Blended cements with limestone filler and kaolinitic calcined clay: Filler and pozzolanic effects

Abstract

In this paper, binary and ternary blended cements (BC) based on calcined clay (CC, 0-30%) obtained from low-grade kaolinitic clay and limestone filler (LF, 0-10%) were developed and the interaction between the filler effect and pozzolanic effect on the compressive strength, hydration phases, and pore-size distribution were studied. Results show that early compressive strength decreases for high levels of replacement (10LF30CC) because of a dilution effect that cannot be compensated for by the filler and pozzolanic effects. Based on calcium hydroxide (CH) content, the addition of limestone filler in ternary blended cements is favorable to the development of pozzolanic reaction of calcined clay at an early age. This study shows that dilution, filler, and pozzolanic effects are relevant at 2 days, filler and pozzolanic effects are important at 7 days, and the pozzolanic effect is the most important at a later age.