This study investigates the fundamental properties of shallow aragonite-component dominant porous coral reef limestone (CRL) to investigate its micromechanical properties and micrometer-scale pore dissolution characteristics. Nanoindentation tests were performed to assess changes in mechanical properties before and after dissolution. A novel numerical model, integrating the level-set method (LSM), reactive-transport modeling, and image processing technology (IPT) was developed to simulate the static dissolution process of a computed tomography (CT)-scanned porous CRL structure. The nanoindentation results showed that after dissolution, the Young's modulus (E) of the primary mineral component aragonite decreased from 34.09 to 30.01 GPa. Numerical simulations further explored the effects of temperature and mineral component on the dissolution characteristics of CRL. In the multicomponent CRL structure, where both aragonite and calcite coexist, selective dissolution occurred, with aragonite inhibiting calcite dissolution and altering the dissolution pathway. Conversely, the monocomponent aragonite structure was more susceptible to forming larger pores during dissolution. Meanwhile, the dissolution volume and porosity increased with temperature, rising by 47% and 4.84%, respectively, whereas the variation in pore radius did not exhibit a consistent trend with increasing temperature. The macroscopic E was estimated using both the Mori-Tanaka approach and simulation methods, demonstrating that pore dissolution weakens the macromechanical properties of the CRL. This comprehensive analysis enhances the understanding of the physical and chemical properties of CRL, providing valuable insights for the safe and stable construction of islands and reefs.

中文翻译：

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多孔珊瑚礁石灰岩的微观力学性质和溶解特性研究


本研究研究了浅层文石成分为主的多孔珊瑚礁石灰岩 （CRL） 的基本性质，以研究其微观力学性能和微米级孔隙溶解特性。进行纳米压痕测试以评估溶解前后机械性能的变化。开发了一种集成水平集法 （LSM）、反应输运建模和图像处理技术 （IPT） 的新型数值模型，用于模拟计算机断层扫描 （CT） 扫描多孔 CRL 结构的静态溶解过程。纳米压痕结果表明，溶解后，主要矿物成分文石的杨氏模量 （E） 从 34.09 GPa 降低到 30.01 GPa。数值模拟进一步探讨了温度和矿物成分对 CRL 溶出特性的影响。在文石和方解石共存的多组分 CRL 结构中，发生了选择性溶解，文石抑制方解石溶解并改变溶解途径。相反，单组分文石结构在溶解过程中更容易形成更大的孔隙。同时，溶出体积和孔隙率随温度的增加而增加，分别增加了 47% 和 4.84%，而孔半径的变化随温度的升高而变化的趋势并不一致。使用 Mori-Tanaka 方法和模拟方法估计宏观 E，证明孔隙溶解削弱了 CRL 的宏观机械性能。这种全面的分析增强了对 CRL 物理和化学性质的理解，为岛礁的安全稳定建设提供了有价值的见解。