Experimental and numerical investigation of novel reinforced bamboo aggregate beams

Abstract

To reduce the carbon emissions of concrete materials and alleviate the shortage of natural aggregate resources, this study developed bamboo coarse aggregate (BCA) concrete (BAC) and investigated the flexural performance of reinforced BAC beams using a combined experimental and numerical simulation approach, thereby filling a research gap in the application of BAC in structural members. Three‐point bending tests were conducted on six unreinforced beams and 12 stirrup‐reinforced beams, systematically investigating the effects of the longitudinal reinforcement ratio ( ρ  = 0%, 1.47%, 2.34%) and the BCA replacement ratio ( r  = 0%, 25%, 45%). Test results showed that as ρ increased, the failure mode of BAC reinforced beams shifted from flexural failure to shear failure. An increase in ρ enhanced the initial stiffness and ultimate deflection of the concrete beams; as r increased, the mechanical performance of the concrete beams decreased, but the peak load ( P _u ) still retained more than 95% of that of the normal aggregate concrete (NAC) beams when r reached 25%. The incorporation of BCAs significantly improved the crack propagation behavior and ductility of the beams, with the ductility index increasing by up to approximately 24.6%, and BAC beams exhibited larger strains than NAC beams at the same load level. Finite element simulations successfully reproduced the failure modes and load‐deflection curves of the reinforced BAC beams observed in the tests. Finally, various standards and existing models were referenced to evaluate the ultimate moment, deflection, and shear bearing capacity of reinforced BAC beams.