掺钢渣再生骨料自密实混凝土耐久性及寿命预测研究

发布时间：2018-05-22 18:58

本文选题：钢渣混凝土 + 碳化性能　；参考：《江苏科技大学》2017年硕士论文

【摘要】：当前我国钢渣的年产量很大,可钢渣的综合利用效率却很小,大量钢渣被置弃,造成严重污染。为此,课题组已对钢渣再生骨料自密实混凝土进行了系列的研究。在此基础上,本文主要通过碳化试验和氯离子渗透试验,对掺钢渣再生骨料自密实混凝土的抗碳化性能和抗氯离子渗透性能进行了研究,分析了不同因素的影响,在此基础上建立了混凝土寿命预测模型。此外,还对不同钢渣掺量下混凝土碳化和氯离子侵蚀的相互作用进行了试验研究。主要得到的研究结论如下:1、掺钢渣再生骨料自密实混凝土的碳化深度随着钢渣掺量的逐步增大,呈现出先降低后提高的趋势,而且不论养护时间的长短,钢渣掺量对掺钢渣再生骨料自密实混凝土碳化深度的影响规律基本一致。随着养护时间的增加,掺钢渣再生骨料自密实混凝土的抗碳化性能渐渐提升。当掺入10%的钢渣时,掺钢渣再生骨料自密实混凝土的抗碳化性能最好。2、在不同的养护龄期下,随钢渣掺量的变化,掺钢渣再生骨料自密实混凝土氯离子渗透性能有着不同的变化规律。当养护龄期为7天和14天时,随着钢渣掺量的增加,掺钢渣再生骨料自密实混凝土的氯离子扩散系数都呈现出增加的趋势;当养护龄期为28天、56天和90天时,掺入10%的钢渣时,掺钢渣再生骨料自密实混凝土的抗氯离子渗透性能最好。且随着钢渣掺量的逐步增大,掺钢渣再生骨料自密实混凝土的氯离子扩散系数都呈出先降低后增加的趋势。3、在充分考虑掺钢渣再生骨料自密实混凝土的钢渣掺量、养护龄期、保护层厚度等影响因素的情况下。考虑到混凝土随时间变化的CO2扩散系数,创建了综合因素下的碳化寿命预测方程。同样,在Fick第二定律的基础上,进而创建了综合因素下的氯离子扩散系数模型。模型的建立将会为掺钢渣再生骨料自密实混凝土的寿命预测提供依据。4、通过二组对比试验发现,碳化能够降低混凝土氯离子扩散系数,氯离子的侵蚀却使混凝土的抗碳化性能得以提升。
[Abstract]:At present, the annual output of steel slag in our country is very large, but the comprehensive utilization efficiency of steel slag is very small, a large number of steel slag is discarded, which causes serious pollution. Therefore, a series of researches have been carried out on steel slag recycled aggregate self-compacting concrete. On this basis, the carbonation resistance and chloride ion permeability of self-compacting concrete with steel slag recycled aggregate were studied by carbonation test and chloride ion permeation test, and the influence of different factors was analyzed. On this basis, a concrete life prediction model is established. In addition, the interaction between concrete carbonation and chloride ion erosion with different steel slag content was studied experimentally. The main conclusions are as follows: (1) the carbonation depth of recycled aggregate self-compacting concrete with steel slag increases gradually with the increase of steel slag content, and the carbonation depth decreases first and then increases, regardless of the length of curing time. The effect of steel slag content on the carbonation depth of self-compacting concrete with steel slag recycled aggregate is basically consistent. With the increase of curing time, the carbonation resistance of self-compacting concrete with steel slag recycled aggregate is improved gradually. When 10% steel slag is added, the carbonation resistance of self-compacting concrete with recycled steel slag is the best. The chloride ion permeability of self-compacting concrete mixed with steel slag is different. When the curing age is 7 days and 14 days, with the increase of steel slag content, the chloride diffusion coefficient of recycled steel slag aggregate self-compacting concrete shows an increasing trend, and when the curing age is 28 days, 56 days and 90 days, 10% steel slag is added. The self-compacting concrete with steel slag recycled aggregate has the best resistance to chloride ion permeation. With the increase of steel slag content, the chloride diffusion coefficient of self-compacting concrete with steel slag is decreased first and then increased. The content of steel slag and curing age of self-compacting concrete are fully considered. Protective layer thickness and other influencing factors in the case. Considering the CO2 diffusion coefficient of concrete with time, the prediction equation of carbonation life is established. On the basis of Fick's second law, the model of chloride diffusion coefficient is established. The establishment of the model will provide a basis for predicting the life of self-compacting concrete with steel slag recycled aggregate. Through two sets of comparative tests, it is found that carbonation can reduce the chloride diffusion coefficient of concrete. The corrosion of chloride ion can improve the carbonation resistance of concrete.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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