AN EXPERIMENTAL INVESTIGATION ON SHEAR ENHANCEMENT OF PARTIALLY CRACKED RC BEAMS WITH BI-DIRECTIONAL CARBON FABRICS

摘要

This paper exemplifies the shear enhancement of partially cracked reinforced concrete rectangular beams with Bi-Directional Carbon Fibre Reinforced Polymer (CFRP) fabrics. Nine rectangular beams were constructed and tested under simply supported condition. The beams were partially cracked prior to the bonding of carbon FRP fabric strips. The CFRP fabric strips were bonded to the web and soffit of beams to enhance the shear capacity. The beams were tested with different (ⅰ) tensile reinforcement ratios (ⅱ) shear span to effective depth ratios and (ⅲ) spacing and orientation of CFRP strips to examine the ultimate shear capacity and modes of failure. These beams were cast in the absence of internal shear reinforcement. The contribution of externally bonded carbon fibre strips to the shear capacity was investigated. The repaired or strengthened beams with Bi-Directional CFRP reinforcement, achieved increases in ultimate shear capacity of 35% to 107%. The comparison of experimental results shows good agreement with the theoretical results.