Effect of anchoring schemes for beams aged by accelerated corrosion and strengthened with carbon fibre-reinforced polymer

Abstract

The deterioration of concrete structures, and particularly highway bridges, has motivated the use of fibre-reinforced polymer (FRP) composites for retrofitting damaged components, typically using externally bonded carbon fibre-reinforced polymer (CFRP) fabrics or laminates. The application of this technology in practice has been highly successful, but there are concerns about the long-term performance of this technology. This article is part of a comprehensive rehabilitation program with CFRP of hundreds of concrete T-beam bridges for the Pennsylvania Department of Transportation. The focus of this article was to evaluate the effect of different FRP anchoring schemes (ASs) on the behaviour of concrete beams damaged by accelerated corrosion, reinforced for flexure with CFRP fabric and tested to failure. The experimental program consisted of testing large-scale beams [15.2 × 20.3 × 198.1 cm (6 × 8 × 78 inch)], damaged by the effects of rebar corrosion caused by induced electric current. After repairing the concrete substrate, and subsequent bonding of the CFRP flexural reinforcement and shear anchors, the beams were subjected to fatigue loading, and then tested to failure under four-point bending. This research is expected to contribute to guidelines for concrete patch-repair of CFRP-retrofitted concrete bridge girders, to assure better long-term performance under service loads and environmental effects.