Concrete curing is the process of keeping the concrete damp or moist and warm after the initial setting of concrete or removal of formwork or shuttering. Proper concrete curing maintains the satisfactory moisture content and favorable temperature inside the concrete so that hydration of cement may continue until the desired properties are developed. Curing of concrete must be continued for a reasonable period of time to achieve its desired strength and durability.
There are different concrete curing methods used on site depending on the size and nature of the work. There are three major concrete curing methods by which concrete can be kept moist and humid or kept at a favourable temperature.
Courtesy - 123rf
01. Water Curing:
This is a most general method of curing as it satisfies all the requirements of curing. These methods maintain the presence of moisture in the concrete during the early hardening period.
Water curing can be done in the following types:
- Spraying or fogging
- Wet covering
02. Membrane Curing(Wet Covering):
These methods prevent the loss of mixing water from the surface of the concrete. Sometime concreting is carried out at a remote place where there might be an acute shortage of water. A large amount of water required for water curing is not possible for economic reasons too.
Therefore, Membrane curing can be done in the following types:
- Plastic sheeting
- Curing compounds.
03. Application of Heat(Steam Curing):
These methods accelerate strength gain by supplying heat and additional moisture to the concrete. When concrete is subjected to higher temperature, it accelerates the hydration process and hence resulting in faster development of strength. Materials subjected to this hardening technique tend to cure more uniformly and much more rapidly than other processes.
In steam curing, objects to be cured are placed inside a chamber or room. An operator can set the temperature and humidity level by using a control panel. The heat and moisture penetrate in the materials quickly hence hydrate the concrete fully and harden them. Steam curing requires a fraction of the time involved with conventional curing and quickly strengthens the products so they can be used immediately.
The exposure of concrete to a higher temperature is done in the following manner:
- Steam curing at ordinary pressure.
- Steam curing at high pressure.
- Curing by Infra-red radiation.
- Electrical Curing
Concrete Curing methods varies with different concrete structures or members. All concrete curing methods cannot be applied for all type of concrete structures.Choose the appropriate concrete curing method to achieve designed strength. We have also discussed different methods of concrete curing.