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Q.1 Explain in detail meaning of cost-effective construction?

Answer:- The important need and everyone's dream to have there own home with individual needs.

Since India is a developing country, the economy haves importance. The housing is so impacted with the cost based construction.

So, there are various cost effective techniques of construction. Lots of them are also energy efficient and easily adoptable.

Essential requirement to human existence is a HOME next only to food and clothing. A breakthrough for application of sustainable and cost effective technologies for better housing in rural and urban areas is an urgent need considering spiraling construction costs.

There is a need for the adoption of strong, durable, environment friendly, ecologically appropriate, energy efficient and yet cost effective materials and appropriate technologies in construction.

ar. Laurie baker is one who worked on cost effective construction techniques as its best.

Baker showed, in fact, that sustainable technologies when adopted with care and creativity, could lead to a unique architectural expression, one that moved the expert and the layman alike.

Proper materials is the basic need to develop any construction technique.

Brick, wood, stone are three major materials which can be used in India for any type of construction.

Factors Affecting Cost Estimation:-

Building type Size Building cost Special Construction Project accessibility Labor Rates Material Costs General Economic Pressures Time of Year

Q.2 What do you understand by eco-friendly construction?

Answer:- Eco-friendly, or ecological, construction is building a structure that is beneficial or non-harmful to the environment, and resource efficient. Otherwise known as green building, this type of construction is efficient in its use of local and renewable materials, and in the energy required to build it, and the energy generated while being within it.

Eco-friendly construction has developed in response to the knowledge that buildings have an often negative impact upon our environment and our natural resources. This includes transporting materials hundreds or thousands of miles, which has a negative impact in the energy required to transport them, and also in emissions of hazardous chemicals from a poorly designed building that creates, and traps them.

The ecofriendly construction included:

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Rooftop solar panels Increased insulation Custom energy efficient windows Programmable thermostats Low VOCs in paints, carpets and other building materials Water efficient plumbing fixtures Compact florescent lighting Landscaping with native plants and water conservation measures Protected green space

Benefits of Eco-Friendly Building

Conservation of natural resources Enhancement and protection of the property’s natural surroundings Improved indoor air quality Improved health and comfort of residents Minimized impact on the local infrastructure Reduction of construction waste sent to landfills

Q.3 Explain National and International standards for eco-friendly construction.

Answer :-

National Green building codes :-

1.LEED INDIA along with other IGBC rating systems administered by the Indian Green Building Council (http://www.igbc.in)

2. Green Rating for Integrated Habitat Assessment, or GRIHA conceived by The Energy Resources Institute and developed jointly with the Ministry of New and Renewable Energy, Government of India. (http://www.grihaindia.org/)

International green building codes :-

1. IPCC Fourth Assessment Report

Climate Change 2007, the Fourth Assessment Report (AR4) of the United Nations Intergovernmental Panel on Climate Change (IPCC), is the fourth in a series of such reports. The IPCC was established by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess scientific, technical and socio-economic information concerning climate change, its potential effects and options for adaptation and mitigation

2. UNEP and Climate change

United Nations Environment Program UNEP works to facilitate the transition to low-carbon societies, support climate proofing efforts, improve understanding of climate change science, and raise public awareness about this global challenge.

3. GHG Indicator

The Greenhouse Gas Indicator: UNEP Guidelines for Calculating Greenhouse Gas Emissions for Businesses and Non-Commercial Organizations

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4. Agenda 21

Agenda 21 is a programme run by the United Nations (UN) related to sustainable development. It is a comprehensive blueprint of action to be taken globally, nationally and locally by organizations of the UN, governments, and major groups in every area in which humans impact on the environment. The number 21 refers to the 21st century.

5. IPD Environment Code

The IPD Environment Code was launched in February 2008. The Code is intended as a good practice global standard for measuring the environmental performance of corporate buildings. Its aim is to accurately measure and manage the environmental impacts of corporate buildings and enable property executives to generate high quality, comparable performance information about their buildings anywhere in the world.

Q.4 Explain Properties and uses of Following materials.

(1) Flyash :-

Fly ash closely resembles volcanic ashes used in production of the earliest known hydraulic cements about 2,300 years ago. Those cements were made near the small Italian town of Pozzuoli – which later gave its name to the term pozzolan. A pozzolan is a siliceous/aluminous material that, when mixed with lime and water, forms a cementitious compound. Fly ash is the best known, and one of the most commonly used, pozzolans in the world.

Instead of volcanoes, today’s fly ash comes primarily from coal-fired, electricity-generating power plants. These power plants grind coal to powder fineness before it is burned. Fly ash – the mineral residue produced by burning coal – is captured from the power plant’s exhaust gases and collected for use.

The difference between fly ash and portland cement becomes apparent under a microscope. Fly ash particles are almost totally spherical in shape, allowing them to flow and blend freely in mixtures. That capability is one of the properties making fly ash a desirable admixture for concrete.

Properties :-

the spherical shape of fly ash creates a ball bearing effect in the mix, improving workability without increasing water requirements.

Fly ash also improves the pump-ability of concrete by making it more cohesive and less prone to segregation. The spherical shape improves the pump-ability by decreasing the friction between the concrete and the pump line.

fly ashes have been shown to significantly decrease heat generation as the concrete hardens and strengthens. Fly ash, as do all pozzolanic materials, generally provide increased concrete strength gain for much longer periods than mixes with portland cement only.

The biggest reason to use fly ash in concrete is the increased life cycle expectancy and increase in durability associated with its use.

During the hydration process, fly ash chemically reacts with the calcium hydroxide forming calcium silicate hydrate and calcium aluminate, which reduces the risk of leaching calcium hydroxide and concrete’s permeability.

Fly ash also improves the permeability of concrete by lowering the water-to-cement ratio, which reduces the volume of capillary pores remaining in the mass. The spherical shape of fly ash improves the consolidation of concrete, which also reduces permeability.

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Other benefits of fly ash in concrete include resistance to corrosion of concrete reinforcement, attack from Alkali-silica reaction, sulfate attack and acids and salt attack.

Uses :-

Concrete production, as a substitute material for Portland cement and sand Embankments and other structural fills (usually for road construction) Grout and Flow able fill production Waste stabilization and solidification Cement clinkers production - (as a substitute material for clay) Mine reclamation Stabilization of soft soils Road sub base construction As Aggregate substitute material (e.g. for brick production) Mineral filler in asphaltic concrete Agricultural uses: soil amendment, fertilizer, cattle feeders, soil stabilization in stock feed yards, and

agricultural stakes Loose application on rivers to melt ice[15] Loose application on roads and parking lots for ice control

(2)- Ferro cement :-

Ferro cement or Ferro-cement (also called thin-shell concrete or Ferro-concrete) is a system of reinforced mortar[1] or plaster (lime or cement, sand and water) applied over layers of metal such as chicken wire or woven or expanded metal (iron) mesh or fibres and possibly closely spaced small-diameter steel rods such as rebar. It is used to form relatively thin, hard, strong forms in many shapes for such applications as hulls for boats, shell roofs, and water tanks. Ferro cement originated in the 1840s in France and is the origin of reinforced concrete. It has a wide range of other uses including sculpture and prefabricated building components. The term "Ferro cement" has been applied by extension to other composite materials, including some containing no cement and no ferrous material.

Properties:-

a wider range of elasticity greater resistance to extension better behaviour at dynamic stress increased value of the breaking effort out of extension

Uses :-

Housing Marine Agricultural Rural Energy Anticorrosive Membrane Treatment.

(3)- Red Mud :-

Red mud or red sludge is a waste product generated in the industrial production of aluminium. Red mud is one of the most important disposal problems in the mining industry. Red mud is a side-product of the Bayer process, the principal means of refining bauxite en route to alumina. The resulting alumina is the raw material for producing

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aluminium by the Hall–Harold process. A typical bauxite plant produces one to two times as much red mud as alumina. This ratio is dependent on the type of bauxite used in the refining process and the extraction conditions.

Properties:-

brick red in colour and slimy having average particle size of <10um, about 35% by weight of solids have size less than 5 micrometer and

80% less than 8 micrometer It is alkaline and thixotropic high surface area in the range of 13-16 with a true density of 3.30g/cc.

Uses :-

Metallurgical Uses (iron and steel production, titania, alumina and alkali, minor constituents recovery) Production of building materials (constructional brick, light weight aggregates, bricks roofing and flooring

tiles, cements etc) Catalysis Ceramics (pottery, sanitary ware, special tiles and glasses, glazes, ferrites) Miscellaneous direct uses (in waste treatment, as a filler, as a fertiliser, etc)

(4)- Rice husk ash :-

Rice husk ash is obtained by burning rice husk in a controlled manner without causing environmental pollution. Rice husk ash (RHA) is about 25% by weight of rice husk when burnt in boilers. When properly burnt it has high SiO2 content and can be used as a concrete admixture. Rice husk ash exhibit high pozzolonic properties and contribute to high strength and high impermeability or concrete.

Properties :-

RHA is a carbon neutral green product RHA is a good super-pozzolan Flame retarder Good absorbent Water Proofing

Uses :-

green concrete high performance concrete refractory ceramic glaze insulator roofing shingles specialty paints carrier for pesticides

(5)- Soil :-

Soil is the mixture of minerals, organic matter, gases, liquids, and the countless organisms that together support life on Earth. Soil is a natural body known as the pedosphere and which performs four important functions: it is a

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medium for plant growth; it is a means of water storage, supply and purification; it is a modifier of Earth's atmosphere; it is a habitat for organisms; all of which, in turn, modify the soil.

Properties :-

Flocculated and dispersed Structure Density of typical soil particle is 2.60 to 2.75 grams per cm3 Porosity which is open space occupied by either gases or water Consistency is the ability of soil resist deformation and rupture Soil temperature which depends on the ratio of the energy absorbed to that lost Color and texture

Uses :-

it is used in agriculture to nourish plants Soil is an important part of the building process Clay soil is used in making ceramics, or pottery Soil is commonly used in antibiotics because Microbes created in the soil are harmful to bacteria. Beauty products where used soil is used in the production include blush and foundation.

(6)- Lime :-

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3). Most limestone is composed of skeletal fragments of marine organisms such as coral, forams and molluscs.

Properties :-

Hardness -3 to 4 on Moh's Scale Density -2.5 to 2.7 Kg/cm3 Compressive Strength -60-170 N/mm2 Water Absorption -Less than 1% Porosity -Quite low Weather Impact -Resistant

Uses :-

Flooring Wall cladding Vanity tops Furniture Cement Production RefiningMetals Blackboard chalk

Q.5 Give the design specification of the house using locally available materials lime stone, soil, wood, country/Mangalore tiles. Explain various components used in foundation, plinth, flooring, walling, roofing, plaster, door and windows. Also give energy and water requirement.

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Answer :-

Materials used in house construction :-

Stone :- Limestone, marble, granite, sandstone and other durable rocks are used for construction. These rocks are altered and polished for specific needs and come in almost any shape imaginable. They are load bearing and durable often lasting thousands of years or more. Stone is used as facing, for internal support and augments or is augmented by brick and timber constructions.

Soil :- Soils with high clay contents are pulverized moistened and dumped into frames or formed into walls. Compaction is created by ramming. These buildings are allowed to sun dry. Structurally sound and weather resistant, these buildings survive for several hundred years or more.

Wood :- Wood is a product of trees, and sometimes other fibrous plants, used for construction purposes when cut or pressed into lumber and timber, such as boards, planks and similar materials. It is a generic building material and is used in building just about any type of structure in most climates. Wood can be very flexible under loads, keeping strength while bending, and is incredibly strong when compressed vertically.

Mangalore Tiles :- Mangalore tiles (also Mangalorean tiles) are a type of tile native to the city of Mangalore, India. They provide excellent ventilation especially during summer and aesthetically as well. Some of them are especially made to be placed over kitchen and bathroom for the smoke to escape. Over a period of time, these tiles become dark to black from constant exposure to soot and smoke. These red colored clay tiles, unique in shape and size are so famous and export to all the corners of world.

Low cost housing elemensts :-

Foundations :-

Random rubble masonry in mud/cement mortar placed in excavation over thick sand bed. Rubble pointing above ground level in stabilized cement mortar.

Use of lean cement concrete mix 1:8:16 for base with brick masonry in 1:6 cement mortar footings. Use of lean cement concrete mix as above for base and over burned bricks masonry in cement lime mortar

(1:2:12) footings. Arch foundations in place of spread foundations Normally the foundation cost comes to about 10 to 15% of the total building . It is recommended to adopt a foundation depth of 2 ft.(0.6m) for normal soil like gravely soil, red soils etc. It is suggested to adopt arch foundation in ordinary soils. In case of black cotton and other soft soils, it is recommend to use under ream pile foundation which saves

about 20 to 25% in cost over the conventional method of construction. Arch foundation-

This type of foundation was used in olden times where in spread foundation is replaced by inverted arch It reduces the construction cost up to 40% Advantage of this is-In soft soils that the depth of foundation can be greatly reduced; disadvantage is

that the end piers have to be specially strengthened by buttresses so as to avoid the thrust to arch action tending to rapture the piers junction.

Plinth :-

It is recommended to adopt 1 ft. height above ground level for the plinth and may be constructed with a cement mortar of 1:6.

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The plinth slab of 4 to 6″ which is normally adopted can be avoided and in its place brick on edge can be used for reducing the cost.

By adopting this procedure the cost of plinth foundation can be reduced by about 35 to 50%.

Walling :-

Wall thickness of 6 to 9″ is recommended for adoption in the construction of walls all-round the building and 41/2 ” for inside walls. It is suggested to use burnt bricks which are immersed in water for 24 hours and then shall be used for the walls

1. Rat – trap bond wall

It is a cavity wall construction with added advantage of thermal comfort and reduction in the quantity of bricks required for masonry work. By adopting this method of bonding of brick masonry compared to traditional English or Flemish bond masonry, it is possible to reduce in the material cost of bricks by 25% and about 10to 15% in the masonry cost. By adopting rat-trap bond method one can create aesthetically pleasing wall surface and plastering can be avoided.

2. Concrete block walling

In view of high energy consumption by burnt brick it is suggested to use concrete block (block hollow and solid) which consumes about only 1/3 of the energy of the burnt bricks in its production. By using concrete block masonry the wall thickness can be reduced from 20 cms to 15 Cms. Concrete block masonry saves mortar consumption, speedy construction of wall resulting in higher output of labour, plastering can be avoided thereby an overall saving of 10 to 25% can be achieved.

3. Soil cement block technology

It is an alternative method of construction of walls using soil cement blocks in place of burnt bricks masonry. It is an energy efficient method of construction where soil mixed with 5% and above cement and pressed in hand operated machine and cured well and then used in the masonry. This masonry doesn’t require plastering on both sides of the wall. The overall economy that could be achieved with the soil cement technology is about 15 to 20% compared to conventional method of construction.

Roofing :-

Domes and vaults in brick or stabilized mud block with appropriate mortar. Upgraded thatch roof on appropriate frame work. Pre-cast RCC “L” panel Precast RCC cored units in M15 concrete. Precast RCC channel units in M15 concrete Precast Waffle units in M15 concrete Burnt clay tube roofing in vault form. Other Methods :-

1. Filler slabs (Refer Q.29)2. Jack arch roof/floor

They are easy to construct, save on cement and steel, are more appropriate in hot climates. These can be constructed using compressed earth blocks also as alternative to bricks for further economy.

3. Ferrocement channel/shell unit

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Provide an economic solution to RCC slab by providing 30 to 40% cost reduction on floor/roof unit over RCC slabs without compromising the strength. These being precast, construction is speedy, economical due to avoidance of shuttering and facilitate quality control.

Doors and windows :-

It is suggested not to use wood for doors and windows and in its place concrete or steel section frames shall be used for achieving saving in cost up to 30 to 40%.Similiarly for shutters commercially available block boards, fibre or wooden practical boards etc., shall be used for reducing the cost by about 25%.By adopting brick jelly work and precast components effective ventilation could be provided to the building and also the construction cost could be saved up to 50% over the window components

Cost effective door, windows and chajjas :-

Ferro cement chajjas Precast RCC frames with wood insert Resin bonded saw dust frame Polyvinyl chloride frame Fiber reinforced plastic frame Plantation timber styles with particle board inserts. Medium density fiber board doors. Cement bonded particle board Plantation timber style with rice husk board inserts Red mud polymer panel doors. Ferrocement doors Polyvinyl chloride doors panels.

Finishing Works :-

The cost of finishing items like sanitary, electricity, painting etc., varies depending upon the type and quality of products used in the building and its cost reduction is left to the individual choice and liking

Q.9 Describe various technologies for water and soil conservation

Subsistence farmers suffer not only from depleted soils but from challenges with water: too little water, too much water, and erosion from water. This field guide looks at different ways of managing water and conserving soil by developing barriers on farm fields for stopping the flow of water so that it can percolate into the soil and build up soil moisture. The barriers also reduce the loss of soil from erosion.

Barriers to Water Movement

On sloping farm fields, creating barriers reduces the speed of water movement so that it can be absorbed into the soil rather than simply running off the land. These barriers also catch topsoil that the water carries preventing the loss of this valuable resource and offer the added benefit of creating level planting areas behind the barriers as the soil accumulates. Barriers can be terraces, stone or earth walls called bunds, or living barriers such as hedges and grass strips.

Building terraces and stone retaining walls can be very labor intensive. Less formal constructions such as soil bunds, hedgerows or rows of grass can be less labor-intensive and potentially more attractive to farmers. Construction can be spread out over several years.

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One thing that all barriers have in common is that they run horizontally along a level contour across the falling slope of a field. An A-frame leveling device is used to determine the level contour lines which are marked with stakes or with stones.

Here are four techniques for farmers to consider. The technique chosen by each individual farmer will be based upon how steeply a farmer's field slopes, how big their field is, whether they are in a high rainfall or low rainfall region, and how much time they have available for investing in the technique.

Contour Ridges.

Ridges with furrows on the uphill side are formed approximately 1.5m to 2m apart. This 2m area is the catchment area for rainwater. The ridges are only 15 to 20 cm high—simply high enough to contain the run off—which collects in the furrow. Crops with higher water requirements can be planted close to the side of the furrow. Contour ridges represent the least time investment of these four techniques and can be developed, maintained and improved during preparation for each planting season.

Soil Bunds

Soil bunds are a method for both containing water and reducing erosion using on-site materials. After marking the horizontal contour line on the sloping field, a ditch 60 cm deep and 60 cm wide is dug. The soil is placed on the downhill side of the ditch creating the soil wall. The base of the wall is typically twice as wide as the wall is high. The soil is well compacted by hand.

Soil bunds are placed from between 5m apart on steep land to 20m apart on more gently sloping land. To determine spacing between the bunds, one rule of thumb is that the top of one bund is level with the base of the adjacent uphill bund. However farmer preferences and the size of the farmer’s field are other determinants.

Fodder grasses, trees and crops are planted on the bund to stabilize it. Water collects in the ditch during rainstorms and can slowly percolate into the soil increasing soil moisture. As rainwater erodes soil uphill of the bund, the soil will accumulate above the bund and begin creating an increasingly level planting strip. Soil bunds will need annual maintenance—and will need to be checked after heavy rainfall and breaches repaired immediately.

Hedgerows.

Hedgerows can also be planted along the contour lines of a hillside—in similar spacing as soil bunds depending on the steepness of the slope of the field. Hedges are usually chosen from nitrogen fixing plants, and from plants that when pruned can be used as fodder for farm animals. Initially, these cuttings can be laid at the base of the hedges on the uphill side to trap eroded topsoil. After two or three years, sufficient topsoil will have accumulated to form a terrace uphill of the hedgerow. Hedgerows represent substantially less time investment than soil bunds—and use less space making more land available for planting.

Vetiver Grass Strips.

An inexpensive alternative, vetiver grass can be planted along the contour line of a sloping field to prevent the loss of topsoil, and to reduce the rate at which water runs downhill enhancing infiltration. Topsoil builds up on the uphill side and over time creates level planting areas. Grass strips represent substantially less time investment than soil bunds—and use less space. Grass strips need to be maintained over time to keep them from encroaching into the cropping areas. Grass trimmings can be used as fodder. Vetiver grass is very popular, but check with farmers for local favorites.

Q.10 What are the various methods for ground water recharge.

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Answer :- The various methods for ground water recharge are-

Reused plastic barrels method

This cost effective and simple method has been developed by A.R. Shiva Kumar. In this method, Overflow of rainwater from the storage structure and water from the roof other than the roof connected to the storage structure may be allowed to flow through a Popup Filter. This filter will filter floating elements and to some extent the silt coming in the water. Relatively cleaner water comes out of the filter and is allowed to flow into ground water recharge gallery.

Direct recharge through open wells and bore wells

Rainwater from the roof may be allowed to flow through PopUp filter and recharge ground water from an existing open well or a bore well. In case of an open well, filtered rainwater may be directly let in to the well through pipe from any one side of the well. It is advised not to allow the filtered rainwater from the PopUp filters in to the bore well (live or failed). Fine silt or dust from the roof may pass through the filter and block the micro pores or aquifers in the bore well causing permanent damage to the bore well

Infiltration Gallery for large buildings

Infiltration Gallery is to store rainwater temporarily and allow the stored water to infiltrate into underground aquifers. When the rainwater from the roof is allowed to flow on the ground infiltration (water percolating into the ground) is less, causing more of runoff, thereby majority of rainwater quickly reaches drains or storm water drains or streets and flows away from the building. To artificially increase infiltration, two parameters are important:

(a) increasing the surface area of the soil / earth in contact

(b) creating water head on the soil / earth

Increase in any of the above or both will influence greater infiltration of rainwater into ground. The level of infiltration also depends on the structure of the soil.

Spreading Methods

This method consists in spreading the water over the surface of permeable open lands and pits. From where it directly infiltrates to rather shallow aquifers. In this method, the water is temporarily stored in shape ditches or is spread over an open area by constructing life earth dykes called percolation bunds

Q.11 Describe in detail green energy concepts.

Answer :-

Green Energy :-

Green energy comes from natural sources such as sunlight, wind, rain, tides, plants, algae and geothermal heat. These energy resources are renewable, meaning they're naturally replenished. In contrast, fossil fuels are a finite resource that take millions of years to develop and will continue to diminish with use.

Renewable energy sources also have a much smaller impact on the environment than fossil fuels, which produce pollutants such as greenhouse gases as a by-product, contributing to climate change. Gaining access to fossil fuels typically requires either mining or drilling deep into the earth, often in ecologically sensitive locations.

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Green energy, however, utilizes energy sources that are readily available all over the world, including in rural and remote areas that don't otherwise have access to electricity. Advances in renewable energy technologies have lowered the cost of solar panels, wind turbines and other sources of green energy, placing the ability to produce electricity in the hands of the people rather than those of oil, gas, coal and utility companies.

Green energy can replace fossil fuels in all major areas of use including electricity, water and space heating and fuel for motor vehicles.

Types of green energy

Research into renewable, non-polluting energy sources is advancing at such a fast pace, it's hard to keep track of the many types of green energy that are now in development. Here are 6 of the most common types of green energy:

Solar Power - The most prevalent type of renewable energy, solar power is typically produced using photovoltaic cells, which capture sunlight and turn it into electricity. Solar energy is also used to heat buildings and water, provide natural lighting and cook food. Solar technologies have become inexpensive enough to power everything from small hand-held gadgets to entire neighbourhoods.

Wind Power - Air flow on the earth's surface can be used to push turbines, with stronger winds producing more energy. High-altitude sites and areas just offshore tend to provide the best conditions for capturing the strongest winds. According to a 2009 study, a network of land-based, 2.5-megawatt wind turbines in rural areas operating at just 20% of their rated capacity could supply 40 times the current worldwide consumption of energy.

Hydropower - Also called hydroelectric power, hydropower is generated by the Earth's water cycle, including evaporation, rainfall, tides and the force of water running through a dam. Hydropower depends on high precipitation levels to produce significant amounts of energy.

Geothermal Energy - Just under the earth's crust are massive amounts of thermal energy, which originates from both the original formation of the planet and the radioactive decay of minerals. Geothermal energy in the form of hot springs has been used by humans for millennia for bathing, and now it's being used to generate electricity. In North America alone, there's enough energy stored underground to produce 10 times as much electricity as coal currently does.

Biomass - Recently-living natural materials like wood waste, sawdust and combustible agricultural wastes can be converted into energy with far fewer greenhouse gas emissions than petroleum-based fuel sources. That's because these materials, known as biomass, contain stored energy from the sun.

Biofuels - Rather than burning biomass to produce energy, sometimes these renewable organic materials are transformed into fuel. Notable examples include ethanol and biodiesel. Biofuels provided 2.7% of the world's fuels for road transport in 2010, and have the potential to meet more than 25% of world demand for transportation fuels by 2050.

Q.12 What is the role of fly ash in present construction scenario.

Answer :-

1. Advantage of fly ash in concrete applications :-• Better workability• Reduced Permeability• Reduced Heat of Hydration• Improved pump ability• Improved Sulphate and Chloride Resistance

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• Reduced Risk of Alkali Aggregate Reaction• Increased Long term Strength• Better Concrete Finish• Reduced Bleeding and Segregation• Reduced Shrinkage and many more

2. Advantage of fly ash in masonry applications :-• Reduces drying shrinkage cracks• Good Bonding, less rebound hence reduces the wastage during• plastering• Better coverage area in plaster• Excellent permeability resistant• Improves labour productivity• Smooth finish• Eco friendly• Cost saving and many more

3. Fly ash utilization in Agriculture :-

Fly Ash also holds potential to improve the physical health of agriculture soil,

provide micro nutrients and as a result increase the yield of cereals, oil seeds, pulses,

cotton, and sugarcane etc. by 10-15%, vegetables by about 20-25% and root

vegetable by about 30-40% waste lands, degraded lands as well as problematic soils

such as Saline – Alkali soils, Alkali saline impermeable (salt pane) as well as eroded

soils even in arid zones can be successfully reclaimed by application of fly ash.

4. Application of Fly ash in Zeolite synthesis :-

Fly ash is oxide-rich and can be used as the raw material for different industries. For

the first time fly ash is used as a combine source for alumina and silica for

hydrothermal crystallization of commercially important zeolites beta and ZSM-12.

Until now no report is available on direct conversion of fly ash to commercially

important zeolite of type beta.

Q.13 What is the role of water cement ratio in the strength of concrete.

Answer :-

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the water/cement ratio is defined as the ratio of the weight of water to the weight of cement used in a concrete mix. Let us consider the following two cases :-

Case 1 : When the water/cement ratio is high.

If the w/c ratio is high, a large amount of water is available per unit weight of cement in the concrete mix. So if a fixed volume of concrete is poured into a cube of formwork, there are a large number of water-filled voids in the cube. So when the hydration reaction starts on the surface of the cement particle, the gel-like products of hydration get precipitated in the water - away from the surface of cement particles.

The gels formed in such a case are termed as Outer Products of Hydration. Now there are two reasons why the strength of concrete is low in this case, namely -

Since there is a large space for them to develop, the outer products of hydration are large in size. And we know, from the size effect, that larger sized particles have lower strength compared to particles of smaller size.

No matter how high the water consumption rate of the reaction is, due to the large amount of water present in the mix, some water will still be left when the concrete hardens and is ready for use. This trapped water will gradually evaporate, leaving some voids in the concrete block. The presence of voids results in greatly reduced strength.

Case 2 : When the water/cement ratio is low.

In this case, there will be very less amount of water in the block of formwork when the concrete is poured into it, and hence lesser voids. When the hydration reaction proceeds, the gels formed do not have enough space to migrate out and precipitate in the voids. So they get deposited on the surface of the cement particle itself. Such products of hydration are termed as Inner Products of Hydration. The space available for the crystals to grow is limited, so they remain much smaller in size compared to the outer products of hydration.

The strength of concrete is more when the w/c ratio is low, because of the following reasons -

As per the law of size effect, the smaller sized gels formed in this case have much greater strength as compared to those formed when the w/c is high.

Since the water available for hydration is very less, almost all of it is utilized during the reaction. So no water is left to get evaporated later, and hence the strength-reduction due to subsequent void formation is also much lower when the w/c ratio is low.

Q.14 What do you understand by leaching pit. Also define the working.

Answer :- Leach pits hold solid fecal material in the same way as the pit of a pit latrine, while allowing wastewater to percolate into the ground. When the ground is free of cracks, the soil is reasonably permeable, and the groundwater table does not reach within about 2 meters of the bottom of the pit. Under these conditions, natural microbiological processes in the ground should ensure that pathogens do not reach the groundwater (these requirements may be relaxed where the groundwater is not used for drinking water supply).

Advantages:

Where applicable, leach pits provide a simple means of disposing of wastewater without harming the environment or public health.

Disadvantages:

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There may be a risk that high concentrations of leach pits in urban areas may increase levels of nitrates, bacteria and other groundwater contaminants. However, the resultant risks are likely to be less than those of disposal above ground, and will depend on whether the groundwater is used for water supply. Pits have to be desludged from time to time and there are costs and health risks associated with this. As water use rises, separate provisions normally have to be made for the disposal of sullage. If attempted wastewater percolation into the soil exceeds its capacity, surface flooding of sewage will result.

Q.15 Give short note on soil stabilization.

Answer :-

1. Soil Stabilization with Cement:

The soil stabilized with cement is known as soil cement. The cementing action is believed to be the result of chemical reactions of cement with siliceous soil during hydration reaction. The important factors affecting the soil-cement are nature of soil content, conditions of mixing, compaction, curing and admixtures used. Lime, calcium chloride, sodium carbonate, sodium sulphate and fly ash are some of the additives commonly used with cement for cement stabilization of soil.

2. Soil Stabilization using Lime:

Slaked lime is very effective in treating heavy plastic clayey soils. Lime may be used alone or in combination with cement, bitumen or fly ash. Sandy soils can also be stabilized with these combinations. Lime has been mainly used for stabilizing the road bases and the subgrade.

Lime changes the nature of the adsorbed layer and provides pozzolanic action. Plasticity index of highly plastic soils are reduced by the addition of lime with soil. There is an increase in the optimum water content and a decrease in the maximum compacted density and he strength and durability of soil increases.

3. Soil Stabilization with Bitumen:

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Asphalts and tars are bituminous materials which are used for stabilization of soil, generally for pavement construction. Bituminous materials when added to a soil, it imparts both cohesion and reduced water absorption. Depending upon the above actions and the nature of soils, bitumen stabilization is classified in following four types:

Sand bitumen stabilization Soil Bitumen stabilization Water proofed mechanical stabilization, and Oiled earth.

4. Chemical Stabilization of Soil:

Calcium chloride being hygroscopic and deliquescent is used as a water retentive additive in mechanically stabilized soil bases and surfacing. The vapor pressure gets lowered, surface tension increases and rate of evaporation decreases. The freezing point of pure water gets lowered and it results in prevention or reduction of frost heave.

Sodium chloride is the other chemical that can be used for this purpose with a stabilizing action similar to that of calcium chloride.

Sodium silicate is yet another chemical used for this purpose in combination with other chemicals such as calcium chloride, polymers, chrome lignin, alkyl chlorosilanes, siliconites, amines and quarternary ammonium salts, sodium hexametaphosphate, phosphoric acid combined with a wetting agent.

5. Electrical Stabilization of Clayey Soils:

Electrical stabilization of clayey soils is done by method known as electro-osmosis. This is an expensive method of soil stabilization and is mainly used for drainage of cohesive soils.

6. Soil Stabilization by Grouting:

In this method, stabilizers are introduced by injection into the soil. This method is not useful for clayey soils because of their low permeability. This is a costly method for soil stabilization.

This method is suitable for stabilizing buried zones of relatively limited extent. The grouting techniques can be classified as following:

Clay grouting Chemical grouting Chrome lignin grouting Polymer grouting, and Bituminous grouting

7. Soil Stabilization by Geotextiles and Fabrics:

Geotextiles are porous fabrics made of synthetic materials such as polyethylene, polyester, nylons and polyvinyl chloride. Woven, non-woven and grid form varieties of geotextiles are available. Geotextiles have a high strength. When properly embedded in soil, it contributes to its stability. It is used in the construction of unpaved roads over soft soils.

Reinforcing the soil for stabilization by metallic strips into it and providing an anchor or tie back to restrain a facing skin element.

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Q.17 What is the role of Ferro cement drains in the waste water disposal system

Answer :- Advantages of ferrocement drains are as follow:-

The components of ferrocement drains, covers and storage tank are machine made having assured quality. These are brought to site and placed manually or using small crane.

There is no phenomena of any plaster application. The manufactured surfaces are smooth, better than plaster surfaces.

The ferrocement has unparallel feature of waterproof quality. There are no leakages through ferrocement drains as well as the tanks. The joints are very much leak proof.

Ferrocement drains and water storage tank consist of thin ferrocement plates about 25 mm thick. There is very much large quantum of space saving.

The ferrocement drains and water storage tanks construction saves space to a very large extent. This is most significant in cities where there is a shortage of space

No manhole cover is required for ferrocement drains. Covers to the ferrocement drains are removable for cleaning. These are 2.5 mtr. long and can be easily handled.

Thus the cleaning of drains is most convenient at reasonably low cost.

Q.19 How fibre change the property of concrete

Answer :-

Fiber-reinforced concrete (FRC) is concrete containing fibrous material which increases its structural integrity. It contains short discrete fibers that are uniformly distributed and randomly oriented. Fibers include steel fibers, glass fibers, synthetic fibers and natural fibers – each of which lend varying properties to the concrete. In addition, the character of fiber-reinforced concrete changes with varying concretes, fiber materials, geometries, distribution, orientation, and densities.

Fibers are usually used in concrete to control cracking due to plastic shrinkage and to drying shrinkage. They also reduce the permeability of concrete and thus reduce bleeding of water. Some types of fibers produce greater impact–, abrasion–, and shatter–resistance in concrete. Generally fibers do not increase the flexural strength of concrete, and so cannot replace moment–resisting or structural steel reinforcement. Indeed, some fibers actually reduce the strength of concrete.

Polypropylene and Nylon fibers can:

Improve mix cohesion, improving pumpability over long distances Improve freeze-thaw resistance Improve resistance to explosive spalling in case of a severe fire Improve impact resistance– and abrasion–resistance Increase resistance to plastic shrinkage during curing Improve structural strength Reduce steel reinforcement requirements Improve ductility Reduce crack widths and control the crack widths tightly, thus improving durability

Steel fibers can:

Improve structural strength

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Reduce steel reinforcement requirements Improve ductility Reduce crack widths and control the crack widths tightly, thus improving durability Improve impact– and abrasion–resistance Improve freeze-thaw resistance

Q.20 Give a short note on sisal fibre.

Answer :-

Sisal fibre is derived from the leaves of the plant. It is usually obtained by machine decortications in which the leaf is crushed between rollers and then mechanically scraped. The fibre is then washed and dried by mechanical or natural means. The dried fibre represents only 4% of the total weight of the leaf. Once it is dried the fibre is mechanically double brushed. The lustrous strands, usually creamy white, average from 80 to 120 cm in length and 0.2 to 0.4 mm in diameter.

Sisal fibre is fairly coarse and inflexible. It is valued for cordage use because of its strength, durability, ability to stretch, affinity for certain dyestuffs, and resistance to deterioration in saltwater. Sisal is used by industry in three grades:

The lower grade fibre is processed by the paper industry because of its high content of cellulose and hemicelluloses.

The medium grade fibre is used in the cordage industry for making: ropes, baler and binders twine. Ropes and twines are widely employed for marine, agricultural, and general industrial use.

The higher-grade fibre after treatment is converted into yarns and used by the carpet industry.

Q.21 Explain Manufacturing of Ferro-cement shell roof?

Answer :- The building system uses pre-cast ferrocement roofing channels of a segmental arch profile which are placed adjacent to each other and spanning over two supports. After partly filling the valley between channels with concrete, the channels form an idealized T-beam and are able to carry the load of a roof / floor. Ferrocement comprises of a uniform distribution of reinforcement by use of chicken wire mesh and welded mesh encapsulatedin rich cement mortar, thereby achieving significant reduction in both steel reinforcement and dead weight of roof. This composition provides a more uniform distribution of strength as compared to RCC.

Pre-cast Ferrocement Channels

FC Channels are pre-cast shell units made with rich cement mortar (1:2 to 1:3) and reinforcement consisting of a continuous layer of chicken mesh with steel bars provided at two ends of the channel. These shell units are cast either manually on a masonry mould or mechanically on steel moulds mounted on table vibrator. The channels are supported on ends either on load bearing masonry or on a frame structure (RCC or steel).

Restraining Beams

Any lateral moment and deflection of FC Channel gets balanced by thrust of adjacent channel. In order to balance the channel movement at ends, restraining beams must be provided to prevent differential movement of FC roof in case of any instability in the support structure. The restraining beam will be a part of RCC bands required for structural strengthening, specially in disaster prone areas.

Concrete Filling

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After the Channels have been placed side by side, they are joined together with a concrete infill of at least M15 grade (1:2:4) laid to 150 mm thickness. This concrete completes the T-beam structural action of the FC Channels and creates a basic roof. In case of an intermediate floor, the remaining portion of the valley can be filled the with lean concrete, brick jelly lime concrete or light-weight material and finished with a floor.

Q.22 What is energy efficient roofing? Explain.

Answer :-

Energy-efficient roofing materials can dramatically reduce household energy use, thereby decreasing greenhouse gas emissions and significantly lowering utility bills. Though the initial price of an energy-efficient roof can be slightly higher, the investment is made up for in reduced utility bills over the life of the building. Many Energy Star-rated roofs are also eligible for tax credits.

Cool Roofs

"Cool roofs" is an umbrella term for several different roofing systems. In short, a cool roof is a roof designed to reflect sunlight and heat. Conventional roofing materials reflect only 5 to 15 percent, which means they absorb 85 to 95 percent of the energy and heat from the sun. The coolest roofing materials reflect more than 65 percent, absorbing 35 percent or less of the energy from the sun. Thermal emittance determines how readily a surface gives up heat. Ideally, a roof will have a high percentage of reflectance and a high percentage of emittance.

Low-Sloped Roofs

Low-sloped roofs are normally found on commercial buildings, industrial buildings and multifamily homes. They can be made more efficient through the application of cool coating or single-ply membrane. Cool coating is the consistency of thick paint and can be applied to existing surfaces, such as asphalt, gravel, metal and various single-ply materials. Cool coatings have additional benefits, including improved adhesion, durability, suppression of algae growth and an ability to self-wash under normal rainfall. Single-ply membranes come in prefabricated sheets and are generally glued or mechanically fastened in place over the entire surface of the roof.

Steep-Sloped Roofs

Steep-sloped roofs are generally found on residential homes. The most common types of cool roofing systems for steep-sloped roofs include tiles and painted metal. Typical tiles, made of clay or concrete, reflect only 10 to 30 percent. "Cool-colored" tiles contain pigments that reflect 25 to 70 percent of solar energy, depending upon the color. Cool-colored metal roofing also contains pigments that reflect 20 to 90 percent. Metal roofing is more common than tile, as it is highly durable.

Heat Islands

Heat islands are urban areas that are hotter than nearby rural areas. A city with 1 million people or more can be 1.8 to 5.4 F warmer than its surroundings. Heat islands affect community-wide energy demands, air-conditioning costs, air pollution, greenhouse gas emissions and water quality. Cool roofs play a vital role in reducing the environmental and economic impact of large cities.

Green Roofs

Although green roofs fall into their own category, they provide similar benefits as cool roofs. Green roofs are gardens or mini-ecosystems that cover an existing roof with the aid of special planters. The greenery essentially shades the roof, reducing heat transfer and thereby keeping the building cool. (See References 4, page 4) Green roofs also act as insulators in cold weather and have a host of other benefits, such as absorbing rainfall for better

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stormwater management, reducing air pollution and providing garden space in densely populated areas where parkland is rare.

Q.24 Explain manufacturing of MCR tiles.

Answer :-

The roofing tiles developed through a technique called Micro Concrete Roofing, is a result of worldwide research and is being extensively used in South America, African and South East Asian countries. M.C.R tiles are widely used in India too.

Speciality of M.C.R Tiles

M.C.R tiles are better than other traditional forms of roofing like tin sheet, asbestos sheets or khaprail for the following characteristics:

These have more strength as cement is added to them. These are lighter than other tiles. Manufacturing process of these tiles is very simple and any individual can master the art in seven days. White washing of roof is not required when these tiles are used. These tiles are warmer in winters and cool in summers. They donot make noise when it rains. Colours can be added for attractive look.

The M.C.R tiles are certified by Building Material Technology Council, Housing Ministry, Government of India.

Manufacturing :-

The manufacturing process of M.C.R. tiles is very simple. First a balanced mixture of cement, concrete stones, sand and water is prepared. In this mixture cement, stone chips (6 mm) and sand/ stone dust are mixed in 1:1:2 ratio. This mixture is put in a vibrating machine and adequate amount of vibrations are given. These mixture is poured in plastic/ fiber moulds and left in it for at least 24 hours. After 24 hours, these tiles are put in water tank for curing. The tiles are put in water tank for seven day period. This strengthens the tiles. After curing, the tiles are painted with cement paint or plastic paint. Mostly cement paint is used for this purpose. After painting the tiles they are sent for marketing.

Q.25 What is non-erodible mud plaster? Explain process of its preparation and its application.

Answer :-

Most of the houses in villages are built either with kachha (Sun Dried) bricks or blocks, or with lumps of mud stacked over one another (‘cob’ technique). Mud walls are protected against damage from rain by applying mud plaster, consisting of local soil or mud collected from village pond mixed with bhusha (wheat straw) on outer walls, rendering with gobri (Cow dung slurry). This traditional method of application of mud plaster of course is cheap; however it cannot with sand continuous rainfall.

During continuous rain, moisture penetrates through the plaster and softens the surface of the wall in contact with the plaster, thereby weakening the bond between the wall face and the plaster. Normally on drying out, the adhesion between the wall surface and the plaster should be fully restored, but due to the differential shrinkage between plaster and wall, local stresses develop, which are too high for the weakened bond between the plaster and

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the softened wall face to overcome. A partial separation thus occurs, and by repeated cycles of wetting and. drying, the plaster ultimately comes off in flakes and is eroded. As a result, considerable damage is done to the walls and consequently, the house. Thus a waterproof mud rendering on mud walls can save the walls from frequent damage and substantially increase its durability to more than 25 years years with normal annual maintenance.

The Central Building Research Institute Roorkee has developed a "Non-erodible mud plaster" based on bitumen cutback, and have been successfully adopted on several houses to prove its effectiveness. In this technique, a bitumen cutback is prepared with bitumen having 80/100 penetration & kerosene oil – this is mixed with ordinary mud mortar (having bhusa) and applied on the mud wall, providing a non-erodible and water proof plastered surface.

Preparation and application :-

Mix mud with water and knead it thoroughly Add measured quantities of cement to mud Add measured quantity of lime to the mud mix Mix the mud thoroughly and knead Sprinkle water and apply prepared mud plaster Apply mud plaster upto 150cm height from the ground Allow the plaster to dry for 2 days and apply mud and cowdung mix as plaster

Q.26 Explain in details how effective planning and selection of proper construction material reduces construction cost.

Answer :-

Importance of planning :-

It is the process of selecting a particular method and the order of work to be adopted for a project from all the possible ways and sequences in which it could be done. It essentially covers the aspects of ‘What to do’ and ‘How to do it’

Importance of construction project planning :

Planning helps to minimize the cost by optimum utilization of available resources. Planning reduces irrational approaches, duplication of works and inter departmental conflicts. Planning encourages innovation and creativity among the construction managers. Planning imparts competitive strength to the enterprise.

Importance of construction material selection :-

The selection of building materials and products represents one important strategy in the design of a building. Building materials offer specific benefits to the building owner and building occupants and are follows:

Reduced maintenance/replacement costs over the life of the building. Energy conservation. Improved occupant health and productivity. Lower costs associated with changing space configurations. Greater design flexibility.

Q.29 Explain Filler slab.

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They are normal RCC slabs where bottom half (tension) concrete portions are replaced by filler materials such as bricks, tiles, cellular concrete blocks, etc.These filler materials are so placed as not to compromise structural strength, result in replacing unwanted and nonfunctional tension concrete, thus resulting in economy. These are safe, sound and provide aesthetically pleasing pattern ceilings and also need no plaster

Technique :-

The filler slab is based on the principle that for roofs which are simply supported, the upper part of the slab is subjected to compressive forces and the lower part of the slab experience tensile forces. Concrete is very good in withstanding compressive forces and steel bears the load due to tensile forces. Thus the lower tensile region of the slab does not need any concrete except for holding the steel reinforcements together.

Therefore in a conventional RCC slab lot of concrete is wasted and it needs extra reinforcement due to added load of the concrete which can otherwise be replaced by low-cost and light weight filler materials, which will reduce the dead weight as well as the cost of the slab to 25% (as 40% less steel is used and 30% less concrete)

Mechanism :-

The filler slab is a mechanism to replace the concrete in the tension zone. The filler material, thus, is not a structural part of the slab. By reducing the quantity and weight of material, the roof become less expensive, yet retains the strength of the conventional slab. The most popular filler material is the roofing tile. Mangalore tiles are placed between steel ribs and concrete is poured into the gap to make a filler slab. The structure requires less steel and cement and it is also a good heat insulator.

Conventional tests by different institutions and laboratories has proved the load bearing capacity of filler slab and found it no less in performance from the conventional R.C.C. slab. Since filler roof tiles are firmly bonded to and covered by concrete, it does not collapse under the impact of say, a coconut falling on the roof.

Benefits :-

Saving on cost The savings on cost can be from 15 per cent to 25 per cent. But designing a filler slab requires a structural engineer to determine the spacing between the reinforcement bars.

Thermal insulationThe air pocket formed by the contours of the tiles makes an excellent thermal insulation layer. The design integrity of a filler slab involves careful planning taking into account the negative zones and reinforcement areas.

Q.6 Describe various cost effective techniques for building/house construction (residential building construction)

Answer :- Refer Q.5

Q.7 Plan and design cost effective and eco-friendly road construction using locally available material for light traffic.

Q.8 Describe cost effective sanitation for rural and urban areas including basic structure and disposal system

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Answer :-

Rural Areas :-

1. Plinth level toilet with temporary superstructure

This is one of the simplest designs and it is best suited where space is a constraint. It is quite easy to empty filled pits, can be constructed within a day and cost investment is definitely on the lower side. The total cost of construction comes to about Rs. 1500. Superstructure can be made from locally available materials such as banana leaves, bamboo sticks and gunny bags. It can be a simple solution for sanitation around festival places and during emergencies. Estimated cost of 1 toilet: Rs. 1500

2. Toilet only model with hollow bricks

The superstructure here is made of hollow bricks. This model is suitable for all purposes, it is comparatively low cost and is most suitable where space is limited. Estimated cost of 1 toilet: Rs. 5500

3. Toilet attached bathroom (w/ hollow bricks and no roof)

A multifunctional low cost structure, this toilet and bathroom design accommodates provision for water storage, bathing and washing facilities inside the toilet. Additionally, using water waste for kitchen garden is possible and most importantly it provides privacy for ablution, especially keeping in mind women and adolescent girls. Estimated cost of 1 toilet: Rs. 7257

4. Toilet only model (w/ concrete rings pit and roof)

It is a low cost design, especially suited for small areas, and provides privacy and safeguards during rainy season. Estimated cost of 1 toilet: Rs. 6875

5. Twin pit – Pour flush latrine

Slightly larger space may be needed to construct this toilet but the cost is still low. Having two pits is certainly an advantage as when the first pit gets filled up, the flow of excreta has to be diverted to the second pit. In this design, two leach pits are connected to one single pour-flush toilet. Twin-pit toilets have a high convenience – when emptying one pit, people use second pit. Estimated cost of 1 toilet: Rs. 7257

6. ECO-SAN toilets

This toilet design might be costly but prevents contamination of water sources and soil. Human waste can be composted and used as a natural fertilizer. Unlike other designs, emptying pits is not a requirement. This design is great in the areas where water logging and scarcity is a concern. It is most effective in coastal and rock areas, as it

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promotes soil fertility and crop production. Historically, such ecological methods of sanitations were utilized by the Romans, Chinese, in Mexico, Peru and Yemen. Some places which have excelled in this technology in the current age are Guangxi province, China; KfW, Frankfurt, Germany where they use vacuum toilets with provisions of grey water treatment and Tanum Municipality in Sweden. Ecosan was implemented in Haiti as part of the emergency relief effort following the 2010 earthquake. In India, these designs are notably used in Tamil Nadu where the Tamil Nadu State Government provides subsidies. Estimated cost of 1 toilet: Rs. 10,747

7. Bio-gas linked toilets

Talk about alternate energy alternatives and here is one. This design offers support to convert waste matter to Bio-gas, a non-conventional energy source. The fuel generated can be used as local source for electricity, heat and light. Also, the waste can be composted to Bio-manure which increases productivity and catalyses soil conservation. In 2012, UNICEF chose two districts in West Bengal to pilot this kind of design in India and approximately 19,000 Kg of methane gas that was produced from waste alone each day was converted to produce biogas. UNICEF successfully piloted this program with a local NGO – Ramakrishna Mission Lokashiksha Parishad to implement this program at Medinipur district. Look at the Banka bio-loo model. Estimated cost of 1 toilet: Rs. 21, 167

Urban Areas :-

1 Simple Pit Latrine

The simple pit latrine is found almost everywhere in the world. It is a pit dug into the ground, covered with a slab with a drop hole in it, and usually has some sort of structure around it for privacy. Smells, flies and other vectors will be reduced if the simple pit latrine is well maintained, the slab is kept clean and the hole is kept covered. The latrine’s components can be made out of local materials such as wood, brick, metal, thatch or concrete.

2 Ventilated Improved Pit Latrine

The ventilated improved pit (VIP) latrine is an improved version of the simple pit latrine. The

main differences are:

A ventilation pipe is incorporated. Fresh air flows into the superstructure through a vent that can be made from plastic, concrete or brick. The air travels through the drop hole and the smelly air and gases from the

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pit are drawn out through the vent pipe. The pipe is covered at the top with a fine mesh (often mosquito mesh) to prevent flies and other insects that may be attracted by the smell from entering the pit.

The superstructure is built so that it is always dark inside. Flies that do get in the pit by coming in through the vent or door will be attracted to the light at the top of the vent pipe but will get stuck in the mesh and die.

The drop hole is not covered. It needs to stay open so that the air can flow into the pit and then up and out of the vent.

3 Pour Flush Pit Latrine

A pour flush latrine is a version of the simple pit latrine that requires water to move excreta into the pit. A pour flush pan is built into the slab and is used instead of a drop hole. The pan is designed so that there is a water seal created in the pipe. This stops smells from escaping from the pit and flies and rodents from entering the pit. Well designed, smooth pour flush pans require as little as 2-3 litres to flush; however inefficient pans may need 5-6 litres to flush properly. Pour flush pans can be made from concrete, ceramics, plastics or enamelled steel. Plastic pans tend to be cheapest as they are quite smooth and easy to clean, but they are often less robust than other materials. The pit can be offset from the superstructure with a short section of pipe or covered channel connecting it to the pour flush pan. This allows simpler and lighter slabs to be used to cover the pit. It also means that the superstructure can be built out of heavier materials such as brick and block because it will be better supported by the earth. Pour flush latrines are particularly appropriate for people who use water for anal cleansing. Soft wiping materials (e.g. toilet paper) can be flushed, but those who use solid materials will need a separate sanitary method for disposing of the soiled material.

4 Twin-Pit Latrines

The twin-pit latrine is made of two lined pits dug side by side. When one pit is full, the other pit is then used. When the second pit it full, the first pit is emptied and re-used. The pits are lined to stop them from caving in when they are emptied. The type of latrine used with twin-pits can be a simple pit, VIP, or a pour flush latrine. Composting and dehydrating latrines also use a twin pit system, but they require special operation that will be discussed further in the ecological sanitation section. A twin-pit latrine is used where it is necessary to empty latrines and dispose of the contents elsewhere once they are full. This includes places where there is limited space or where more permanent structures are desired. The pits should be sized so that each pit fills up over the course of one or two years. This way the pit contents can sit while the other pit fills up. A two year period is recommended in most climates for the pit contents to decompose and for the pathogens to die off. The pit contents can then be removed safely (WHO, 2006).

Q.16 How will you construct a national highway using plastic. Take both flexible and rigid pavement

Answer :-

The following types of waste plastic can be used in the construction of rural roads:

Films ( Carry Bags, Cups) thickness up to 60micron (PE, PP and PS) Hard foams (PS) any thickness Soft Foams (PE and PP) any thickness. Laminated Plastics thickness up to 60 micron (Aluminum coated also) packing materials used for biscuits,

chocolates, etc. Poly Vinyl Chloride (PVC) sheets or Flux sheets should not be used in any case.

Process Of laying :-

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Process Step 1:

Plastics waste (bags, cups, thermo Cole) made out of PE,PP and PS cut into a size between 2.36mm and 4.75mm using shredding machine, (PVC waste should be eliminated).

Process Step 2:

The aggregate mix is heated to 165°c (as per the HRS specification) and transferred to mixing chamber.

Process Step 3:

Similarly the bitumen is to be heated up to a maximum of 160°c (HRS Specification) to have good binding and to prevent weak bonding. (Monitoring the temperature is very important).

Process Step 4:

At the mixing chamber, the shredded plastics waste is to be added. It get coated uniformly over the aggregate within 30 to 60 seconds, giving an oily look.

Process Step 5:

The plastics waste coated aggregate is mixed with got bitumen and the resulted mix is used for road construction. The road laying temperature is between 110°c to 120°c. The roller used is 8-ton capacity.

Advantages of Plastic Tar Road :-

A well constructed Plastic Tar Road will result in the following advantages.

Strength of the road increased (Increased Marshall Stability Value) Better resistance to water and water stagnation No stripping and have no potholes. Increased binding and better bonding of the mix. Increased load withstanding property( Withstanding increased load transport) Overall consumption of bitumen decreases. Reduction in pores in aggregate and hence less rutting and raveling. Better soundness property. Maintenance cost of the road is almost nil. The Road life period is substantially increased. No leaching of plastics. No effect of radiation like UV.

Q.18 Give the brief comparison of a G+1 residential building with locally available conventional material and with cost effective construction material.

Answer :- Following are the advantages of Low cost housing over Conventional Methods :-

Economic benefits:

Reduce operating costs Enhance asset value and profits Improve employee productivity and satisfaction Optimize life cycle economic performance

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Qualifying for various tax rebates, zoning allowances and other incentives in many cities Become a selling point to potential buyers Increase the market for an engineer’s or contractor’s skills Lowering a building’s overall life cycle cost

Environmental benefits:

Improve air and water quality Reduce solid waste Conserve natural resources Enhance and protect ecosystems and biodiversity

Health and community benefits:

Improve air, thermal, and acoustic environments Enhance occupant comfort and health Possibly limiting growth of mold and other airborne contaminants that can affect worker productivity and/or

health

Q.23 Explain working of Concrete block manufacturing machine.

Q.27 Give rate analysis of solid concrete block of size 300x200x150 Cubic mm.

Q.28 Workout plastering rates for plastering 10sqm wall surface with non-erodible mud plaster?