疲劳荷载下纤维编织网增强混凝土加固RC梁的弯曲性能

Experimental research on flexural performance of RC beams strengthened with TRC under fatigue load

为了研究纤维编织网增强混凝土(TRC)加固方式、配网率、梁的损伤程度对TRC加固RC梁疲劳性能的影响,对7根梁进行了弯曲疲劳试验。其中,1根梁不加固、3根梁采用三面加固(U型加固)、3根梁采用单面加固。试验结果表明:TRC加固梁在疲劳荷载作用下与其在静载作用下有着不同的破坏形态。加固梁的疲劳寿命与配网率的大小有关,当配网率较低时,加固梁的疲劳寿命与未加固梁的几乎相当;当配网率大于某一值时,加固梁的疲劳寿命随着配网率的增大而提高。同样配网率下,单面加固方式对疲劳寿命的提高、纯弯段弯曲裂缝的控制优于U型加固,而U型加固对斜裂缝的控制优于单面加固。TRC对损伤梁有较好的加固效果,损伤程度的大小会影响梁加固后的疲劳寿命。

In order to study the influences of reinforcing way, reinforcement rate and damage on the fatigue performance of reinforced concrete beams strengthened with textile-reinforced concrete （TRC）, 7 beams were made and tested for flexural fatigue behavior,including one without strengthened,three reinforced with three sides,another three reinforced with one side. The results show that failure modes of RC beams reinforced with TRC under fatigue load are different from those under static load. The fatigue life of reinforcing beams is related to the ratio of textile reinforcement. The fatigue life of beams with TRC is almost the same with unreinforced one when the ratio of textile reinforcement is low;while it would increase with increasing ratio of textile reinforcement when the ratio of textile reinforcement exceeds a certain value. Furthermore,the fatigue life and flexural crack of one side reinforced beam performs better than the U-shaped reinforced;however, the control of inclined crack of U-shaped reinforcement is better than the former. Using TRC for reinforcing has good effect on damaged beams,and the degree of injury of the damaged beams will affect the fatigue life of the reinforced specimens.