BEHAVIOR OF REPAIRED COMPOSITE MODIFIED REACTIVE POWDER CONCRETE I-SECTION BEAMS WITH OPENING UNDER PURE TORQUE

الملخص

In this paper, an experimental study has been conducted to investigate the behavior of composite concrete beams damaged and cracked under pure torsion , and then repaired by external strengthening with high strength CFRP(Carbon Fiber Reinforced Polymer) laminates bonded with epoxy after doing all the appropriate preparations for the concrete adhesion substrate. Four composite modify reactive powder concrete (MRPC) I- beams,1300mm length,100mm web width and 320mm height, with different type of section (Solid & with opening) were tested to obtain the effect of amount of CFRP laminate on beams cracking torque behavior, angle of twist and failure modes. The results obtained from the adopted repairing technique showed a significant effect of external high strength CFRP laminates on effectively restore of section solid the range of 84% to 85.33% of crack torsional strength effectively restore. As well as the results show that effectively restore of section opening by 80%- 82.22% of crack torsional strength.