Flexural Stiffness And Crack Widths Of Rectanglar Reinforced Concrete Beams Strengthened With Externally Bonded CFRP Sheets

This study investigates the flexural stiffness and crack widths of RC beams strengthened with externally bonded CFRP sheets. 14 same rectangle section RC beams were constructed, with 2 contrast beams and 12 CFRP strengthened beams. Three parameters are considered in experiments, which are reinforced ratio, strengthening ratio and pre-crack condition. All these strengthened or unstrengthened RC beams are statically loaded under four point bending. Structural testing of the beams shows that CFRP strengthening can increase flexural stiffness and reduce crack widths.Theorial analysis and experimental analysis are combined to investigate the flexural stiffness and crack widths of RC beams strengthened with externally bonded CFRP sheets. Firstly, two models for the prediction of crack width and flexural stiffness in a repaired specimen are proposed based on the classical theory of reinforced concrete beams. Then undetermined coefficients in those models are determined by the statistic analysis of experiment results. Those models are validated by experiments.Only the short-term flexural stiffness and crack widths are referred in this article.