Experimental and numerical study on concrete beams reinforced with Basalt FRP bars under static and impact loads

The application of fiber-reinforced-polymer (FRP) bars to reinforce concrete structures could mitigate the corrosion-induced damage of steel reinforcements. No study has been reported in open literature on flexure-critical or shear-critical concrete beams reinforced with Basalt FRP (BFRP) bars under impact loads. In this study, six BFRP bars reinforced concrete beams were tested under quasi-static and impact loads. The test results showed the flexure-critical beams experienced the failure mode changing from flexure-governed under quasi-static loads to flexure-shear combined under impact loads. The shear-critical beams still failed in diagonal shear under impact loads, but experienced severer concrete spalling and more critical diagonal cracks on both sides of the beams. The impact performance of concrete beams with higher strength concrete may not be necessarily superior to that of beams with normal strength concrete due to the increased brittleness. Moreover, a numerical model of the tested beams under impact loads was developed and calibrated in LS-DYNA. Numerical results showed increasing tension reinforcement ratio could change the failure mode from flexure-governed to flexure-shear combined along with the reduced maximum midspan deflection. The BFRP bars reinforced concrete beams had comparable impact resistant performance with the conventional steel reinforced concrete beam