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EVA胶粉改性水下抗分散修补砂浆的制备与性能研

作者:陈昀昀1,朱清帅2,刘宁3,余剑英3

关键字:EVA,胶粉,改性,水下,抗分散,修补,砂浆

 
(1.中国电力工程顾问集团华北电力设计院有限公司,北京 100120;
2.南水北调中线干线工程建设管理局河南分局,河南 郑州  450003;
3.武汉理工大学 材料科学与工程学院,湖北 武汉  430070)
 
    摘要:采用醋酸乙烯-乙烯共聚物(EVA)胶粉、硫铝酸盐水泥、普通硅酸盐水泥、砂、聚丙烯酰胺和高效减水剂等制备了改性水下抗分散修补砂浆,研究了EVA胶粉对修补砂浆水下粘结强度、水下抗折和抗压强度、流动性及水下凝结时间的影响,通过扫描电镜(SEM)观察了EVA胶粉改性砂浆的微观形貌。结果表明:EVA胶粉显著提高了修补砂浆的水下粘结强度和抗折抗压强度。与未掺EVA的修补砂浆相比,掺加8%EVA胶粉的修补砂浆28 d水下粘结强度提高了50%、抗折强度提高了30%。SEM分析表明,EVA胶粉在砂浆中形成了聚合物膜,并且随着EVA胶粉掺量的增加,逐渐形成连续结构的聚合物膜。
    关键词:EVA胶粉;水下修补砂浆;抗分散性;粘结强度
    中图分类号:TU57+8.1        文献标识码:A        文章编号:1001-702X(2018)01-0118-04
 
Preparation and properties of an underwater dispersion resistant repair mortar modified by EVA
CHEN Yunyun1,ZHU Qingshuai2,LIU Ning3,YU Jianying3
(1.China Electric Power Engineering Consulting Group North China Power Design Institute Co. Ltd.,Beijing 100120,China;2.Henan Branch of Construction and Administration Bureau of South-to-North Water Diversion Middle Route Project,Zhnegzhou 450003,China;3.School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China)
    Abstract:An underwater dispersion resistant repair mortar was prepared with vinyl acetate ethylene copolymer(EVA) powder,sulphoaluminate cement,Portland cement,sand,polyacrylamide and superplasticizer. Effect of EVA powder on underwater adhesion strength, compressive strength,flexural strength,flow resistance and setting time of the underwater dispersion resistant repair mortar was investigated,and the microstructure of the mortar modified by EVA powder was observed by scanning electron microscopy(SEM). The results indicated that the underwater adhesion strength,compressive strength and flexural strength of the repair mortar was significantly improved by the EVA powder. Compared with the repair mortar without EVA,the adhesive strength of 28 d increases by 50% and the flexural strength increases by 30% by the addition of 8%EVA powder. SEM of the repair mortar showed that the EVA gradually formed a continuous polymer film with the increase of EVA powder content.
    Key words:EVA powder,underwater repair mortar,dispersion resistant,adhesion strength