自密实混凝土徐变性能试验研究

Experimental research on creep of self-compacting concrete

对28个开放和28个经密封处理的自密实混凝土和普通混凝土试件进行加载徐变试验及同条件对比收缩试验,比较分析自密实混凝土基本徐变和干燥徐变构成特点,并与普通混凝土进行对比。试验结果表明,自密实混凝土干燥徐变所占比例较大;随着水胶比的减小,自密实混凝土徐变度减小;自密实混凝土总徐变度较普通混凝土早期增长较快,且随着龄期增长逐渐减小低于普通混凝土。根据试验结果,建议采用双曲线幂函数形式计算徐变时变曲线,以供自密实混凝土实际工程应用参考。

28 sealed and 28 unsealed self-compacting concrete （SCC） and normal concrete （NC） specimens were tested to investigate the characteristics of basic and drying creep of SCC. Based on the test, the comparison on creep between SCC and NC were performed. The experimental results indicate that the drying creep of SCC takes larger proportion in total creep and the creep of SCC decreases with the increasing water to binder ratio （W/B）. Comparison between SCC and NC shows that the creep rate of SCC is larger than that of NC at early age. With the increasing age the rate of creep of SCC decreases more than NC. According to the experimental data, the hyperbolic power formula is proposed for the prediction of the creep of SCC.