盐类侵蚀纳米SiO_2补偿收缩混凝土拉压试验分析  

Tensile and compressive tests and analyses of nano-SiO_2 shrinkage-compensation concrete eroded by sulfate and chloride

作　　者：马芹永[1] 张伟[1] 

机构地区：[1]安徽理工大学矿山地下工程教育部工程研究中心,安徽淮南232001

出　　处：《中国科技论文》2015年第1期60-63,共4页China Sciencepaper

基　　金：高等学校博士学科点专项科研基金资助项目(20133415130001)

摘　　要：为提高补偿收缩混凝土材料的抗盐类侵蚀性能,在补偿收缩混凝土中添加不同掺量的纳米SiO2,采用连续浸泡法对纳米SiO2补偿收缩混凝土实施硫酸盐和氯盐双重侵蚀,并在不同侵蚀时间下进行混凝土的拉压强度试验。研究表明,掺加纳米SiO2能有效改善补偿收缩混凝土受硫酸盐和氯盐双重侵蚀后的拉压性能。纳米SiO2补偿收缩混凝土拉压性能及拉压抗侵蚀系数随侵蚀时间增长均表现出先上升后下降的变化趋势,且侵蚀150d时,其拉压性能较好。纳米SiO2的微集料填充作用能有效改善混凝土内部孔体结构,使硫酸根离子和氯离子在补偿收缩混凝土中的扩散受阻。试验表明,较为合理的纳米SiO2掺量为0.6%。To improve resistance of shrinkage-compensation concrete against combined erosion by sulfate and chloride,nano-SiO2 was added with various mass contents.Continuous immersion method was adopted to carry out sulfate and chloride erosion test for nano-SiO2 shrinkage-compensation concrete.Tensile and compressive tests of nano-SiO2 shrinkage-compensation concrete were also carried out for various erosion times.The results show that adding nano-SiO2 in shrinkage-compensation concrete could improve its tensile and compressive properties effectively after erosion by sulfate and chloride.Both tensile and compressive properties and resistance coefficient of nano-SiO2shrinkage-compensation concrete present a variational trend with firstly increaseing and then decreassing with erosion time growing.It is noted that at the erosion age of 150 d,the tensile and compressive properties reach the maxima.Because of the micro-aggregate filling effect of nano-SiO2,the interior pore structure of concrete is improved and the diffusion of sulfate and chloride ions in shrinkage-compensation concrete is then retarded.It is also found that the optimal mass content of nano-SiO2 in shrinkage-compensation concrete is 0.6%.

关 键 词：补偿收缩混凝土 纳米SIO2 硫酸盐侵蚀 氯盐侵蚀 拉压性能 

分 类 号：TU528[建筑科学—建筑技术科学]