VAE改性砂浆自收缩与抗压强度相关性研究  

Study on the correlation between auto-shrinkage and compressive strength of VAE modified mortar

作　　者：王智鑫 梅军鹏 徐智东 李海南[2] WANG Zhixin;MEI Junpeng;XU Zhidong;LI Hainan(School of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,China;Department of Construction Cost,Wuhan Textile University,Wuhan 430200,China)

机构地区：[1]武汉科技大学城市建设学院,湖北武汉430065 [2]武汉纺织大学工程造价系,湖北武汉430200

出　　处：《混凝土》2023年第7期140-144,共5页Concrete

基　　金：国家自然科学基金(51908434);湖北省教育厅科学技术研究计划项目(Q20191706)。

摘　　要：研究了醋酸乙烯-乙烯共聚乳胶粉(Ethylene-vinyl acetate copolymer powder,VAE,1%~4%)对水泥基材料3、7、14、21、28 d自收缩及抗压强度的影响,分析了自收缩与抗压强度的相关性,并利用X射线衍射分析(X-Ray Diffraction,XRD)、扫描电镜(Scanning Electron Microscope,SEM)和电阻率法(Electrical Resistivity Method,ERM)探究了VAE对水泥基材料水化进程的影响及自收缩与抗压强度的相关性机理。结果表明,VAE降低了水泥熟料的溶解速率,延缓了加速期的到来,减少了水化产物生成,降低了早期水化速率并抑制了Ca(OH)2与粉煤灰的火山灰反应,从而降低了水泥基材料的自收缩和抗压强度,且随着VAE掺量的增加,抗压强度和自收缩不断减小.VAE改性水泥砂浆的自收缩和抗压强度存在良好的线性相关,研究结果可为实际工程中预测自收缩提供一定参考。The effects of vinyl acetate(VAE,1%~4%)on auto-shrinkage and compressive strength of cement-based materials at 3,7,14,21 d and 28 d were investigated,and the correlation between auto-shrinkage and compressive strength was analyzed.Also,an attempt to explore the hydration process of cement-based materials and the correlation between auto-shrinkage and compressive strength had been done with the means of X-Ray Diffraction(XRD),Scanning Electron Microscope(SEM)and Electrical Resistivity Method(ERM).Analyses indicated that the addition of VAE could reduce the dissolution rate of cement clinker,decrease the hydration product formation and capillary water consumption,and lessen the early hydration rate of cement and the secondary hydration degree of fly ash.Consequently,the auto-shrinkage and compressive strength of cement-based materials were reduced,and the higher the VAE dosage,the more obvious the decrease.There was a good linear correlation between auto-shrinkage and compressive strength in VAE modified cement mortars and the results could be used to predict auto-shrinkage in practice engineering.

关 键 词：VAE 自收缩 抗压强度 XRD SEM 电阻率 相关性分析 

分 类 号：TU528.01[建筑科学—建筑技术科学]