作　　者： ; ; ;

机构地区： 东南大学土木工程学院混凝土及预应力混凝土结构教育部重点实验室

出　　处： 《土木工程学报》 2009年第2期11-16,23,共7页

摘　　要： 针对苏通大桥辅桥主梁采用的C60高强混凝土,通过室内标准环境下的混凝土徐变试验,将试验结果与现有5种徐变预测模型(ACI209-82、CEB-FIP90、GZ1993、B3和GL2000)进行比较,得到适用于苏通大桥辅桥高强混凝土的徐变模型,并根据高强混凝土的特点对其中的某些参数进行了修正。根据素混凝土和三种配筋率混凝土试件的收缩徐变试验,得出配筋对混凝土收缩徐变的影响规律。考虑混凝土收缩、徐变和松弛三者共同影响,推导了非预应力筋重心和预应力筋重心位置在不同截面高度时配筋对收缩徐变的影响系数计算公式,和试验结果吻合较好。最后根据大跨度预应力梁桥采用的混凝土特性和非预应力筋的布置状况,给出了大跨梁桥中配筋对混凝土收缩徐变影响系数的实用公式。 Based upon indoor creep test of the high-strength concrete （C60） used in the Sutong Auxiliary Bridge, and by comparing the test results with the creep coefficient value estimated by using the ACI209-82, CEB-FIP90, GZ1993, B3 and GL2000 prediction models, a model which was fit for the concrete was chosen, and the parameters in the model were modified. According to the experimental results of creep and shrinkage of concrete specimens with different reinforcement ratios, the influence of steel restraint on concrete creep and shrinkage was investigated. Taking account of the interaction of concrete shrinkage, creep and relaxation of prestressing tendons, an equation of the steel restraint influence coefficient on concrete creep and shrinkage was derived when the height of centroid of the non-prestressed steel was different with the centroid of tendons in the section. Comparison between theoretical values and experimental results indicate that the presented equation achieved higher accuracy. Based on the features of concrete and configuration of non-prestressed steels used in long-span beam bridges, practical formulas of steel restraint influence coefficient on shrinkage and creep were presented.

关 键 词： 大跨度桥梁 预应力混凝土 高强混凝土 收缩 徐变 配筋率 影响系数

领　　域： [建筑科学] [建筑科学] [交通运输工程]