粘贴碳纤维布加固钢筋混凝土预裂梁试验研究

EXPERIMENTAL STUDY ON PRE-CRACKED RC BEAMS STRENGTHENED WITH CFRP

结合在役钢筋混凝土桥梁的损伤特点,对粘贴碳纤维布加固混凝土预裂梁在正常使用荷载水平下的钢筋应变及挠度变化规律,进行了详细的室内试验。通过比较每根试验梁加固前后的挠度及钢筋应变的变化规律,研究了持荷水平、预裂程度及配筋率对加固效果的影响程度,避免了不同试件因材料力学性能差异而导致的试验误差,模拟了实际公路桥梁加固前后的荷载试验过程,增加了室内试验数据与野外检测结果的可比性。室内试验结果表明,粘贴碳纤维布可大大提高预裂梁的刚度,有效降低钢筋应力水平,与桥梁现场静载试验结果是一致的。该研究为碳纤维布加固技术在桥梁加固维修中的应用提供了可靠的依据,具有较强的实用性。

On the basis of the destructive characteristics of aging RC beam bridges, experiments are conducted to examine the behavior of pre-cracked RC beams strengthened with CFRP under working load conditions. In particular, for one of the strengthened RC beams, data are collected before and after reinforcement, including the deflections and strains in steels, so as to avoid the experimental errors in different mechanical properties of the material used in beams. The influence of beams with different pre-cracking loads on the strength and stiffness provided by the bonded laminates is assessed. The experiment results show that strengthening preracked beam with CFRP can not only enhance its stiffness, but also decrease cracks on the surface of beams and reduce the tensile strain in steel. The experimental results are consistent with those collected from field bridges.