ACKNOWLEDGEMENT

It  is  indeed a great pleasure and privilege  to present  this  report on training at CPWD.

I am extremely grateful  to my  training and placement officer  for  issuing a Training letter, which made my training possible at CPWD,Durgapur

                   I would like to express my gratitude to Er C.P SHARMA for his invaluable  suggestions, motivation,guidance and support  through out  the  training His methodology to start from simple ant then deepen through made me to bring out this project report without anxiety.

                       Thanks to all other CPWD officials, operators and all other members of CPWD, yet uncounted for their help in completing the project and see the light of success.

      I am very thankful to friends, colleagues and all other persons who rendered their assistance directly or indirectly to complete this project work successfully.

I extended my due  thanks  to Er. S.P SHARMA who gave mevaluabletime

and suggestions and guide me a  lot at various stages of my Summer Training.

AKASH KUMAR

PREFACE

The purpose of preparing the report is to give a detailed description of the

site visits that I had done during my summer training in NIT Durgapur

Campus under CPWD (Central Public Works Department) from 10/05/2016

to 03/06/2016. This report is an amalgamation of site inspections,

interactions with engineers at work site, studies of the important principles

of construction including concrete technology, design of concrete structures

& important machines involved and finally the conclusions, lessons and

ideas which are collected during this brief period of practical experience.

The various structural members along with its reinforcement detailing as in

the photos is main content along with description of site laboratory and

main instruments that was being used in the site.

ABOUT CPWD

CPWD came into existence in July, 1854 when Lord Dalhousie

established a central agency for execution of public works and set up

Ajmer Provincial Division. It has now grown into a comprehensive

construction management department, which provides services from

project concept to completion, and maintenance management. It is

headed by DG who is also the Principal Technical Advisor to the

Government of India. The regions and sub-regions are headed by

Special DGs and Additional DGs respectively, while the zones in all state

capitals (except a few) are headed by Chief Engineers. With country

wide presence, the strength of CPWD is its ability to undertake

construction of complex projects even in difficult terrains and

maintenance in post construction stage.

Presentation on Summer Training

held at Construction Site of

G+12 Building insideNIT Campus under

Central Public Works Department

PROJECT REPORT

WELCOMEPRESENTATION SUBMITTED BY:-

AKASH KUMAR

ROLL NO:-13/CE/26

(CE-4th YEAR)TRAINING PERIOD:-10MAY-03JUNE

NATIONAL INSTITUTE OF TECHNOLOGY DURGAPUR

GUIDED BY:-Er. C.P. SHARMA

EXECUTIVE ENGINEER

INDEX

S.NO

DESCRIPTION

1. INTRODUCTION2. PROJECT OVERVIEW3. SITE LOCATION4. SAFETY UNDER CONSTRUCTION

SITE5. FRAMWORK6. SEQUENCE OF STRUCTURE WORK7. PROJECT MONITORING8. QUALITY9. CONCLUSION

INTRODUCTIONAbout CPWD:-

The Central Public Works Department of India is a Central Government owned authority that is in charge of public sector works in the Country.

Central Public Works Department (CPWD) under Ministry of Urban Development is entrusted with construction and maintenance of buildings for most of the Central Government Departments, Public undertakings and autonomous bodies.

CPWD, Delhi is the premier agency of Govt. of India engaged in planning, designing, construction and maintenance of Government assets in the field of built environment and infrastructure development. Assets in built environment include Hospitals, Schools, Colleges,

Technical Institutes, Buildings, Prisons,Courts etc.

GOVERNMENT OF INDIA

NIT DURGAPUR PROJECT DIVISION

CENTRAL PUBLIC WORKS DEPARTMENT

DURGAPUR:- 713209

NAME OF WORK:- Construction of 1250 Boy’s Hostel building

A G REE M ENT NO. : 06/CE/EE/NITPD/DRG/2013-14

NAME OF CONT R AC T O R : NCC LIMITED

NAME OF EXECUTIVE ENGINEER:- Er. C.P. SHARMA

TENDER AMOUNT :- Rs- 93,92,93,120/

D A TE OF COMMENCEMENT:- 07/03/2014

COMPLETION DATE AS PER AGGREMENT:-06/03/2016

ACTUAL D A TE OF COMPLETION:- Work is Under Progress (60% work is completed)

TI M E A LL OWED :- 24 MONTHS

SITE LOC ATION

A dv a n ta g es of this Si t e

Land StoreHealth Unit CanteenConnectivity of the YardEase Of transportation facilities

Site and SafetyImportance of following safety site rules

•Accident rates are higher in

Construction sites because people

doesn’t pay much attention to the

surrounding and the warning

signboards that is placed outside of

the construction site.

Personal Protective Equipment (PPE) All refers to protective clothing, helmet, goggles or other garments or equipment

designed to protect the bearer’s body from injury Staffs and workers must wear and use PPE as appropriate

• Sub-con and their workers must

not wear short pants/slipper to work.

Site safety rules:-Safety helmets must be worn:- Foot protection should be worn in this area:-

•To prevent any injuries on

the head as it is the most

dangerous part.

•To prevent dust particals from the

construction site to draw on

the head.

•To reduce electrical shock

hazard when near exposed

electrical conductors which

could contact the head.

High visibility clothing

must be worn in this area

• So that when to

construction work is

going on’ it will be easier

to be noticed by the

bright color of the

clothing to prevent any

accidents from happening

•To prevent danger of foot injuries due to falling or rolling objects or objects piercing the sole and where such employee’s feet are exposed to electrical hazards

•No person who is under the influence of

alcohol or drugs are allowed in the site

• as a drunk person may not be

conscious , it may be dangerous

as they could walk to buildings

which are not complete which

are full of metal bars therefore

First aid box

• First aid equipment is

kept in the site managers

office as it is easier and faster

access in case of emergency

Children must not

play in the site

• When the construction

activity is going on, it will

be dangerous for the

children as any accidents

might happen such as

getting hit by vehicles or

falling object

Scaffolding platform

• Helps to minimize the

risk of fall when a

worker is doing the

construction work

high up the building

General Safety Rules & Regulation

Do’s & don’t:

1. No workmen below 18 years and above 58 years of age shall be engaged for a job.

2. All workmen shall be screened before engaging them on the job. Physical fitness of the person to certain jobs like working at height or other dangerous locations to be ensured before engaging the person on work. The final decision rests with the site management to reject any person on the ground of physical fitness.

3. Smoking is strictly prohibited at workplace.

4. Sub-contractors shall ensure adequate supervision at workplace. They shall ensure that all persons working under them shall not create any hazards to self or to co-workers.

5. Nobody is allowed to work without wearing safety helmet. Chinstrap of safety helmet shall be always on.

6. No one is allowed to work at or more than two meters height without wearing safety belt and anchoring the lanyard of safety belt to firm support preferably at shoulder level.

7. No one is allowed to enter into workplace and work at site without adequate foot protection.

8. All PPE like shoes, helmet, safety belt etc. shall be arranged before starting the job as per recommendation of PROJECT HSE Head.

9. All excavated pits shall be barricaded and barricade to be maintained till the backfilling is done.

10. Adequate illumination at workplace shall be ensured before starting the job at night.

11. All major, minor accidents and near misses to be reported to PROJECT HSE Head to enable the management to take necessary steps to avoid the recurrence.

12. All scaffoldings / work-platforms shall be strong enough to take the expected load.

Safety googles must be worn.

The dust particles at the site

may be harmful to the eye

therefore by wearing a

safety google it can prevent

the dust from entering the

13. Adequate firefighting equipment shall be made available at workplace and persons are to be trained in firefighting techniques with the co-ordination of safety personnel.

Training for Workers:The following Safety Training topics as minimum shall be covered with all employees and work force prior to starting work assignment. Visitors and vendors will be given a short Safety orientation before being allowed into any construction area.

a. Safety Policy

b. Personal Protective Equipmentc. Emergency evacuation procedure and Alarmsd. Fire and Fire Extinguisherse. Scaffold Safetyf. Basic Electrical Safetyg. Fall Preventionh. Ladder Safetyi. Tool Box Talkj. Welding and Gas cutting Safetyk. Excavation safety

Concreting Safety:• Workers doing concreting work, whether inside excavation or above

ground, shall wear proper protective hard hats, Gumboots, PVC gloves etc.

Concrete transportations shall be carried out through hand trolleys/Tuff rider (Mini dumper)/Transit Mixer.

Cement /aggregate handling employees must use Dust Mask.

When transporting concrete in the pan, the person should use special type of hard hat.

Use crane /Builder hoist for vertical transportation of the concrete.

Train the employee on safe handling of concrete.

Concrete pump shall be operate by well-trained operator, Its joint should be tightly braced.

The workmen engaged in this operation shall be trained properly.

Hot Work Safety (Welding & Gas Cutting): Only trained & experienced

personnel shall be

Gas cylinders to be kept away from open flames and other sources of heat.

Gas cylinders in use should be mounted on trolleys for ease of movement for ease of movement.

authorized for welding & gas cutting work.

When torches are being changed or welding stopped for a short time, valves of the cylinders should be kept closed.

Work @ Height Safety:-

Whenever in doubt contact Site engineer/Project manager

Check the stability & Bracing of Scaffolding

Keep the planks on scaffolding & tie them with wire

Barricade the scaffolding

When you are standing on scaffolding or its plank always use Safety Belt

When working 2 meters and above HEIGHTS, Safety belt

must be worn by employee as well as he has to anchor another end of safety belt to a fixed part which can take his load in case of his fall.

FRAMEWORK:-SIG N IFICANCE OF F ORM W ORK : -

1) Formwork constitutes 30% of the cost and 60% of the time in concrete construction.

2) Quality of concrete finish and soundness of concrete depends very much on the formwork system.

3) Desired shape of concrete is not possible if formwork not done properly.

4) Formwork should be properly designed, fabricated and erected to receive concrete.

5) Accidents happen because of the faulty formwork and scaffolding or staging.

SAFE T Y IN USING F ORM W ORK : -

Components are light in weight for manual handling. Loose or hanging components are minimal. Appropriate use of tools. Minimum operations are involved in each reuse. Trained & experienced safflowers shall only do erection, dismantling and

modification of scaffold as per approved designed.

Scaffold should be made of sound materials & adequate strength to support the weight for the work load on it and that it is securely anchored and stable.

Sufficient sills or under pinning shall be provided for all scaffolds erected on filled or ground.

Before making use scaffold shall be ensured whether it is safe for the purpose or not by providing tags (Green for Safe and Red with cross mark to unsafe).

Check scaffolds periodically and especially after rains and storm to ensure that locking pins are intact, all nuts-bolts are tightened, footing intact and that there is no scouring below the footing. A daily visual check will also be carried out by the supervisor to remove defects, if any. If any defect / unsafe is noticed, the proper warning (‘NOT SAFE FOR USE’) in local language shall be displayed at the start of access to the scaffold with Red Cross mark.

PLANT AND MACHINERIESThe plants and machineries to be used at the site are either owned by the company or hired. They have different fuel and power consumption and different output. So, the planning section is responsible in maintaining these records. They are enlisted below –

Serial no. Machineries Company name Capacity

1 Backhoe loader JCB .25 m3

2 Transit mixer TATA, Ashok Leyland 6 m3

3 Bar cutting machine JAYMAC, JAYPEE -

4 Bar bending machine JAYMAC, JAYPEE -

5 Concrete pump Schwing Stetter 30 m3/hr

6 Hydra ACE 11 ton

7 Builder hoist PRIMAX 1000 kg

8 Passenger hoist KANGBO 1500 kg

9 Rope suspended platform JAYPEE 800 kg

10 Tower crane JIANGLU 10 ton

11 Multifunctional hoist SPARTAN 1500 kg

Bar bending & Bar cutting Machine: This type of machine is used for bending and cutting of bars. This machine is powered by electric motor.

Hydra:- It carries load from one place

to another place. Its capacity is 11 ton.

Concrete pump:- A concrete pump is used

for transferring concrete by pumping through

pipeline to reach it to the proper place.

Tower Crane: A crane is a type of machine that can be used for both to lift and lower material and to move them horizontally. It’s mainly used for lifting heavy things and transporting them to other places.

Builder hoist: A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It maybe manually operated, electrically or pneumatically driven and may use chain, fiber or wire ropes as its lifting medium. The load is attached to the hoist by means of a lifting hook.

Transit mixer: It is made to transport and mix concrete up to the construction site. They can be charged with dry materials and water, with the mixing occurring during the transportation. The concrete mixing transport truck maintains the materials’ liquidity state through agitation or turning of the drum, unit delivery.

Hydraulic pump: These are very common pumps as we are familiar with it in day to day work. Generally it is used to sprinkling water in curing of concrete work. Generally it has a capacity of 1HP.

Generator: It is an electrical instrument used for generating power and it brings other machineries in the plant to work while there is insufficiency of electricity.

Winches: Winches helps in vertical movement of any machine. e.g. for driving piles, raising & lowering hoists or other materials.

Backhoe loader:-Backhoe-loader is engineering vehicle, which consist of a tractor, fitted with a shovel or bucket on the front and a small backhoe on the back.

Uses:- Digging shallow excavations Digging trenches General grading Lifting loads Loading and carrying materials

FINENESS MODULUS OF FINE AGGREGATE

OBJECT: To determine the fineness modulus of aggregate.

THEORY: Sieve analysis helps to find particle size distribution of fine aggregates

IS SPECIFICATIONS: As per table 4 of IS 383-1970

IS SIEVE GRADING GRADING GRADING GRADING

DESIGNATION ZONE I ZONE II ZONE III ZONE IV

10 mm 100 100 100 100

4.75 mm 90-100 90-100 90-100 95-100

2.36 mm 60-95 75-100 85-100 95-100

1.18 mm 30-70 55-90 75-100 90-100

.600 mm 15-34 35-59 60-79 80-100

.300 mm 5-20 8-30 12-40 15-50

.150 mm 0-10 0-10 0-10 0-15

PROCEDURE: The test sample oven dried at temp. 100 0 C →Arrange the sieve as 10mm,4.75 mm,2.36 mm,1.18 mm,600 micron,300 micron,150 micron,75 micron &Pan→1000 gm. sample taken and sieved→ Take weight retrained in gm. from each individual sieve→ Calculation describe below:

The following limits are taken as guidelines:-

Fine Sand : Fineness Modulus : 2.2-2.6

Medium Sand : Fineness Modulus : 2.6-2.9

Coarse Sand : Fineness Modulus : 2.9-3.2

EXPWRIMENTA DATA :-

SIEVE SIZE WEIGHT % WEIGHT CUMULATIVE % CUMULATIVE %

(mm) RETAINED(gm.) RETAINEDRETAINED

PASSING

10 0 0 0 100

4.75 4 0.4 0.4 99.6

2.36 18 1.8 2.2 97.8

1.18 157 15.7 17.9 82.1

.600 137 13.7 31.6 68.4

.300 280 28 59.6 40.4

.150 348 34.8 94.4 5.6

.075 53 5.3 99.7 0.3

PAN

Calculation:- Summation of cumulative % retained

=∑ (0.4+2.2+17.9+31.6+59.6+94.4) =206.1

Fineness Modulus= 206.1/100=2.06

TESTS FOR CEMENT:a) Standard Consistency of cement by Vicat’s Apparatus : This is a test to estimate the quantity of mixing water to from a paste of normal consistency defined as that percentage water requirement of the cement paste, the viscosity of which will be such that the Vicat’s plunger penetrates up to a point 5 to 7 mm from the bottom of the Vicat’s mould. The water requirement for various tests of cement depends on the normal consistency of the cement.

OBJECTIVE: To determine the amount of water added to the cement to form a cement paste.

APPARATUS USED: The main apparatus used in this experiment is Vicat’s Apparatus. It consist of a non-porous plate and a needle of diameter 10mm which will penetrate on the mould.

CEMENT SPECIFICATION Brand name: ULTRATECH CEMENT

Type of cement: Portland pozolana cement

Temperature: 32°C

Humidity: 75%

RESULT SHEET

SERIAL WEIGHT OF % OF WEIGHT OF PENETRATION STANDARD

NO CEMENT WATER WATER READING FROM CONSISTENCY

TAKEN(gm) ADDED ADDED(gm) BOTTOM OF VALUE

MOULD(mm)

1 300 30% 90gm 35mm

2 300 33% 99gm 26mm

373 300 36% 108gm 12mm

4 300 37% 111gm 7mm

b) Initial and Final setting time:

These tests shall be conducted at a temperature of 27±2°c and 65+5% of relative humidity of the laboratory. A paste of 300 gm. of cement is prepared with 0.85 times the water required to give a paste of standard consistency. The Vicat’s mould is filled with these paste making it level with the top of the mould and slightly shake to expel air.

Setting time of cement: When water is added to cement, the resulting paste starts to stiffen and gain Strength and lose the consistency simultaneously. The term setting implies Solidification of the plastic cement paste. Initial and final setting times may be regarded as the two stiffening states of cement. At the beginning of solidification, called the initial set, marks the point in time when has become unworkable. Initial setting time may be defined as the time taken by the paste to stiffen to such an extent that the Vicat’s needle is not permitted to move down through the paste to within 5±0.5mm measured from the bottom of the mould.

The final setting time is the point at which the set cement has acquired a sufficient firmness to resist a certain defined pressure. In the experiment it is determined as the time elapsed between the time of adding water to the cement to the time when the ring fails to make any impression on the mould surface. Most specifications require an initial minimum setting time at ordinary temperatures of about 30 minutes and a final setting time not more than 600 minutes.

Observation value:

Weight of sample taken: 300gm

% of calculated water: (0.85 ×37) = 31.45% Water added to cement on 94.5gm

Initial setting time: 81 min

Final setting time: 190 min

c) FINENESS OF CEMENT:

Fineness was long controlled by sieve tests, but more sophisticated methods are now largely used. The most commonly method used both for control of the grinding process and for testing the finished cement, measures at the surface per unit weight of the cement by a determination of the rate of passage of air through a bed of the cement. The degree of fineness of cement is the measure of the mean size of the grains in it. The sieve method-90 micron sieve is used.

RESULT:

Sample taken: 100gm

Therefore, the standard consistency of cement is 37%.

Retained on 90 micron sieve : 6gm

Passing through 90 micron sieve: 94gm

Therefore, fineness of cement is 6%.

compressive Strength Test of Concrete:

Cement, fine aggregate and coarse aggregate (up to38mm) to be used for making concrete are brought to from temperature (preferably 27±3°C) before commencing the test. The ingredients are weighed in the ratio to be used in the field and are mixed by hand mixing or by machine mixing. First, the cement and mixed till these are distributed uniform colour is achieved. The coarse aggregate are then added and mixed till these are distributed throughout the mix. The water is then added and the entire batch mixed until the concrete appears to be homogeneous and has the desired.

The test specimens recommended are 150mm × 150mm × 150 mm cubes. The mixed concrete is filled into the mould in layers of 50mm to achieve full compaction. Each layer of mix so placed is tamped with bar, 16mm in diameter and 600mm long, 35 times. The test specimen are stored at a temperature of 27±2°C and at 90% humidity for 24 ± 1⁄2 hour from the time of addition of water to the dry ingredients. After this period the specimens are removed from the mould and placed in water and kept there until taken out just prior to test. Normally the recognized age of test of specimens is 7 and 28 days.

The specimen is placed between the platens of the compression testing machine with the care that the axis of specimen is aligned with the centre of thrust of the spherically seated platen. The applying load procedure is same as for brick test

)Example:-Grade of concrete: M40

Date of casting : 29/4/16

Date of testing : 27/5/16

Applied load : 1060 KN

After 28 days, the compressive strength of cube=(applied load on the cube / cube surface area)

=1060*103 N /150*150 mm2 = 47.1 Mpa

COMPRESSION TESTING MACHINE

BEAMS

Beams are flexural elements which carry the load from the slabs to transfer it to the columns. The beams were designed using LSM (Limit State Method) for 25 combinations

1. 1.5 (DL + IL) 2. 1.2 (DL + IL + EXTP) 3. 1.2 (DL + IL + EXTN) 4. 1.2 (DL + IL – EXTP) 5. 1.2 (DL + IL – EXTN) 6. 1.2 (DL + IL + EZTP) 7. 1.2 (DL + IL + EZTN) 8. 1.2 (DL + IL – EZTP) 9. 1.2 (DL + IL – EZTN) 10.1.5 (DL + EXTP) 11.1.5 (DL – EXTP) 12.1.5 (DL – EXTN) 13.1.5 (DL + EZTP) 14.1.5 (DL + EZTN) 15.1.5 (DL – EZTP) 16.1.5 (DL – EZTN)

DL DownwardsIL (Imposed/Live load) DownwardsEXTP (+Torsion) +X; Clockwise torsion due to EQ

EXTN (-Torsion) +X; Anti-Clockwise torsion due to EQEQ EZTP (+Torsion) +Z; Clockwise torsion due to EQEZTN (-Torsion) +Z; Anti-Clockwise torsion due to EQEXTP: EQ load in X direction with torsion positiveEXTN: EQ load in X direction with torsion negativeEZTP: EQ load in Z direction with torsion positiveEZTN: EQ load in Z direction with torsion negative

Based on the above combinations moment envelope for a particular beam is developed. Reinforcements are calculated and then maximum reinforcement out of all the cases is being used. In the design process of a beam, first we determine the main tensile bars required to resist the bending moment. Out of these bars, we bent one or two to resist shear near the supports. The bars at the bottom corners are not bent. They remain 'straight', and are extended from support to support to anchor the stirrups properly. It can also be seen that beyond the bottom point of bent, the bent-up bar is no longer available at the tension zone of the beam. In general, this does not cause a problem because nearer the supports, the Bending moment (sagging

type) is of a lesser magnitude, and so all the bars will not be required there. However in every design process, it is important to ensure that the bent-up bars are no longer required beyond the point of the bent, and that development length requirements are satisfied.

We have to consider another point while using bent-up bars for shear reinforcement. That is., the design should not be in such a way that all the design load due to shear is resisted by the bent-up bars. We must provide stirrups also. Cl.40.4 of the code specifies that “Where bent-up bars are provided, their contribution towards shear resistance shall not be more than half that of the total shear reinforcement.”

Few notable points that need to be essentially checked in beam reinforcements are: -

The length of the hooks in case of stirrups should be 10d (d=diameter of bar). This is as per Special Publications (SP 34).

The hooks must be left in the compression zone otherwise initiation of cracks due to stress concentrations may take place.

Proper provision of clear cover must be done using small concrete/stone pieces.

For cantilever beams tension reinforcements are often placed at the bottom (a common mistake due to carelessness of the workers).

Adequate transverse bars needs to be provided in case the longitudinal bars of the beam are parallel to the main reinforcements

in the adjacent one way slab. This is done to ensure the integral action of the beam and slab.

Hooks of alternate stirrups on opposite sides is the correct method of placing stirrups.

COLUMNS

Columns are the compression members often accompanied by moments about

one or both axes. The column is designed for resisting the compression and

moments. In case of the hostel building the columns are designed as short

columns as effective length to least dimension ratio is less than 12 in all cases &

hence does not requires to be designed for buckling as well. (Refer to clause

25.1.2 of IS 456:2000)

The column section shall be designed just above and just below the beam column joint and larger of the two reinforcements shall be adopted. This is similar to what is done for design of continuous beam reinforcements at the support. The end moments and end shears are available from computer analysis.

All columns are subjected to biaxial moments and biaxial shears. The longitudinal

reinforcements are designed for axial force and biaxial moment as per IS: 456. Since the analysis is carried out considering centre-line dimensions, it is necessary to calculate the moments at the top or at the bottom faces of the beam intersecting the column for economy.

Detailing:

Detailing of reinforcement as obtained is discussed in SP 34. The reinforcement area

obtained above at various column-floor joints for lower and upper column length. The

area required at the beam-column joint shall have the larger of the two values, viz.,

for upper length and lower length. Since laps can be provided only in the central half

of the column, the column length for the purpose of detailing will be from the Centre

of the lower column to the Centre of the upper column. This length will be known by

the designation of the lower column. It may be noted that analysis results may be

such that the column may require larger amounts of reinforcement in an upper storey

as compared to the lower storey. This may appear odd but should be acceptable.

Few notable points that must be remembered in checking the column reinforcements are:-

Adequate lapping or splicing must be provided to maintain a strong tie between continued and discontinued bars conforming to clause

26.2.5 of IS 456:2000. Sometimes casting work is done overlooking the

non availability of adequate lapping length of a particular longitudinal bar.

Adequate transverse reinforcements must be provided in the columns to effectively hold the concrete in its position and prevent premature

buckling.(Refer clause 26.5.3.2 of IS 456:2000)

Column reinforcement at the site

SLABS

Slabs are plates which are designed based on the Imposed load and dead loads

coming on the slab by its intended users in this case the hostel boarders. All the slab

panels are designed as two way slabs except the corridors which are designed as

one way slabs. Table 26 of IS 456:2000 gives us the moment coefficients based on

different edge conditions, which are used to calculate the moments and hence for

design of slabs. Few important points during slab construction are:-

Main reinforcement should always be along the shorter side which is a common mistake done.

Cantilever portions should be definitely checked for proper placement of reinforcements i.e. the tension reinforcements should be above unlike that of other slab panels.

Proper clear cover must be maintained using concrete blocks/stone.

Cranking of rods at 0.15l from the face of the support(l=effective span of the slab in that direction) must be done in order to take account of the hogging bending moment arising due to partial fixity at the supports.

STAIRCASES

A stair is a series of steps, each elevated a measured distance, leading from one level of a structure to another. When the series is a continuous section without breaks formed by landings or other constructions, the terms flight of stairs or run of

Electrical connections at the slab

stairs are often used. Other terms that can be properly used include stairway and staircase. For a period of time, the popularity of the one-story structure in residential construction minimized the frequency of stair construction. Framing carpenters could usually handle the relatively simple task of constructing the service stairs leading from the first floor to the basement level. However, revival of traditional two story styles along with split-level and multilevel designs has again made fine stair construction an important skill. However, in new construction, public rooms are usually on the first floor. Due to this, there is a trend to move the stairs to a less conspicuous location. Stair construction requires a high degree of skill. The quality of the work should compare with that found in one cabinetwork. The parts for main stairways are usually made in millwork. The Live loads acting on the stairs can also be obtained from the data books or relevant codes. IS 875: 1987(part II) recommends a uniformly distributed load of 5kN/m2. This load is to be applied on both the sloping portion and the horizontal landing. In buildings such as residences, where the specified Live loads on the floors do not exceed 2kN/m2, and the stairs are not liable to be overcrowded, the Live load can be taken as 3kN/m2. As in the case of self wt. of finishes, the LL obtained from data books or codes, is assumed to act vertically on a horizontal plane, and so there is no need make any modifications, and we can apply it directly. Dead Load is to be considered as per the dimensions of the staircases. The horizontal portion of the stair is called the Landing. The horizontal distance between the first and last risers is called the Going. In the above elevation and plan views, we can see that the step near the intermediate landing is contributing towards making up the area of the Landing. This situation can be seen at the top most landing also. At the intermediate landing, the two flights are connected together. But as we will soon see in the ‘design of reinforcements for the stairs’, the main bars of the two flights are not connected together. Only the distributor bars in the intermediate landing will be common to the two flights. So there is no transfer of force between the two flights. In other words, the loads and forces in one flight will not have any effect on the other flight.

One important point about stairs is placing of chairs at appropriate place to maintain

the effective depth between upper and lower layers of reinforcements. The picture

shows the chairs & its positioning.

In case of stairs even at the support region i.e. at the landings negative reinforcement are to be provided in order to take into account of the hogging moments arising out of partial fixity of the support.

SITE EXECUTION1. Formwork:

Purpose of Formwork: Shuttering or formwork is the temporary arrangement by wood/steel/ply to hold concrete in required shape and size up to certain period for gaining adequate strength of the concrete.

Materials used:

Steel plate and channel

Plywood (film coated 12mm thick)

Soft pine Runner

Hard Wood Runner

MS Wailer

MS Channel

Vertical adjustable prop

or CT prop (3m)

Cup lock System

2.Formwork for Slab Casting:

Apparatus Used:

Hammer Crow-bar Crane Leveling Instrument Plumb bob Measuring Tape Right Angle Rope

Plywood (film coated 12mm thick)

Soft pine Runner

Hard Wood Runner

MS Wailer

MS Channel

Vertical adjustable prop

or CT prop (3m) Tie rod (16mmØ)

Cup lock System

H-frame

Clamps

Ring nut

Base plate

Sole plate

Nail

Binding wire

3.Reinforcement Work:

Purpose of Reinforcement Work: The purpose of placing of reinforcement is to provide tensile capacity to cement concrete which itself has very low tensile strength but sound compressive strength.

Apparatus used: Hammer Chisel Bar bending machine Bar cutting machine Dice for local bending

4. Concreting:

Purpose of Concreting: Concreting is the most important operational part of a project having structures made of Reinforcement Cement Concrete. It provides compressive strength to the members of the RCC structures.

Apparatus Used:

Batching Plant

Mechanical Mixer with Weigh

Batcher

Transit mixer

Concrete Pump

Air Compressor

Vibrator

Wooden Hammer/Leveler

Spade

Shovel

Trowel

Curing job:-

Cement gains strength and hardness because of the chemical action between cement and water. This chemical reaction requires moisture favourable temperature and time referred to as the curing period. Curing of freshly placed concrete is very important for optimum strength and durability. Curing of any construction member is done for at least 7 days. For slab and beams, bonding is required, but for columns, moist gunny bags are used for curing.

6. Brickwork:

Purpose of Brickwork: Brickworks are of two types, load bearing and non-load bearing. Non-load bearing brickworks, generally done in the frame structure construction are for providing privacy and protection from weathering.

Apparatus used:

Shovel

Mixture Machine

Iron Pan

Trowel

Plumb bob

Spirit level

Wooden ruler for pointing

Broom

Platform

7. Plastering:-

Purpose of Plastering: The purpose of plastering over Concrete or Brick is to provide a smoother surface on which colour or any other surface treatment could be done.

Apparatus Used:- Mixture machine ,Shovel, Iron pan, Trowel, Spirit level, Plumb bob, Broom, Platform, Staging props, clamps, etc.

Make sure to wet the surface at which you are applying plaster. This will ensure better sticking of the plaster.

Don’t use dry cement over the plastic surface, as there is chances of it getting distorted. Use the appropriate amount of water while mixing chemicals or else, there are chances that it won’t set up to the brick wall.

Wait for 24 hours after plastering the wall and splatter water over it for the next 3-4 days. The splattered water will ensure better set up of the plaster.

8. Waterproofing:

Purpose of Waterproofing: The purpose of water proofing is to make any surface of a structure impervious to water or moisture.

Apparatus used: Mixture Machine

o Shovel

o Iron pan

o Plumb Bobo Wooden Plainer or channel

8. Shuttering: 12mm thick plywood is used with a section of (2440 mm×1220mm) size. Sometimes steel plate of (600mm×1200mm)is also used instead off ply-board. Shuttering members should be strong enough to withstand the ideal load of the poured concrete until the concrete gets hardened.

Supporting Members:

Vertical props or cup-lock members are used to support the formwork for beams and slabs. The formwork for beam is constructed first and then they are fitted at an exact level by extending the props up to this level. Cup-lock is used to attach the horizontal brace to the vertical support to prevent the undesirable horizontal movement of the vertical props. Each supporting member has a maximum length of 3.5m. Whenever this 3.5m height of vertical members appears to be insufficient to reach to the soffit level of the slab or beam, some adjustable props are used. Adjustable prop is a kind of vertical supporting member in which one can adjust the height as required. In case of columns, vertical shuttering members are used with supporting wooden members. Wooden battens of(75mm×50mm) size are attached to the plywood to prevent bulging of the formwork under the load of placed concrete inside the formwork. There are primary and secondary supporting members for column formworks and both are essential to make the formwork strong enough.

Grade of Concrete to be used in construction:

MEMBER/STRUCTURE GRADE

Column and beam column junction M40

Beam M25

Slab M25

Basement M25

Pile M25

Cover provided to Reinforcement :

MEMBER/STRUCTURE CLEAR COVER

Beams 20 mm

Columns 40 mm

Floors/ roof slab 20 mm

Wall 25 mm

Pile 50 mm

SECTION OF COLUMNS

SHUTTERING OF COLUMN POURING CONCRETE INTO COLUMN

PROJEC T MONITORING

PROJECT MONITORING SYSTEM

The following three reports are made for the tracking-

Monthly progress report

Job cost report

Project performance report

Quality

Qua l ity C ont r ol S y s t em of C P WD Field Level

Circle Level

Core Wing at Directorate Level

Quality Assu r an c e U nits In The R egion Contract & Manual

Standards and Specifications

Quality Assurance

Techno-Legal matters

Technology Application & Standards units.

CONCLUSION It was a wonderful learning experience at CPWD office.

I gained a lot of insight regarding FINISHING aspects of Construction site.

I was given exposure in almost all the departments at the site, but I had liked to highlight the areas of safety, quality management, material management and execution.