高强混凝土指数型收缩徐变预测模型及工程应用  

Prediction Model of Index Type Shrinkage and Creep for High-Strength Concrete and Its Engineering Application

作　　者：柯敏勇[1] 刘海祥[1] 陈灿明[1] 陈松[1] 

机构地区：[1]南京水利科学研究院,江苏南京210029

出　　处：《桥梁建设》2011年第4期49-52,共4页Bridge Construction

基　　金：国家863计划资助项目(2007AA112106);西部交通建设科技资助项目(200631822327);中央级公益性科研院所基本科研业务费专项资金(Y411009)

摘　　要：收缩徐变是导致大跨度预应力混凝土箱梁桥长期变形的重要因素,现有桥梁长期变形分析中通常采用CEB-FIP 90模型,计算结果会出现较大偏差。为减小预应力混凝土箱梁桥长期变形的计算误差,以某三跨预应力混凝土连续箱梁桥为背景,对该桥相同配比的高强混凝土进行了标准徐变试验,将实测数据拟合得到指数型收缩徐变模型,并根据该桥混凝土构件实际尺寸效应、湿度效应、钢筋配筋率和持荷年限对徐变系数进行修正。由此计算得到该桥的长期变形与实测数据吻合较好,验证了指数型收缩徐变模型比现有徐变模型具有更高的预测精度。The shrinkage and creep is an important factor causing long-term deformation of long span prestressed concrete （PC） box girder bridges. In the current analysis of the long-term deformation of the bridges, the CEB-FIP 90 model is usually employed and the errors of calculation by the model are great. To minimize the errors of the calculation, a three-span PC continuous box girder bridge was cited as an example and the standard creep tests for the high-strength concrete having the same mix proportioning with that of the bridge were made. The measurement data were fitted, the index type shrinkage and creep model was obtained and the creep coefficients were modified in accordance with the actual dimension effect, humidity effect, reinforcement ratios and load holding years of concrete components of the bridge. The long-term deformation of the bridge calculated in accordance with the model is well agreeable with the measured deformation, verifying that the model has even higher prediction precision as compared to that of other existing shrinkage and creep models.

关 键 词：预应力混凝土结构 连续梁桥 变形 收缩徐变 

分 类 号：U448.35[建筑科学—桥梁与隧道工程]