Study and predicting the stress-strain characteristics of geopolymer concrete under compression

The present investigation is mainly focused on studying the complete stress-strain characteristics of geopolymer concrete (GPC) with different fine aggregate blending. In this study, granite fines (GF) were used as a partial replacement of fine aggregate. Sand and GF were used as fine aggregates blended in different proportions (100:0, 80:20, 60:40 and 40:60) (sand:GF) by weight. GPC cylindrical specimens were tested under compression and the results obtained from the tested data were analyzed to determine the compressive strength (fcm), stress-strain relationship, peak strain (ep), linearity of the stress-strain curve, ultimate strain (eu), various modulus of elasticity (MOE) values, and Poisson’s ratio (μ) of GPC after a period of 7, 28 and 90 days respectively. From the results, it is concluded that the increasing trend was observed in the properties till 40% (60:40) of GF replacement and then these values were decreased. So, optimum fine aggregate was blended at 60:40. Based on the test results, new models were developed for predicting the stress-strain characteristics of GPC under compression by using regression analysis. The results of proposed models were then compared with the experimental values and the predicted equations by various codes and past research.