Metakaolin

Concrete is the most commonly used material for construction. The worldwide production of cement has greatly increased since 1990.Production of cement results in a lot of environmental pollution as it involves the emission of CO2 gas. Cement Strength Enhancer (CSE) or Supplementary cementitious materials (SCM) are finely ground solid materials that are used to replace a portion of the cement in a concrete mixture. These supplementary materials may be naturally occurring, manufactured or manmade waste. Various types of pozzolanic materials that improve cement properties have been used in cement industry for a long time.

One of the important ones is Met kaolin. It is a dehydroxylated aluminium silicate. It is an amorphous non crystallized material, constituted of lamellar particles. From the recent research works using Metakaolin, it is evident that it is a very effective pozzolanic material and it effectively enhances the strength parameters of concrete.

The metakaoline is a highly reactive pozzolan hydroxide produced from free lime during the hydration of metakaoline cement, forming calcium silicate and alumino silicate hydrates. These cementitious products supplement the binding action in concrete. This formulation provides increased density, resulting in reduced porosity and permeability and increased chemical resistance. In many ways, the pozzolanic reaction is similar to that with fly ash, but with finer particle size and higher surface area enables the pozzolan to react much faster and more frequently