Physical and Mechanical Properties and Porosity of Cement Mortar Modified by Hydroxyethyl Methyl Cellulose
ZHANG Shaokang1, WANG Ru1,2, XU Linglin1,2, ZHONG Shiyun1,2, ZHANG Guofang1,2, WANG Peiming1,2
1 School of Materials Science and Engineering, Tongji University, Shanghai 201804, China 2 Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Tongji University, Shanghai 201804, China
Abstract: In order to study the influence of different hydroxyethyl methyl celluloses (HEMCs) on the properties of cement mortar, three kinds of HEMCs were used to prepare modified cement mortar in this paper. Those HEMCs are high, low substitution degree and polyacrylamide (PAAm) modified HEMC. The influence of the HEMCs on cement mortar was compared from the mechanical properties, porosity and pore size distribution. The results show that the addition of HEMCs can improve the water retention rate and consistence of fresh cement mortar, increase the tensile bond strength, but decrease the compressive strength and flexural strength. The substitution degree and PAAm have minor influence on the water retention rate and flexural strength. Compared to HEMC with low substitution degree, HEMC with higher substitution degree have higher consistence, tensile bond strength and dry shrinkage rate. PAAm significantly decreases the consistence of HEMC-modified cement paste and decreases the tensile bond strength too. The result of mercury intrusion porosimeter (MIP) shows that the small pores of mortar are reduced by the addition of HEMCs, meanwhile a considerable number of micro-sized macropores are introduced, and the porosity of cement mortar also are increased; but no significant difference observed among the HEMC-modified mortars.
作者简介: 张绍康,2016年6月毕业于中国矿业大学,获得工学学士学位。现在同济大学攻读硕士学位,主要从事聚合物改性水泥砂浆的研究。王茹,同济大学教授,博士研究生导师。2003年毕业于四川大学获得材料学专业博士学位,先后在同济大学和奥地利维也纳技术大学进行博士后研究工作,回国后在同济大学工作至今,2010—2011年在美国哥伦比亚大学进行访问;兼任国际聚合物混凝土学会理事会副理事长。主要从事聚合物水泥基复合材料的基础理论和工程应用研究,发表相关学术论文100余篇,多数被SCI和EI收录;主编Progress in Polymers in Concrete和《干混砂浆原材料及产品检测方法》等著作。
引用本文:
张绍康, 王茹, 徐玲琳, 钟世云, 张国防, 王培铭. 羟乙基甲基纤维素改性水泥砂浆的物理力学性能和孔隙率[J]. 材料导报, 2020, 34(Z2): 607-611.
ZHANG Shaokang, WANG Ru, XU Linglin, ZHONG Shiyun, ZHANG Guofang, WANG Peiming. Physical and Mechanical Properties and Porosity of Cement Mortar Modified by Hydroxyethyl Methyl Cellulose. Materials Reports, 2020, 34(Z2): 607-611.