Behavior of plain concrete beams with DSSF strengthened in flexure with anchored CFRP sheets—Effects of DSSF content on the bonding length of CFRP sheets

In this study, the behavior of the anchored carbon fiber reinforced polymer (CFRP) plain concrete beams with various dosages of macro discontinuous structural synthetic fiber (DSSF) were investigated. Seventy two plain concrete beams were casted and tested. The investigated parameters in this study are the dosages of DSSF, length of CFRP sheets, and with and without CFRP anchorage sheets. Therefore, the feasibility of using macro synthetic fibers and anchored CFRP sheets for enhancing the behavior of plain concrete beams is of enormous interest. The behavior characteristic of each tested beam was evaluated in terms of failure mode, load versus mid-span deflection curve, ultimate load capacity, ultimate deflection, stiffness, energy absorption, performance factor, displacement ductility index, energy absorption ductility index, and CFRP and concrete strain. The tested results reveal a considerable enhancement on the majority of the investigated parameters and show the efficiency of using a combination macro synthetic fibers and anchored CFRP sheets in terms of the behavior characteristic of tested beams. The enhancements were recognized primarily to the efficiency of the used anchored CFRP and macro synthetic fibers in providing external and internal, respectively, cracks arresting mechanism after cracking and even after reaching the ultimate load capacity.