Water
: Cement Ratio ( w/c ratio):
This is one of the important factor in deciding the quality
of concrete. Cement needs only 23 % water for its reaction. That means in a
mix of one bag of cement, we need only 11.5 liters of water for the chemical
reaction to happen. For practical purpose we add app. 25 liters of water, per
bag of cement, in making the concrete. This extra water is required to place
the concrete at the required location & for proper compaction. It is generally
seen that in site mix concrete w/c ratio is not at all taken into consideration.
Water is added by eye judgment of laborer. With this water quantity up to 50n
liters per bag of cement is added in the concrete. As a result concrete after
hardening becomes porous. Due to this porosity, water from rains & other
polluted gases in the atmosphere enters into the concrete. This damages not
only the concrete but corrodes steel bars also. This leads to seepage of water
inside the rooms. Hence lot of money is spent on repair & maintenance of
building. At CRSons RMC, the concrete is made with utmost care. Highly qualified
technical staff maintains state of the art laboratory & checks every batch
of the concrete that is made at the plant, round the clock. Here the concrete
is such designed that w/c ratio is strictly maintained as per the BIS norms.
Not only strength is kept as a criterion in designing the Ready Mix Concrete,
but Durability – i.e. life of the structure, is also taken into consideration.