基于分形维数的硫酸盐环境下混凝土抗蚀系数及微观机理研究  

Study on Corrosion Resistance Coefficient and Micro-mechanism of Concrete Under Sulphate Environment Based on Fractal Dimension

作　　者：杨军兆 张戎令[1,2] 薛彦瑾 王小平 窦晓峥 宋毅 YANG Junzhao;ZHANG Rongling;XUE Yanjin;WANG Xiaoping;DOU Xiaozheng;SONG Yi(College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Bridge Engineering National Local Joint Engineering Laboratory of Disaster Prevention and Contral Technology,Lanzhou Jiaotong University,Lanzhou 730070,China;China Railway Construction Bridge Engineering Bureau Group Co.,Ltd.,Wuhan 430050,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]兰州交通大学道桥工程灾害防治技术国家地方联合工程实验室,兰州730070 [3]中铁大桥局集团有限公司设计分公司,武汉430050

出　　处：《材料导报》2025年第7期89-95,共7页Materials Reports

基　　金：国家重点研发计划政府间重点专项(2024YFE0115200);国家自然科学基金-铁路基础研究联合基金(U2368209);甘肃省交通运输厅基金项目(2023-16)。

摘　　要：为研究硫酸盐环境对混凝土的性能影响,基于新疆台特玛湖地区的实际工程环境,模拟现场腐蚀环境进行室内硫酸盐腐蚀试验。研究了混凝土宏观抗蚀系数、微观孔结构与腐蚀产物等随侵蚀时间的演变规律。并对混凝土孔结构进行分形维数的计算,分析了分形维数、孔隙率与抗蚀系数的关系。结果表明:随着腐蚀时间的延长,抗蚀系数呈先增大后减小的趋势;总孔隙率先降低后增加,有害孔与多害孔占比先减后增,孔隙率与抗蚀系数呈线性关系;分形维数和孔隙大小有关,腐蚀前期混凝土内部孔结构细化,密实度增加,孔隙分布复杂,分形维数增大,当钙矾石、石膏等膨胀性腐蚀产物发生膨胀作用,混凝土内部孔结构粗化,孔隙分布简单,分形维数降低。通过XRD侵蚀产物分析可知钙矾石、石膏产生膨胀作用是引起混凝土劣化的主要原因,且侵蚀早期主要发生钙矾石侵蚀,侵蚀后期主要发生石膏侵蚀。研究成果可为西北盐渍土地区混凝土抗腐蚀提供参考和借鉴。In order to study the effect of sulphate environment on the performance of concrete,indoor sulphate corrosion test which simulated the on-site engineering corrosive environment in Xinjiang Taitama Lake area was carried out.From the perspective of concrete macroscopic corrosion resistance coefficient,microscopic pore structure and the evolution of corrosion products with the erosion time and other perspectives,and the pore structure of concrete fractal dimension calculation,analysed the relationship between fractal dimension,porosity and corrosion resistance coefficient.The results show that with the growth of corrosion time,the corrosion resistance coefficient is first enhanced and then weakened;the total porosity first decreases and then increases,the harmful pore and multi-harmful pore ratio first reduces and then increases.The porosity and corrosion resistance coefficient have a linear relationship.Fractal dimension is related to the pore size,at the pre-erosion,the pore structure of concrete is refined,the compactness of the concrete increases,the distribution of pore space is complex,fractal dimensions increase.When the expansion effect of calcium alumina,gypsum and other expansive corrosion products occurs,the internal pore structure of concrete is coarsened,the pore distribution is simple,and the fractal dimension decreases.Through the analysis of XRD erosion products,it is found that the expansion of calcium alumina and gypsum is the main reason for the deterioration of the concrete,and calcium alumina erosion mainly occurs in the early stage of erosion,and gypsum erosion mainly occurs in the late stage of erosion.The research results can provide some references for the corrosion resistance of concrete in the salty soil area of Northwest China.

关 键 词：硫酸盐腐蚀 抗蚀系数 核磁共振 孔结构 分形维数 

分 类 号：TU528[建筑科学—建筑技术科学]