钢箱组合梁混凝土裂缝特征试验  

Experiments on Concrete Cracking of Steel-concrete Composite Box Girder

作　　者：苏庆田[1] 杨国涛[1] 吴冲[1] 

机构地区：[1]同济大学桥梁工程系,上海200092

出　　处：《中国公路学报》2012年第5期74-81,共8页China Journal of Highway and Transport

基　　金："十一五"国家科技支撑计划项目(2009BAG15B02);国家自然科学基金项目(50708075)

摘　　要：为了解斜腹板钢箱组合连续梁负弯矩区混凝土裂缝的特征,选取2根斜腹板钢箱组合梁进行负弯矩受力性能试验,考察负弯矩荷载作用下组合梁混凝土板裂缝的出现、发展过程和裂缝宽度变化,以及钢筋和混凝土板上缘的应变分布。结果表明:组合梁混凝土在荷载较低时就产生开裂,混凝土板中的裂缝分布特性与配筋率有关;当配筋率较小时混凝土开裂引起其附近的钢筋应变突然增加,钢筋屈服后随着荷载的增加裂缝宽度也增长较快;当配筋率合理时,混凝土产生的0.2mm宽裂缝对应荷载为初始开裂荷载的3倍以上;裂缝间距与混凝土板中横向配筋间距和剪力钉间距有一定关系。In order to investigate the concrete cracking in the hogging moment zone, two specimens of steel-concrete composite box girder with inclined webs under hogging moment were tested. The cracking pattern of concrete slab, its development, its width, and the strain distribution of the reinforcement and the top flange of the concrete slab were studied. The results show that the concrete of composite girder cracks when the load is small. The cracking distribution has relation with the reinforcement ratio. In composite girder with less reinforcement ratio, the strain of reinforcement increases abruptly after concrete cracks and the cracking width increases with the increase of load quickly when the longitudinal reinforcement yields. Within rational reinforcement ratio, the load of the composite girder with the concrete cracking width of 0.2 mm is three times more than the load which causes the initial concrete cracking. Crack spacing is related to transverse reinforcement spacing and longitudinal spacing of the studs.

关 键 词：桥梁工程 混凝土裂缝 负弯矩区受力试验 钢箱组合梁 斜腹板 

分 类 号：U448.216[建筑科学—桥梁与隧道工程]