Understanding the basics of concrete 

Concrete comes in different grades and strengths. Normally, engineers specify the concrete’s design strength, which varies according to the building’s parts. Using weak concrete will lead to problems in its structure, which could cause cracking and catastrophic failure of the building. Using higher-grade concrete for construction is expensive. 

Using a cement mixer, you can mix strong cement, water, sand, aggregates, and other materials to form concrete on the building site. When ordering it, you should specify the cement grade or strength and the amount of concrete required. The strength of the concrete depends on the ratio of cement to water. More cement strengthens the concrete, and vice versa. 

Other ingredients and their composition 

• Stone 

If you find your cement too watery, add stone to reduce it. However, too much stone makes the concrete difficult to work with and creates voids. The stones should be clean, dust-free, and uniform in size. 

• Sand 

It helps create a cement paste that fills the voids between the stones. Sand should be free of contamination, such as roots, sticks, rubbish, and impurities. Not all sand is suitable to include in the concrete composition. The best type is river sand with even grading. Fine sand will require more water to make it wet. If the sand is very wet, add less water to the mixture. Sand for concrete should be kept covered and dry, especially during monsoon. 

Pouring concrete 

Concrete usually sets within four hours of being mixed, but the time will be shorter when it is very hot. When constructing bigger structures, you should ensure that the first concrete placed does not dry out before the fresh load of the next batch is added. When pouring concrete on slabs and beams, start from one side of the structure, bring it to the top surface, and steadily advance with the new ones.  

The old and new concrete should knit together for a stronger structure. Scheduling the concrete deliveries at the correct frequencies is essential to avoid long gaps in the setting time. You must place the concrete fast enough so that it does not start setting before a fresh layer is added. 

Mixture 

The concrete mixture should always be workable, including sufficient water, strong cement, and sand, so that it easily flows into voids, between and around reinforcing steel, and readily compacted. Remember, more water equals weaker concrete. As the mixture starts setting, the top surface should be evened out.  

The final finish depends on what you add on top of the concrete. Carpet or vinyl floors require a smooth finish. Floors that require tiling may need a rougher finish. 

Conclusion 

Builders should ensure they use the correct concrete grade. As soon as the concrete is mixed or delivered to the project, ensure it is poured or placed into the structure.