Study the Pozzolanic Activity of Fresh Basalt

Abstract

This paper aims to study the pozzolanic activity of the fresh basalt. Natural and artificial pozzolanas have been used to obtain hydraulic binders for over a thousand years. Hardening of pozzolanic pastes can result from the reaction between pozzolana and the lime. Chemical and mineralogical composition of the fresh basalt was considered using FTIR, XRD and DSC. The fresh basalt was substituted with lime up to 30 wt%. The pozzolanic activity of the fresh basalt was evaluated by determination of combined water, free lime and acid insoluble residue contents as well as compressive strength up to 360 days. The results showed that the pozzolanic activity of fresh basalt increases as the lime content increases up to 20 wt% and then decreases. The fresh basalt has slightly pozzolanic activity at early ages, mainly due to the ion exchange capacity of basalt, but with time its reactivity increases due to pozzolanic reaction.