Some useful tips for labor in Cement Concrete
Cement is the major element in building construction. It is considered as one of the expensive item in construction. Cement is categorized as Plain Cement Concrete and Reinforced Cement Concrete. Cement Concrete comprises of several components like cement, fine aggregate, coarse aggregate and water.
Plain cement concrete has good resistance strength against compression but it has poor strength against tension. To increase the strength of concrete in tension MS Steel bars are provided in cement concrete and it is known as Reinforced Cement Concrete (RCC).
The design of the building is made by the structural engineer on the basis of load and bearing strength of building. The proportion of cement & concrete is also set by the structural engineer for being utilized in several parts of building as per needs of the building bearing the security of the structure in mind.
In cement concrete RCC centering and shuttering play an important role and it should be performed cautiously for retaining full strength of structure.
Labor Guideline: In order to gain full strength from cement concrete mix, ensure that laying process of cement concrete is done as per prescribed specification. The placement of cement concrete should be done based on the following points :-
1. At the time of laying Cement Concrete, the mix should be done with machine and vibrated.
2. Prior to arrange cement concrete, make sure that all the gradients applicable in cement concrete like cement, fine aggregate, coarse aggregate and water should be as per specification and the quantity should be adequate.
3. Ensure that several gradients of concrete mix should be computed in a proper manner. The ratio should be maintained as per design.
4. Prior to place cement concrete, ensure that centering and shuttering or form work is perfect in shape according to drawing. The form work should remain in level and it should have enough strength to bear load/ pressure of concrete.
5. No voids should exist in the plates since the cement slurry will be discharged from the mix and the strength will be decreased.
6. Make sure that the shuttering plates are cleansed and oiled prior to place the MS Steel bars.
7. Examine that MS steel bars diameter, their placing, bending and binding are done as per the specification of design.
8. Make sure that the length of the overlap, height of crank bars and supports under the crank bar are maintained properly.
9. Ensure that all the conduit pipes, fan hook and other required fittings are placed on steel bars as per requirement and design.
10. Prior to place the concrete, verify that the cover under the steel bar in slab, and all around in column and beam are provided as per specification.
11. Make sure that the MS Steel bars should not be affected by labor throughout lying of mix and to get rid of this planks or plates are arranged on MS Steel bars for labor movement at the time of placing the mix.
12. Precautionary measure should be undertaken in case of rains.
13. Verify that the top surface of concrete mix remain in level, finished and thickness should be as per design.
14. Make sure that arrangement of curing is perfect to maintain smooth curing of RCC member once the concrete is placed.