低收缩LUHPC钢桥面铺装组合基本性能试验研究  

Experimental Study on Basic Performance of Low Shrinkage LUHPC Steel Bridge Deck Pavement

作　　者：付军[1,2] 徐梦豪 王哲世 丁庆军[2] FU Jun;XU Meng-hao;WANG Zhe-shi;DING Qing-jun(Wuhan University of Technology,Wuhan Hubei 430063,China;State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan Hubei 430070,China)

机构地区：[1]武汉理工大学,湖北武汉430063 [2]武汉理工大学硅酸盐建筑材料国家重点实验室,湖北武汉430070

出　　处：《公路交通科技》2023年第8期89-95,共7页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51878003,U21A20149)。

摘　　要：为降低大跨度钢桥面铺装荷载,减少水泥基铺装材料的收缩,制备了多组低收缩轻质超高性能混凝土(LUHPC),测试其基本力学性能,在满足力学要求和扩展度的前提下,确定了较低密度的基准配合比。面向实际设计需求,分析了配筋和覆膜养护工艺对LUHPC收缩特性的影响,通过试验与理论分析讨论了LUHPC钢桥面铺装组合的抗推移能力。结果表明:通过材料配合比调整,LUHPC的密度可以控制在2100 kg/m^(3)以下,28 d抗压强度大于110 MPa,抗折强度在14 MPa以上,扩展度不低于450 mm,满足设计要求;相对于空白对照组的LUHPC试件,覆膜组和配筋组试件的收缩应变明显降低,最高降幅达到40.7%,且收缩应变随着配筋率的增大而减小,其中轻集料的“释水”作用、覆膜“保水”作用以及膨胀剂的加入共同作用,可以显著降低LUHPC的收缩量,使LUHPC的150 d收缩应变控制在150με以下,满足设计要求;推出试验得到的剪力连接件破坏模式为焊缝剪断,其抗剪承载能力实测值为70.83 kN,大于根据各国规范得到的计算值,满足设计要求;LUHPC组合结构推出试验得到了连接件的荷载-滑移曲线,根据试验数据对荷载-滑移曲线进行拟合分析得到了抗剪刚度。研究结果可为LUHPC类组合钢桥面铺装的设计与应用提供参考。In order to reduce the load of long-span steel deck pavement and the shrinkage of cement-based pavement materials,several groups of low shrinkage LUHPC are prepared and their basic mechanical properties are tested.To meet the mechanical requirements and expansion,the benchmark mix proportion with lower bulk density is determined.Based on practical design requirements,the influence of reinforcement and membrane curing process on the shrinkage characteristics of LUHPC is analyzed,the pushing resistance ability of LUHPC steel bridge deck pavement combination is discussed through experimental and theoretical analysis.The result shows that(1)By adjusting the material mixing ratio,the gravity of LUHPC can be controlled below 2100 kg/m^(3),with 28 d compressive strength greater than 110 MPa,flexural strength greater than 14 MPa,and extensibility not less than 450 mm,which can meet the design requirements.(2)Compared with the specimens of the blank control group,the shrinkage strains of the specimens of the film coated group and the reinforcement group are significantly reduced,with maximum decrease of 40.7%,and the shrinkage strain decreases with the increase of the reinforcement ratio.The combined effect of the“water release”of light aggregate,the“water retention”of film-coating and the addition of expansion agent can significantly reduce the shrinkage of LUHPC,which can control the 150 d shrinkage strain of LUHPC to 150μεand meet the design requirements.(3)The failure mode of the shear connector obtained from the push-out test is weld shear,its measured shear bearing capacity is 70.83 kN,which is greater than the calculated values obtained according to the foreign specifications and meets the design requirements.(4)The load-slip curve of the connector is obtained from the push-out test on LUHPC composite structure.The shear stiffness is obtained by fitting and analyzing the load-slip curve based on experimental data.The study result can provide reference for the design and application of LUHPC composite stee

关 键 词：桥梁工程 钢桥面铺装 收缩试验 轻质超高性能混凝土 推出试验 荷载-滑移曲线 

分 类 号：TU528.2[建筑科学—建筑技术科学]