Analysis of Air Voids Evolution in Cement Pastes Admixed with Non-ionic Cellulose Ethers  

作　　者：欧志华 XIAO Yi 王菁菁 MA Baoguo JIANG Longmin JIAN Shouwei 

机构地区：[1]School of Civil Engineering,Hunan University of Technology,Zhuzhou 412007,China [2]State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2018年第4期915-923,共9页武汉理工大学学报（材料科学英文版）

基　　金：the National Natural Science Foundation of China(Nos.51461135001 and 51741804);the Natural Science Foundation of Hunan Province,China(No.2017JJ2066);the Scientific Research Project of Education Department,Hunan Province,China(No.17A054)

摘　　要：Four cellulose ethers（CEs） were compared for their effects on the pore structure of cement paste using mercury intrusion porosimetry. The experimental results show that the total pore volume and porosity of cement pastes containing the four cellulose ethers are significantly higher than that of the pure cement pastes and the total pore volume and porosity of cement pastes containing HEC（hydroxyethyl cellulose ether） or low viscosity cellulose ethers are low in four CEs. By changing the surface tension and viscosity of liquid phase and the strengthening of liquid film between air voids in cement pastes, CEs affect the formation, diameter evolution and upward movement of air voids and the pore structure of hardening cement paste. For the four CEs, the pore volume of cement pastes containing HEC or low viscosity cellulose ethers is higher with the diameter of 30-70 nm while lower with the diameter larger than 70 nm. CEs affect the pore structure of cement paste mainly through their effects on the evolvement of the small air voids into bigger ones when the pore diameter is below 70 nm and their effects on the entrainment and stabilization of air voids when the pore diameter is above 70 nm.Four cellulose ethers（CEs） were compared for their effects on the pore structure of cement paste using mercury intrusion porosimetry. The experimental results show that the total pore volume and porosity of cement pastes containing the four cellulose ethers are significantly higher than that of the pure cement pastes and the total pore volume and porosity of cement pastes containing HEC（hydroxyethyl cellulose ether） or low viscosity cellulose ethers are low in four CEs. By changing the surface tension and viscosity of liquid phase and the strengthening of liquid film between air voids in cement pastes, CEs affect the formation, diameter evolution and upward movement of air voids and the pore structure of hardening cement paste. For the four CEs, the pore volume of cement pastes containing HEC or low viscosity cellulose ethers is higher with the diameter of 30-70 nm while lower with the diameter larger than 70 nm. CEs affect the pore structure of cement paste mainly through their effects on the evolvement of the small air voids into bigger ones when the pore diameter is below 70 nm and their effects on the entrainment and stabilization of air voids when the pore diameter is above 70 nm.

关 键 词：cellulose ethers cement pastes pore structure air voids diameter evolution 

分 类 号：TQ172.1[化学工程—水泥工业]