单面干燥条件下混凝土的收缩变形分布特征-硅酸盐学报.pdf

第37 卷第1 期 李明利等：改进草酸盐共沉淀法制备钛酸锶钡粉体 · 87 · 第37 卷第1 期 硅 酸 盐 学 报 Vol. 37 ，No. 1 2 0 0 9 年 1 月 JOURNAL OF THE CHINESE CERAMIC SOCIETY January ，2009 单面干燥条件下混凝土的收缩变形分布特征 高小建，阚雪峰，杨英姿 (哈尔滨工业大学土木工程学院，哈尔滨 150006) 摘 要：通过固定多组位移传感器，研究了单面干燥条件下不同水灰比混凝土试件距离表面不同深度处的收缩变形，同时埋置湿度传感器，研究了不 同深度处混凝土中相对湿度变化。结果表明：混凝土试件内层(距表面55 mm 和100mm) 的收缩和相对湿度降低明显小于混凝土近表层(距表面10mm) 的；水灰比越小，沿混凝土干燥表面垂直方向的收缩与湿度梯度差越大；单面干燥条件下，不同深度混凝土层的收缩与其相对湿度降低值之间均存在 较好的线性关系，在达到相同湿度条件时的表层混凝土收缩小于内层混凝土。 关键词：混凝土；单面干燥；收缩；相对湿度；非均匀分布 中图分类号：TU528 文献标志码：A 文章编号：0454–5648(2009)01–0087–05 SHRINKAGE DISTRIBUTION OF CONCRETE WITH ONE SURFACE EXPOSED TO DRY CONDITION GAO Xiaojian，KAN Xuefeng ，YANG Yingzi (School of Civil Engineering, Harbin Institute of Technology, Harbin 150006, China) Abstract: The shrinkage strain of concrete with different water-cement ratios was measured in various depths from the exposed sur- face by using several pairs of fixed sensors. Only one surface of the concrete specimen was exposed to the dry condition during the experiment. The relative humidity change of concrete at various depths from the exposed surface was also studied by using embedded humidity sensors. The results show that the shrinkage and relative humidity reduction are markedly lower in the internal layer (55 mm and 100 mm from the surface) than that in the near surface layer (10 mm from the surface) of concrete. Such differential distributions of shrinkage strain and relative humidity according to depths from the exposed concrete surface become worse with decreasing water-cement ratio. When one surface of a concrete specimen is exposed to a drying condition, there is a good linear relatio