蒸养预应力混凝土箱梁早期温度及应变试验研究  

Experimental Study on Early Temperature and Strain of Steam Curing Prestressed Concrete Box Girders

作　　者：金清平[1] 梁颖强 高永红[1] 汪西华 许平华 宋国映 JIN Qingping;LIANG Yingqiang;GAO Yonghong;WANG Xihua;XU Pinghua;SONG Guoying(School of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,China;Hubei Exchange Shuangliu Yangtze River Bridge Co.,Ltd,Wuhan 430416,China;China Railway 11 Bureau Group First Engineering Co.,Ltd,Xiangyang 441199,China;China Railway 3 Bureau Group Second Engineering Co.,Ltd,Shijiazhuang 050031,China)

机构地区：[1]武汉科技大学城市建设学院,武汉430065 [2]湖北交投双柳长江大桥有限公司,武汉430416 [3]中铁十一局集团第一工程有限公司,襄阳441199 [4]中铁三局集团第二工程有限公司,石家庄050031

出　　处：《硅酸盐通报》2024年第12期4350-4358,共9页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(52178158);湖北省高等学校优秀中青年科技创新团队计划项目(T2022002)。

摘　　要：为研究蒸汽养护对大体积混凝土箱梁的影响,本文结合某长江大桥高温蒸养预制混凝土箱梁项目,在30 m箱梁内埋设了温度和应变传感器,得到了箱梁在蒸汽养护及后期养护过程中的温度及应变变化规律。结果表明:测试截面的平均温度在66 h后才低于入模温度;混凝土水化热在11~13 h达到峰值,截面各区域测点温度峰值由大到小依次为顶腹板交界处、顶板、腹板、底板、底腹板交界处;顶腹板交界处和顶板的温度峰值高于其他区域;箱梁内部和表面、表面和外部最大温差分别为18.62和14.29℃,均出现于蒸汽养护前;在整个养护过程中,箱梁内部产生的拉应力小于混凝土劈裂抗拉强度,梁体无开裂风险;预应力钢束张拉完成后,各测试截面的应变均为压应变,且后期变化幅度不大。In order to study the influence of steam curing on high volume concrete box girder,combined with high temperature steam curing precast concrete box girder project of a Yangtze River Bridge,the temperature and strain sensors were embedded in the 30 m box girder,and the temperature and strain changes of box girder during steam curing and later curing were obtained.The results show that the average temperature of test section is lower than mold temperature after 66 h.The hydration heat of concrete reaches the peak value at 11~13 h,and the peak temperature of measuring points in each area of the section from large to small is the junction of top web plate,the top plate,the web plate,the bottom plate and the junction of bottom web plate.The peak temperature at the junction of top web plate and top plate is higher than that in other areas.The maximum temperature difference between interior and surface,and between surface and exterior of box girder is 18.62 and 14.29℃,respectively,both of which appear before steam curing.During the whole curing process,the tensile stress generated inside the box girder is less than splitting tensile strength of concrete,and there is no risk of cracking in girder.After the tension of prestressed steel beam is completed,the strain of each test section is compressive strain,and the later change range is not large.

关 键 词：预应力混凝土箱梁 蒸汽养护 水化热 温度场 应变场 

分 类 号：U448.35[建筑科学—桥梁与隧道工程]