Abstract The alkali-silica reaction (ASR) causes internal expansion that leads to severe concrete degradation. The structure of the ASR products remains largely unclear, due to the limitation of laboratory probes in micro-chemical-crystallographic study. We hereby performed synchrotron-radiation-based X-ray absorption spectroscopy and diffraction investigations to both ASR product samples collected from the field, and reference samples with known structure. Our results suggest that the field ASR crystals from distinct sources are nearly identical. They share a layer-silicate structure similar to the mineral shlykovite, whereas the stacking of the layers in field ASR crystals is altered in several ways, such as the variable basal spacing and significant glide of adjacent layers along the b-axis. We also demonstrate that the amorphous ASR product highly resembles C-S-H. Our study adds new insights to the atomistic structure of ASR products.

中文翻译：

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从 X 射线衍射和显微 X 射线吸收数据精炼的碱-二氧化硅反应产物的原子结构

摘要 碱硅反应（ASR）引起内部膨胀，导致混凝土严重退化。由于实验室探针在微化学晶体学研究中的局限性，ASR 产品的结构在很大程度上仍不清楚。我们在此对从现场收集的 ASR 产品样品和具有已知结构的参考样品进行了基于同步辐射的 X 射线吸收光谱和衍射研究。我们的结果表明，来自不同来源的场 ASR 晶体几乎相同。它们共享类似于矿物石板岩的层状硅酸盐结构，而场 ASR 晶体中层的堆叠以多种方式改变，例如可变的基底间距和相邻层沿 b 轴的显着滑移。我们还证明无定形 ASR 产品非常类似于 CSH。我们的研究为 ASR 产品的原子结构增加了新的见解。