低温对水泥浆体早期力学性能和孔结构的影响
Effect of Low Temperature on Early Mechanical Properties and Pore Structure of Cement Slurry
任杰 1李晓英 1王莹佳 1黄西雅 1卢忠远2
作者信息
- 1. 西南科技大学材料与化学学院,绵阳 621000
- 2. 西南科技大学环境友好能源材料国家重点实验室,绵阳 621000
- 折叠
摘要
基于水泥基材料水化特征和孔结构分形理论,研究了低温条件对水泥浆微观结构和宏观力学性能的影响,重点研究了 0 ℃时水泥基材料孔隙结构的演变及其与宏观性能的关联.结果表明:低温对早龄期水泥浆体水化具有显著的抑制作用,与对照组相比,低温养护12 h、48 h和96 h各水灰比试样水化抑制程度分别在59.96％～69.07％、23.86％～38.09％以及3.09％～7.40％之间.低温养护水泥浆的抗压强度低于同龄期标准养护试样,且阈值孔径、最可几孔径、孔隙率较大.通过分形维数定量分析发现,低温作用下早期水泥浆体孔结构在凝胶孔区、细毛管孔区和宏观孔隙具有明显分形特征,分形维数为2.000～2.789 6;区域Ⅰ、区域Ⅱ、区域Ⅴ分形维数与抗压强度具有明显的线性关系且与水灰比无关,揭示了 0 ℃时水泥浆体孔隙结构的演变规律.
Abstract
Based on the hydration characteristics of cement-based materials and the fractal theory of pore structure,the influence of low temperature conditions on the microstructure and macroscopic mechanical properties of cement slurry was studied.The evolution of pore structure of cement-based materials at 0 ℃ and its correlation with the macroscopic proper-ties were mainly studied.The results show that low temperature can significantly inhibit the hydration of cement slurry at early age.Compared with the control group,the hydration inhibition degree of water-cement ratio samples for 12 h,48 h and 96 h is between 59.96％～69.07％,23.86％～38.09％and 3.09％～7.40％,respectively.The compressive strength of the low temperature curing cement slurry is lower than that of the standard curing sample of the same age,and the threshold pore size,the maximum pore size and the porosity are larger.The quantitative analysis of fractal dimension shows that the pore structure of early cement slurry under low temperature has obvious fractal characteristics in gel pore area,capillary pore area and macroscopic pore area,with fractal dimension ranging from 2.000 to 2.789 6.The fractal di-mensions of region Ⅰ,region Ⅱ and region Ⅴ have obvious linear relationship with compressive strength and are inde-pendent of water-cement ratio,which reveals the evolution law of pore structure of cement slurry at 0 ℃.
关键词
低温/早期/力学性能/孔结构/分形维数Key words
low temperature/early stage/mechanical properties/pore structure/the fractal dimension引用本文复制引用
出版年
2024
NETL
NSTL
万方数据