Investigation on enhancing flexural p erformance of CFRP strengthened concrete beams

Abstract

Strengthening of reinforced concrete structures is inevitable to preserve structural integrity and protracted service life due to the effects of numerous elements contained within the natural or artificial environment surrounding it. Carbon Fibre Reinforced Polymer (CFRP) composites have been progressively more utilized for decades as a strengthening material due to its outstanding characteristics such as high strength to weight ratio, reduced weight, excellent resistance to corrosion and environmental degradation and ease of handling during construction which have distinguished it well apart from the other strengthening techniques. However, the ultimate load capacity of CFRP strengthened concrete composites is comparatively lower than CFRP material due to premature debonding which reported as the most frequently observed failure mode in CFRP/concrete composites. In the current study, alternative bonding techniques were investigated to achieve enhanced bond performance by delaying premature debonding failure. A total of 18 CFRP strengthened concrete beams with different bonding techniques were tested using three point bending test. The test results show convincing evidence on strength enhancements. Moreover, a numerical model was also developed to inspect the performance of existing CFRP anchors. Finally, a parametric study was carried out and a new type of anchor; “Tri-leg anchor” is introduced. This paper summarizes the overview of the test programme, finite element modeling, results and analysis.