Novel strategies for enhancing lap spliced reinforced concrete beam behavior for mitigating failure risk

In addition to one control beam with continuous tensile bars and one control beam with splice, nine reinforced concrete (RC) beams with lap-spliced bars were constructed and strengthened. This was carried out in order to enhance the flexural performance of RC beams that had a short tension reinforcement splice. Spliced beams were strengthened by the use of external post-tensioned rebars (EPTR), near surface mounted (NSM), and strain hardening cementitious composites (SHCC) confinement. The variables in this study include performing a short splice, using one strengthening technique (SHCC, NSM, or EPTR), combining two strengthening techniques, changing the diameter of the NSM rod that is horizontally implanted at the beam soffit, and using a novel end anchorage in the NSM rod. The failure pattern, load-deflection curve, ultimate capacity, ultimate deflection, stiffness, and ductility of the strengthened spliced beams were all examined, and the results were given. The ultimate load of spliced beams increased by 45, 55, and 58%; the ultimate deflection increased by 45, 68, and 75%; and the ductility increased by 111, 120, and 159% as a result of the NSM, SHCC, and EPTR systems, respectively. Conducting SHCC alone produced an ultimate load of 55.2%, an ultimate deflection of 68%, and ductility of 120%; however, functioning both SHCC and EPTR systems produced an ultimate load of 137%, an ultimate deflection of 146%, and a ductility of 771%. Ultimate load, ultimate deflection, and ductility are all increased by 40-60%, 37-84%, and 41-57%, respectively, due to NSM strengthening at the spliced beam soffit.