Evaluation of Flexural Behaviour of Post-tensioned RC Beams Strengthened Using CFRP Laminates with NSM Technique

Abstract

A large number of investigations are available on the flexural evaluation of strengthened reinforced concrete beams using several structural materials and techniques. However, very limited information is available on the performance of strengthened post-tensioned (PT) beams. Carbon fibre-reinforced polymer (CFRP) strengthening material with near-surface mounted (NSM) technique has evolved as the promising material and method due to their superior performance. This paper focused on the structural strength and deformation behaviour of PT RC beams, and flexural strength with NSM technique using CFRP laminate. Four PT beams were tested in the present experimental and analytical investigation, in which one beam was regarded as control beam, and the remaining three beams with increase over the area of CFRP laminates by a factor of 1, 2 and 3, respectively. The aim of this experiment and analytical work was to demonstrate the strength and deformation behaviour of the PT beams tested under static condition over four points bending. The results revealed that the cracking and ultimate load-carrying capacity of strengthened PT beams increased linearly compared with control beams. Increase in ductility index with reduction in the deflection at the level of ultimate load was recorded for the strengthened PT beams.