Adding limestone fines as cementitious paste replacement to lower carbon footprint of SCC

Abstract

Besides adding supplementary cementitious materials to replace part of the cement, the cement consumption and carbon footprint of concrete may also be lowered by reducing the cementitious paste volume. However, the cementitious paste volume should not be inadvertently reduced because the paste volume has to be more than enough to fill the voids between aggregate particles so as to provide excess paste to form paste films on aggregate surfaces. Herein, it is proposed to add limestone fines (LF) to replace an equal volume of cementitious paste so that when reducing the cementitious paste volume, the paste volume is replenished by the LF volume. Trial concrete mixing has demonstrated that with such addition of LF as cementitious paste replacement, the performance of self-consolidating concrete (SCC) can be maintained and more importantly, the cementitious paste volume of SCC can be reduced to as low as 22% in order to minimize the carbon footprint.