Effect of blast furnace slag and pumice on the properties of cement mortar

In this study, the effect of ground granulated blast furnace slag (GGBFS) and pumice powder (PP) substitution on the properties of fresh and hardened mortar was investigated. 480 samples were prepared for ten different mixtures with GGBFS and PT substitutes, and two different cures (laboratory and temperature-humidity controlled room) were applied to the samples. The spreading properties of the mixtures were tested to determine the effect of GGBFS and PP on the fresh mortar properties. The physical properties such as unit volume, water absorption, porosity, and mechanical properties such as flexural and compressive strength of the hardened mortar samples, which were cured for 3, 7, 28, and 90 days, were investigated. It was observed that the P0C20 samples containing 50% GGBFS and 0% PP showed high spreading, and the substitution of GGBFS and PP decreased the physical property values compared to the reference sample. The specimens cured in a temperature-humidity controlled condition showed higher mechanical properties than the laboratory cured specimens. It was determined that the GGBFS and PP substitution had a negative effect on the early age strength, but the compressive and flexural strengths of the 90-day samples with 35% GGBFS replacement were increased.