纤维编织网增强混凝土加固钢筋混凝土梁受弯性能研究

Investigation on the flexural behavior of reinforced concrete beam strengthened with textile-reinforced concrete

从改善纤维编织网增强混凝土(TRC)加固层中纤维束和精细混凝土的界面粘结及新老混凝土的界面特性入手,研究TRC增强钢筋混凝土(RC)梁的弯曲性能。试验结果表明:纤维编织网的表面黏砂处理能更好地发挥其有效约束能力,从而充分发挥TRC增强层的限裂和增强作用;新老混凝土的界面植入U型抗剪销钉可以提高增强后RC梁的整体受力性能,而涂抹界面剂对其几乎没有影响。此外,精细混凝土中掺加聚丙烯纤维有助于提高构件的起裂荷载;在RC梁配筋率一定的情况下,提高TRC层中的配网率可以有效地延缓结构主裂缝的发展,减小裂缝的宽度和间距,明显地提高梁的屈服荷载和极限承载力。最后,基于RC结构的抗弯设计理论,模拟TRC增强RC梁的荷载与跨中位移曲线,计算值与试验结果吻合得较好,证明了计算方法的可行性。

From the point of improving the interfacial bond between the textile and the fine grained concrete in textile reinforced concrete（TRC） and the interfacial characteristics of old and new concrete,the flexural performance of reinforced concrete（RC） beams strengthened with TRC was studied.The experimental results show that sticking sands on the epoxy resin-impregnated textile can make its anti-crack ability better exerted and thus the crack-control and reinforcing function of TRC layer can be fully utilized,and embedding U-shaped pins into the old concrete contributes to improve the whole mechanical behavior of RC beams strengthened with TRC,but smearing interfacial agent on the surface of the old concrete has almost no effect on the beams.In addition,mixing polypropylene fiber into fine grained concrete is helpful to enhance the initial cracking load of the component,and when the ratio of steel reinforcement is constant,increasing the ratio of textile reinforcement in TRC can effectively delay the development of main cracks of the structure,and decrease the crack width and the crack spacing and significantly improve the yield load and ultimate bearing capacity of the beams.Finally,based on the bending design theory of RC elements,this paper simulates the curves of load vs.mid-span deflection of RC beams reinforced with TRC.Comparison between the calculated and the experimental results reveals satisfactory agreement and thus verifies that the calculation method is practicable.