蒸养条件下超高性能混凝土收缩试验研究  

Experimental Investigation on Shrinkage Effect of Ultra‑High Performance Concrete under Steam Curing

作　　者：李兵 杨腾宇 方昌乐 罗滋润 李传习 谭珂 LI Bing;YANG Tengyu;FANG Changle;LUO Zirun;LI Chuanxi;TAN Ke(Foshan Jianying Development Group Co.,Ltd.,Foshan,Guangdong 528000,China;Foshan Transport Technology Co.,Ltd.,Foshan,Guangdong 528000,China;School of Civil Engineering,Changsha University of Science&Technology,Changsha,Hunan 410114,China.)

机构地区：[1]佛山市建盈发展有限公司,广东佛山528000 [2]佛山市交通科技有限公司,广东佛山528000 [3]长沙理工大学土木工程学院,湖南长沙410114

出　　处：《中外公路》2024年第6期90-97,共8页Journal of China & Foreign Highway

基　　金：国家自然科学基金资助项目(编号:52078059);湖南省交通科技项目(编号:202016)。

摘　　要：确定UHPC自收缩是分析钢-UHPC组合桥面板收缩效应的重要基础。为此,基于某工程拟用的UHPC材料,制作了3批UHPC自收缩试件,每批制作3个试件。通过测试试件养护过程中的应变及温度,得到UHPC自收缩应变-龄期曲线、试件温度-龄期曲线,探讨了该UHPC收缩应变发展及变化规律。根据试验结果,结合Tazawa&Miyazawa收缩预测模型和阿伦尼乌斯温度效应经验公式,通过引入等效时间,拟合得到适用于UHPC自收缩的预测模型。基于试验结果的回归分析,得出了修正模型的各项系数。结果表明:时间零点至试件温度升到90℃期间的收缩占蒸养期间全部收缩的42%,而后保持90℃蒸养的48 h内自收缩不仅能发展至蒸养期间总收缩的95%以上,而且收缩应变曲线会在此期间逐渐趋于平稳。UHPC在等效20℃密封养护条件下,其自收缩会在时间零点后40 d左右基本发展完成。Determining the free shrinkage of UHPC is an important basis for analyzing the shrinkage effect of steel UHPC composite bridge deck.Therefore,based on the UHPC materials to be used in a project,three batches of UHPC free shrinkage specimens were made,and three specimens were made in each batch.By testing the strain and temperature of specimens during curing,the free shrinkage strain-age curve and temperature-age curve of UHPC were obtained.The development and variation law of UHPC shrinkage strain are discussed.Based on the experimental results,the equivalent time is introduced on the basis of Arrhenius empirical formula,and a modified model of free shrinkage is proposed.Finally,based on the regression analysis of the test results,the coefficients of the modified model are obtained.According to this discussion,the corresponding theoretical UHPC shrinkage stress calculate formula is obtained.The results show that the shrinkage from time zero to the point that temperature rise to 90℃accounts about 42%of the total shrinkage during steam curing,and then the free shrinkage developed to more than 95%of the total shrinkage during steam curing within 48 hours after steam curing with 90℃.and the shrinkage strain curve will gradually stabilize during this period.And under the equivalent sealing curing condition of 20℃,the free shrinkage of UHPC will be basically completed about 40 days after time zero.

关 键 词：桥梁工程 UHPC自收缩 等效时间 时间零点 自收缩预测模型 

分 类 号：U414[交通运输工程—道路与铁道工程]