Structure Repairs Using Carbon Fiber Composites

Abstract

This report examines the performance of reinforced concrete bridge deck slabs externally strengthened using carbon fiber reinforced polymer (CFRP) composite plates shop-manufactured by the pultrusion process. Eleven full-scale reinforced concrete bridge deck specimens were constructed with 3,640 psi and 3,840 psi concrete and were reinforced with number 5 steel reinforcing bars near the top and bottom surface. Five specimens were subjected to two loading cycles. In the first cycle, the specimens were loaded until significant cracks were developed and the tensile reinforcing steel yielded. The specimens were then strengthened with carbon FRP composite plates. The second loading cycle was applied until failure of the deck specimens occurred. Six specimens were strengthened before cracking and then loaded to failure. The average ultimate strength increased by 30% after rehabilitation or strengthening. This increase was attained after allowing the epoxy adhesive to cure at least 10 days.