硫酸盐侵蚀与冻融循环作用下混凝土损伤试验研究.pdfVIP

学兔兔 2010年第2期 混凝 土与水 泥制品 2010 N02 4月 CHINA C0NCRETE AND CEMENT PRODUCTS April 硫酸盐侵蚀与冻融循环作用下混凝土损伤试验研究 安新正 ，易 成 ，刘 燕 。，张结太 (1．中国矿业大学煤炭资源与安全开采国家重点实验室，北京100083； 2．河北工程大学土木学院，邯郸056038；3．河北农业大学城乡建设学院，保定071001) 摘 要：研究了水灰比为0．44的泵送混凝土在6．O％ (质量分数)Na2SO 溶液中浸泡一自然干燥循环以及浸泡一干燥循环后再 经冻融循环条件下混凝土的损伤失效规律和特点。结果表明，在浸泡一干燥循环初期，其损伤变量D (T)=O，并且相对动弹性模量 呈线性增加，但随着浸泡一干燥循环周期的增加，其损伤变量D经历了从0到缓慢增加、再到快速增加的过程，而相对动弹性模 量E 从线性增加转而呈现缓慢下降。与单一的浸泡一干燥循环相比，浸泡一干燥循环与冻融循环的共同作用大大加速了混凝土的 损伤进程。 关键词：泵送混凝土；硫酸盐侵蚀；干一湿循环；冻融循环；损伤 Abstract：In the process of life-cycle of concrete，sulfate attack and freeze-thaw cycles are two important factors that affect the durability of concrete structures．The damage process of pumping concrete with water to cement ratio of 0．44 under immersion-dry cycles or immersion—dry—freeze—thaw cycles in solutions of 6．O％ N 2SO4 is studied．The results show that the relative dynamic modulus of elasticity E increases linearly and the damage variable Dm(．r)=0 in the initial stage of immersion—dry cycles，but according to the immersion—dry cycles increased，the damage variable D experienced the process from 0 to slow increasing，at last rapid increasing，and the relative dynamic modulus of elasticity E experienced the process from increasing linearly to decreasing slowly．Compared with the immersion—dry cycles，the interactive effects of immersion—dry cycles and freeze—thaw cycles have greatly accelerated the process of concrete damage． Key words：Pumping concrete；Sulfate attack；Immersion—-dry cycles；Freeze——thaw cycles；Damage 中图分类号：TU528 文献标志码：A 文章编号：1000-4637(2010)02一O1—03 0 前言 湿循环一冻融循环条件下泵送混凝土的损伤失效规律