Bond Performance of Steel Bar and Fly Ash-Based Geopolymer Concrete in Beam End Tests

This paper presents a comprehensive investigation of the bond characteristics of steel bar reinforced geopolymer concrete (GPC). The ASTM A944 beam end tests were conducted on GPC beams reinforced with plain or ribbed bars. The bond–slip curves and the bond strength of GPC beams were obtained. The relationship between the bond stress and relative slip in plain and ribbed bar reinforced GPC has been represented by empirical formulae. The bond testing results were compared with those of corresponding ordinary Portland cement concrete (OPC) using statistical hypothesis tests. The results of hypothesis testing showed that GPC was significantly superior to OPC in terms of bond capability with plain bars and bond stiffness with ribbed bars. The statistical analysis indicated that the bond–slip relations derived for OPC are inapplicable to GPC; thus, new bond–slip relations are suggested to estimate the development of bond stress and relative slip between GPC and steel bars