钢-UHPC组合板受弯性能的试验研究  

Experimental study on flexural behavior of steel-UHPC composite slabs

作　　者：李文光[1,2] 邵旭东[1] 方恒[1] 张哲[1] 

机构地区：[1]湖南大学,湖南长沙410082 [2]长沙市规划设计院有限责任公司,湖南长沙410007

出　　处：《土木工程学报》2015年第11期93-102,共10页China Civil Engineering Journal

基　　金：国家自然科学基金(51378194;51178177);交通运输部重大科技专项(2011318494160)

摘　　要：提出钢-UHPC轻型组合桥面系,以消除正交异性钢桥面铺装层易损和钢桥面板疲劳开裂两类病害。为探究该组合桥面系在局部轮载作用下的横向受弯性能,对10块钢-UHPC组合板进行试验研究与理论分析。试验结果表明：负弯矩作用下,组合板的弹性阶段取决于UHPC的弹性性能;保护层厚度与截面配筋率对UHPC开裂影响十分显著;纵向配筋率越高,纯弯段裂缝分布越密集;当裂缝宽度小于0.2mm时,荷载与最大裂缝宽度关系近似线性;破坏形态为UHPC层受拉断裂。正弯矩作用下,组合板的弹性阶段取决于钢板与UHPC层界面的自然黏结强度;纯弯段裂缝间距几乎与横向钢筋的间距相同;在极限荷载前,荷载与最大裂缝宽度关系近似线性;钢板将纯弯段UHPC最大裂缝宽度有效限制在0.2mm左右;破坏形态为剪跨区栓钉被剪断。按截面换算法计算UHPC的开裂强度为18.1~32.7MPa,满足工程要求;按塑性分析方法计算钢-UHPC组合板的抗弯承载力,与试验值吻合较好。An innovative composite bridge deck system that consists of the orthotropic steel deck and the thin Ultra High Performance Concrete（ UHPC） layer is proposed to relieve damage in asphalt surfacing and fatigue cracking in orthotropic steel decks. In order to investigate the transversal flexural behavior of the steel-UHPC composite deck under wheel loads,eight steel-UHPC composite slabs were brought to bear negative bending moments,and two were exposed to positive bending moments. The test results indicate that the elastic behavior of the composite slabs in negative bending depends on the elastic strength of UHPC. The reinforcement ratio and cover thickness of steel rebars affect the crack strength of UHPC layer significantly. The higher the reinforcement ratio,the closer the crack spacing. The load increase approximately linearly with the cracking width when the crack width was less than 0. 2mm. The failure model of the slabs in negative bending is the tensile fracture of UHPC. On the other hand,the elastic behavior of composite slabs under positive bending depends on the natural adhesive strength at the steel-UHPC interface. Crack spacing in in the pure bending portion of the slabs is almost the same as that of transverse steel rebars. The maximum crack width increased approximately linearly with load prior to the peak load,and the maximum crack width was only about 0. 2mm because of the contribution of steel plates. The slabs failed when the shear stud fractured in shear spans. In addition,theoretical results agree well the test results. The cracking strength of UHPC in the composite slabs is between 18. 1 and 32. 7MPa,which can satisfy the stress requirement in UHPC in design. The research results can provide reference for the design of the steel-UHPC composite decks under transversal bending loads.

关 键 词：超高性能混凝土 钢-UHPC组合板 开裂强度 最大裂缝宽度 抗弯承载力 

分 类 号：U443.32[建筑科学—桥梁与隧道工程] TU398.9[交通运输工程—道路与铁道工程]