Engineering properties of concrete made with GGBS and pulverised fuel ash

Abstract

The utilisation of supplementary cementitious byproducts, including ground granulated blast-furnace slag (GGBS) and pulverised fuel ash (PFA) as a part of cement in concrete technology, has received great attention in recent years.  This paper delineates the influence of using GGBS and PFA as a cement substitute on the physico-mechanical characteristics of concrete. To do so, different concrete formulations were compositionally blended at water to cement ratio of 0.5, and a fixed blending proportion of 1 cement: 2 sands: 3 aggregates. Subsequently, multi-scale analyses entailing the slump, density, compressive strength, tensile strength test were performed to assess their performance. Correspondingly, the results revealed an increase in consistency as a result of incorporating GGBS or PFA as a 60% cement substitution, especially for concrete formulation rich in GGBS. As for the strength observations, it was indicated that using GGBS and PFA induced a reduced UCS, particularly in at earlier curing age, but such a decrease was compensated at longer curing period. As for the TSS performance, the results showed that GGBS-based concrete yielded a superior TSS at 28 days, while PFA induced a gradual TSS reduction as the PFA content increased. These promising outcomes suggest the possibility of developing sustainable concrete by incorporating high amount of GGBS and PFA, providing an attractive way for preserving the environment from the impact of cement manufacturing.