摘要
掺入少量氧化石墨烯(GO)能显著改善水泥基材料的综合性能。但GO极易在水泥水化的高钙高碱性介质中聚沉并降低新拌浆体的流动性。目前国内外还未有对同时改善GO在水泥浆体中分散能力及其掺配砂浆的流动性的系统研究。本文研究了在聚羧酸减水剂(PC)存在下,蔗糖(T)对GO在饱和氢氧化钙(CH)溶液中的分散性能以及GO掺配砂浆流动性与力学性能的影响。相比只用PC分散剂,额外添加少量T能显著提升GO在CH溶液中稳定分散的能力并能改善浆体流动性。力学性能测试表明,T能大幅增加GO掺配砂浆抗压强度和抗折强度。相对于PC/GO空白砂浆试件,当GO、T掺量分别为0.07%、0.175%(质量分数)时,试件28 d抗折和抗压强度分别提高25.42%和20.16%,电通量降低33.6%。微观结构测试表明T能进一步促使GO在水泥基材料中均匀分散,有利于形成结构更规整密实的水泥水化产物以及空洞裂缝等缺陷更少的水泥石。
Incorporation of a small amount of graphene oxides(GO)can significantly improve the overall performance of cementitious materials.However,GO easily aggregates in the high calcium and alkaline cement hydration system and reduces the fluidity of the fresh slurry.At present,there is no systematic study at home and abroad to simultaneously improve the dispersibility of GO in cement pastes and the fluidity of mortar blended with it.In this paper,the effect of sucrose(T)on the dispersion of GO in saturated calcium hydroxide(CH)solution and the fluidity and mechanical properties of GO mixed mortar in the presence of polycarboxylate superplasticizer(PC)was studied.The addition of a small amount of T significantly increases the dispersion of GO in CH solution and improves the fluidity of the slurry compared with using only PC as a dispersant.Mechanical tests show that T greatly increases the compressive strength and flexural strength of GO mixed mortar.When the GO and T dosages are 0.07%and 0.175%(mass fraction),the 28 d flexural strength and compressive strength increase by 25.42%,20.16%and the electric flux reduces by 33.6%compared with the PC/GO blank mortar specimen.The detailed microstructure characeterizaiton tests show that T can further promote the uniform dispersion of GO in the cementitious materials,which is conducive to the formation of a more regular and dense structure of cement hydration products and less voids or cracks in the harden cement.
作者
王远贵
袁小亚
高军
魏致强
杨森
郑旭煦
WANG Yuangui;YUAN Xiaoya;GAO Jun;WEI Zhiqiang;YANG Sen;ZHENG Xuxu(College of Materials Science and Engineering,Chongqing Jiaotong University,Chongqing 400074,China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《硅酸盐通报》
CAS
北大核心
2020年第11期3453-3462,共10页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金(51402030)
重庆市基础科学与前沿技术研究专项基金(cstc2017jcyjBX0028)
重庆市教育委员会科学技术研究项目(KJZD-K201800703)。
关键词
氧化石墨烯
蔗糖
分散
力学性能
流动性
graphene oxide
sucrose
dispersion
mechanical property
fluidity
