Dynamic size effect in shear behavior of BFRP reinforced concrete beams without stirrups with different shear-span ratios

Abstract

The purpose of the research is to investigate the influence of strain rate and shear-span ratio on the shear strength and size effect of Basalt Fiber Reinforced Plastics (BFRP) reinforced concrete beams without stirrups, and then to establish the theoretical formula quantitatively describing the size effect. A three-dimensional meso-scale numerical model of BFRP reinforced concrete beams was established to simulate the shear failure of geometrically similar specimens. Finally, a new size effect law was established to predict the shear capacity of BFRP reinforced concrete beams with different structural sizes under dynamic loadings. The results indicate that: 1) the shear capacity of BFRP reinforced concrete beams increases with the increase of strain rate, while the size effect in shear failure of BFRP reinforced concrete beams is weakened simultaneously; 2) the increase of shear-span ratio weakens the strain-rate effect, but has an ignorable influence on the size effect; 3) the new size effect law can be used to quantitatively describe the effect of strain rate on size effect and is in good agreement with the existing experiments.