【摘要】 为了研究预应力CFRP布加固钢筋混凝土梁的疲劳性能,进行了4根CFRP布加固的钢筋混凝土和1根对比梁的试验研究.试验中考虑的变量为碳纤维应力强度比、疲劳荷载幅和CFRP布粘贴层数.试验梁采用双点对称等幅、等频率加载.试验结果表明:未加固的对比梁受疲劳荷载作用时,裂缝少而宽;非预应力CFRP布加固梁,裂缝多而密,裂缝高度较低,宽度较小.预应力CFRP布加固梁,裂缝总数量更多,高度更低,宽度更小.由于碳纤维布参与工作,限制了试验梁在疲劳加载时裂缝的开展,从而有效地提高了加固梁的疲劳寿命,改善了梁的正常使用性能.CFRP布施加预应力后加固效果更为明显.更多还原

【Abstract】 Four RC(reinforced concrete) beams strengthened with non-prestressed/prestressed CFRP(carbon fiber reinforced polymer) sheets and one contrast beam were tested to investigate the fatigue behavior.The prestressing levels of CFRP sheet,the amount of prestressed CFRP sheets,and the amplitude of fatigue loads were taken into consideration.The symmetrical two-point loads with constant amplitude and frequency were applied on all test beams.The test results show that the cracks of contrast beam are fewer and wider under fatigue loads.The cracks of the beam strengthened with non-prestressed CFRP sheets are more and denser with lower height and narrower width than the former.However in beams with prestressed CFRP sheets the amount of cracks is even more,the value of height and width become even smaller.The development of cracks are hindered and the stress amplitude of the tensioned bar is decreased and the fatigue life is obviously increased as compared to normal strengthening method.When RC beams are strengthened with prestressed CFRP sheets,the effect is more obvious.更多还原