自密实轻集料混凝土的离子侵蚀性能及微观机理

发布时间：2018-03-02 00:17

本文关键词： 自密实轻集料混凝土离子侵蚀氯离子扩散系数显微硬度　出处：《南昌大学学报(理科版)》2017年03期 　论文类型：期刊论文

【摘要】：为了探明自密实轻集料混凝土(Self-compacting light-weight aggregate concrete,SCLC)离子侵蚀性能及微观机理,采用溶液浸泡法、RCM法分别测试了SCLC35和SCLC50的离子侵蚀性能和氯离子扩散系数,采用ESEM和显微硬度来测试SCLC界面过渡区的微观结构。结果表明,SCLC浸泡在5% Na_2SO_4和5%NaCl混合溶液中强度为先增大后减小,120d左右达到最大值,和浸泡在清水中相比,浸泡龄期120d时强度低3%,浸泡龄期360d时强度低10%左右;SCLC氯离子扩撒系数随龄期增大逐渐减小,SCLC35为9.387×10~(-13) m~2·s~(-1)~4.254×10~(-13) m~2·s~(-1),SCLC50为8.136×10~(-13) m~2·s~(-1)~2.959×10~(-13) m~2·s~(-1),均能达到混凝土氯离子迁移系数中的很好等级,SCLC35和SCLC50具有良好的抗离子侵蚀性能。SCLC的水化产物更加均匀致密,界面过渡区得到显著改善;SCLC50比SCLC35显微硬度值大10kgf·mm~2以上并且从集料区经过过渡区到浆体区显微硬度值逐渐增大:浆体区过渡区集料区,界面薄弱区显微硬度增加,抗离子侵蚀性能得到改善。
[Abstract]:In order to investigate the ion erosion performance and microscopic mechanism of self-compacting light-weight aggregate concrete (SCLC), the ion erosion properties and chloride diffusion coefficients of SCLC35 and SCLC50 were measured by solution immersion method. ESEM and microhardness were used to measure the microstructure of SCLC interface transition zone. The results showed that the strength of SCLC in mixed solution of 5% Na_2SO_4 and 5 Na_2SO_4 increased first and then decreased to a maximum value about 120 days, compared with soaking in clear water. At 120 days of immersion age, the strength of chloride ion is 3% lower than that of 360 days of immersion period. The diffusing coefficient of chloride ion decreases gradually with the increase of age. The SCLC35 is 9.387 脳 10 ~ (-13)) m ~ (2) 路s ~ (-1) ~ (-1) ~ 4.254 脳 10 ~ (10) ~ (-13)) m ~ 2 路s ~ (-1) C ~ (50) is 8.136 脳 10 ~ (10) ~ (-13) 路m ~ (2) 路s ~ (-1) C ~ (-1) C ~ (-1), which can reach the good grades of chloride ion transport coefficient of concrete. The hydration products of SCLC50 have better corrosion resistance. The microhardness of interfacial transition zone was significantly improved by more than 10kgf 路mm~2 than that of SCLC35, and the microhardness increased gradually from the transition zone to the slurry zone, and the microhardness increased in the weak zone of the interface between the transition zone and the slurry zone. The resistance to ion erosion was improved.
【作者单位】：南昌大学材料科学与工程学院;南昌大学建筑工程学院;
【基金】：国家自然科学基金项目(51562024) 江西省杰出青年人才资助计划项目(20162BCB23014) 江西省科技厅科技支撑计划项目(20133BBE50027)
【分类号】：TU528.2

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