Experimental investigation on torsional behaviour of carbon fiber reinforced polymer strengthened concrete beams curved in horizontal plane

Experimentally investigated the torsional resistance of externally bonded, Carbon Fiber Reinforced Polymer(CFRP) strengthened concrete beams curved in the horizontal plane. Twelve beams with radius of curvature 2000 mm and 4000 mm were tested for different CFRP strengthening schemes which include 90°("U" wrap) and 45°(spiral) wrappings. Two beams from each radius of curvature were used as control beams. Beams with 4000 mm radius of curvature have shown percentage increases of 34.21% and 26% in torsional capacity for the 90° and 45° wrappings respectively. Percentage increases of 33.03% and 34% were observed for beams with 2000 mm radius of curvature for U and spiral wrapping schemes respectively. The failure modes observed included torsion induced tensile failure of concrete and CFRP debonding