CURING

CURING

 Curing is process of keeping the concrete moist and warm enough, so that the hydration of cement can continue. In fact concrete derives strength by the hydration of cement. 

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        Curing it the process of maintaining a satisfactory moisture content and a  favourable temperature in concrete, so that hydration of  cement may contiune until the concrete developes desired properties. 

        If curing is neglected in the early period of hydration, the quality of concrete will experience a sort of loss. If curing is not done well after placing of concrete, it will not give the desirable bond and strength characteristics.

METHOD OF CURING

• Water curing
• Membrane curing
• Application of hear 
• Application of curing compounds 

Water curing

     Water curing is the best method of curing. In this method, water is applied on the concrete surface for certain duration.

Way of Water Curing

•  Ponding 
• Spraying
• Wet covering.

          Slabs, roofs, etc are covered under water by developing water pond on the concrete surfaces. Vertical walls, columns, plastered surfaces are cured by sprinkling of water on it. Vertical surface are also cured by using some wet coverings such as gunny bags, cloth, jute matting, straw etc. Horizontal surface are kept wet by covering concrete with wet saw dust etc.

Membrane curing

        In some places where there is acute shortage of water, membrane curing is adopted. Generally water. Mixed for making concrete is more than sufficient to  hydrate the cement. Membranes are applied all around the concrete which will effectively seal off the concrete. The membranes seal over the concrete by means of a firm impervious film to prevent moisture in concrete from escaping by evaporation. This prevention of moisture in concrete will worked as a curing of concrete. 

Application of Heat

       When concrete is subjected to higher temperature, it accelerates the hydration process and results in higher development of strength. Concrete cannot be subjected to dry heat because of moisture is also an essential requirement. Therefore for achieving this goal concrete is required to subjected, the steam curing. Steam curing will give not only economical advantage, but also technical advantages to the concrete. It is applied generally o perfabricated  concrete elements.

Application of curing compounds

         There are certain curing compounds those keeps the concrete wet. Calcium chloride is the one curing compound. It can be used as a surface coating or as admixture. calcium chloride is a salt, it shows affinity for moisture. The salt, not only absorb the moisture from atmosphere but also retain it at the surface. It keeps the concrete wet for a long time to promote hydration.