Use of metakaolin as a supplementary cementitous material in concrete

Abstract

© 2017 Nova Science Publishers, Inc. All rights reserved. In its most basic form, the main cementitious material in concrete is the Portland cement. However, most concrete mixes contain supplementary cementitious materials (SCM), which replaces some part of cement. SCMs are used to improve the performance of concrete both in its fresh and hardened state. Some of the commonly used SCMs in concrete are fly ash, microsilica, ground granulated blast furnace slag and metakaolin. Metakaolin (MK) is a thermally activated alumino-silicate material obtained by calcining kaolin clay within the temperature range 650-800°C. An important difference between MK and other SCMs is that MK is a primary product, whilst others are either secondary products or by-products. Therefore, MK can be produced with a controlled process to achieve the desired properties. In recent years, MK has been increasingly used to produce high-strength and high-performance concrete with improved durability properties. This chapter provides an overview on the use of MK as a SCM in concrete production.