龄期和掺合料对混凝土孔隙影响的分形学评价  

Fractal evaluation of hydration age and admixtures on concrete porosity

作　　者：班顺莉 高嵩[1] 宫尧尧 曹剑 张蕾 BAN Shunli;GAO Song;GONG Yaoyao;CAO Jian;ZHANG Lei(School of Civil Engineering,Qingdao University of Technology,Qingdao 266033,China;Shandong China West Construction Co.,Ltd.,Qingdao 266032,China;Shandong Provincial Communications Planning and Design Institute,Jinan 250000,China)

机构地区：[1]青岛理工大学土木工程学院,山东青岛266033 [2]山东中建西部建设有限公司,山东青岛266032 [3]山东省交通规划设计院,山东济南250000

出　　处：《混凝土》2023年第1期13-16,共4页Concrete

基　　金：国家自然科学基金(51978353)。

摘　　要：为研究龄期和掺合料对混凝土孔隙的影响,采用压汞法测试不同龄期和不同掺合料混凝土的孔结构参数,并计算混凝土孔隙的体积分形维数,探究孔隙体积分形维数的变化及其与强度和耐久性的关系。结果表明:混凝土的孔结构具有明显的分形特征,随着龄期的增长,孔隙率逐渐降低,而孔隙体积分形维数逐渐增大,混凝土孔隙结构越来越不规则;不同掺合料混凝土孔隙体积分形维数与强度和氯离子渗透系数都有一定相关性,强度随分维的增大而增大,氯离子渗透系数随分维增大而降低;掺合料会影响混凝土孔隙结构,掺加矿粉会使混凝土的孔隙率降低,孔隙体积分形维数增大,而掺加粉煤灰会使混凝土早期孔隙率增大,孔隙体积分形维数降低。In order to study the influence of ages and admixtures on concrete pores,the pore structure parameters of concrete with various ages and admixtures were tested by MIP(Mercury Intrusion Porosimetre),and the volume fractal dimension of pores was calculated to explore the change of pore volume fractal dimension and its relationship with strength and durability.The results show that pore structure of concrete has fractal characteristics.With the increase of age,the porosity of concrete decreases gradually,while the fractal dimension of pores increases slightly,and the pore structure becomes more irregular.The pore volumefractal dimension ofconcrete with different admixtures has correlation with strength and chloride ion permeability coefficient,and the strength increases with the fractal dimension,while the chloride ion permeability coefficient decreases with the fractal dimension.Furthermore,the usage of admixtures affects the pore structure of concrete.Mixing of slag reduces the porosity and increases the fractal dimension of pore volume,while addition of fly ash increases the porosity and decreases the fractal dimension of pore volume in the early hydration stage.

关 键 词：混凝土 掺合料 分形维数 抗压强度 孔结构 

分 类 号：TU528.01[建筑科学—建筑技术科学]