Shear behavior of reinforced one-part geopolymer concrete beams

Abstract

Geopolymers, emerging as a novel low-carbon cementitious material, have garnered growing attention in recent years. Notably, the recently developed “one-part geopolymer” (OPG) has shown mechanical properties and durability comparable to those of ordinary Portland cement (OPC). However, the mechanical behavior of one-part geopolymer concrete (OPGC) structural members remains insufficiently understood, which limits its engineering application. This study explores the shear behavior of reinforced OPGC beams. Ten beams were tested under four-point loading to examine their damage modes and evaluate the effects of shear span ratio and stirrup ratio, with an OPC concrete (OPCC) beam considered a counterpart for comparison. Test results revealed that the shear capacity of OPGC beams decreases as the shear span ratio increases. OPGC beams with low stirrup ratios exhibit brittle shear failure, whereas this can be effectively mitigated by increasing the stirrup ratio. OPGC beams demonstrated slightly better load-carrying capacity and ductility compared to OPCC beams. In addition, this study evaluated the applicability of theoretical shear capacity formulas from existing structural design codes in China, the UK, the United States, and Japan for the shear design of OPGC beams. The results revealed that all the design codes were overall applicable to the shear design of OPGC beams. Finally, the overall performance of OPGC and OPCC beams was evaluated and compared by considering environmental and economic indicators. This study offers valuable insights for the design and analysis of OPGC beams subjected to shear.