热孔计法表征不同龄期下混凝土孔结构的研究  

Study on Pore Structure Characterization of Concrete at Different Ages by Thermoporometry

作　　者：蒋正武[1] 邓子龙[1] 袁政成[1] 李文婷[1] 张楠[2] 

机构地区：[1]同济大学先进土木工程材料教育部重点实验室,上海201804 [2]中国建筑股份有限公司技术中心,北京101300

出　　处：《建筑材料学报》2013年第6期1044-1048,共5页Journal of Building Materials

基　　金：国家重点基础研究发展计划(973计划)项目(2011CB013805);国家自然科学基金资助项目(51278360;51078269);"十二五"国家科技支撑计划项目(2011BAE14B06);中央高校基本科研业务费专项资金资助项目;高性能土木工程材料国家重点实验室开放基金资助项目(2011CEM008)

摘　　要：采用热孔计法测试了3,28,90d龄期下普通混凝土和高强混凝土孔结构特征及其变化,并与压汞法、氮吸附法进行了比较,进一步分析了混凝土微孔结构及孔隙率与其宏观力学性能的关系.结果表明:与压汞法相比,热孔计法能较好地表征混凝土中直径小于100nm的孔结构变化情况.高强混凝土养护28d后,孔径大于20nm的孔隙率变化较小,而在普通混凝土中这类孔仍然持续减少.相较于孔隙率的变化,孔径分布的变化能更好地解释混凝土宏观性能的差异.对普通与高强混凝土来说,直径小于20nm的孔对其宏观力学性能的影响不大.Pore structures and their changes of ordinary strength concrete and high-strength concrete at dif- ferent curing ages of 3, 28, 90 d were studied using thermoporometry, and the results were compared with those from MIP and NAD. The relationship among micro pores and porosity of concrete and its macroscop- ic properties was also studied. The results indicate that compared to MIP, thermoporometry can character- ize the features of pores with the diameter smaller than 100 nm in concrete accurately. The differences of macroscopic mechanical properties of concretes can be explained using the changes of their pore size distri- bution. After curing age of 28 d, the amount of pore with the diameter larger than 20 nm in high strength concrete changes little, but it decreases gradually in ordinary strength concrete. And pores with diameter smaller than 20 nm in concrete have little influence on the macroscopic mechanical property of concrete.

关 键 词：热孔计法 混凝土 孔隙率 孔径分布 

分 类 号：TU528.01[建筑科学—建筑技术科学]