EXPERIMENTAL INVESTIGATION ON THE COMPOSITE BEAMS STRENGTHENED WITH CFRP SHEETS

Abstract

Abstract: This paper presents the works of investigating the structural behaviors of composite beams before and after being strengthened with CFRP strips at the tension soffit. Seven samples were examined by the four-point bending loading tests. Among the seven samples, one was un-strengthened and the remaining six were strengthened by bonding CFRP strips of different numbers, width and length, respectively. All samples were tested beyond their ultimate failure. By recording the load-deflection data for the entire history, the first crack load, the CFRP debonding load or concrete longitudinal failure loads were identified. Meanwhile, the typical failure modes are documented and their respective mechanisms are analyzed. Comparing the strengthened beams with the reference one, the ultimate strength of composite beams strengthened by CFRP strips is significantly increased, and the most effective one is the beam strengthened by the CFRP strip of 60% beam length. In addition, a truss model is proposed to calculate the internal forces in the concrete, steel beam and FRP strips, from which the prediction for the failure load can be performed.

Key words: FRP composites, concrete-steel composite beam, four-points bending test, failure modes, loading capacity, truss model

CLC Number:

TB332

LU Yi-hui, YANG Jian, WANG Fei-liang, LIU Qing-feng. EXPERIMENTAL INVESTIGATION ON THE COMPOSITE BEAMS STRENGTHENED WITH CFRP SHEETS[J]. Fiber Reinforced Plastics/Composites, 2019, 0(2): 13-19.

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