酸雨作用下碳酸盐岩类文物的溶蚀过程与机理

发布时间：2018-02-10 04:28

  本文关键词： 碳酸盐岩 模拟酸雨 溶蚀机理　出处：《岩土工程学报》2017年11期 　论文类型：期刊论文

【摘要】：通过模拟硫酸型酸雨加速侵蚀石灰岩的室内试验,监测了试验过程中试样的质量变化、Ca~(2+)释放量、酸雨pH值变化、计算了H~+消耗速率及试样的表面硬度变化率,对试样的微观结构进行了观察和测量,对比分析了酸雨的淋蚀作用和浸泡作用,根据试验结果讨论了酸雨溶蚀石灰岩的机理,并分析了孔隙特征对石灰岩溶蚀过程的影响。试验结果表明:酸雨的淋蚀作用会溶解石灰岩中的碳酸盐并剥离岩石表面,造成新鲜岩石继续与酸雨作用,加速了石灰岩的质量损失和Ca~(2+)的释放,同时试样的表面硬度和表层微观结构发生相应的改变,但是,溶蚀产物会部分填充石灰岩内的微孔隙和微裂隙,可以有效减缓小尺寸孔隙(0.01μm)的破坏;孔隙特征对酸雨侵蚀石灰岩的过程有重要影响,孔隙率越高,酸雨越容易进入岩石内部并造成破坏;孔隙率一定的情况下,孔隙尺寸越大,酸雨作用的时间和程度会越充分,对石灰岩的破坏也越严重;在相同的试验条件下,试验选取的3种石灰岩中南响堂山石窟石灰岩的抗酸雨侵蚀能力最弱。
[Abstract]:By simulating the accelerated erosion of limestone by sulphuric acid rain, the mass change of the sample and the pH value of the acid rain are monitored. The rate of H ~ ~ consumption and the change rate of the surface hardness of the sample are calculated. The microstructure of the sample was observed and measured, and the leaching and soaking of acid rain were compared and analyzed. Based on the experimental results, the mechanism of acid rain dissolution of limestone was discussed. The effect of pore characteristics on the dissolution process of limestone is analyzed. The experimental results show that the leaching of acid rain can dissolve the carbonate in limestone and peel off the rock surface, causing the fresh rock to continue to interact with acid rain. The mass loss of limestone and the release of Ca~(2) were accelerated, and the surface hardness and microstructure of the sample changed accordingly. However, the dissolution products partially filled the micro-pores and fractures in the limestone. The pore characteristics have an important effect on the process of acid rain eroding limestone. The higher the porosity, the easier it is to enter the rock and cause damage. The larger the porosity is, the larger the pore size is. The more sufficient the time and degree of acid rain, the more serious the damage to limestone, and under the same test conditions, the ability of acid rain resistance of the limestone in the south Xiangtangshan Grottoes is the weakest under the same test conditions.
【作者单位】： 中国科学院地质与地球物理研究所中国科学院页岩气与地质工程重点实验室;中国科学院大学;中国文化遗产研究院文物修复所;兰州大学土木工程学院;
【基金】：财政部基本科研业务费课题(2014-JBKY-06) 科技部支撑计划课题(2014BAK16B02)
【分类号】：K85;TU45
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