Curing may be defined as the process of maintaining satisfactory
moisture and temperature conditions for freshly placed concrete for some
specified time for proper hardening of concrete. Curing in the early ages of
concrete is more important. Curing for 14 days is very important. Better to
continue it for 7 to 14 days more. If curing is not done properly, the strength
of concrete reduces. Cracks develop due shrinkage. The durability of concrete
structure reduces.
The following
methods are employed
(a) Spraying of water
(b) Covering the surface with wet gunny bags, straw etc.
(c) Ponding
(d) Steam curing and
(e) Application of curing compounds.
(a) Spraying of water: Walls, columns, plastered surfaces are
cured by sprinkling water.
(b) Wet covering the surface: Columns and other vertical
surfaces may be cured by covering
the surfaces with wet gunny bags or straw.
(c) Ponding: The horizontal surfaces like slab and floors are
cured by stagnating the water to a
height of 25 to 50 mm by providing temporary small hunds with
mortar.
(d) Steam curing: In the manufacture of pre-fabricated concrete
units steam is passed over the
units kept in closed chambers. It accelerates curing process,
resulting into the reduction of curing period.
(e) Application of curing compounds: Compounds like calcium
chloride may be applied on
the curing surface. The compound shows affinity to the moisture
and retains it on the surface. It keeps
the concrete surface wet for a long time.
