Capacity prediction and crack width calculation of RC beam strengthened with textile and modified concrete

The capacities and crack resistance of reinforced concrete (RC) members are the main factors affect the safety and serviceability of RC structures. To investigate the mechanical properties and crack resistance of RC beams strengthened with textile and modified concrete, theoretical analysis and experimental study have been carried out. Firstly, the theoretical calculation methods of the load-deflection curve and flexural capacity of RC beam strengthened with textile and modified concrete are proposed through the force analysis of cross-section. Then, the shear capacity calculation method based on the truss-arch model and the crack width calculation method based on the bond-slip theory is proposed through the overall force analysis. Finally, twelve beams were designed and manufactured for four-point loading test. The test variables include the carbon textile, anchorage measures, modified concrete types and modified concrete pouring thickness. The capacity test results indicate that the specimens strengthened with textile and modified concrete have excellent mechanical properties and crack control ability. Anchoring the carbon textile can effectively avoid debonding failure. The modified concrete pouring thickness has a minor effect on the flexural capacity of the specimen if it exceeds a certain value. The accuracy of theoretical calculation methods proposed by the theoretical analysis in this study is proved according to the experimental results and numerical analysis results. •Adopted modified concrete and textile to improve the performance of RC beams.•Established calculation methods of the flexural capacity and shear capacity.•Proposed the crack width calculation method based on the bond-slip theory.•Carried out the tests of RC beams strengthened with modified concrete and textile.•Verified the accuracy and applicability of the proposed calculation methods.