Shear capacity experiment, load-bearing capacity calculation, and numerical simulation of reinforced geopolymer concrete beams

Geopolymer concrete, an innovative eco-friendly building material, effectively reduces carbon dioxide emissions while advancing green and sustainable societal development. Nine reinforced geopolymer concrete beams with varying stirrup ratios and shear span ratios were designed. Under monotonic loading, the failure processes, failure modes, load-displacement responses, critical loads, and corresponding displacements were analyzed. The experimental bearing capacities were compared with the calculated values from Chinese, American, and European design codes. A shear capacity equation for reinforced geopolymer concrete beams was proposed, incorporating stirrup ratio, shear span ratio, and other influencing factors. Additionally, a finite element model of the beams was developed using ABAQUS software. Experimental and simulated load-displacement curves and failure modes were compared. Results indicate that all specimens exhibited shear failure. Increasing the stirrup ratio enhanced shear capacity by up to 20.4%. Conversely, a higher shear span ratio reduced peak load by 39.6–43.3% while increasing peak deformation capacity by 197.8–241.5%. The proposed shear capacity equation aligns closely with experimental results, and the finite element model accurately replicates both load-displacement behavior and failure modes. These findings provide experimental and theoretical foundations for engineering applications of geopolymer concrete materials.