Effects of different methods of curing on strength of concrete

Curing is the name given to the procedures used for promoting the hydration of the cement and consists of control of temperature and of moisture movement from and into the concrete. Curing allows continuous hydration of cement and consequently continuous gain in the strength, once curing stops strength gain of concrete also stops. Proper moisture conditions are critical because the hydration of the cement virtually ceases when the relative humidity within the capillaries drops below 80%. With insufficient water, the hydration will not proceed and the resulting concrete may not possess the desirable strength and impermeability. The continuous pore structure formed on the near surface may not allow the ingress of deleterious agents and would cause various durability problems. Curing is defined as maintaining satisfactory moisture content and temperature in the concrete for a specified period of time immediately after placing and finishing so that the desired properties may be develop. Curing plays a crucial role in concrete strength development and durability. After adding water to the dry mixed concrete (Cement, Sand, & Aggregate), the exothermic reaction (hydration) takes place, which assists the concrete to harden. Hardening of concrete is not a quick process and continues for a longer period in which the concrete kept moist to prevent it from loss of moisture due to atmospheric temperature. Curing must be undertaken for useful period of time if concrete is to attain its potential strength and durability. Curing is necessary if concrete is to achieve its intended function over the design life of the structure. Curing can be done in a number of methods while the most suitable means of curing may be dictated by the site conditions or the construction method. The need for adequate curing of concrete cannot be overemphasized. Proper curing will increase durability, volume stability, strength, water tightness, abrasion resistance, and resistance to freezing and thawing. The exposed slab surfaces are particularly sensitive to curing as strength development and freeze thaw resistance of the surface of a slab can be reduced considerable when curing is defective. If temperature is favorable, hydration is relatively rapid in the first few days after concrete is placed. Curing of concrete is done by various methods depending on the type of structure, site location and site conditions and sometimes due to various errors at the construction site, the process of curing may be defective or may not be sufficient or may not be done at all. In this project work, we are intending to study the effects of different types of curing methods on the strength parameters of concrete