24-10-2014, 10:15 AM
Abstracts: High-reactivity metakaolin (MK) is one of the recently developed supplementary cementing materials for high-performance concrete. It is produced by calcining purified kaolinite clay at a specific temperature range to drive off the chemically bound water in the interstices of kaolin and destroy the crystalline structure, which effectively converts the material to the MK phase, which is an amorphous aluminosilicate. The particle size of MK is generally less than 2micron, which is significantly smaller than that of cement particles. It is typically incorporated into concrete to replace 5 to 16 by volume of cement.The compressive and flexural strength developments of the MK mixtures are significantly faster than those of the non-pozzolanic control mixture.