Meso-scale modelling of size effect on shear behavior of Basalt fiber reinforced concrete deep beams

Abstract

The work aims to examine the size effect on shear failure of deep concrete beams with Basalt Fiber Reinforced Polymer (BFRP) bars. A mesoscale numerical model for the deep concrete beam with BFRP bars was built to explicitly model the shear failure, considering concrete heterogeneity and concrete/bars interaction. The mesoscale simulation approach was firstly verified against the available test observations. It was then utilized to study the shear failure of geometrical-similar concrete deep beams having different structural sizes with BFRP bars and steel bars. The influence of beam depth, stirrup ratio and reinforcement type (i.e., steel bars and BFRP bars) on the shear failure and the corresponding size effect of concrete deep beams was explored. The simulation results indicate that: 1) the failure modes of concrete deep beams with BFRP bars and steel bars are basically similar, and they all exhibit noticeable size effect; 2) stirrups (i.e., steel bars and BFRP bars) can hinder the development of diagonal cracks within concrete, and thus weaken the size effect in shear strength; 3) the shear failure in beams with BFRP bars presents more substantial size effect than that of beams with steel bars; 4) the calculation models of shear capacity in the international codes do not apply to concrete deep beams with BFRP bars. Moreover, it is found that the size effect law developed previously can also be suitable for the shear failure of concrete deep beams with BFRP bars.