Alkali–silica reaction (ASR) is an ongoing problem that causes damage to concrete constructions and reduces their durability. Therefore, minimizing this undesired reaction is of great interest for both safety and economic reasons. Additives containing high aluminium content are very effective in reducing the release of silica and enhancing the durability of concrete; however, the mechanism for this effect is still under discussion. In this study, an enrichment of aluminium in the near‐surface region was observed for natural quartzite rock after storage in Al (OH)₃ and metakaolin as aluminium sources, from which we conclude that the formation of aluminosilicate sheets of a few nanometres inhibits the silica release; this hypothesis is supported by high‐resolution spectra of Al 2p, Si 2p and O 1s.

中文翻译：

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铝暴露后天然石英岩岩石近表面区域的铝富集

碱-硅石反应（ASR）是一个持续存在的问题，会对混凝土结构造成损坏并降低其耐久性。因此，出于安全和经济原因，使这种不期望的反应最小化是非常重要的。铝含量高的添加剂在减少二氧化硅的释放和增强混凝土的耐久性方面非常有效。但是，这种作用的机制仍在讨论中。在这项研究中，观察到天然石英岩岩石在Al（OH）₃和偏高岭土作为铝源储存后，在近地表区域富集了铝，由此我们得出结论，形成几纳米的铝硅酸盐薄片会抑制铝的形成。二氧化硅释放；Al 2p，Si 2p和O 1s的高分辨率光谱证明了这一假设。