【作者】 王传波；

【导师】 杨彦克；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2007， 硕士

【摘要】 早在20世纪50年代末中国就已吸取国外工程因AAR而发生破坏的经验教训，并采取了相应的预防措施。但是直到1990年后在立交桥、机场、工业及民用建筑发现因AAR而导致的破坏之后，才引起了对研究碱骨料反应问题的重视。矿物外加剂是最常用的预防碱集料反应的措施之一，已有许多专家、学者对矿渣、粉煤灰等抑制AAR的机理进行了研究，但是由于实验条件、方法的不同，得出的结论差异较大。为了解决这种差异、采取更有效的预防措施，对掺合料抑制碱-硅酸反应的机理进行深入的研究是非常有必要的。本文结合国内最新科研成果《青藏铁路梁体混凝土掺合料抑制碱-骨料反应有效性实验操作规程》，采用快速砂浆棒法对矿渣、粉煤灰、硫铝酸盐水泥抑制碱-硅酸反应机理进行研究，结合扫描电镜对样品进行微观分析，以观察不同试件反应产物的变化。经分析得出主要结论：砂浆棒法中宜采用降温至20℃检测；矿渣和粉煤灰抑制碱-硅酸反应的机理是因为消耗了大量的Ca（OH）₂，同时反应生成了低n（Ca）／n（Si）比的水化硅酸钙凝胶，“固定”了大量的碱，降低了与活性SiO₂反应的程度；硫铝酸盐水泥因其水化产物中缺乏Ca（OH）₂而不易与活性骨料反应，可以与硅酸盐水泥一起混合或在特殊地区单独使用来预防碱-硅酸反应。更多还原

【Abstract】 As early as the late 1950s China had learned from the damage due to AAR in the overseas civil engineering, and takes the corresponding preventive measures. But until 1990 before the destruction caused by the AAR in the intersection, airports, industrial and civil buildings, we attached importance to study alkali-aggregate-reaction. Mineral admixture is one of the most commonly used measures, A number of experts and scholars studied the mechanism of depressing AAR on the slag, fly ash and etc. but because of the environment and the different methods, the conclusions are not always the same. In order to resolve the differences, and take more effective preventive measures, It’s necessary to have a deep study on the mechanism of the admixture depressing alkali-silica reaction.The study is combined with the latest domestic research results "the experimental practices of the effectiveness about the beam-concrete’ admixture depressing the alkali-aggregate reaction in Qinghai-Tibet Railway ", taking the Accelerating Motar-bar Method to study the mechanism of lag, fly ash, sulfur-aluminum cement depressing alkali-silica reaction, then observing the reaction products of different specimen under the scanning electron microscopy.The main conclusions reached by the analysis: 20℃is a better temperature for testing in the Accelerating Mortar-bar Method; Much of Ca （OH）₂ is used up, the hydration calcium silicate which has lower n（Ca）/n（Si） is produced,numbers of alkali is fixed and reduce the reaction with the active SiO₂ are the reason why the slag and fly ash can depress alkali -silica reaction; sulfur-aluminum cement lacks of Ca（OH）₂, and it’s not easy to react with the active SiO₂. So it can be used to guard against the alkali-silica reaction with the Portland cement or only itself.更多还原