Nonlinear finite element analysis of traditional flexural strengthening using betung bamboo (Dendrocalamus asper) on concrete beams

Structural failure, which can be caused by design miscalculation or changes in the building's function, can be dangerous if left untreated. Consequently, structural strengthening is done by providing steel plates, fiber-reinforced-polymer, or in the traditional way using bamboo fibers. In this study, a numerical calculation for bamboo strengthening using the FEM method is conducted. Bamboo strengthening was installed on concrete beams and attached using mortar. The analysis was carried out with ATENA software dealing with beam specimens, namely Control Beam (BC) and Bamboo-strengthened Beam using M13 and M20 mortar (BB13 and BB20). The materials used are CC3DNonLinCementitious2 and CCD3DBiLinearSteelVonMises for concrete and bamboo, respectively. The concrete and mortar use the fracture concept of a uniaxial stress-strain law and the constitutive model of the bamboo is based on a linear stress-strain law. The results of comparing the numerical and experimental results for the load-carrying capacity ratio are 0.96, 0.90, 0.77 for BC, BB13, and BB20, respectively. The crack pattern of the specimens shows that collapse is by flexural cracking starting from the mid-span. This is in accordance with previous laboratory results. In conclusion, the analyses using ATENA program and experimental methods show the appropriate results.