Predicting the mechanical strength of coal pond ash based geopolymer concrete using linear regression method

Abstract

Geopolymer concrete (GPC) is an innovative alternate material that can replace traditional Portland cement concrete. Generally, GPC requires heat or steam chamber during curing for optimal geopolymerization response on concrete specimens, which is tedious and a time-consuming process. Modified GPC is introduced to overcome these limitations as well as to improve the characteristics of specimens. This study goal was to assess and examine the mechanical strength of GPC when mixed with slaked lime, ground granulated blast furnace slag (GGBS), and pond ash (PA) at various proportions. Slaked lime was added at a rate of 1%, 2%, 3%, 4%, 5%, and 6% by combined weight of PA and GGBS. Concrete specimens were casted and cured for 7, 28, 56, and 90 days at ambient environmental condition. Experimental test results showed that PA and GGBS based GPC significantly gained mechanical strength than conventional GPC at 7, 28, 56, and 90 days. The admixtures PA and GGBS not only increased the strength of GPC but also reduced the curing time. In addition, it was found that the improvement in properties was the result of densification of microstructures over curing time.