Optimization of flexural performance for bamboo-CFRP hybrid reinforced concrete beams using Response surface methodology (RSM) and FEM simulation

In the study the optimization on flexural performance of bamboo and carbon fibre-reinforced polymer (CFRP) hybrid reinforcement as alternative to conventional steel reinforcement in RC beams has been carried out using Response Surface methodology (RSM). Thirteen proportions of hybrid reinforcement in concrete beams for various combinations of bamboo and CFRP bars were tested for flexure, and an additional beam reinforced using only steel bars as a control beam was also tested. The results indicated that the bamboo reinforced beams produced a very low load-carrying capacity and failed at relatively low deflections, whereas the CFRP bar reinforced beams carried high loads and failed at relatively large deflections. The load carried by the tested beams was optimized by developing model equations and validating them using ANOVA by adopting the 95% level of significance. The optimized reinforcement’s percentage proportions were obtained as 1% of bamboo and 1% of CFRP. The flexural load capacity of the optimum hybrid reinforced concrete beam was found to be 97.84% that of the reinforced steel concrete beam. Validation was done for the models, and optimized results were obtained experimentally and were found to have a desirability of more than 0.96. The experimental results were also simulated with FEM based software ABAQUS, and it was found that the results have a deviation of generally within ±15% endorsing the reliability and precision of the numerical model in predicting the ultimate load of reinforced concrete beams. • Flexural behavior of bamboo–CFRP hybrid reinforced concrete beams was investigated. • RSM-based optimization identified 1% bamboo and 1% CFRP as the optimum combination. • Optimized hybrid reinforced beam achieved 97.84% flexural strength of steel-reinforced beam. • Model validation showed high desirability (>0.96) and FEM results within ±15%