Curing Of Concrete

Meaning of the term: The concrete surfaces are kept wet for a certain period after placing of concrete so as to promote the hardening of cement. It consists of a control of temperature and of the moisture movement from and into the concrete. The term curing of concrete is used to indicate all such procedures and processes.

Purposes: Following are the objects or purposes of the curing of concrete:

(1) The curing protects the concrete surfaces from sun and wind.

(2) The presence of water is essential to cause the chemical action which accompanies the setting of concrete. Normally, there is an adequate quantity of water at the time of mixing to cause hardening of concrete. But it is necessary to retain water until the concrete has fully hardened.

(3) The strength of concrete gradually increases with age, if curing is efficient. This increase in strength is sudden and rapid in early stages and it continues slowly for an indefinite period.

(4) By proper curing, the durability and impermeability of concrete are increased and shrinkage is reduced.

(5) The resistance of concrete to abrasion is considerably increased by proper curing.


Period of curing: This depends on the type of cement and nature of work. For ordinary Portland cement, the curing period is about 7 to 14 days. If rapid hardening cement is used, the curing period can be considerably reduced.

Effects of improper curing: Following are the major disadvantages of improper curing of concrete:


(1) The chances of ingress of chlorides and atmospheric chemicals are very high.

(2) The compressive and flexural strengths are lowered.

(3) The cracks are formed due to plastic shrinkage, drying shrinkage and thermal effects.

(4) The durability decreases due to higher permeability.

(5) The frost and weathering resistance are decreased.


(6) The rate of carbonation increases.

(7) The surfaces are coated with sand and dust and it leads to lower the abrasion resistance.

Factors affecting evaporation of water from concrete:Following are the four basic factors on which the evaporation of water from the concrete surface depends

(1) air temperature;

(2) fresh concrete temperature;

(3) relative