冻融循环与持载对CFRP加固高强混凝土梁变形性能的影响

Influence of Freeze-thaw Cycles and Sustained Loads on Deformation Performance of High Strength Concrete Beam Strengthened with CFRP

通过四点弯曲试验,研究了冻融循环与持载对碳纤维增强复合材料(CFRP)加固高强钢筋混凝土梁变形性能的影响。分析了不同环境作用下试验梁的承载力、刚度及破坏形态变化规律。结果表明:在冻融循环单独作用下,试验梁的性能变化很小;冻融与持载耦合作用时,两者均对梁的性能造成不利影响,且随着冻融循环次数的增加,承受持载梁的CFRP-混凝土界面黏结性能有所下降;在冻融循环作用下,CFRP-混凝土界面存在应力时会增大界面的劣化程度,从而引起加固梁性能的下降。

The four-point bending test was conducted to investigate the influence of freeze-thaw cycles and sustained loads on the deformation performance of high strength concrete beams strengthened with carbon fiber reinforced polymer （CFRP）. The bearing capacity, stiffness and failure mode of the test beam under different environmental conditions were analyzed. The results show that the performance of test beam changes little under the action of freeze-thaw cycles. Both of the two factors have negative effects on the performance of beam under the coupling action of freeze-thaw and sustained load, and the bond behavior of CFRP-concrete interface of beam under sustained load decreases with the increase of freeze-thaw cycles. The stress of CFRP-concrete interface will increase the deterioration degree of the interface under freeze-thaw cycles, and the performance of strengthened beam will decrease.