Amelioration of crushed brick - lime composites using nano-additives

Abstract

Crushed brick is widely known as a pozzolanic additive for composite building materials. However, crushed brick - lime composites usually show high porosity, low compressive strength and slow reaction kinetics. In this paper, we present multidisciplinary research on the amelioration of crushed brick - lime composites, using nanosilica (SiO2) and nanotitania (TiO2) as additives at 3% w/w of binder. The results suggest that despite the dominant effect of the crushed brick, nanosilica significantly improves the early-age properties of the composites, while nanotitania potentially increases their resistance against salt crystallization. Supplementary FTIR, DTA/TG and SEM analyses confirm the better hydration and carbonation evolution of lime composites with crushed brick and nano-additives.