预应力钢丝绳加固钢筋混凝土梁桥抗剪性能
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摘要
通过对24片RC梁的抗剪试验,系统研究了抗剪加固的机理以及原梁设计参数、带载水平、损伤度、钢丝绳布置方式对抗剪加固效果的影响。研究结果表明:预应力钢丝绳可有效延迟RC梁的斜截面开裂,限制斜裂缝的发展,提高极限抗剪承载能力;钢丝绳对抗剪承载力提高的作用机理与RC梁的腹筋作用相似;原梁的设计参数对抗剪加固效果具有较明显的影响;随着带载水平的提高,抗剪极限承载能力提高的程度逐渐降低;原梁损伤度对抗剪加固效果有一定的影响,原梁裂缝宽度小于0.2 mm时,注胶效果不理想,提高幅度较小,宽度大于0.2 mm后注胶效果改善,承载力有所提高,但当裂缝宽度大于0.5 mm后,加固效果处于稳定阶段;U型布束加固效果优于斜向布束;对于T梁,U型部束方案优于U型闭布束。
Twenty-four reinforced concrete beams were tested to shear failure. The mechanism of shear strengthening was investigated. The influence of the beam design parameters,Loading level of original beam,damage degree of original beam and arrangement of wire rope,on shear strength was investigated.The results show that ropes can effectively delay shear crack development,limit diagonal crack growth,and increase the ultimate shear capacity. The action mechanism of steel wire rope to increase shear capacity is similar to that of web reinforcement in reinforced concrete beams. The design parameters of the original beam have obvious influence on the effect of shear reinforcement;with the increase of loading level,the degree of improvement of shear ultimate bearing capacity gradually decreases;the damage degree of the original beam has some influence on the effect of shear reinforcement. When the crack of the original beam is less than 0.2 mm,the effect of glue injection is not ideal and the increase is small. When the width is more than 0.2 mm,the effect of glue injection is improved and the bearing capacity is improved. However,when the crack width is greater than 0.5 mm,the reinforcement effect is in a stable stage;the U ‐shaped beam is better than the oblique beam;and the U‐shaped beam is better than the U‐shaped closed beam.
Twenty-four reinforced concrete beams were tested to shear failure. The mechanism of shear strengthening was investigated. The influence of the beam design parameters,Loading level of original beam,damage degree of original beam and arrangement of wire rope,on shear strength was investigated.The results show that ropes can effectively delay shear crack development,limit diagonal crack growth,and increase the ultimate shear capacity. The action mechanism of steel wire rope to increase shear capacity is similar to that of web reinforcement in reinforced concrete beams. The design parameters of the original beam have obvious influence on the effect of shear reinforcement;with the increase of loading level,the degree of improvement of shear ultimate bearing capacity gradually decreases;the damage degree of the original beam has some influence on the effect of shear reinforcement. When the crack of the original beam is less than 0.2 mm,the effect of glue injection is not ideal and the increase is small. When the width is more than 0.2 mm,the effect of glue injection is improved and the bearing capacity is improved. However,when the crack width is greater than 0.5 mm,the reinforcement effect is in a stable stage;the U ‐shaped beam is better than the oblique beam;and the U‐shaped beam is better than the U‐shaped closed beam.
引文
[1]赵晋,张雪丽.CFRP板条加固钢筋混凝土梁的抗剪性能试验研究[J].混凝土,2007(11):8-11.Zhao Jin,Zhang Xue-li.Experimental study of shear characteristic of reinforced concrete beams strengthened with CFRP laminates[J]Concrete,2007(11):8-11.
[2]Khalifa A,Nanni A.Rehabilitation of rectangular simply supported RC beams with shear deficiencies using CFRP composites[J].Construction&Building Materials,2002,16(3):135-146.
[3]王兴国,周朝阳,曾宪桃,等.粘贴预应力CFRP板--混凝土梁抗剪加固试验研究[J].四川建筑科学研究,2005,31(5):46-49Wang Xing-guo,Zhou Zhao-yang,Zeng Xian-tao,et al.Experimental study on shear reinforcement of prestressed CFRP plate-concrete beam[J].Sichuan Building Science,2005,31(5):46-49.
[4]卜良桃,王月红.复合砂浆钢筋网加固RC简支梁抗剪性能的试验研究[J].华中科技大学学报:自然科学版,2006,23(4):35-38.Bu Liang-tao,Wang Yue-hong.Experimental study on RC beams strengthened with ferrocement mortar shear performance[J].Journal of Huazhong University of Science and Technology(Natural Science Edition),2006,23(4):35-38.
[5]聂建国,蔡奇,张天申,等.高强不锈钢绞线网-渗透性聚合砂浆抗剪加固的试验研究[J].建筑结构学报,2005,26(2):10-17.Nie Jian-guo,Cai Qi,Zhang Tian-shen,et al.Experimental study on shear behavior of RC beams strengthend with stainless steel wire mesh and permeability polymer mortar[J].Journal of Building Structures,2005,26(2):10-17.
[6]黄华,刘伯权,刘卫铎,等.高强钢绞线网-聚合物砂浆抗剪加固梁二次受力试验研究[J].工业建筑,2009,39(2):123-127.Huang Hua,Liu Bo-quan,Liu Wei-duo,et al.Experimental study of shear behavior of RC beams strengthened with stainless steel wire mesh and polymer mortar under secondary load[J].Industrial Construction,2009,39(2):123-127.
[7]Kim S Y.Tests of reinforced concrete beams strengthened with wire rope units[J].Engineering Structures,2007,29:2711-2722.
[8]崔长利.预应力钢丝绳加固RC混凝土梁桥抗剪性能试验[J].公路交通科技:应用技术版,2018,14(10):204-206.Cui Chang-li.Experimental study on shear performance of RC concrete beam bridge strengthened with prestressed steel wire rope[J].Journal of Highway and Transportation Technology(Application Technology Edition),2018,14(10):204-206.
[9]司建辉,赵恒,刘茂社.预应力绕丝加固RC梁抗剪性能试验研究[J].工程抗震与加固改造,2018,40(4):112-116.Si Jian-hui,Zhao Heng,Liu Mao-she.Experimental research on shear strengthening of reinforced concrete beams using prestressed wire-rope hoops[J].Earthquake Resistant Engineering and Retrofitting,2018,40(04):112-116.
[10]许心怡.预应力高强钢丝绳抗剪加固混凝土梁试验研究[D].南京:东南大学交通学院,2017.Xu Xin-yi.Experimental study on shear-reinforced concrete beams with prestressed high-strength steel wire rope[D].Nanjing:School of Transportation,Southeast University,2017.
[11]于天来,黄巍.基于遗传算法的体外预应力钢丝绳加固RC梁抗剪承载力计算方法[J].公路交通科技,2015,32(10):82-90,96.Yu Tian-lai,Huang Wei.Calculation method of shear capacity of RC beams strengthened with external prestressed steel wire ropes based on genetic algorithm[J].Journal of Highway and Transportation Research and Development,2015,32(10):82-90,96.
[12]郭子雄,杨军民,叶勇,等.闭合预应力钢丝绳加固RC梁抗剪性能试验研究[J].中南大学学报:自然科版,2015,46(7):2590-2596.Guo Zi-xiong,Yang Jun-min,Ye Yong,et al.Experimental study on shear resistance of RC beams strengthened with closed prestressed steel wire ropes[J].Journal of Central South University:Science and Technology,2015,46(7):2590-2596.
[2]Khalifa A,Nanni A.Rehabilitation of rectangular simply supported RC beams with shear deficiencies using CFRP composites[J].Construction&Building Materials,2002,16(3):135-146.
[3]王兴国,周朝阳,曾宪桃,等.粘贴预应力CFRP板--混凝土梁抗剪加固试验研究[J].四川建筑科学研究,2005,31(5):46-49Wang Xing-guo,Zhou Zhao-yang,Zeng Xian-tao,et al.Experimental study on shear reinforcement of prestressed CFRP plate-concrete beam[J].Sichuan Building Science,2005,31(5):46-49.
[4]卜良桃,王月红.复合砂浆钢筋网加固RC简支梁抗剪性能的试验研究[J].华中科技大学学报:自然科学版,2006,23(4):35-38.Bu Liang-tao,Wang Yue-hong.Experimental study on RC beams strengthened with ferrocement mortar shear performance[J].Journal of Huazhong University of Science and Technology(Natural Science Edition),2006,23(4):35-38.
[5]聂建国,蔡奇,张天申,等.高强不锈钢绞线网-渗透性聚合砂浆抗剪加固的试验研究[J].建筑结构学报,2005,26(2):10-17.Nie Jian-guo,Cai Qi,Zhang Tian-shen,et al.Experimental study on shear behavior of RC beams strengthend with stainless steel wire mesh and permeability polymer mortar[J].Journal of Building Structures,2005,26(2):10-17.
[6]黄华,刘伯权,刘卫铎,等.高强钢绞线网-聚合物砂浆抗剪加固梁二次受力试验研究[J].工业建筑,2009,39(2):123-127.Huang Hua,Liu Bo-quan,Liu Wei-duo,et al.Experimental study of shear behavior of RC beams strengthened with stainless steel wire mesh and polymer mortar under secondary load[J].Industrial Construction,2009,39(2):123-127.
[7]Kim S Y.Tests of reinforced concrete beams strengthened with wire rope units[J].Engineering Structures,2007,29:2711-2722.
[8]崔长利.预应力钢丝绳加固RC混凝土梁桥抗剪性能试验[J].公路交通科技:应用技术版,2018,14(10):204-206.Cui Chang-li.Experimental study on shear performance of RC concrete beam bridge strengthened with prestressed steel wire rope[J].Journal of Highway and Transportation Technology(Application Technology Edition),2018,14(10):204-206.
[9]司建辉,赵恒,刘茂社.预应力绕丝加固RC梁抗剪性能试验研究[J].工程抗震与加固改造,2018,40(4):112-116.Si Jian-hui,Zhao Heng,Liu Mao-she.Experimental research on shear strengthening of reinforced concrete beams using prestressed wire-rope hoops[J].Earthquake Resistant Engineering and Retrofitting,2018,40(04):112-116.
[10]许心怡.预应力高强钢丝绳抗剪加固混凝土梁试验研究[D].南京:东南大学交通学院,2017.Xu Xin-yi.Experimental study on shear-reinforced concrete beams with prestressed high-strength steel wire rope[D].Nanjing:School of Transportation,Southeast University,2017.
[11]于天来,黄巍.基于遗传算法的体外预应力钢丝绳加固RC梁抗剪承载力计算方法[J].公路交通科技,2015,32(10):82-90,96.Yu Tian-lai,Huang Wei.Calculation method of shear capacity of RC beams strengthened with external prestressed steel wire ropes based on genetic algorithm[J].Journal of Highway and Transportation Research and Development,2015,32(10):82-90,96.
[12]郭子雄,杨军民,叶勇,等.闭合预应力钢丝绳加固RC梁抗剪性能试验研究[J].中南大学学报:自然科版,2015,46(7):2590-2596.Guo Zi-xiong,Yang Jun-min,Ye Yong,et al.Experimental study on shear resistance of RC beams strengthened with closed prestressed steel wire ropes[J].Journal of Central South University:Science and Technology,2015,46(7):2590-2596.