海水海砂砂浆力学与毛细吸水性能及微观结构研究

摘要/Abstract

摘要： 对不同龄期、水灰比的海水海砂砂浆(SSM)试块开展了抗压、抗折强度测试,通过称重法研究了水灰比、龄期及水温对SSM毛细吸水性能的影响,并基于低场核磁共振技术研究了SSM力学、毛细吸水性能与微观结构的关系,最后将基于多孔介质毛细管吸水模型计算的代表性毛细管直径与基于低场核磁横向弛豫时间估算的砂浆孔隙直径进行了对比分析与讨论。结果表明,SSM前3天强度发展较快,水灰比为0.4的SSM试块养护3 d时的抗压、抗折强度分别为养护28 d时的56.2%、70.3%。当水温从20 ℃升至40 ℃时,水灰比为0.4、养护28 d的SSM试件毛细吸水系数增大1.2倍。长期一维吸水过程中,试件单位面积累计毛细吸水量与吸水时间的0.25次幂呈线性关系。随龄期增长,SSM试件孔隙率呈减小趋势。基于毛细管吸水模型得出的代表性毛细管直径与基于低场核磁横向弛豫时间估算的砂浆孔隙直径较为接近。

关键词: 海水海砂砂浆, 低场核磁共振, 毛细吸水系数, 孔隙直径, 孔隙率, 力学性能

Abstract: In this paper,compressive and flexural strength tests of seawater sea sand mortar (SSM) with different curing ages and water-cement ratios were carried out. The influences of water-cement ratio, curing age and water temperature oncapillary water absorption properties of SSM were studied by weighing method. The relationship between mechanical properties or capillary water absorption properties and corresponding microstructure of SSM was studied based on low field nuclear magnetic resonance technology. Finally, the representative capillary diameter calculated based on the water absorption model of porous media capillary was compared with the pore diameter estimated based on the transverse relaxation time of low field nuclear magnetic resonance technology. The results show that the strength of SSM developed rapidly in the first 3 days, and the compressive and flexural strength of SSM specimens with water-cement ratioof 0.4 curing for 3 d are 56.2% and 70.3% of those of SSM specimens curing for 28 d. When the water temperature rises from 20 ℃ to 40 ℃, the capillary water absorption coefficient ofSSM specimen with water-cement ratio of 0.4 curing for 28 d increases 1.2 times. In the long-term one-dimensional water absorption process, the cumulative capillary water absorption volume per unit area of specimen is linearly related to the 0.25 power of the water absorption time. The porosity of SSM specimens decreases with the increase of curing age. The typical capillary diameter based on capillary water absorption model is close to the mortar pore diameter estimated based on transverse relaxation time of low field nuclear magnetic resonance.

Key words: seawater sea sand mortar, low field nuclear magnetic resonance, capillary water absorption coefficient, pore diameter, porosity, mechanical property

中图分类号:

TU528

于星星, 薛善彬, 张鹏, 郭旗. 海水海砂砂浆力学与毛细吸水性能及微观结构研究[J]. 硅酸盐通报, 2022, 41(10): 3377-3385.

YU Xingxing, XUE Shanbin, ZHANG Peng, GUO Qi. Mechanical Properties, Capillary Water Absorption Properties and Microstructure of Seawater Sea Sand Mortar[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(10): 3377-3385.

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