CONCRETE CURING BY POURING WATER

WHY DO WE CURE CONCRETE BY POURING WATER?

Curing of concrete is the process that is done for a certain time in order that the concrete can attain the required strength, all we have to know is how water pouring functions on curing?, what happens if we do not pour water on concrete as curing method?, are there any other methods of curing out of pouring water?

WATER POURING AS CURING METHOD

Pouring water as curing method is the most common and traditional method which can be done by either of the following methods

1. Ponding 

This is the most common and inexpensive method of curing flat surfaces such as floor slabs, flat roofs, pavements and other horizontal surfaces.

2. Sprinkling, fogging & mist curing:

Using a fine spray or fog or mist of water can be an efficient method of supplying water to the concrete surface especially during hot weather, which helps to reduce the temperature of concrete, eventually conserving moisture inside the body of concrete.

3. Wet coverings:

Water absorbent fabrics such as hessian, burlaps, cotton mats, rugs etc. may be used to maintain water on the concrete surface by completely covering the surface immediately after the concrete has set. They must be continuously kept moist to prevent the fabric from absorbing water from the body of concrete, due to capillary action.

Curing of concrete (strengthening of concrete) occurs as there is hydration process take place between cement and water, this hydration process is the exothermic chemical reaction that form crystal that hold together aggregate and cement paste in concrete formation.

The designed amount of water for concrete mixing is enough for concrete to complete hydration process and attain full strength then why do we cure again by pouring water into concrete?

I know most of us need to know the answer of above question, the reason why we still pour water onto concrete while the designed water is enough for concrete to have complete hydration (attain full strength) are as described below.

 1. To maintain the concrete temperature

During hydration process there is formation of heat as the core temperature which should be maintained to avoid slow or fast curing of concrete, as we all know change in temperate can alter the speed of chemical reaction.

Change in speed can cause the hardened concrete to have different properties compared to desired one.

2. To maintain water content for hydration

Due to the fact that during hydration process heat is generated and cause water to evaporate (loss of water to the atmosphere), water on the concrete surface can account on water that is lost due to evaporation and make the hydration process to takes place continuously until the desired strength is attained without stopping.

When hydration process stops it cannot be started again and the desired strength will not be attained     as the hydration process will not be completed.

3.  To avoid cracking of hardened concrete

Water losses due to evaporation not only happens due to core temperature but also due to a atmospheric temperature, winds etc.

In fresh concrete surface we had seen cracks due to shrinkage of concrete, this occur due to the atmospheric temperature at surface of concrete which evaporates the water from surface thus leads to crack on the surface (More cracking occurs in summer compare to winter).

Water on concrete surface reduce direct heat on the concrete surface and keep it cool throughout curing period (hydration process time)

All on all from above point we can now say that “A bad Concrete can be turned into a good Concrete by doing proper curing and A good Concrete Becomes Bad if we don't cure it properly”.

By above reasons can also answer that question what will happen if we will not pour water on concrete let check on other question that are there other curing method out of pouring water method?

Yes, there are other methods out of water curing method, on the coming post we will explain different curing methods used in construction industry besides the one discussed.