Self curing concrete
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What is curing of concrete?
Curing is the maintenance of a satisfactory moisture content and temperature in concrete for a period of time immediately following placing and finishing so that the desired properties may develop.
Curing has a strong influence on the properties of hardened concrete ; proper curing will increase, durability, strength, watertightness, abrasion resistance, volume stability, and resistance to freezing and thawing etc.
DEFINATION OF CURING;
(as per ACI-308R)
The term "curing" is frequently used to describe the process by which hydraulic-cement concrete matures and develops hardened properties over time as a result of the continued hydration of the cement in the presence of sufficient water and heat.
(as per IS:456-2000 )
“ curing is the process of preventing the loss of moisture from the concrete.”
What is self curing concrete?
It has been pointed out earlier that curing does not means application of water ,it means also creation of condition for promotion of Uninterrupted and Progressive hydration.
It is also pointed out that the quantity of water, normally mixed for making concrete is sufficient to hydrate the cement content.
Why self curing concrete?
Some times works are carried out in place where there is acute shortage of water and the application of water curing is not possible for reasons of economy.
prevention of moisture loss from the surface of flat concrete works such as highways and airports have been challenging task for construction managers.
If the evaporation of moisture from concrete are not prevented properly it may results in plastic shrinkage cracks, poorly formed hydrated products, finishing problems and other surface defects.
Sometimes concrete is placed in some inaccessible , difficult or far places. Where curing cannot be properly done or supervised.
How the self curing is being done?
Membrane forming curing compounds are used to retard the loss of water from concrete during the early age.
They are used not only for curing fresh concrete but also further curing after removal of formwork.
Application of these compounds seals the concrete surface effectively by forming monomolecular film on the surface.
Membrane forming curing compounds is a long chain of hydrocarbon molecules.
Which forms monomolecular film on the surface of the concrete immediately after placing.
White-pigmented concrete curing compounds
White-pigmented concrete curing compounds are wax-based dispersions with selected white pigments.
When properly applied, which optimizes water retention. The white pigment reflects the sun's rays and helps to keep the concrete surface cooler and prevent excessive heat buildup.
It is ideal for application on exterior, horizontal surfaces, such as highways, airports pavements.
When properly applied, provides a premium-grade film, which optimizes water retention.
Protects by reflecting the sun's rays to keep the concrete surface cooler and prevent excessive heat buildup, which can cause thermal cracking.
Furnished as a ready-to-use, true water-based compound. Produces hard, dense concrete ... minimizes hair checking, thermal cracking, dusting and other defects.
Offers a compressive strength significantly greater than improperly or uncured concrete.
Improves resistance to the abrasion and corrosive actions of salts and chemicals ... minimizes shrinkage.
In short, discussed all above curing compounds are effective tool to avoid the occurrence of plastic shrinkage cracks in a windy, low humid and exposed to sun condition.
Contractor can benefit by able to expedite the work schedule and placing more concrete while client benefits by obtaining concrete free of plastic shrinkage crack and having greater durability value.