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1 DGMAP PHASE II JALANDHAR AND SURANASI A PROJECT REPORT Submitted by In partial fulfillment for the award of the degree Of BACHELOR OF TECHNOLOGY IN CIVIL ENGINEERING Under The Guidance of Submitted by Lecturer (Civil Engg Dept.)

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DGMAP PHASE II JALANDHAR AND SURANASI

A PROJECT REPORT

Submitted by

In partial fulfillment for the award of the degree

Of

BACHELOR OF TECHNOLOGY

IN

CIVIL ENGINEERING

Under The Guidance of Submitted by

Lecturer (Civil Engg Dept.)

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ABSTRACT

In order to accommodate personnel of our esteemed armed forces, the government of India has commenced work on a residential facility in Jalandhar Cantonment area such that our soldiers can live with their families while being near their place of work.

The said structure is an RCC framed structure, with the total cost of construction estimated to be around 138 Crore rupees. The structure will cater to the demands of around 2000 families such that all the basic as well as convenient amenities are provided.

The entire process of construction was performed in a very professional and systematic manner. I experienced various activities involved in the construction process like labor management, material selection, tests performed on site and shuttering and scaffolding placement.

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DECLARATION

Certified that this project report entitled “DGMAP Phase II Construction” submitted by “___”, Reg. no. , a student of Civil Engineering department, ________ was carried out under my supervision.

This report has not been submitted to any other university or institution for the award of any degree.

SIGNATURE SIGNATURE

HEAD OF THE DEPARTMENT SUPERVISOR

(Department of Civil Engg.)

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ACKNOWLEDGEMENT

I am sincerely grateful to Ms. Arshdeep Kaur who has guided me throughout the making of this project and without whom the completion of this project would be a utopian task.

I am also extremely grateful to Er. Aatma Singh without whom I would not have had the golden opportunity of working on this project. I am also thankful to NKG Infrastructures Ltd. who gave me the opportunity of working on this project

Last but not the least, I am thankful to my family and friends for their guidance in every step of the way. I am also thankful to my delightful co-trainees for making this experience memorable and worthwhile.

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TABLE OF CONTENT Page

List of table …………….……………………………………………………………………6

List of figures ………………………………………………………………………………..6

1. Introduction………………………………………………………………………………..7

1.1 About site……………………………………...…………………………………… ...7

1.2 Sequence of construction ...…………………………………………………………..9

2. Construction process and material used …………………………………………………11-37

2.1 Cement ………………………………………………………………………………..11

2.2 Aggregate…………………………………………………………………………….14

2.3 Concreting ……………………………………………………………………..……..16

2.4 Test for quality control……………………………………………………………….20

2.5 Concrete mixture……………………………………………………………….…….22

2.6 Shuttering and scaffolding…………………………………………………….……..23

2.7 Reinforcement………………………………………………………………….…….25

2.8 Erection of formwork ……………………………..…………………………….……29

2.9 Column construction…………………………….……………………………………31

2.10 Beam construction …………………………….…………………………………….32

2.11 Slab construction ……………………………….…………………………………….35

2.12 Pouring and consolidation…………………….….………………………..…………36

2.13 Curing………………………………………………………………….……………..36

2.14 Leakage and water proofing…………………………………………………..............37

3. Conclusion ………………………………………….……………………………………38

3.1 References……………………………………...……………………………….……..39

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List of Tables Page No.

Table 1.1……………………………………………………………………………41

List of Figures

Fig 1.1……………………………….……………………………… ……………..14

Fig 1.2………………………………………………………………………………17

Fig 1.3………………………………………………………………………………18

Fig 1.4………………………………………………………………………………25

Fig 1.5………………………………………………………………………………28

Fig 1.6………………………………………………………………………………30

Fig 1.7………………………………………………………………………………32

Fig 1.8………………………………………………………………………………36

Fig 1.9……………………….…….………………………………………...............38

Fig 1.10…………………………….……………………………………………….40

Fig 1.11…………………………….……………………………………………….43

Fig 1.12…………………………..….………………………………… …………..46

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INTODUCTION ABOUT SITE

Under Phase II Package No. 6 Faridkot, Adampur, Jalandhar and Suranussi Stations occur.

The project Station at Jalandhar & Suranussi was issued to NKG Infra. Ltd. On 29 Nov.

2010. M/S Span Consultant Pvt. Ltd. Noida. is the consultant to this project. The detailed

project report cost of building is 125.42 Crores and external services of 13.418 Crores. The

dwelling units are to be constructed at different locations in Jalandhar Cantonment which

are named as pockets. These Pockets consists certain number of Blocks which are G+6

story buildings. A particular block floor has 4 quarters equally divided with a stair case and

lift provided throughout the block and a water tank at the top of the Block. The Ground

Floor is to be used as parking.

NAME OF POCKET DWELLING UNITS

POCKET- G 528

POCKET- H 240

POCKET- N 336

POCKET- K 326

POCKET- M 360

POCKET- J-2 180

Project DGMAP PHASE II

Region Punjab

Address of the Project Site Hudson Line, Jalandhar Cantt.

Project Type Lump Sum

Business Segment Residential

Name of the Client Military Engineering Services

Overall Responsibility DGMAP

Project Management Consultancy SNC Lavalin Infrastructure Ltd. Noida.

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No of Dwelling Unit 528

Project Manager Er. Sukhdev Singh

Structural Consultant M/S Span Consultant Pvt. Ltd. Noida

Total Value of Project 138 Crores

Date of Commencement Jan. 2011

Date of Completion Extended

Name of Pocket G-A

No of Block 22

Structure Stilt +6

Area of Block 5000sq ft.

Area of Pocket 17.19 Acres

Before starting the construction work on the site, some important points to keep in mind are:-

- We need a drawing (plan) of building.- Structural drawing (drawings of beam, column, footing, etc.)- Levelling and marking.- Availability of materials.- Arrangements of electricity and water supply- Machinery ( mixture, generator, and other equipment)- Arrangement of store, cement store, labour rooms.- Staff members

Site engineer Billing engineer Site supervisor Forman Accountant

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SEQUENCE OF CONSTRUCTION

o Site clearanceo Demarcation of siteo Surveying and layouto Excavationo Bar Bending and placements of foundation steelo Shuttering and scaffoldingso Concretingo De-shutteringo Plasteringo Final completion and handling over the projects

SITE LOCATION

Demarcation of site: - the whole area on which construction is to be done is marked so as to identity the construction zone. In my project, a plot of 2(25mx4.5m) was chosen and the respective marking was done.

Position of central coordinate and layout: - the center points was marked with the help of a thread and plumb bob as per the grid drawing. With respect to this center point, all the other points of columns were decided so its exact position is very critical.

EXCAVATION

Excavation was carried out by Back Hoe and manual labor. Adequate precautions are taken to see that the excavation operations do not damage the adjoining structures. Excavation is carried out providing adequate side slopes and dressing of excavation bottom. The soil present beneath the surface was too clayey so it was dumped and was not used for back filling. The filling is done in layer not exceeding 20cm layer and then it’s compacted. Depth of excavation was 1.5m-2.5m from ground surface.

SITE ENGINEER: - A site engineers perform a technical, organizational and supervisory role on construction projects, including setting out roads, drains, sewer and structures involved in construction operations.

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Site engineers apply design and plans to mark out the site and can be involved in projects ranging from small scale to multi-million pound ventures. This may include civil, road, rail and other infrastructure projects.

A site engineer works as part of the site management team liasoning with and working alongside architect, engineers, construction manager, supervisor, planner, surveyors and subcontractors. They share responsibility for site security, health, and safety, and the organization and supervision of material and human resources

Typical work activities include:

- Acting as the main technical advisor on a construction site for subcontractor, crafts people and operatives;

- Setting out, levelling and surveying the site- Checking plans, drawing and quantities for accuracy of calculation;- Ensuring all materials used and work performed are as per specification;- Agreeing the selection and requisition of materials and plant;- Agreeing a price for material, and making cost-effective solution and proposal for the intended

projects; Overs- Managing, monitoring and interpreting the contract design documents supplied by the clients/

architect;- Liaising with any consultants, sub-contractors, supervisors, planner, quantity surveyors and the

general work force involved in the project;- Leasing with the local authority to ensure compliance with local construction regulations and

by-laws;- Liaising with clients and their reprehensive (architect, engineer, and surveyor), including

attending regular meeting to keep them informed of progress.- Day to day management of the site, including supervising and monitoring the site labour force

and the work of any subcontractor;- Planning the work and efficiently organizing the plant and site facilities in order in order to

meet agreed deadlines;- Overseeing quality control, health and safety matters on site;- Preparing reports as required;- Resolving any unexpected technical difficulties, and other problems that may airs

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CONSTRUCTION PROCESS AND MATERIAL USED

CEMENT

Portland cement is composed of calcium silicates and aluminates and alumino-ferrite. It is obtained by predetermined proportions limestone clay and other minerals in small quantities which is pulverized and heated at high temperature- around 1500 degree centigrade to produce ‘clinker', The clinker is then ground with small quantities of gypsum to produce a fine powder called Ordinary Portland Cement (OPC). When mixed with water, sand and stone, it combines slowly with the water to form a hard mass called concrete. Cement is a hygroscopic material meaning that it absorbs moisture in presence of moisture it undergoes chemical reaction termed as hydration. Therefore cement remains in good condition as long as it does not come in contact with moisture. If cement is more than three months old then it should be tested for its strength before being taken into use.

The Bureau of Indian Standards (BIS) has classified OPC in three different grades. The classification is mainly based on the compressive strength of cement-stand mortar cubes of face area 50 cm2 composed of 1 part of cement to 3 part of standard sand by weight with a water-cement ratio arrived at by a specified procedure. The grades are

i) 33 grade

ii) 43 grade

iii) 53 grade

The grade number indicates the minimum compressive strength of cement sand mortar with N/mm2 at 28 days, as tested by above mentioned procedure.

Portland Pozzolana Cement (PPC) is obtained by either intergrading a Pozzolana material with clinker and gypsum, or by blending ground Pozzolana with Portland cement. Nowadays good quality fly ash is available from Thermal

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Fig 1.1 cement

ADVANTAGE of using Portland Pozzolana cement over OPC

Pozzolana combines with lime and alkali in cement when water is added and forms compounds which contribute to strength, impermeability and sulphate resistance. It also contributes to workability, reduced bleeding and controls destructive expansion from alkali-aggregate reaction. It reduces heat of hydration thereby controlling temperature differentials, which causes thermal strain and resultant cracking and mass concrete structures like dams. The color of PPC comes from the color of the pozzolanic material used. PPC containing fly ash as a Pozzolana will invariably be slightly different color than the OPC. One thing should be kept in mind that is the quality of cement depends upon the raw material used and the quality control measures adopted daring its manufacture, and not on the shade of the cement. The cement gets its color from the nature and color of raw materials used, will be different from factory. Further, the color of the finished concrete is affected also by the colour of the aggregates, and to a lesser extent by the colour of the cement. Preference for any cement on the basis of colour alone is technically misplaced.

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Settling of Cement:-

When water is mixed with cement, the paste so formed remains pliable and plastic for a short time. During this period it is possible to disturb the paste and remit it without any deleterious effects. As the reaction between water and cement continues, the paste loses it plasticity. This early period in the hardening of cement is referred to as ‘setting' of cement.

Initial and final setting time of cement:-

Initial set is when the cement paste loses its plasticity and stiffens considerably. Final set is the point when the paste hardens and can sustain some minor load. Both are arbitrary points and these are determined by Vicat needle penetration resistance.

Slow or fast setting normally depends on the nature of cement. It could also be due to extraneous factors not related to the cement. The ambient conditions play an important role. In hot weather, te sitting is faster, in cold weather, setting is delayed some types of salts, chemicals, clay, etc if inadvertently get mixed with the sand, aggregate and water could accelerate or delay the sitting of concrete.

Storage of Cement

It needs extra care or else can lead to loss not only in term of financial loss but also in terms of loss in the quality. Following are the don't that should be followed-

i) Do not store bags in a building or a godown in which the walls, roof and floor are not completely weatherproof.

ii) Do not store bags in a new warehouse until the interior has thoroughly dried out.

iii) Do not be content with badly fitting windows and doors, make sure they fit properly and ensure that they are kept shut.

iv) Do not stack bags against the wall. Similarly, don't pile them on the floor unless it is a dry concrete floor. If not, bags should be stacked on wooden planks or sleepers.

v) Do not forget to pile the bags close together

vi) Do not pile more than 15 bags high and arrange the bags in a header-and-stretcher fashion.

vii) Do not disturb the stored cement until it is to be taken out for use.

viii) Do not take out bags from one tier only. Step back two or three tiers.

ix) Do not keep dead storage. The principle of first-in first-out should be followed in removing bags.

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x) Do not stack bags on the ground for temporary storage at work site. Pile them on a raised, dry platform and cover with tarpaulin or polythene sheet.

Coarse aggregate

Fig 1.2

Coarse aggregate for the works should be river gravel or crushed stone. It should be hard, strong, dense, durable, clean, and free from clay or loamy admixture or quarry refuse or vegetable matter. The pieces of aggregates should be cubical, or rounded shaped and should have granular or crystalline or smooth (but not glossy) non-powdery surfaces. Aggregates should be properly screened and if necessary washed clean before use.

Coarse aggregates containing flat, elongated or flunky pieces or mica should be rejected. The grading of coarse aggregates should be as per specifications of IS-383.

After 24-hrs immersion in water, a previously dried sample of the coarse aggregate should not gain in weight more than 5%.

Aggregates should be stored in such a way as to prevent segregation of sizes and avoid contamination with fines.

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Depending upon the coarse aggregate colour, there quality can be determined as:

Black=> Very Good Quality

Blue=>Good

Whitish=>Bad Quality

Fine Aggregate

Fig 1.3

Aggregate which is passed through 4.75 IS Sieve is termed as fine aggregates. Fine aggregate is added to concrete to assist workability and to bring uniformity in mixture. Usually, the natural river sand is used as fine aggregate. Important thing to be considered is that fine aggregates should be free from coagulated lumps.

Grading of nature sand or crushed stone i.e. fine aggregates shall be such that not more than 5 percent shall exceed 5 mm in size, not more than 10% shall IS sieve

No. 150 not less than 45% or more than 85% shall pass IS sieve No.1.18 mm and not less than 25% or more than 60% shall pass IS sieve No. 600 micron.

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Concreting

Concrete has two main stages Concrete is a mixture of cement, sand, stone aggregates and water. A cage of steel rods used together with the concrete mix lead to the formation of reinforcement cement concrete popularly known as RCC.

1) Fresh concrete

2) Hardened concrete

Fresh concrete should be stable and should not segregate or bleed during transportation and placing when it is subjected to forces during handling operations of limited nature. The mix should be cohesive and mobile enough to be placed in the form around the reinforcement and should be able to cast into the required shape without losing continuity or homogeneity under the available techniques of placing the concrete at a particular job. The mix should be amenable to proper and through compaction into dense, compact concrete with minimum voids under the existing facilities of compaction at the site. A best mix from the point of view of compatibility should be a 99% elimination of the original voids present.

Hardened concrete

One of the most important properties of the hardened concrete is its strength which represents the ability if concrete to resist forces. If the nature of the force is to produce compression, the strength is term compressive strength. The compressive strength of hardened concrete is generally considered to be the most important property and is often taken as the index of the overall quality of concrete. The strength can be indirectly gives an idea of the most of the other properties of concrete which are related to the structure of the hardened cement paste.

A stronger concrete is dense, compact, impermeable and resistant to weathering and to some chemicals. However, a strong concrete may exhibit higher drying shrinkage with consequent cracking, due to the presence of higher cement concrete. Some of the other desirable properties like shear and tensile strengths, modulus of elasticity, bond, impact and durability etc. are generally related to compressive strength. As the compressive strength can be measured easily on standard sized cube or cylindrical specimens. It can be specified as a criterion for studying the effects on any variable on the quality of concrete. However, the concrete gives different values of any property under different testing conditions. Hence method of testing, size of specimens and the rate of loading etc. are stipulated while testing the concrete to minimize the variations in test results. The statistical method is commonly used for specifying the quantities value of any particular property of hardened concrete.

Segregation

The stability of a concrete mix requires that it should not segregate and bleed during the transportation and placing. Segregation can be defined as separating out of the ingredients of a

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concrete mix, so that the mix is no longer in a homogenous condition. Only the stable homogenous mix can be fully compacted.

The segregation depends upon the handling and placing operations. The tendency to segregate. Amount of coarse aggregate, and with the increase slump. The tendency to segregate can be minimizes by:

-Reducing the height of drop by concrete.

-Not using the vibration as a means of spreading a heap of concrete into level mass over a large area.

-Reduction the continued vibration over a longer time, as the coarse aggregate

-Adding small quantity of water which improves cohesion of mix.

Bleeding is due to rise of water in the mix to the surface because of the inability of the solid particles in the mix to hold all the mixing water during settling of particles under the effects of compaction. The bleeding causes formation of porous, weak and non-durable concrete layer at the top of placed concrete. In case of lean mixes bleeding may create capillary channels increasing the permeability of the concrete. When the concrete is placed in different layers and each layer is compacted after allowing certain time to lapse before the next year is laid, the bleeding may cause a plane of weakness between two layers. Any laitance formed should be removed by brushing and washing before a new layer is added. Over compacting the surface should be avoided.

Compressive strength

The compressive area of cross section in uniaxial compression under given rate of loading. The strength of concrete strength of concrete is defined as the load which causes the failure of specimens per unit is expressed as N/mm2. The compression strength at 28 days after casting is taken as a criterion for specifying the quality of concrete. This is termed as grade of concrete. IS 456-2000 stipulates the use of 150 mm cubes.

Tensile Strength

The concrete has low tensile strength; it ranges from 8-12% of its compressive strength. An average value of 10% is generally adopted.

Shear strength

The concrete subjected to bending and shear stress is accompanied by tensile and compressive stresses. The shear failures are due to resulting Diagonal tension. The shear strength is generally 12-13% of its compressive strength.

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Bond strength

The resistance of concrete to the slipping of reinforcing bars embedded in concrete is called bond strength. The bond strength is provided by adhesion of hardened cement paste, and by the friction of concrete and steel. It is also affected by shrinkage of concrete relative to steel. On an average bond strength is taken as 10% of its compressive strength.

Facts about cement and concrete

1. Water required by 1 bag of cement is something in the average of 25-28 liters.

2. Quality of concrete has nothing to do with colour.

3. The mortar/ concrete should be consumed as early as possible after addition of water to it. As the hydration progresses the cements paste starts stiffening and loses its plasticity. The concrete should not be disturbed after this. Normally, this is about 40-50 minutes.

Compressive strength of concrete depends on following factors.

1. Water cements ratio.

2. Characteristic of aggregates.

3. Time of mixing.

4. Degree of compaction.

5. Age of concrete

6. Air entertainment.

7. Condition of testing

Factors affecting the choice of mix proportions

1. Compressive strength

It is one of the most important properties of concrete and influences many other describable properties of the hardened concrete. The mean compressive strength required at a specific age, usually 28 days, determines the nominal water: cement ratio of the mix. The other factor affecting the strength of concrete at a given age and cured at a prescribed temperature is the degree of compaction. According to Abraham’s law the strength of fully compacted concrete is inversely proportional to the water: cement ratio.

2. Workability

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The degree of workability required depends on three factors. These are the size of the section to be concreted, the amount of reinforcement, and the method of compaction to be used. For the narrow and complicated section with numerous corners or inaccessible parts, the concrete must have a high workability so that full compaction can be achieved with a reasonable amount of effort. This also applies to the embedded steel sections. The desired workability depends on the compacting equipment available at the site.

3. Durability

The durability of concrete is its resistance to the aggressive environmental conditions. High strength concrete is generally more durable than low strength concrete. In the situations when the high strength is not necessary but the conditions of exposure are such that high durability is vital, the durability requirement will determine the water: cement ratio to be used.

4. Maximum nominal size of aggregate

Generally, larger the maximum size of aggregate, smaller is the cement requirement for particular water: cement ratio, because the workability of concrete increases with increase in maximum size of the aggregate. However the compressive strength tends to increase with the decrease in size of aggregate.

IS 456:2000 and IS 1343:1980 recommend that the nominal size of the aggregate should be as large as possible.

5. Grading and type of aggregate

The grading of aggregate influences the mix proportions for a specified workability and water: cement ratio. Coarser the grading leaner will be mix which can be used. Very lean mix is not desirable since it does not contain enough finer material to make the concrete cohesive. The type of aggregate influences strongly the aggregate-cement ratio for the desired workability and stipulated water cement ratio. An important feature of a satisfactory aggregate is the uniformity of the grading which can be achieved by mixing different size fractions

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Quality control

The degree of control can be estimated statistically by the variations in test results. The variation in strength results from the variations in the properties of the mix ingredients and lack of control of accuracy in batching, mixing, placing, curing and testing. The lower the difference between the mean and minimum strengths of the mix lower will be the cement-content required. The factor controlling this difference is termed as quality control

Tests for Quality Control

Slump Test

Fig 1.4

This is test to determine the workability of the ready mixed concrete just before it’s placing to final position inside the formwork, and is always conducted by the supervisor on site. This is a site

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However in mid of concreting process, should the site supervisor visually finds that the green concrete becomes dry or the placement of concrete has been interrupted, a re-test on the remaining concrete should be conducted in as follows:-

1. Ensure the standard Slump Cone and associated equipment are cleaned before test and free from hardened concrete, particularly of the pour for congested reinforcement area. The area. The procedure of test in brief is

2. Wet the Slump Cone and drain away the superfluous water.3. Request the mixer or concrete truck to well mix the concrete for additional 5 minutes.4. Place the Slump Cone on one side (i.e. not in middle) of the base plate on the levelled ground

and stand with feet on the foot-pieces of cone.5. Using a scoop and fill the cone with sampled concrete in 3 equal layers, each of about

100mm thick.6. Compact each layer of concrete in turn exactly 25 times with Slump Rod, allowing the rod

just passes into the underlying layer.7. While tamping the top layer, top up the cone with slight surcharge of concrete after the

tamping operation.8. Level the top by a “sawing and rolling” motion of the Slump Rod across the cone.9. With feet are still firmly on the top-pieces, wipe the cone and base plate clean and removed

any leaked concrete from bottom edge of the Slump Cone.10. Leave the foot-pieces and lift the cone carefully in vertical up motion in a few seconds time.11. Invert the cone on other side and next to the mound of concrete.12. Lay the Slump Rod across the inverted cone such that it passes above the slumped concrete at

its highest point.13. Measure the distance between the underside of rod and the highest point of concrete to the

nearest 5mm.14. This reading is the amount that the sampled concrete has slumped.15. If the concrete does not show an acceptable slump, repeat the test with another sample.16. If the repeated test still does not show an acceptable slump, record this fact in the report, or

reject that load of concrete.

Compression test

The compression test is a laboratory test to determine the characteristic strength of the concrete but the making of test cube is sometime carried out by the supervision on site. This cube test result is very important to the acceptance of institute concrete work since it demonstrates the strength of the design mix.

The procedure of making the test cube is as follows:-

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1. 150mm standard cube mould is to be used for concrete mix and 100mm standard cube mould is to be used for grout mix.

2. Arrange adequate number of required cube mould to site in respect with the sampling sequence for the purposed pour.

3. Make sure the apparatus and associated equipment are cleaned before test and free from hardened concrete and superfluous water.

4. Assemble the cube mould correctly and ensure all nuts are tightened.5. Apply a light coat of proprietary mould oil on the internal faces of the mould.

Concrete mixtures

Fig 1.5 Concrete mixture is machine with a rotating drum in which the components of concrete are mixed. A concrete mixer (also commonly called as cement mixture) is a device that homogenously combines cement, aggregate such as sand or gravel, and water to form concrete. A typical concrete mixer uses a revolving drum to mix the components. For smaller volume works portable concrete mixers are often used so that the concrete can be made at the construction site. Giving the workers ample time to use the concrete before it hardens. An alternative to a machine is mixing concrete or cements by hand. This is usually done in a wheelbarrow; however, several companies have recently begun to sell modified tarps for this purpose.

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Some of the importance purpose for which the admixture could be used is

1. Acceleration of the rate of strength development at early ages.2. Retardation of the initial setting the concrete.3. Increase in strength.4. Improvements in workability.5. Reduction in heat of evolution.6. Increase in durability or in resistance to special conditions of exposure.7. Control of alkali-aggregate expansion.8. Reduction in the capillary flow of water and increase in impermeability to liquids.9. Improvement of pump ability and reduction in segregation in grout mixtures,10. Production of collared control or mortar.

The best way to test the admixture is by taking trial mixes with the concrete materials to be used on the job and carefully observing and the changes in the properties. This way the compatibility of the admixture and the materials to be used, as well the effect of the admixture on the properties of fresh and hardened concrete can be observed. The amount of admixture recommended by the manufacture or the optimum quantity determined by laboratory test should be used.

SHUTTERING AND SCAFFOLDING

The term 'SHUTTERING' or 'FORMWORK' includes all forms, molds, sheeting, shuttering planks, walrus, poles, posts, standards, V-Heads, struts, and structure, ties, frights. Walling steel rods, bolts, wedges, and all oth4) temporary supports to the concrete during the process of sheeting.

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Form Work

Fig 1.6

Forms or molds or shutters are the receptacles in which concrete is placed, so that it will have the desired shape or outline when hardened. Once the concrete develops adequate strength, the forms are removed. Forms are generally made of the materials like timber, plywood, steel, etc. Generally camber is provided in the formwork for horizontal members to counteract the effects of deflection caused due to the weight of reinforcement and concrete placed over that. A proper lubrication of shuttering plates is also done before the placement of reinforcement. The oil film sandwiched between concrete and formwork surface not only helps in easy removal of shuttering but also prevents loss of moisture from the concrete through absorption and evaporation.

The steel form work was designed and construed to the shapes, lines and dimensions shown on the drawings. All forms were sufficiently water tight to prevent leakage of mortar. Forms were so constructed as to be removable in sections. One side of the column forms were left open and the open side filled in board by board successively as the concrete is placed and compacted except when vibrator are used. A key was made at the end of each casting in concrete columns of appropriate size to give proper bodings to columns and wall a as per relevant IS.

Cleaning and Treatment of Forms

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All rubbish, particularly chippings, shavings and saw dust, was removed from the interior of the forms (steel) before the concrete is placed. The form work in contact with the concrete was cleaned and thoroughly wetted or treated with an approved composition to prevent adhesion between form work and concrete. Care was taken that such approved composition is kept out of contact with the reinforcement.

Design

The form-work should be designed and constructed such that the concrete can be properly placed and thoroughly compacted to obtain the required shape, position, and levels subject.

REINFORCEMENT

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Fig 1.7

Steel reinforcements are used, generally, in the form of bars of circular cross section in concrete structure. They are like a skeleton in human body. Plain concrete without steel or any other reinforcements is strong in compression but weak in tension. Steel is one of the best forms of reinforcements, to take care of those stresses and to strengthen concrete t bear all kinds of loads mild steel bars conforming to IS: 432 (part I) and Cold-worked steel high strength reformed bars conforming to IS: 1786(grade Fe 415 and grade Fe 500, where 415 and 500 indicate yield stresses 415N/mm2 and 500N/mm2 respectively are commonly used. Grade Fe 415 is being used most commonly nowadays. This has limited the use of plain mild steel bars because of higher yield stress and bond strength resulting in saving of steel quantity. Some companies have brought thermo mechanically treated (TMT) and corrosion resistant steel (CRS) bars with added features.

Bars range i diameter from 6 to 50 mm. Cold-worked steel high strength deformed bars start from 8 mm diameter. For general house constructions, bars of diameter 6 to 20mm are used. Transverse reinforcements are very important. At my site bars of diameter 8 to 25 mm are used. They not only take care of structural requirements but also help main reinforcements to remain in desired position. They play a very significant role while abrupt changes or reversal of stresses like earthquake etc.

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They should be closely spaced as per the drawing and properly tied to the main/longitudinal reinforcement

TERMS USED IN REINFORCEMENT

BAR BENDING SCHEDULE

Bar bending schedule or bar scheme diagram is the comprehensive representation of cut and bend bars as per the design requirements of reinforcement detailer. It helps in determining appropriate material quantities, strength and cost estimation.

Bars bending schedule is used as a guide in positioning various structural members such as footings, beams, columns, girders, piles, walls etc.

Lap length

Lap length is the length overlap of bars tied to extend the reinforcement length. Lap length about 50 times the diameter of the bar is considered safe. Laps of neighboring bar lengths should be staggered and should not be provided at one level/line. At one cross section, a maximum of 50% bars should be lapped. In case, required lap length is not available at junction because of space and other constraints, bars can be joined with couplers or welded (with correct choice of method of welding).

Anchorage Length

This is the additional length of steel of one structure required to be inserted in other at the junction. For example, main bars of beam in column at beam column junction column bars in footing etc. The length requirement is similar to the lap length mentioned in previous question or as per the design instruction.

Cover Block

Cover blocks are placed to prevent the steel rods form touching the shuttering plates and thereby providing a minimum cover and fix the reinforcements as per the design drawings. Sometimes it is commonly seen that cover gets misplaced during the concreting activity. To prevent this tying of cover with steel bars using thin steel wires called binding wires (projected from cover surface and placed during making or casting of cover blocks) is recommended. Covers should be made of cement sand mortar (1:3). Ideally, over should have strength similar to the surrounding concrete, with the least perimeter so that changes of water to penetrate through periphery will be minimized. Provision of minimum covers as per the Indian standards for durability of the whole structure should be ensured. Shape of the cover blocks could be cubical or cylindrical. However, cover indicates thickness of the cover block. Normally, cubical cover blocks are used. As a thumb rule, minimum cover of 27 in footings, 1.5" in columns and 1" for other structures may be ensured.

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Things of Note

Reinforcement should be free from loose rust, oil paints, mud etc. It should be cut, bent and fixed properly. The reinforcement shall be placed and maintained in position by providing proper cover blocks, spacers, supporting bars, laps etc. Reinforcements shall be placed and tied such that concrete placement is possible without segregation, and compaction possible by an immersion vibrator.

For any steel reinforcement bar, weight per running meter is equal to, where d is diameter of the bar in mm. For example, 10 mm diameter bar will weigh=0.617 Kg/m.

Three types of bars were used in reinforcement of a slab. These include straight bars, crank bar and an extra bar. The main steel is placed in which the straight steel is bonded first, then the crank steel is placed and extra steel is placed in the end. The extra steel comes over the support while crank is encountered at distance of 1/4 (1-distance between the supports) from the surroundings supports.

For providing nominal cover to the steel in beam, cover blocks were used which were made of concrete and were casted with a thin steel wire in the center which projects outward. These keep the reinforcement at a distance from bottom of shuttering. For maintaining the gap between the main steel and the distribution steel, steel chairs are placed between them.

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Erection of Formwork

Fig 1.8

The following applies to all formwork:-

1) Care should be taken that all formwork is set to plumb and true to line and level.

2) When reinforcement passes through the formwork care should be taken to ensure close fitting joints against the steel bars so as to avoid loss of fines during the compaction of concrete.

3) If formwork is held together by bolts or wires, these should be so fixed that no iron is exposed on surface against which concrete is to be laid.

4) Provision is made in the shuttering for beams, columns and wall for a port hole of convenient size so that all extraneous materials that may be collected could be removed just prior to concreting.

5) Formwork is so arranged as to permit removal of forms without jarring the concrete. Wedges, clamps, and bolts should be used where practicable instead of nails.

6) Surfaces of forms in contact with concrete are oiled with a mold oil of approved quality. The use of oil, which darkens the surface of the concrete, is not allowed. Oiling is done before reinforcement is placed and care taken that no oil comes in contact with the reinforcement while it is placed in position. The formwork is kept thoroughly wet during concreting and the whole time that it is leapt in place.

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Immediately before concreting is commended, the formwork is carefully examined to ensure the following:

1) Removal of all dirt, shavings, sawdust and other refuse by brushing and washing.

2) The tightness of joint between panels of sheathing and between these and any hardened core.

3) The correct location of tie bars bracing and spacers, and especially connections of bracing.

4) That all wedges are secured and firm in position.

5) That provision is made for traffic on formwork not to bear directly on reinforcement steel

Verticality of the Structure

All the outer columns of the frame were checked for plumb by plumb-bob as the work proceeds to upper floors. Internal columns were checked by taking measurements from outer row of columns for their exact position. Jack was used to lift the supporting rods called props.

COLUMN

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Column before concreting

Fig 1.9

Column in a structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below, in other words a column is a compression member. The term column applies especially to a large round support with a capital and base and made of stone or appearing to be so. For the purpose of wind earthquake engineering other compression members are often termed "columns" because of the similar stress conditions. Columns are frequently used to support beams or arches on which the upper parts of walls or ceilings rest.

DETAILS OF COLUMN

No. Of bars used- 8 (eight)

Diameter of bar- 20 mm.

Size of column- 12” x 18”

Spacing of stirrup

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- 4” between two stirrup at upper part- 8” between two stirrup at middle - 4” between two stirrup at lower end of column

Column type

1. Based on shape Rectangle Square Circular Polygon

2. Based on slenderness ratio Short column <12 Long column > 12

3. Based on type of loading Axially loaded column A column subjected to axial load and un axial bending A column subjected to axial load and biaxial bending

4. Based on pattern of lateral reinforcement Tied columns Spiral columns

BEAM

A beam is a structural element that is capable of withstanding load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads, own weight, span and external reactions to these loads is called a bending moment.

Beams are traditionally descriptions of building or civil engineering structural elements, but smaller structures such as truck or automobile frames, machine frames, etc.

Details of beam

Diameter of bars- 16 mm

Size of beam - 12” x 18”

Approximate kg of steel bar for per beam used as follow:-

Sl.No.

Item of works

@kg/m Nos. Length (m)

Breadth(m)

Height(m)

Total Remarks

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2 Steel useda)main bars at top & bottom of 16ɸ

1.58 3+3 5.64 53.5kg L=4.8768+0.762=5.64

b)Bars straight of 16ɸ

1.58 6 3.49 33.07kg L=4.8768-1.6764+18D=3.49

c)stirrups A of 8ɸ

0.39 24 1.49 13.98kg L=0.4572+0.91+0.127=1.49Nos.=2.4384/(4x0.0254)=24

d)stirrups B of 8ɸ

0.39 16 1.49 9.29kg Nos.=3.2016/(8x0.0254)=16

Table 1.1

TYPE OF BEAM

1. Simply supported beam

2. Fixed beam

3. over hanging beam

4. Continuous beam

5. Cantilever beam

Stress in beam

Internally, beams experience compressive, tensile and shear stresses as a result of the loads applied to them. Typically, under gravity loads, the original length of the beam is slightly reduced to enclose a smaller radius arc at the top of the beam, resulting in compression, while the same original beam length at the bottom of the beam is slightly stretched to enclose a larger radius arc, and so is under tension. There are some reinforced concrete beams in which the concrete is entirely in compression with tensile forces taken by steel tendons. These beams are known as pre stressed concrete beams, and are fabricated to produce a compression more than the expected tension under loading conditions. High strength steel tendons are stretched while the beam is cast over them. Then, when the concrete has cured, the tendons are slowly released and the beam is immediately under eccentric

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axial loads. This eccentric loading creates an internal moment, and, in turn, increases the moment carrying capacity of the beam.

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SLAB

Bar bending in slab

Fig 1.10

A concrete slab is a common structural element of modern buildings. Horizontal slabs of steel reinforced concrete, typically between 100 and 500 millimeters thick, are most often used to construct floors and ceilings, while thinner slabs are also used for exterior paving.

In many domestic and industrial buildings a thick concrete slab, supported on foundations or directly on the subsoil, is used to construct the ground floor of a building. These can either be "ground-bearing" or "suspended" slabs. In high rise buildings and skyscrapers, thinner, pre-cast concrete slabs are slung between the steel frames to form the floors and ceilings on each level.

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Pouring and consolidation

Concrete (M20) was used for all works in column, beams, and slab. It was well consolidated by vibrating using portable mechanical vibrators. Care was taken to ensure that the concrete is not over vibrated so as to cause segregation. The layers of concrete are so placed that the bottom layer does not finally set before the top layer is placed. The vibrators maintain the whole of concrete under treatment in an adequate state of agitation, such that demarcation and effective compaction is attained at a state commensurate with the supply of concrete from the mixers. The vibrator continue during the whole period occupied by placing of concrete, the vibrators being adjusted so that the centre vibrations approximate to the centre of the mass being compacted at the time of placing. Shaking of reinforcements for the purposes of the compaction should be avoided. Compaction shall be completed before initial setting i.e. within thirty minute of addition of water to the dry mixture.

The concrete was deposited in its final position in a manner to preclude segregation of ingredients. In case of column and walls, the shuttering was so adjusted that the vertical drop of concrete is not more than 1.5 m at a time. In case of concreting of slabs and beam, the pipes from the batching plant were directly to the closest point.

Finish to concrete work:

a) All concrete while being poured against formwork was worked with vibrator rods and trowels as required so that good quality concrete is obtained.

b) All exposed surface of RCC lintels, beams, columns tec. Were plastered to match with adjoining plastered face of walls after suitably hacking the concrete surface.

Curing

The term curing is used to include maintenance of a favorable environment for the continuation of chemical reactions, i.e. retention of moisture within, or supplying moisture to the concrete from an external source and protection against extremes of temperature

Following are the method of curing building parts:-

Walls: - water should be sprinkled from the top such that it covers the whole area of the wall and it should be remain wet.

Slab: - ponding should be done on the slab by constructing bunds of mortar.

Beam and columns:-beam and column can be maintained wet by trying gunny bags around the periphery and by maintaining it wet always.

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Ponding, continuous sprinkling, covering with wet cloth, cotton mats or similar materials. Covering with specially prepared paper, polyethylene, sealing coat applied as a liquid commonly known as ‘curing compound’ which harden to form a thin protective membrane, are some of the methods by which concrete is cured. Curing should be started just after the surface begins to dry. Normally 7 to 14 days curing is considered adequate.

Admixture

Admixture is those ingredients/ materials that are added to cement, water and aggregate mixture during mixing in order to modify or improve the properties of concrete for a required application.

Broadly the following five changes can be expected by adding an admixture

1. Air entertainment.2. Water reduction for better quality.3. Acceleration of strength development.4. Improving the workability.5. Water retention

Leakage and water proofing

There are many reasons for leakage in concrete. Due to this leakage, the concrete not only loses its strength but also cause problems to the user. Normal concrete construction should not require water proofing materials, if it is designed and constructed properly with good quality and workmanship. But still to make it safe against the ill effect of water, liquid and powder form of water proofing materials is used depending upon the availability of the material.

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CONCLUSIONS

.

By working on this project, I learnt the various techniques uses in the construction of residential buildings. I also learnt about the application and operation of a variety of equipment used in construction sites.

I also learnt about the various tests which are performed on the site to ensure proper quality of materials used and to check the material standard.

This project helped me in understating how the various theoretical concepts of Civil engineering are used in practical fields.

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REFERENCES

1. Henrdickson, C., et al. "Expert System for Construction Planning." J. of Constr. Engg. And Mgmt., ASCE, Vol. 1, No. 4, 1987, pp. 241-252.

2. Johnson, R.V., "Resource Constrained Scheduling Capabilities of Commercial Project Management Software, Project Management Journal, Vol. 22, No.4, 1992, pp. 39-43.

3. Moselhi, O. and Nicholas, M.J., "Hybrid Expert System for Construction Planning and Scheduling."J. of Constr. Engg. and Mgmt., ASCE, Vol. 116, No. 2, 1990, pp. 221-238.

4. Morad, A.A. and Beliveau, Y.J., "Knowledge-Based Planning System," J. of Construction Engineering and Mgmt., ASCE, Vol. 117, No. 1, 1991, pp. 1-12.

5. Shaked, O. and Warszawski, A. CONSCHED: Expert System for Scheduling of Modular

Construction Projects," J. of Constr. Engg. and Mgmt., ASCE, Vol. 118, No. 3, 1992,