盐蚀-干湿循环作用下玄武岩纤维混凝土腐蚀劣化试验研究

Corrosion Degradation Test of Basalt Fiber Concrete under Salt-wet Cycle

为探究新疆南部地区不同掺量玄武岩纤维混凝土腐蚀劣化规律,结合该地区的盐渍土壤环境和极端干旱沙漠性气候条件,采用本地区既有结构混凝土所常用的强度等级C35,在混凝土中分别掺入0%、0.1%、0.2%、0.3%的玄武岩纤维,开展现场暴露试验和室内加速对比试验,选取相对质量评价参数和相对动弹性模量评价参数为主要指标进行分析,研究结果表明:(1)纤维掺量越多,混凝土试件表面的可见裂缝越少,表观损伤程度越轻。(2)当纤维掺量为0.3%时,试件的相对质量评价参数变化波动较其他掺量变小,说明混凝土抵抗复合盐侵蚀的性能随纤维掺量的增加而增强。(3)室内外的相对动弹性模量评价参数分析表明,室内混凝土侵蚀开始时间早于室外,且侵蚀的速度也较室外快。室外混凝土试件主要在210 d开始进入较为明显的腐蚀阶段,且劣化速度随纤维掺入的增加而减小。

In order to explore the law of corrosion and degradation of basalt fiber concrete with different content in the south of Xinjiang,under the condition the saline soil environment and extreme arid and desert climate conditions in the area,the strength grade C35 commonly used in the existing structural concrete in this area is used.The concrete is mixed separately into 0%,0.1%,0.2%,0.3%of basalt fiber and carries out on-site exposure test and indoor accelerated comparison test,where relative quality evaluation parameters and relative dynamic elastic modulus evaluation parameters as the main indicators for analysis are selected.The research results show that:(1)The more fiber content,the fewer visible cracks on the surface of the concrete specimen and the lighter the apparent damage.(2)When the fiber content is 0.3%,the variation of relative quality evaluation parameters of the specimen becomes smaller than that of other content,indicating that the performance of concrete resisting compound salt erosion increases with the increase of fiber content.(3)The analysis of the evaluation parameters of the relative dynamic elastic modulus of indoor and outdoor shows that the start time of indoor concrete erosion is earlier than outdoor,and the erosion rate is also faster than outdoor.The outdoor concrete specimens mainly entered the more obvious corrosion stage at 210 d,and the deterioration rate decreased with the increase of fiber incorporation.