酸雨对泰山古碑石刻侵蚀的模拟研究

为研究我国华东典型山地地区的酸沉降对文物古迹的影响,选取与泰山古碑石刻材质相同的花岗石,采用pH分别为3.0、3.8、4.7、5.6的人工模拟酸雨对泰山花岗石进行周期浸泡实验,测定不同pH值下的腐蚀速率;同时利用扫描电子显微镜(SEM)观测试验前后样品表面特征;并对浸泡前后的样品表面粉末进行X射线衍射分析。实验结果表明:影响石材腐蚀的主要因素是酸雨的酸度;花岗石石样受到侵蚀后,质量减少百分数随pH值降低而增大,最大质量损失达到0.073%,而当pH值大于3.8时,石样的最终腐蚀情况基本一致,基本在0.02%左右;并且无论是高酸度酸雨,还是低酸度酸雨,都对材料外观造成了损害;蚀后样品查出了CaSO4和MgSO4相分。

Deterioration of Historic Carved Stone at Mount Tai by Simulated Acid Rain

For the study of east China’s acid deposition on impact of cultural relics,materials with the same Mount Tai historic carved stone were selected. Simulated periodical immersion experiments were done by applying artificial acid rain with pH value of 3.0,3.8,4.7 and 5.6 onto granite stone until 10 cycles. Rates of deterioration for different pH were obtained. Facial characteristics were observed through scanning electronic microscope,and X -ray diffraction analysis was used to analyze the powders from the samples’surface before and after immersion. Laboratory results indicated that the acidity was a major factor on the impact of granite stones. After the corrosion,the quality reduction percentage reduced along with pH increase,but when pH was above 3.8,eventual corrosion reached basically the same situation,and whether it was high acidity or low pH,it would arouse the harm to the material. After the corrosion,CaSO4 and MgSO4 were found in the samples.