Carbon Fiber-Reinforced Polymer for Continuity in Existing Reinforced-Concrete Buildings Vulnerable to Collapse

Carbon fiber-reinforced polymer (CFRP) can provide continuity in reinforced concrete beams and thereby reduce the likelihood of progressive collapse if a supporting column were lost due to extreme loading (blast or impact). Seven half-scale specimens representing two spans of a reinforced concrete (RC) frame with a center supporting column removed were tested. The capacity of vulnerable RC building beams with discontinuous reinforcing steel were evaluated and compared with beams using CFRP. to provide continuity, and with beams designed with continuous reinforcing steel. It was found that CFRP is capable of providing sufficient continuity to withstand the loss of a supporting column through either catenary (or cable) action, which reduces material usage, or flexural action, which reduces deflections. Furthermore, beams with continuous reinforcement may not be able to withstand the loss of a center-supporting column due to limited rotational ductility of the beam.