Planning And Execution Involve In Construction Project

CONSTRUCTION METHODS

PRE-PLANING FOR DEVELOPMENT AREA

JOB LAYOUT means fix location of a non-development area like site office (for client and contractor ), material godown, RMC plant location + raw material, quality check or Lab, Labour house, water tank, entry, or exit gate with security cabin and canteen.

     

SURVEY POINT MARKING

Site corner marking for the reference will help in marking the object of the building with-out less error. However, they also help to find the center location of any structure like footing and column. Consequently know about our wall or boundary or safe line don’t cross the line for construction.

LINE-OUT

It very essential before the excavation for because unless know about excavation portion of the building very dangerous for the deep foundation show every time after mark building or house corner point first recheck with another survey point after excavation. In the layout two types of method normally work first is manual use by Thread, it is very time consume than, the total station machine use.

EXCAVATION

In market two types of foundation as per the soil bearing capacity to resist the whole building load, first is shallow foundation it's fast digging. However, deep foundation digging working a little complicated because of the more than 3.0 MTR.  or 10’ feet deep foundation also cutting like step because for soil collapse from the side by side below show a photo.

 

(STEPWISE FOUNDATION 10 MTR DEPTH)

P.C.C

Plain cement concrete is basically placed for plan surface below the footing and any other RCC structure are connect with direct soil or sand next is soil moisture content does not directly connect with RCC structure so that use the PCC for plan surface as well as use for footing and column marking and obstruction with soil among RCC structure.  

MARKING FOOTING WITH COLUMN

After placed PCC proper marking footing or column location and any other structure with two types of method one is manual and second is using a total station, it is very fast work compare to manual and less manpower use for marking.

STEEL AND FORMWORK

After doing all the above task finally place the steel As per the structural drawing before the cutting the steel also calculate the BBS ( BAR BANDING SCHEDULE ), Due to know how much steel consume in the all work and form-work are 2 type one is steel plats and another are wooden play, however steel plats life more than the wooden play.

PLACEING CONCRETE

Concrete casting method depends on the structure because every buddy knew the concrete pump use only for the large or mass concrete-like footing, slab and road and another type is manual and boom presser use for a vertical structure like column, retraining-wall and any other object. ( Note: Concrete place up-to 1.5 MTR height neither concrete segregate )

(BOOM CONCRETE PUMP)

(NORMAL CONCRETE PUMP)

CURRING

Shading concrete work

Covering concrete surfaces with hessian or gunny bags

Sprinkling of water

Ponding method

Membrane curing

Steam curing

1. SHADING OF CONCRETE WORK

The object of shading concrete work is to prevent the evaporation of water from the surface even before setting. This is adopted mainly in the case of large concrete surfaces such as road slabs. This is essential in dry weather to protect the concrete from heat, direct sun rays, and wind. It also protects the surface from rain. In cold weather shading helps in preserving the heat of hydration of cement thereby preventing freezing of concrete under mild frost conditions. Shading may be achieved by using canvas stretched on frames. This method has a limited application only.

2. COVERING CONCRETE SURFACES WITH HESSIAN OR GUNNY BAGS

This is a widely used method of curing, particularly for structural concrete. Thus exposed surface of the concrete is prevented from drying out by covering it with hessian, canvas, or empty cement bags. The covering over vertical and sloping surfaces should be secured properly. These are periodically wetted. The interval of wetting will depend upon the rate of evaporation of water. It should be ensured that the surface of the concrete is not allowed to dry even for a short time during the curing period. Special arrangements for keeping the surface wet must be made at nights and on holidays.

3. SPRINKLING OF WATER

The sprinkling of water continuously on the concrete surface provides efficient curing. It is mostly used for curing floor slabs. The concrete should be allowed to set sufficiently before sprinkling is started. The spray can be obtained from a perforated plastic box. On small jobs sprinkling of water may be done by hand. Vertical and sloping surfaces can be kept continuously wet by sprinkling water on top surfaces and allowing it to run down between the forms and the concrete. For this method of curing the water, the requirement is higher.

4. PONDING METHOD

This is the best method of curing. It is suitable for curing horizontal surfaces such as floors, roof slabs, road and airfield pavements. The horizontal top surfaces of beams can also be ponded. After placing the concrete, its exposed surface is first covered with moist hessian or canvas. After 24 hours, these covers are removed and small ponds of clay or sand are built across and along the pavements. The area is thus divided into several rectangles. The water is filled between the ponds. The filling of water in these ponds is done twice or thrice a day, depending upon the atmospheric conditions. Though this method is very efficient, the water requirement is very heavy. Ponds easily break and water flows out. After curing it is difficult to clean the clay.

5. MEMBRANE CURING

The method of curing described above come under the category of moist curing. Another method of curing is to cover the wetted concrete surface by a layer of waterproof material, which is kept in contact with the concrete surface of seven days. This method of curing is termed as membrane curing. A membrane will prevent the evaporation of water from the concrete. The membrane can be either in solid or liquid form. They are also known as sealing compounds. Bituminous waterproof papers, wax emulsions, bitumen emulsions, and plastic films are the common types of membrane used.

Whenever bitumen is applied over the surface for curing, it should be done only after 24 hours curing with gunny bags. The surface is allowed to dry out so that loose water is not visible and then the liquid asphalt sprayed throughout. The moisture in the concrete is thus preserved. It is quite enough for curing.

This method of curing does not need constant supervision. It is adopted with an advantage at places where water is not available in sufficient quantity for wet curing. This method of curing is not efficient as compared with wet curing because the rate of hydration is less. Moreover the strength of concrete cured by any membrane is less than the concrete which is moist cured. When the membrane is damaged the curing is badly affected.

6. STEAM CURING

Steam curing and hot water curing is sometimes adopted. With these methods of curing, the strength development of concrete is very rapid.

These methods can best be used in precast concrete work. In steam curing the temperature of steam should be restricted to a maximum of 750C as in the absence of proper humidity (about 90%) the concrete may dry too soon. In the case of hot water curing, the temperature may be raised to any limit, ay 1000C.

At this temperature, the development of strength is about 70% of 28 days strength after 4 to 5 hours. In both cases, the temperature should be fully controlled to avoid non-uniformity. The concrete should be prevented from rapid drying and cooling which would form cracks.