Zhang Xinyu, Li Wei, Huang Xiaojun, Wang Zhixin, Deng Min
College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China.
Materials (Basel). 2025 Sep 21;18(18):4404. doi: 10.3390/ma18184404.
The alkali-dolomite reaction (ADR) describes the interaction between alkalis in concrete and dolomite which results in dedolomitization, leading to cracking and deterioration of the concrete. A large number of research has explored the chemical products associated with the ADR, mechanisms of expansion, and methods of identification, but our understanding of the occurrence and progression of the ADR chemical reaction is substantially limited. Key factors controlling the ADR chemical reaction are generally not understood. This paper investigates the migration process of alkali ions in dolomitic limestone and reaction process with dolomite crystals and alkali. Dolomitic limestone samples were selected for experimentation. The amount of Sodium (Na) was measured as a means of assessing alkali ion migration. We measured the degree of dedolomitization using X-ray diffraction (XRD). Microstructure was evaluated using field emission scanning electron microscopy (FESEM). This research provides new insights into dedolomitization. The pore network provides the physical pathway for alkali ion migration. Concentration gradients drive the migration of alkali ions, and their interactions control the efficiency of alkali ion migration.
碱-白云石反应（ADR）描述了混凝土中的碱与白云石之间的相互作用，这种相互作用会导致白云石脱矿化，进而导致混凝土开裂和劣化。大量研究探讨了与ADR相关的化学产物、膨胀机制和识别方法，但我们对ADR化学反应的发生和进展的理解仍然非常有限。控制ADR化学反应的关键因素通常尚不明确。本文研究了碱离子在白云质灰岩中的迁移过程以及与白云石晶体和碱的反应过程。选择白云质灰岩样品进行实验。测量钠（Na）的含量以评估碱离子的迁移情况。我们使用X射线衍射（XRD）测量脱矿化程度。使用场发射扫描电子显微镜（FESEM）评估微观结构。这项研究为脱矿化提供了新的见解。孔隙网络为碱离子迁移提供了物理通道。浓度梯度驱动碱离子迁移，它们之间的相互作用控制着碱离子迁移的效率。
