为保护石质文物免遭其侵害,有必要进行凝结水作用机制研究。基于溶蚀实验研究方法,采用自行研制的静态和动态溶蚀模拟实验系统,全面模拟凝结水对碳酸盐岩的溶蚀。在实验过程中,考虑CO2、温湿度等条件,分析不同因素对溶蚀过程的影响,并实时进行质量损失、微观结构、水质变化等测试分析。最后借助Phreeqc软件进行溶蚀数值模拟,进行对比验证分析,验证模拟实验的准确性。静态和动态模拟实验均表明凝结水会造成碳酸盐岩溶解,且随CO2浓度增大而增加,对灰岩溶蚀效果强于白云岩;动态实验模拟水汽凝结过程中,微观水汽侵入性强,更易造成白云岩溶蚀量和岩石孔隙率显著增大;实验溶蚀过程和计算的溶蚀深度与数值模拟结果一致,溶蚀曲线呈二次型,溶蚀过程前期较快后期较缓,计算1 a内灰岩的溶蚀深度为0.027 6 mm,白云岩的溶蚀深度为0.013 6 mm。
In order to protect stone relics from the infraction of condensation water,it is necessary to study the mechanism of condensation water. Based on dissolution experimental methods,the dissolution of condensation water on carbonate rocks was stimulated with the self-made static and dynamic experimental system. Considering CO2 concentration,temperature and humidity,the effect of different factors on the dissolution process was analyzed and the mass loss,microstructure,water change,and etc. were tested during the experiment process. Finally,the process of dissolution was stimulated by the numerical software Phreeqc to verify the accuracy of simulation experiment. Static and dynamic simulation experiments show that condensation water dissolves carbonate rocks increasing with CO2 concentration and the dissolution of limestone is greater than dolomite. In the dynamic simulation experiment of vapor condensation,dolomite dissolution and rock porosity are significantly increased because the microscopic vapor is strong intrusive. Dissolution process and calculated dissolution depth are consistent with numerical simulation results. Dissolution curve shows quadratic indicating that preliminary dissolution is faster and post-dissolution is gentler. Calculated dissolution depth of limestone is 0.027 6 mm and the dissolution depth of dolomite is 0.013 6 mm in a year.