Advances in development of calcined clays as supplementary cementitious materials

Abstract

Abstract Continuous development and expansion of the raw material base, in response to the increasing environmental and technical requirements for the most consumed commodities, are crucial for the sustainable development of resource-and energy-intensive materials and technologies, including cement production. In recent decades, calcined clays have become significant as supplementary cementitious materials for blended Portland cements. Extensive research and practical experience form the theoretical and practical bases for the application of calcined clays, which are diverse in composition and structure, for effective cement production. However, the scarcity of the most valuable pure kaolin clays has led to extensive feasibility studies on more abundant medium-and low-grade kaolin, multi-mineral kaolin, and non-kaolin clays. This paper reviews the last advances in the field of Portland cement-based systems using calcined clays containing different amounts of 1:1 and/or 2:1 type clay minerals, including their processing features, chemical reactivities, potential controlling factors, and requirements.