板岩骨料ASR抑制措施及膨胀预测模型的试验研究

发布时间：2018-03-16 16:12

本文选题：碱-硅酸反应　切入点：碱活性　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着我国建筑事业的高速发展,工程中对混凝土的需求量越来越大,但是由于天然河砂的严重匮乏,人工机制砂不得不大量的用于混凝土生产过程中,相比天然河沙来说,机制砂的加入无疑会给混凝土带来一系列的问题。碱-硅酸反应(ASR)作为最普遍的碱骨料反应(AAR)类型已经在全球范围了造成了大量混凝土工程的破坏和巨大的经济损失。本文在国内外有关ASR研究基础上,结合贵广铁路碱骨料抑制试验课题开展以下几方面的试验研究:1)分别采用岩相法、砂浆棒长度法(慢速法)、快速砂浆棒法以及混凝土棱柱体法对板岩骨料碱活性进行试验鉴定。试验结果表明,岩相法、快速砂浆棒法以及混凝土棱柱体法均判断出该板岩骨料具有较高的碱活性,而慢速法却给出相反的结论。2)分别采用快速砂浆棒法与混凝土棱柱体法研究养护温度对板岩骨料ASR膨胀影响。以快速砂浆棒法试验结果为例,通过非线性拟合方法得出ASR反应速率常数与温度之间的函数关系式,最终运用Arrhenius方程建立板岩骨料ASR膨胀预测模型。3)分别采用快速砂浆棒法、混凝土棱柱体法、小混凝土柱法以及砂浆柱法进行偏高岭土抑制板岩骨料ASR有效性试验研究,结果表明能有效抑制ASR的最低偏高岭土掺量为20%。对比几种试验方法,结果显示,快速砂浆棒法与混凝土棱柱体法的试验结果相关性最强。并通过微观分析研究偏高岭土抑制板岩骨料ASR的机理所在。
[Abstract]:With the rapid development of China's construction industry, the demand for concrete in engineering is increasing. However, due to the serious shortage of natural river sand, artificial sand has to be used in the process of concrete production in large quantities, compared with natural river sand. The addition of mechnical sand will undoubtedly bring a series of problems to concrete. As the most common type of alkali aggregate reaction, ASR (Alkali-Silic Acid reaction) has caused a great deal of damage to concrete engineering and huge economy all over the world. Loss. Based on the research on ASR at home and abroad, In connection with the test project of alkali aggregate inhibition in Gui-Guangzhou Railway, the following experimental studies were carried out in the following aspects: 1) the lithofacies method was used respectively. The alkali-activity of slate aggregate was tested by the method of length of mortar rod (slow speed method, rapid mortar bar method and concrete prism method). The results show that the lithofacies method can be used to determine the alkali-activity of slate aggregate. Both the rapid mortar bar method and the concrete prism method show that the slate aggregate has high alkali activity. The slow speed method is used to study the effect of curing temperature on the ASR expansion of slate aggregate by using the rapid mortar bar method and the concrete prism method respectively. The test results of the rapid mortar bar method are taken as an example. The function relation between ASR reaction rate constant and temperature is obtained by nonlinear fitting method. Finally, Arrhenius equation is used to establish ASR expansion prediction model of slate aggregate. 3) Rapid mortar bar method and concrete prism method are used, respectively. Small concrete column method and mortar column method are used to study the effectiveness of metakaolin in inhibiting ASR of slate aggregate. The results show that the minimum content of metakaolin can effectively inhibit ASR is 20%. The experimental results of rapid mortar bar method and concrete prism method have the strongest correlation, and the mechanism of inhibiting ASR of slate aggregate by metakaolin is studied by microscopic analysis.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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