摘要
为评估京沪高速公路江苏段扩建工程中既有混凝土桥梁的耐久性状况,为既有桥梁的再利用提供依据,采集了线路中10座桥梁(包含空心板梁桥、组合箱梁桥和T梁桥)的耐久性指标数据,指标包括混凝土强度、碳化深度、钢筋保护层厚度。通过对各类构件的耐久性指标进行现场测试并进行数据统计特性分析,得出:混凝土强度、碳化深度、保护层厚度符合正态分布或对数正态分布;各类构件的混凝土强度变异性较小,变异系数在0.17~0.18;各类构件的碳化深度普遍具有很高的变异性,变异系数在0.35~0.61,墩柱的碳化深度变异性最小,空心板梁变异性最大;各类构件保护层厚度变异性较为稳定,变异系数稳定在0.20~0.32范围,箱梁的保护层厚度变异性最小,T梁的变异性最大。桥梁上部结构混凝土强度主要在40~60 MPa之间,下部结构主要在30~40 MPa之间;上部结构碳化深度主要在1~5 mm之间,下部结构碳化深度主要在10~25 mm之间,上部结构碳化深度远小于下部结构。桥梁上部结构的碳化系数远大于下部结构,上部结构碳化系数均值95%置信区间上限在0.23~0.75 mm·a^(-0.5)范围,下部结构碳化系数均值95%置信区间上限在3.57~3.85 mm·a^(-0.5)范围。碳化深度及碳化系数与混凝土强度有很强的相关性,均符合指数衰减函数。
In order to evaluate the durability of the existing concrete bridges in the extension project of Jiangsu section of Beijing-Shanghai expressway and provide the basis for the reuse of the existing bridges,the durability indicator data of 10 bridges(including hollow slab girder bridge,composite box girder bridge and T-girder bridge) on the expressway are collected,including concrete strength,carbonization depth and thickness of reinforcement protective layer.Through the field test of the durability indicator data of various components and statistical characteristics analysis of the data,it is concluded that(1) the concrete strength,carbonization depth and thickness of protective layer conform to the normal distribution or lognormal distribution;(2) the variations of concrete strength of various members are small and the variation coefficient ranges from 0.17 to 0.18;(3) the carbonization depths of various components generally have high variability,with the variation coefficient ranging from 0.35 to 0.61;(4) the carbonization depth variability of pier columns is the smallest,while that of hollow slab girder is the largest;(5) the variabilities of the protective layer thickness of various components are relatively stable,and the variation coefficients are stable in the range of 0.20-0.32,the variability of the protective layer thickness of box girder is the smallest,while that of T-girder is the largest;(6) the concrete strength of the bridge superstructure is mainly between 40-60 MPa,and that of the bridge substructure is mainly between 30-40 MPa;(7) the carbonization depth of the superstructure is mainly between 1-5 mm,and that of the substructure is mainly between 10-25 mm,the carbonization depth of the superstructure is much smaller than that of substructure,the carbonization coefficient of superstructure is much larger than that of substructure,the upper limit of 95% confidence interval of mean carbonization coefficient of superstructure is in the range of 0.23-0.75 mm/a^(-0.5),and the upper limit of 95% confidence interval of mean carbonization coefficient of substructure is in the range of 3.57-3.85 mm/a^(-0.5);(8) the carbonization depth and carbonization coefficient are strongly correlated with the concrete strength,which conform to the exponential decay function.
作者
陈光伟
王少鹏
杨洋
厉广广
赵尚传
CHEN Guang-wei;WANG Shao-peng;YANG Yang;LI Guang-guang;ZHAO Shang-chuan(Jiangsu Traffic Engineering Construction Bureau,Nanjing Jiangsu 210004;Research Institute of Highway,Ministry of Transport,Beijing 100088)
出处
《公路交通科技》
CAS
CSCD
北大核心
2022年第8期76-85,共10页
Journal of Highway and Transportation Research and Development
关键词
桥梁工程
耐久性
统计分析
混凝土
统计特性
bridge engineering
durability
statistical analysis
concrete
statistical property
作者简介
陈光伟(1971-),男,安徽萧县人,博士研究生,正高级工程师.(1006490647@qq.com)。
