基于准平面假定的外贴CFRP板加固宽缺口混凝土梁刚度研究

Research on the rigidity of wide gap concrete beams strengthened with externally bonded CFRP plates based on the quasi plane assumption

宽缺口混凝土梁是为研究CFRP板与混凝土界面特性而构造一种新型混凝土梁。为分析该新型梁的变形与刚度特性,对11根外贴CFRP板加固的各类混凝土梁进行静载试验,并对其变形刚度进行详细的测试和研究。基于FRP类材料加固混凝土梁应变协调的准平面假定并考量CFRP板的刚度贡献,对加固后宽缺口混凝土梁的刚度计算公式进行理论推导,并将理论公式计算结果与实测结果进行比对。研究结果表明:外贴CFRP混凝土梁的刚度有小幅度提高,CFRP板能延缓裂缝的发展,减小梁的变形。

The wide gap concrete beam is a new type of concrete beam to study the characteristics of CFRP and concrete interface.A total of 11 externally bonded CFRP plates were completed to reinforce each type of concrete beam static load test in order to analyze the deformation and stiffness characteristics of the new beam.And the deformation stiffness was measured and studied in detail.On the premise of fully considering the stiffness contribution of CFRP plates,the theoretical derivation of the calculation formula of the stiffness of the wide gap concrete beam was presented based on the quasi-plane assumption of strain coordination of reinforced concrete beams strengthened with FRP class materials.The calculation results of the theoretical formula were compared with the measured results.The results show that the stiffness of concrete beams reinforced with CFRP plates has a small increase.The CFRP plates can effectively delay the development of cracks and reduce the deformation of concrete beams.