高流动混凝土孔分形特征及其与抗冻性的关系  

Relationship between pore fractal dimension and frost resistance of high fluidity concrete

作　　者：王剑[1] 张金喜[1] 

机构地区：[1]北京工业大学交通工程重点实验室,北京100124

出　　处：《混凝土》2011年第12期12-15,共4页Concrete

基　　金：交通工程北京市重点实验室专项基金项目(JTP-2010-1)

摘　　要：采用压汞法测定了不同矿物掺合料高流动混凝土的孔结构参数,通过基于热力学关系的分形模型计算得到了高流动混凝土的孔结构表面积分形维数,探讨了含不同矿物掺合料高流动混凝土分形维数与小于100 nm孔隙比例、中值孔径、平均孔径及抗冻性的关系。结果表明:孔表面积分形维数随养护龄期和掺合料的种类和掺量的不同而不同;分形维数越大,孔径小于100 nm孔隙比例越大,中值孔径与平均孔径越小,高流动混凝土抗冻性能越好。基于热力学关系的分形模型计算得到的孔表面积分形维数能够很好地表征混凝土孔结构的分布状况与抗冻性能。Pore structure of high fluidity concrete with different admixtures was determined by mercury intrusion porosimetry（MIP）, and fractal model based on thermodynamic method was used to calculate the pore surface fractal dimension of high fluidity concrete.Relationships between pore surface fractal dimension and pore proportion with size smaller than lOOnm, median pore diameter, average pore diameter and frost resistance of high fluidity concrete with different admixtures were discussed.The result indicates that pore surface fractal dimension changes with the curing ages of concrete and species and quantities of admixtures.As fractal dimension increases,the pore proportion with size smaller than lOOnrn in- creases, median pore diameter and average pore diameter increase, and frost resistance of high fluidity concrete becomes better.Pore surface fractal dimension which is calculated by the fractal model based on thermodynamic method can be used to characterize the distribution of pore and frost resistance of concrete.

关 键 词：高流动混凝土 孔结构 分形维数 抗冻性 

分 类 号：TU528.01[建筑科学—建筑技术科学]