Proposed Formulation for Predicting Deflections of CFRP-Rc Beams

Abstract

This research describes an attempt to conduct analytical investigations on the deflection behavior of Carbon Fiber Reinforced Polymer (CFRP)-reinforced concrete beams. The primary objective of this study is to undertake a comprehensive review of formulation studies grounded in deflection equations. To accomplish this objective, a total of eleven test data points from three groups of researchers were acquired. Then, these data are compared against the deflection predictions from four deflection equations, namely, ACI 440.1R-06, ACI 440.1R-15, Bischoff and Gross, and ISIS Canada. An empirically derived model was proposed to predict the effective moment of inertia for reinforced concrete (RC) beams reinforced with CFRP, based on Branson's equation. Furthermore, to enhance the prediction of the moment-deflection relationship up to the ultimate strength, a nonlinear parameter (k) has been introduced in previous research for FRPs. These parameters were added to the formulation and aimed to mitigate the impact of the cracked moment of inertia on the reinforced concrete member. The accuracy of the novel formulation for analyzing deflections in CFRPreinforced concrete beams was statistically evaluated. In a comparative study employing various design codes, the proposed model exhibited greater agreement with experimental test results. Ultimately, the proposed model demonstrated enhanced accuracy and emerged as a familiar approach for structural engineers to forecast and evaluate the deflection behavior of RC beams reinforced with CFRP.