Abstract Several aspects of alkali-silica reaction (ASR) are still poorly understood, for example the formation of ASR products occurring before significant aggregate cracking. This study focuses on the analysis of these products and the comparison with the products formed after crack formation. A novel approach for the characterisation of ASR products was used combining different electron microscopy techniques. This combination allows analysis of the ASR products present in small gaps and cracks with a width below 1 μm present between adjacent mineral grains of aggregates. In the three samples studied, the products in thin grain boundaries show no distinct morphology and they are amorphous. They were defined as untextured ASR products. The products present in larger veins form fibrils and platelets, called platey products, and are mainly crystalline. In spite of the differences in morphology, untextured and platey ASR products are of similar composition.

中文翻译：

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透射电镜测定混凝土中碱硅反应产物的显微结构、结晶度和成分

摘要 碱-二氧化硅反应 (ASR) 的几个方面仍然知之甚少，例如 ASR 产物的形成发生在显着的骨料开裂之前。本研究重点对这些产品进行分析，并与裂纹形成后形成的产品进行比较。结合不同的电子显微镜技术使用了一种表征 ASR 产品的新方法。这种组合允许分析存在于聚集体相邻矿物颗粒之间宽度低于 1 μm 的小间隙和裂缝中的 ASR 产物。在研究的三个样品中，薄晶界的产品没有显示出明显的形态，它们是无定形的。它们被定义为无纹理的 ASR 产品。存在于较大静脉中的产物形成原纤维和血小板，称为板状产物，并且主要是结晶的。尽管形态不同，但无纹理和片状 ASR 产品的组成相似。