| 摘要: |
| 采用图像(IA)法测试水泥乳化沥青(CA)砂浆内的球形封闭孔，采用压汞(MIP)法、恒温恒湿干燥（CTHD）法、核磁共振(NMR)法测试其连通孔.结果表明：CA砂浆中的封闭孔平均直径约为150μm，孔隙率取决于新拌CA砂浆的含气量和铝粉掺量，最大孔隙率（体积分数）超过20%；其连通孔主要是半径为10～100nm的毛细孔，孔隙率随水灰比的增加而增大.对比发现，NMR法、MIP法和CTHD法测得的连通孔总孔隙率相近，但前2种方法能测得连续孔径分布，而CTHD法不能.与MIP法相比，NMR法采用吸水饱和试件且在常压下进行测试，对试件微结构的影响较小，其测试结果能更加精确地表征CA砂浆的原始连通孔结构. |
| 关键词: 水泥乳化沥青砂浆 孔结构 核磁共振法 压汞法 干燥法 图像法 |
| DOI：103969/j.issn1007 9629201605025 |
| 分类号: |
| 基金项目:国家重点基础研究发展计划（973计划）项目（2013CB036200）；国家自然科学基金面上项目（51478476） |
|
| Pore Structure of Cement Emulsified Asphalt Mortar and Comparison of Its Test Methods |
|
DENG Dehua, YE Tao, YUAN Qiang, WANG Yong
|
|
School of Civil Engineering, Central South University, Changsha 410075, China
|
| Abstract: |
| Spherical closed voids in cement asphalt(CA) mortar were measured by image analysis(IA) method. Connected pores in CA mortar were measured by mercury intrusion porosimetry(MIP), constant temperature and humidity drying(CTHD) method and nuclear magnetic resonance(NMR) method. The results show that the average diameter of closed voids is about 150μm. The porosity（by volume） of closed voids is depending on the air content and the amount of aluminum powder in fresh CA mortar and its maximum value is more than 20%. The radius of connected pores is 10100nm. The larger the water cement ratio in fresh CA mortar, the higher the porosity of connected pores. It is found that the total porosity of connected pores in CA mortar obtained by NMR, MIP and CHDT methods is similar. NMR and MIP methods can get continuous pore size distribution, while CTHD method cant. Comparing MIP and NMR methods, some damage of the microstructure in CA mortar is able to occur during drying and measuring process in the former, but is not due to the specimens saturated with water in the latter. NMR method is the best method to accurately measure and characterize the original connected pore structure of CA mortar. |
| Key words: cement asphalt(CA) mortar pore structure nuclear magnetic resonance(NMR) mercury intrusion porosimetry(MIP) drying method image analysis |
