Pulverized Calcined Clay and Carbide Waste as Alternative Binder in Concrete and Mortar Applications for Sustainable Construction

Abstract

Portland cement (PC) based concrete is the world’s most consumed man-made material and this consequently puts lots of demand on cement as a binder. The CO2 gas emission during cement clinker production has placed this important material into non-environmental-friendly classification with the quest for greener alternatives being on the rise. A recent study showed a combination of Pulverized Calcined Clay (PCC) and Calcium Carbide Waste (CCW) as a possible alternative for total PC replacement with resulting appreciable mortar strength but delayed setting times and lower strength than PC mortars. This paper reports on the effects of PCC-CCW as an alternative binder on the strength properties of mortars. The mortar mixes had superplasticizers added to reduce water/binder ratio while the CCW was treated to reduce impurities with a view to improving the strength development and a bid to mitigate the observed setbacks of earlier study. The pozzolanic activity indices of the PCC were determined via X-Ray Fluorescence (XRF) and strength determination (strength activity index). The PCC was combined with Purified CCW to determine the binder’s strengths at varying PCC: CCW replacements to determine the prescribed mix combination for optimum strength. Improved optimized mortar strength of 13.11MPa was achieved compared to 11.89MPa in the previous study.