Dissolution and chemical weathering of carbonate rocks have complex effects on their mechanical properties, accelerating their rate of deterioration that can lead to early failure under external stresses. To investigate the effects of acidic solutions on the mechanical properties of inherently low-porosity karstic limestone, compression tests were performed on sound and weathered samples exposed to different corrosive environments and for different durations. The tested samples exhibited a general increase in porosity and decrease in peak strength and Young's modulus for higher acidity and exposure duration. To establish links between these mechanical changes and those at the micro-scale, microstructures and mechanisms of deformation were also studied. As indicators of the sample degradation, the distribution, orientation and intensity of the fractures in the tested samples and their twinning density were used. Based on these parameters, it was found that chemical erosion influences microcrack propagation, orientation, distribution and intensity, due to modification of the competence contrast between the constituents of the rock. These effects significantly influence the semi-brittle behaviour of the samples, including the distribution and intensity of microcracking and crystal plasticity.

中文翻译：

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化学风化对岩溶灰岩显微组织和力学性能的影响

碳酸盐岩的溶解和化学风化对其力学性质有复杂的影响，加速了它们的退化速度，从而导致在外部应力下过早失效。为了研究酸性溶液对固有低孔隙度岩溶石灰岩力学性能的影响，对暴露于不同腐蚀环境和不同持续时间的声音和风化样品进行了压缩试验。对于更高的酸度和暴露时间，测试样品表现出孔隙率的普遍增加和峰值强度和杨氏模量的降低。为了在这些机械变化与微观尺度之间建立联系，还研究了微观结构和变形机制。作为样本退化的指标，分布，使用了测试样品中裂缝的方向和强度及其孪晶密度。基于这些参数，发现化学侵蚀影响微裂纹的传播、方向、分布和强度，这是由于岩石成分之间的能力对比的改变。这些影响显着影响样品的半脆性行为，包括微裂纹和晶体塑性的分布和强度。