环氧树脂乳液改性水泥砂浆性能的研究.pdf

摘要在前人研究成果的基础之上,本文针对环氧树脂乳液改性水泥砂浆的工作性、力学性能、粘结性能以及耐化学腐蚀性能进行了较为系统的研究。期望对发展聚合物改性水泥砂浆提供基本资料,使水性环氧树脂乳液改性水泥砂浆在混凝土构筑物上有更广泛的应用。首先,本文选用双掺环氧树脂乳液与粉煤灰的改善措施,观察其对新拌水泥砂浆工作性的影响。结果表明,环氧树脂乳液具有减水效果。掺入环氧乳液后, 改性水泥砂浆的密度小于普通水泥砂浆,产生较多的气泡;吸水率与收缩率明显下降,凝结时间延缓。硬化后改性水泥砂浆抗压强度呈现递减趋势,抗折强度在前期降低,在掺入量达到9%时,出现峰值且高于基准水泥砂浆的抗折强度。在研究力学性能的同时,考察了不同养护方法对改性水泥砂浆的影响,得出了最佳养护条件。通过粘结抗折试验,分析了不同界面与环氧乳液掺量对改性水泥砂浆粘结抗折强度的影响。结果表明,网状界面的粘结抗折强度要大于自然断面。耐化学腐蚀性能是反应砂浆耐久性能的主要指标, 本文将乳液改性砂浆放入一定浓度的酸、碱、盐溶液中浸泡,相应龄期后, 测定其抗折、抗压强度。结果表明,双掺乳液和粉煤灰的试件性能要比单掺乳液或粉煤灰的试样性能优良,推测这是由于环氧乳液在水泥水化物中固化成膜以及粉煤灰的三大效应使得水泥砂浆性能有了很大的提高。关键词:环氧树脂乳液;粉煤灰;改性砂浆;耐腐蚀 ABSTRACT Inthisthesis,asystematic research oncemem mortarhas beenperformed through waterborne epoxy resinemulsion,including theworkability,mechanical properties,the bond flexuralperformance andchemically hasbeendesigned to provide some usefulinformation about cement mortarmodified by thepolymer,which couldbeextensivelyapplied inbuildingengineering. Firstly,Double mixing waterborneepoxy resinemulsionandfly ashwerechosen asexperimental assays were performed toexamine theirimpact on theworkability ofthe modified cement resultsdemonstrated thatthe emulsion shows asignificant influenceofdecreasing ,afterbeingmixed, thedensity ofthe modified cemem mortar isless than thatofbenchmark mortar; meanwhile,more bubbles are 、)l,ith waterborneepoxy emdsion, the rateofbibulous andshrinkage decrease obviously,the settingtime strength the flexuralstrength,itbegin to reduce atthebeginning,after mixed晰tll thebestproportion,a peaI【value appeared, which ismuch higher thanthatof thebenchmark cement mortal'.Atthesame time, based on thestudy ofthemechanical properties,in order tooptimize experimental conditions,we examine thedifferentmaintenance method towards theinfluence of modified cement mortarBased on thestudy ofmechanical properties,weanalyze the influence ofthedifferent interfaceand thedifferentr