重复荷载作用后钢筋与自密实混凝土黏结应力-滑移关系研究
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摘要
以自密实混凝土强度、新拌混凝土工作性能和粉煤灰掺量为变量,制作了3个系列共36个钢筋与自密实混凝土黏结试件和1个系列共4个钢筋与普通混凝土黏结试件,进行了重复荷载作用后钢筋与自密实混凝土的黏结应力-滑移关系研究。采用电液伺服加载装置进行重复加载及黏结拉拔试验,探讨了重复荷载作用后钢筋与自密实混凝土的黏结应力-滑移关系的特点,重点分析了各因素对各阶段黏结刚度及各特征点如残留滑移、劈裂点、残余点等的影响。试验结果表明:重复荷载作用后试件拉拔试验的破坏形态分为拔出破坏、钢筋拉断和劈裂破坏,对于拔出破坏的试件其黏结应力-滑移曲线包含滑移段、劈裂段、下降段、残余段等,而对于其余试件则只包含滑移段和劈裂段;自密实混凝土强度对各阶段黏结刚度和特征点的黏结应力、滑移的影响较大,与单调拔出结果相比,自密实混凝土强度越高,滑移段的刚度比越大、下降段的刚度比越小;粉煤灰掺量和扩展度大于600 mm时对各阶段黏结刚度和各特征点参数的影响相对较小。在此基础上,根据各因素的影响程度并考虑公式运用的方便性,回归得到重复荷载作用后钢筋与自密实混凝土黏结-滑移本构关系式。
By considering the parameters,such as strength of self-compacting concrete,workability of fresh concrete and content of fly ash,three series with 36 self-compacting concrete specimens in total and one series with four normal concrete specimens were tested to investigate the bond stress-slip relationship between reinforcement and selfcompacting concrete after repeated loading. An electro hydraulic servo device was adopted for the specimens' loading and reloading as well as the pulling-out tests. According to the test results,the features of bond stress-slip relationship between reinforcement and self-compacting concrete after repeated loading,especially the influences of affecting factors such as residual slip,splitting point and residual point on the bond stiffness in each slip stage were studied. The results show that the failure modes of the specimens' pulling-out test are divided into pulling-out failure,reinforcement tensile failure,and splitting failure after repeated loading. For the pulling-out failure's specimens,their bond stressslip curves between reinforcement and self-compacting concrete include sliding stage,splitting stage,descending stage and residual stage. While for other specimens,only the sliding stage and splitting stage are included. The selfcompacting concrete strength has greater influence on the bond stiffness,bond stress and slip of feature points at each stage. Compared with monotonic pulling-out results,the higher strength of self-compacting concrete is,the greater the stiffness ratio of the sliding stage is and the smaller the stiffness ratio of the descending stage is. The fly ash admixtures and more than 600 mm slump flow have a little effect on the bond stiffness,bond stress and slip of the feature points at each stage. Then, a regression equation was proposed to predict the bond stress-slip relationship between reinforcement and self-compacting concrete,by considering analyzed influence factors,as well as convenience of calculation.
By considering the parameters,such as strength of self-compacting concrete,workability of fresh concrete and content of fly ash,three series with 36 self-compacting concrete specimens in total and one series with four normal concrete specimens were tested to investigate the bond stress-slip relationship between reinforcement and selfcompacting concrete after repeated loading. An electro hydraulic servo device was adopted for the specimens' loading and reloading as well as the pulling-out tests. According to the test results,the features of bond stress-slip relationship between reinforcement and self-compacting concrete after repeated loading,especially the influences of affecting factors such as residual slip,splitting point and residual point on the bond stiffness in each slip stage were studied. The results show that the failure modes of the specimens' pulling-out test are divided into pulling-out failure,reinforcement tensile failure,and splitting failure after repeated loading. For the pulling-out failure's specimens,their bond stressslip curves between reinforcement and self-compacting concrete include sliding stage,splitting stage,descending stage and residual stage. While for other specimens,only the sliding stage and splitting stage are included. The selfcompacting concrete strength has greater influence on the bond stiffness,bond stress and slip of feature points at each stage. Compared with monotonic pulling-out results,the higher strength of self-compacting concrete is,the greater the stiffness ratio of the sliding stage is and the smaller the stiffness ratio of the descending stage is. The fly ash admixtures and more than 600 mm slump flow have a little effect on the bond stiffness,bond stress and slip of the feature points at each stage. Then, a regression equation was proposed to predict the bond stress-slip relationship between reinforcement and self-compacting concrete,by considering analyzed influence factors,as well as convenience of calculation.
引文
[1]郑建岚,庄金平.自密实混凝土与钢筋的粘结性能试验研究[J].工程力学,2013,30(2):112-117.(ZHENG Jianlan,ZHUANG Jinping.Experiment research on bond properties between self-compacting concrete and reinforcement[J].Engineering Mechanics,2013,30(2):112-117.(in Chinese))
[2]DE ALMEIDA FILHO F M,EL DEBS M K,EL DEBSA L H C.Bond-slip behavior of self-compacting concrete and vibrated concrete using pull-out and beam tests[J].Materials and Structures,2008,41(6):1073-1089.
[3]DESNERCK Pieter,DE SCHUTTER Geert,TAERWELuc.Bond behaviour of reinforcing bars in selfcompacting concrete:experimental determination by using beam tests[J].Materials and Structures,2010,43(Suppl.1):53-62.
[4]KORTE Sara,BOEL Veerle,DE CORTE Wouter,DESCHUTTER Geert.Behaviour of fatigue loaded selfcompacting concrete compared to vibrated concrete[J].Structural Concrete,2014,15(4):575-589.
[5]KORTE Sara,BOEL Veerle,DE CORTE Wouter,DESCHUTTER Geert.Static and fatigue fracture mechanics properties of self-compacting concrete using three-point bending tests and wedge-splitting tests[J].Construction and Building Materials,2014,57(1):1-8.
[6]庄金平,郑建岚.自密实混凝土与钢筋局部黏结性能试验研究[J].建筑结构学报,2013,34(6):143-152.(ZHUANG Jinping,ZHENG Jianlan.Experiment research on local bond performance between reinforcement and self-compacting concrete[J].Journal of Building Structures,2013,34(6):143-152.(in Chinese))
[7]混凝土结构试验方法标准:GB/T 50152-2012[S].北京:中国建筑工业出版社,2012.(Standard for test method of concrete structures:GB/T 50152-2012[S].Beijing:China Architecture&Building Press,2012.(in Chinese))
[8]徐有邻,沈文都,汪洪.钢筋砼粘结锚固性能的试验研究[J].建筑结构学报,1994,15(3):26-37.(XUYoulin,SHEN Wendu,WANG Hong.An experimental study of bond-anchorage properties of bars in concrete[J].Journal of Building Structures,1994,15(3):26-37.(in Chinese))
[9]张伟平,罗丹羽,陈辉,顾祥林.不同加载速率下钢筋与混凝土间粘结性能试验[J].中国公路学报,2014,27(12):58-64.(ZHANG Weiping,LUO Danyu,CHEN Hui,GU Xianglin.Experiments on bond behavior between steel bar and concrete under different loading rates[J].China Journal of Highway and Transport,2014,27(12):58-64.(in Chinese))
[10]庄金平,郑建岚.粉煤灰掺量对自密实混凝土与钢筋粘结性能影响的试验研究[J].福州大学学报(自然科学版),2013,41(2):229-234.(ZHUANGJinping,ZHENG Jianlan.Experiment study of fly ash content influence on bond performance between reinforcement and self-compacting concrete[J].Journal of Fuzhou University(Natural Science Edition),2013,41(2):229-234.(in Chinese))
[11]王国杰,郑建岚.自密实混凝土与钢筋的粘结锚固性能试验研究[J].福州大学学报(自然科学版),2004,32(3):334-338.(WANG Guojie,ZHENGJianlan.Bond properties between reinforcement and self-compacting concrete[J].Journal of Fuzhou University(Natural Science),2004,32(3):334-338.(in Chinese))
[12]ASLANI Farhad,NEJADI Shami.Mechanical properties of conventional and self-compacting concrete:an analytical study[J].Construction and Building Materials,2012,36(1):330-347.
[13]PARRA C,VALCUENDE M,GOMEZ F.Splitting tensile strength and modulus of elasticity of selfcompacting concrete[J].Construction and Building Materials,2011,25(1):201-207.
[14]OH Byung Hwan,KIM Se Hoon.Realistic models for local bond stress-slip of reinforced concrete under repeated loading[J].Journal of Structural Engineering,2007,133(2):216-224.
[15]蒋德稳,邱洪兴.重复荷载下钢筋与混凝土粘结本构关系[J].工程力学,2012,29(5):95-100.(JIANG Dewen,QIU Hongxing.Bond-slip basic constitutive relationship model between rebar and concrete under repeated loadig[J].Engineering Mechanics,2012,29(5):95-100.(in Chinese))
[16]蒋德稳,邱洪兴.重复荷载下裂缝间粘结性能研究[J].土木工程学报,2012,45(2):35-42.(JIANGDewen,QIU Hongxing.Study of bond performance between cracks under repeated loading[J].China Civil Engineering Journal,2012,45(2):35-42.(in Chinese))
[2]DE ALMEIDA FILHO F M,EL DEBS M K,EL DEBSA L H C.Bond-slip behavior of self-compacting concrete and vibrated concrete using pull-out and beam tests[J].Materials and Structures,2008,41(6):1073-1089.
[3]DESNERCK Pieter,DE SCHUTTER Geert,TAERWELuc.Bond behaviour of reinforcing bars in selfcompacting concrete:experimental determination by using beam tests[J].Materials and Structures,2010,43(Suppl.1):53-62.
[4]KORTE Sara,BOEL Veerle,DE CORTE Wouter,DESCHUTTER Geert.Behaviour of fatigue loaded selfcompacting concrete compared to vibrated concrete[J].Structural Concrete,2014,15(4):575-589.
[5]KORTE Sara,BOEL Veerle,DE CORTE Wouter,DESCHUTTER Geert.Static and fatigue fracture mechanics properties of self-compacting concrete using three-point bending tests and wedge-splitting tests[J].Construction and Building Materials,2014,57(1):1-8.
[6]庄金平,郑建岚.自密实混凝土与钢筋局部黏结性能试验研究[J].建筑结构学报,2013,34(6):143-152.(ZHUANG Jinping,ZHENG Jianlan.Experiment research on local bond performance between reinforcement and self-compacting concrete[J].Journal of Building Structures,2013,34(6):143-152.(in Chinese))
[7]混凝土结构试验方法标准:GB/T 50152-2012[S].北京:中国建筑工业出版社,2012.(Standard for test method of concrete structures:GB/T 50152-2012[S].Beijing:China Architecture&Building Press,2012.(in Chinese))
[8]徐有邻,沈文都,汪洪.钢筋砼粘结锚固性能的试验研究[J].建筑结构学报,1994,15(3):26-37.(XUYoulin,SHEN Wendu,WANG Hong.An experimental study of bond-anchorage properties of bars in concrete[J].Journal of Building Structures,1994,15(3):26-37.(in Chinese))
[9]张伟平,罗丹羽,陈辉,顾祥林.不同加载速率下钢筋与混凝土间粘结性能试验[J].中国公路学报,2014,27(12):58-64.(ZHANG Weiping,LUO Danyu,CHEN Hui,GU Xianglin.Experiments on bond behavior between steel bar and concrete under different loading rates[J].China Journal of Highway and Transport,2014,27(12):58-64.(in Chinese))
[10]庄金平,郑建岚.粉煤灰掺量对自密实混凝土与钢筋粘结性能影响的试验研究[J].福州大学学报(自然科学版),2013,41(2):229-234.(ZHUANGJinping,ZHENG Jianlan.Experiment study of fly ash content influence on bond performance between reinforcement and self-compacting concrete[J].Journal of Fuzhou University(Natural Science Edition),2013,41(2):229-234.(in Chinese))
[11]王国杰,郑建岚.自密实混凝土与钢筋的粘结锚固性能试验研究[J].福州大学学报(自然科学版),2004,32(3):334-338.(WANG Guojie,ZHENGJianlan.Bond properties between reinforcement and self-compacting concrete[J].Journal of Fuzhou University(Natural Science),2004,32(3):334-338.(in Chinese))
[12]ASLANI Farhad,NEJADI Shami.Mechanical properties of conventional and self-compacting concrete:an analytical study[J].Construction and Building Materials,2012,36(1):330-347.
[13]PARRA C,VALCUENDE M,GOMEZ F.Splitting tensile strength and modulus of elasticity of selfcompacting concrete[J].Construction and Building Materials,2011,25(1):201-207.
[14]OH Byung Hwan,KIM Se Hoon.Realistic models for local bond stress-slip of reinforced concrete under repeated loading[J].Journal of Structural Engineering,2007,133(2):216-224.
[15]蒋德稳,邱洪兴.重复荷载下钢筋与混凝土粘结本构关系[J].工程力学,2012,29(5):95-100.(JIANG Dewen,QIU Hongxing.Bond-slip basic constitutive relationship model between rebar and concrete under repeated loadig[J].Engineering Mechanics,2012,29(5):95-100.(in Chinese))
[16]蒋德稳,邱洪兴.重复荷载下裂缝间粘结性能研究[J].土木工程学报,2012,45(2):35-42.(JIANGDewen,QIU Hongxing.Study of bond performance between cracks under repeated loading[J].China Civil Engineering Journal,2012,45(2):35-42.(in Chinese))