Wang Jie, Du Bin, Shen Mingxuan, Li Yukun, Yuan Shisong
College of Civil Engineering, Guizhou University, Huaxi District, Guiyang, 550025, Guizhou, China.
Sci Rep. 2025 Jan 13;15(1):1868. doi: 10.1038/s41598-024-83364-w.
Long-term erosion by acidic solutions in karst regions leads to continuous deterioration of the physical and mechanical properties at the interfaces of engineering structures, adversely affecting their operational performance. To investigate the degradation patterns of the mechanical properties and corrosion mechanisms of the concrete‒limestone composite (CLC) after exposure to acidic corrosion, three kinds of CLC samples treated with acidic solutions of different pH values were fabricated. Mechanical property analysis was conducted via triaxial compression testing methods. Lemaitre's strain equivalence hypothesis was utilized, and on the basis of the assumption that the strength of rock microelements follows a Weibull distribution, the damage to microelements due to acidic corrosion was combined with compressive failure. The study results indicate that acidic corrosion significantly affects the mechanical properties and failure modes of CLCs. As the pH of the solution decreased from 7 to 5 and then to 3, the peak strengths of the samples decreased by 16.6% and 11.92%, whereas the elastic moduli decreased by 25.36% and 23.13%, respectively. Furthermore, with increasing confining pressure, the peak and residual strengths of the composite significantly improved; the residual strength increased from 8.2 MPa to 86.93 MPa as the confining pressure increased from 0 to 10 MPa. Finally, by introducing a damage constitutive model corrected for postpeak residual strength, the stress‒strain full-process curves of CLCs under different degrees of acidic corrosion were more accurately simulated. The validation results confirm the applicability and accuracy of the established model, providing a theoretical basis and technical support for understanding and predicting the mechanical behavior of limestone-concrete structures in acidic environments.
岩溶地区酸性溶液的长期侵蚀会导致工程结构界面处的物理和力学性能持续劣化，对其运行性能产生不利影响。为了研究混凝土-石灰岩复合材料（CLC）在酸性腐蚀后的力学性能退化模式和腐蚀机制，制备了三种用不同pH值酸性溶液处理的CLC样品。通过三轴压缩试验方法进行力学性能分析。利用了勒迈特应变等效假设，并在岩石微元强度服从威布尔分布的假设基础上，将酸性腐蚀对微元的损伤与压缩破坏相结合。研究结果表明，酸性腐蚀显著影响CLC的力学性能和破坏模式。随着溶液pH值从7降至5再降至3，样品的峰值强度分别降低了16.6%和11.92%，而弹性模量分别降低了25.36%和23.13%。此外，随着围压的增加，复合材料的峰值和残余强度显著提高；当围压从0增加到10MPa时，残余强度从8.2MPa增加到86.93MPa。最后，通过引入针对峰值后残余强度修正的损伤本构模型，更准确地模拟了不同程度酸性腐蚀下CLC的应力-应变全过程曲线。验证结果证实了所建立模型的适用性和准确性，为理解和预测酸性环境中石灰岩-混凝土结构的力学行为提供了理论依据和技术支持。
