酸雨对普通硅酸盐建筑物表面腐蚀的形态模拟研究

A MORPHOLOGY STUDY ON ACID RAIN EROSIONN OF THE SURFACE OF SILICATE-BUILDING MATERIALS

运用ＰＨ＝５．０，４．０，３．０的人工模拟酸雨和ｐＨ＝５．７的人工模拟自然降水，对普通硅酸盐水泥建筑物表面进行了同步模拟降雨的试验，运用扫描电子显微镜（ＳＥＭ）分析被腐蚀的建筑物表面的形态特征．结果表明：当酸雨的ｐＨ≤４．０时，普通硅酸盐建筑物表面被侵蚀过程明显加重，表层细粒的水泥颗粒被腐蚀掉，使亚表层的粗大颗粒暴露程度急剧增大，同时建筑物表面及亚表层微裂纹比率也急剧增高，从而使酸雨对建筑物的侵蚀过程在作用时间和作用面积上相对增大．故控制城市区域高浓度ＳＯ２的排放，减少强酸性酸雨的形成是保护城市建筑物及其人工生态系统平衡的重要措施．

Synchronous sirnulative predpitation experiments of ordinary silicaiC cement constrUCtion surface are conduCted by using man--made sirnulative add rain (PH is 5.0, 4.0 and3.0 aspdrively) and man--made simulative natule preCipitation (PH 5.7). The characteristicmorphology of the eroded constrUction surface is analyst by means of scanning eleCtronmicroscopy (SEM). The results show that when the PH of acid rain is equivalent to or leSsthan 4.0, the profuses of ordinary silicate ~ construCtion surface erosion obviously reinforce.The small granule on the cement suAsce is eroded, tile exposure of subsurface of the largegranule sharply increases,and the ratio of tiny crackle on construCtion surface and subsurfacesharply rises. Tuns the erosion-- profuses of acid rain relatively enlarge in the aspCCt of earthe and effed area. In order tO proton urban construCtion and the equilibrium of man-- madeeresystffo, exhausting SO, of high density must be restricted and foeing incite acid rainmUSt be decreased.