圆钢管活性粉末混凝土界面黏结性能  

Interface bond-slip behavior of reactive powder concrete-filled circular steel tube

作　　者：王秋维[1,2,3] 史庆轩[1,2,3] 徐赵东[2] 张春尧 WANG Qiuwei;SHI Qingxuan;XU Zhaodong;ZHANG Chunyao(State Key laboratory of Green Building in Western China,Xi'an University of Architecture&Technology,Xi’an 710055,China;College of Civil Engineering,Xi'an University of Architecture&Technology,Xi’an 710055,China;Key Lab of Structural Engineering and Earthquake Resistance,Ministry of Education(XAUAT),Xi'an 710055,China)

机构地区：[1]西安建筑科技大学西部绿色建筑国家重点实验室,陕西西安710055 [2]西安建筑科技大学土木工程学院,陕西西安710055 [3]西安建筑科技大学结构工程与抗震教育部重点实验室,陕西西安710055

出　　处：《建筑结构学报》2021年第12期210-218,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51878543,51878540);陕西省教育厅科学研究计划项目(20JS078)。

摘　　要：为研究钢管活性粉末混凝土(RPC)的界面黏结性能,以径厚比、长径比和混凝土抗压强度为变化参数,设计了21个圆钢管RPC试件并对其进行静力推出试验。分析了试件的破坏过程与形态、荷载-滑移曲线、黏结强度和钢管表面应变分布,结果表明:钢管RPC的荷载-滑移曲线分为峰值荷载点后有明显下降段、峰值荷载点后曲线平稳和曲线持续上升三类,取峰值点或第一拐点对应的荷载为黏结破坏荷载;界面初期黏结力由化学胶着力提供,随后转化为机械咬合力和摩阻力,后期则主要由界面摩擦力提供;钢管RPC的黏结强度随着套箍系数增加而增大,钢管主要在加载后期发挥约束作用,其表面纵向应变沿高度方向大致呈指数分布。考虑长径比和套箍系数对实测黏结强度的影响,建立了考虑双因素影响的钢管RPC黏结强度计算模型,理论计算结果与实测结果吻合较好。In order to investigate the interface mechanical behavior of reactive powder concrete(RPC)-filled steel tubes,a total of 21 RPC-filled circular steel tube specimens were designed for push-out test considering the parameters of diameter-thickness ratio,length-diameter ratio,and the compressive strength of concrete.Based on the tests,the failure process and modes,load-slip curves,bond strength,and bond strain distribution were analyzed.The test results show that the load-slip curves of RPC-filled steel tubes can be divided into three categories,including the curves with a notable descending branch after peak load point,the stable curves after peak load point and the curves with gradual increase.The load corresponding to the peak point or the first turning point is regarded as the bond failure load.The bond strength is initially provided by chemical adhesive force and then by mechanical interlocking and friction resistance,and the interfacial friction plays a major role at the later loading stage.The bond strength of RPC-filled steel tube increases with the increase of confinement coefficient.The steel tube mainly exerts confinement effect at the later stage of loading,and the longitudinal strains on its surface exhibit a negative exponent distribution along the height.Considering the effect of length-diameter ratio and confinement coefficient on the measured bond strength,the calculated model of bond strength with two parameters for RPC-filled circular steel tube was established,and the theoretical results agree well with the experimental data.

关 键 词：钢管混凝土 活性粉末混凝土 静力推出试验 界面黏结滑移 黏结强度 

分 类 号：TU398.903[建筑科学—结构工程]