| With the rapid development of construction industry in our country,the demand of concrete become more and more huge,because of the serious lack of natural river sand,artificial sand mechanism has to used in concrete production process,compared with the natural river sand,the artificial sand mechanism will no doubt bring a series of problems to concrete,Alkali-silica reaction(ASR)as the most common type of alkali aggregate reaction(AAR)has been caused a large number of concrete engineering and huge economic losses around the world,In this paper,based on the domestic and foreign research on ASR,and in combination with jingguang railway alkali aggregate inhibition to carry out the following aspects of experimental research:1)The alkali reactivity of slate aggregate was examined by Petrographic Method,Mortar-bar Method,Accelerating Mortar-bar Method and Concrete prism method,The experimental results showed that Petrographic Method,Accelerating Mortar-bar Method and Concrete prism method determine the salte aggregate has high alkali activity,but the Mortar-bar Method giving the wrong conclusion.2)The curing temperature on the ASR expansion of slate aggregate was examined by Accelerating Mortar-bar Method and Concrete prism method.Through nonlinear fitting we find the function relation between reaction rate constant and temperature.The prediction model about ASR expansion was established through Arrhenius equation.3)The effectiveness of Metakaolin on suppressing ASR expansion of slate aggregate was tested by Accelerating Mortar-bar Method,Concrete prism Method,Small Concrete prism and Mortar column Method,the result showed the minimum Metakaolin can effectively inhibit ASR dosage was 20%.According to the result of the tests indicated that the results of Accelerating Mortar-bar Method and Concrete prism Method had best relation.Finally,Through microscopic analysis the mechanism of Metakaolin inhibiting ASR expansion of slate aggregate. |
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