自密实再生混凝土氯离子渗透性能时变规律  

Time-dependent law of chlorine ion penetration performance for recycled aggregate self-compacting concrete

作　　者：姚大立 迟金龙 余芳 胡绍金 YAO Da-li;CHI Jin-long;YU Fang;HU Shao-jin(School of Architecture and Civil Engineering, Shenyang University of Technology, Shenyang 110870, China)

机构地区：[1]沈阳工业大学建筑与土木工程学院,沈阳110870

出　　处：《沈阳工业大学学报》2020年第4期476-480,共5页Journal of Shenyang University of Technology

基　　金：国家自然科学基金项目(51608331)。

摘　　要：为了研究暴露时间对自密实再生骨料混凝土(RA-SCC)抗氯离子渗透性能的影响,并比较其与天然骨料混凝土(NA-C)和自密实天然骨料混凝土(NA-SCC)的抗氯离子渗透性能的差异,将三种混凝土在NaCl溶液中进行浸泡并测定其自由氯离子扩散系数和表面氯离子浓度.结果表明:三种混凝土的氯离子扩散系数随暴露时间的衰减规律符合幂函数变化规律,当混凝土强度等级提高时,RA-SCC表面氯离子扩散系数的时间依赖指数增大,这点与NA-SCC相同而与NA-C相反;三种混凝土的表面氯离子浓度随暴露时间增长规律同样遵循幂函数变化规律,当暴露时间超过60 d时,混凝土表面的氯离子浓度增长不再显著.In order to study the effect of exposure time on the chloride ion penetration resistance of recycled aggregate self-compacting concrete(RA-SCC),and compare the difference of chloride ion penetration resistance among RA-SCC,natural aggregate concrete(NA-C)and natural aggregate self-compacting concrete(NA-SCC),three kinds of concretes were immersed in NaCl solution,and their free chloride ion diffusion coefficient and surface chloride ion concentration were measured.The results show that the decay law of chloride ion diffusion coefficient with exposure time of three kinds of concretes is in accordance with the variation law of power function.When the concrete strength grade increases,the time-dependent index of chloride ion diffusion coefficient on the surface of RA-SCC increases,which is the same as that of NA-SCC but opposite to the NA-C.The increasing law of surface chloride ion concentration of three kinds of concretes with exposure time also follows the variation law of power function.When the exposure time exceeds 60 days,the chloride ion concentration on the surface of concretes will not increase significantly.

关 键 词：自密实混凝土 再生骨料 天然骨料 强度等级 暴露时间 渗透性能 扩散系数 氯离子浓度 

分 类 号：TU528.09[建筑科学—建筑技术科学]