /sqm

sqm

1800.00 11.00 19800.00

8 16.32.1 2cm premix carpet surfacing with 1.8 cum & 0.90 cum of stone chippings of 13.2 mm size and 11.2 mm size respectively per 100 sqm and 52 kg and 56 kg of hot bitumen per cum of stone chippings of 13.2 mm and 11.2 mm size respectively including a tack coat with hot straight run bitumen including consolidation with road roller of 6 to 9 tonne capacity etc complete :(tack coat to be paid for separately): with paving Asphalt 80/100 heated and then mixed with solvent at the rate of 70 grams per kg of

Sqm 1800.00 85.00 153000.00

134

asphalt 9 16.40 Providing and laying seal of

premixed time aggregate (passing 2.36 mm and retained on 180 micron sieve) with bitumen using 128 kg of bitumen of grade 80/100 bitumen per cum of fine aggregate and 0.60 cum of fine aggregate per 100 sqm of road surface including rolling and finishing with road roller all complete

sqm 1800.00 32.00 57600.00

10 2.34 Removal of lime moorumor building rubbish by mechanical transport including loading unloading &stacking with in a lead of 30 kms (malva will be dumped at SLF)

Cum 252.00 145.20 36590.40

499796.82

135

GOOGLE EARTH VIEW OF SITE OF WORK 1:

136

ROUTE MAP OF CONSTRUCTION SITE OF WORK 1:

137

NAME OF WORK 2 :

R/R OF CUT BY DJB FOR WORK P/L/J INTERNAL SEWAGE SYSTEM IN RURAL VILL. PAPRAWAT ROSHAN PURA AND DEENPUR ALONG WITH PERIPHERIAL SEWER BY TRENCHLESS METHOD FOR

RELIANCE FRESH IN NJAFGARH IN C-134 SH: R/R OF CUT BY RMC FROM DAYA SINGH HS. TO MAIN

BIJWASAN ROAD IN DEENPUR VILL IN C-134 NGZ.

FTC NO. :

09/066/66/1076/039/11/C-134/DN-2/03/11/79

TENDER AMOUNT : 499913 UNIT/ESTIMATED RATE : 499913 CONTRACTUAL AMOUNT: 499913/- TIME OF COMPLETION: 2 MONTH

138

HEAD OF ACCOUNT : 66-1076 TENDER NO.:717 NIT NO: UNIT RATE

COST ESTIMATION

Description quantity

rate unit

Amount

Earth work available in surface or volume not exceeding 30 cm in depth but exceeding 1.5 m width As well as 10 m2 on plan including disposal of excavated earth, lead up to 50 m & lift up to 1.5m . disposed soil to be leveled and neatly dressed: All kind of soil

1008 1989=87

m2 200.58

Pdg & laying 75 mm thick compacted bed of dry brick agg of 45mm thick i/c spreding well ramming consolidating & grouting with jamuna sand including finishing smooth etc. complete as per direction of engineer –in -change

504 62=35 m2 31799.00

Providing and fixing kota stone shape :20mm thick & 150 mm wide

_ 31=20 m2 -

Providing and laying c.c With ready mixed concrete from batchig plant . The ready mixed concrete shall be laid and finished with screed board vibrator ,vacuum dewatering process and finally finished by floating by

100.80 4411=00

m3 444629.00

139

breaming with wire brush etc complete as per specification and direction of engineer of change Deduct for using of M-20 grade concreteinstead ofM-25 grade concrete in c.c pavement

100.80 131=00

m3 13205.00

Carriage of material by mechanical transport i/c loading /unloading and stacking with lime moorrum ,building rubbish

118.80 140=00

m3 16632.00

NAME OF WORK 3 :

R/R OF CUT BY DJB FOR WORK P/L/J INTERNAL SEWARAGE SYSTEM IN RURAL VILL. PAPRAWAT ROSHAN PURA AND DEENPUR ALONG WITH PERIPHERIAL SEWER BY TRENCHLESS METHOD FOR RELIANCE FRESH IN

NJAFGARH IN C-134 SH : R/R OF CUT BY RMC FOR MASJID TO SUBBEY TO RANJAN HS. TO BHOOP HS. IN

DEENPUR C-134 NGZ.

FTC NO. : 09/066/66/1076/039/11/C-134/DN-2/03/11/79

TENDER AMOUNT: 497514 UNIT/ESTIMATED RATE : 497514 CONTRACTUAL AMOUNT :497514/-

140

TIME OF COMPLETION: 2 MONTH

HEAD OF ACCOUNT : 66-1076 TENDER NO. : 596 NIT NO: UNIT RATE

COST ESTIMATION

Description quantity

rate unit

Amount

Earth work available in surface or volume not exceeding 30 cm in depth but exceeding 1.5 m width As well as 10 m2 on plan including disposal of excavated earth, lead up to 50 m & lift up to 1.5m . disposed soil to be leveled and neatly dressed: All kind of soil

1008 1989=87

m2 200.58

Pdg & laying 75 mm thick compacted bed of dry brick agg of 45mm thick i/c spreding well ramming consolidating & grouting with jamuna sand including finishing smooth etc. complete as per direction of engineer –in -change

472.5 62=35 m2 29460.00

Providing and fixing kota stone shape :20mm thick & 150 mm wide

_ 31=20 m2 -

Providing and laying c.c With ready mixed concrete from

100.80 4411=00

m3 444629.00

141

batchig plant . The ready mixed concrete shall be laid and finished with screed board vibrator ,vacuum dewatering process and finally finished by floating by breaming with wire brush etc complete as per specification and direction of engineer of change Deduct for using of M-20 grade concreteinstead ofM-25 grade concrete in c.c pavement

100.80 131=00

m3 13205.00

Carriage of material by mechanical transport i/c loading /unloading and stacking with lime moorrum ,building rubbish

118.80 140=00

m3 16632.00

142