https://www.quakewrap.com/frp%20papers/Progress-On-Understanding-Debonding-Problems-In-Reinforced-Concrete-And-Steel-Members-Strengthened-Using-FRP-Composites.pdf

Progress on understanding debonding problems in reinforced concrete and steel members strengthened using FRP composites

Experimental performances of RC beams strengthened with FRP materials

Behavior of reinforced concrete beams strengthened with externally bonded hybrid fiber reinforced polymer systems

Fiber-reinforced polymer composites in strengthening reinforced concrete structures: A critical review

This paper presents both experimental and analytical investigations undertaken to evaluate bond characteristics of near-sutfacemounted (NSM) carbon fiber-reinforced polymer (CFRP) bars. A total of eight concrete beams. strengthened with NSM CFRP bars, were tested under monotonic static loading. Different embedment lengths are studied to determine the development length of the fiber-reinforced polymer (FRP) reinforcement. The performance of two different adhesives used to bond the bars to the surrounding concrete is examined. A general methodology to evaluate the development length of NSM FRP bars of different configurations and types of fibers is presented. A quantitative criterion governing debonding failure is established. The proposed bond model assumes linear elastic behavior jar the concrete, adhesive, and the NSM FRP bars, following the same philosophy oj the ACI provisions for bond analysis and design. The proposed analytical model is validated by comparing the predicted values with test results as well as to nonlinear finite element modelling. The influence of key parameters, including the thickness of the adhesive cover, groove width, groove spacing, and inte171ai steel reinforcement configuration, are discussed.

Bond Mechanism of Near-Surface-MountedFiber-Reinforced Polymer Bars for FlexuralStrengthening of Concrete Structures

Poststrengthening and retrofitting is a growing reality, as existing structures are required to meet the demands of modern society. Apart from the need to increase load capacity, upgrading of a structure may be necessitated through deterioration of the structure by corrosion or accidental damage, a change in the structural system, or to rectify initial design and construction faults. A commonly observed mode of failure for beams strengthened using carbon-fiber-reinforced polymer composite material plates is one due to the plate peeling off prematurely and unpredictably at relatively low magnitudes of applied loading. End plate anchorages and long unanchored plate lengths, which can add significantly to the overall cost of a strengthening solution, overcome this problem. This paper presents the results of flexural tests on ten reinforced concrete beams strengthened with different plate configurations. A strain compatibility and force equilibrium method of analysis, coupled with an empirical rule derived from the test data, is demonstrated to be effective in predicting the ultimate response of simply supported beams in bending with and without end plate anchorages and irrespective of plate length.

Oliver Kelly

Papers

Ultimate Response of RC Beams Strengthened with CFRP Plates