Effects of glass and limestone aggregates and aluminium on porosity, expansion, and strength of mortar bars

Abstract

Alkali-silica-reactions (ASR) generally occur as a result of reactions between alkali in cement and silica in aggregates. The reactions result in expansion, which consequently lead to deteriorated mechanical properties in concrete. Types of aggregate as well as pore contents were reported to influence expansion. This study therefore, aimed at examining effects of aggregates and air entrainment agent on porosity, expansion, and strength of mortar bars. Limestone and glass were used as aggregates, while aluminium powder, with the amount of 0.05, 0.1, 0.15 and 0.2 wt% of cement, was used as air entrainment agent in this study. Experimental results revealed that an increase of aluminium concentration resulted in higher porosity and lower expansion in the mortar bars. Retained strengths, fraction of strength remained after occurrence of ASR, were also enhanced. The results also indicated that the mortar bars with glass aggregate generally exhibited higher porosity, lower expansion, and greater retained strength compared to those with limestone.