Strength efficiency of metakaolin in concrete

The use of mineral admixtures is widely accepted, because of several improvements possible in concrete composites and the overall economy. Of these metakaolin is one mineral admixture that appears to have significant potential for the production of high-strength and high-performance concretes. Although available information on metakaolin concretes is limited, the present paper attempts to quantify the 28-day cementitious efficiency of metakaolin in concrete at various replacement levels from the data available in the literature. It was seen that the efficiency of metakaolin in concretes can also be defined through a procedure adopted earlier for other cementitious materials like fly ash, silica fume and ground granulated blast-furnace slag (GGBS). The overall strength efficiency was found to be a combination of two parameters, one depending on the age and the other depending on the percentage of replacement, as is the case with other pozzolans.