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《【化学工程与工艺专业】【毕业设计+开题报告+文献综述】聚醚型水泥减水剂的合成和性能研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、30(20届)毕业设计聚醚型水泥减水剂的合成和性能研究3030摘要:近年来,随着建筑行业的发展,减水剂作为水泥的主要外加剂应用也越来越广,其主要作用是减少混凝土的用水量,增加强度,同时提高混凝土的耐久性,在改善混凝土性能,提高建筑水平起到了重要作用。减水剂主要经历了3个阶段,从最开始的木质磺酸系减水剂,到萘系减水剂,现在已经发展到了第三代聚羧酸类减水剂,这类新型减水剂较前两类有了很好的提高,而且实现了减水剂的分子设计,为减水剂的发展奠定了重要的理论基础,它主要分为聚醚型和聚酯型两大类,这次主要研究的是聚醚
2、型减水剂。聚醚型高性能减水剂除具有高性能减水(最高减水率可达35%)、改善混凝土孔结构和密实程度等作用外,还能控制混凝土的塌落度损失,更好地控制混凝土的引气、缓凝、泌水等问题。它与不同种类的水泥都有相对较好的相容性,即使在低掺量时,也能使混凝土具有高流动性,并且在低水灰比时具有低粘度及塌落度经时变化小的性能。关键词:聚醚;混凝土;减水剂;聚醚型。3030Abstract:Inrecentyears,withthedevelopmentoftheconstructionindustry,superplast
3、icizerasthemainapplicationofcementadmixtureisbecomingmoreandmorewide,itsmaineffectistoreducewaterconsumption,increasestrengthofconcrete,andenhancethedurabilityofconcrete,concreteperformanceinimproving,improvethebuildinglevelplayedanimportantrole.superplas
4、ticizermainexperiencedthreestages,fromthebeginningofthewoodinesssulfonicacidnaphthalenewater-reducingagent,tofastensuperplasticizer,nowithasdevelopedintoathirdgenerationofclusteringwater-reducingagentcarboxylicacid,thisnewclassofsuperplasticizerrelatively
5、beforetwokindsraiseisverygood,andfulfillingthemoleculardesign,reducingagentforsuperplasticizerdevelopmentprovidesimportanttheoreticalfoundation,itmainlydividedintopolyethertypeandpolyestertypetwokindsbig,themainresearchispolyethertypesuperplasticizer.Poly
6、carboxylatesuperplasticizeradditiontohigh-performancewater-reducing(thehighestwaterratesupto35%),improvingthedensityofconcreteporestructureanddegreeofeffects,butalsocontrolofconcreteslumploss,bettercontrolofair-entrainingconcrete,retarding,bleedingandothe
7、rproblems.Itiswithdifferenttypesofcementhaverelativelygoodcompatibility,evenatlowdosage,theycanmakeconcretewithhighfluidity,andlowwater-cementratio,havelowviscosityandtheslumpbythetimechangeasmallperformanceKeywords:Polycarboxylate;concrete;superplasticiz
8、er.3030目录摘要1Abstract1一绪论31选题背景、意义31.2减水剂的概念和作用原理……………………………………………………………..52相关研究的最新成果和动态62.1减水剂的研究发展………………………………………………………………….......72.2国外聚羧酸类减水剂的发展……………………………………………………………82.3国内聚羧酸类减水剂的发展……………………………………………………………93聚羧酸类