矿渣微细粉对水泥基材料抗酸雨侵蚀特性研究  

Anti-acid rain erosion performance of cement materials of slag micro-fine powders

作　　者：马保国[1] 肖君[1] 汪海贵[1] 王凯[1] 

机构地区：[1]武汉理工大学硅酸盐材料工程教育部重点实验室,湖北武汉430070

出　　处：《混凝土》2009年第1期23-26,共4页Concrete

基　　金：国家863计划项目(2005AA332010)

摘　　要：模拟中国硫酸型酸雨情况,以普通硅酸盐水泥空白砂浆为参比体系,研究采用矿渣微细粉对于改善混凝土抗酸雨性能的影响,分别从质量损失率、抗压强度、抗折强度和微观显微分析手段研究了各项性能变化规律。研究结果表明:在试验条件下矿渣微细粉存在最佳掺量区间,以20%～30%为最佳。当掺量超过30%时,砂浆不能生成足够的C-S-H凝胶,结构较疏松,内部微裂纹未被新的水化产物填充密实,H+和SO42-更容易进入浆体内部,导致更严重的腐蚀破坏;而当掺量少于20%时,火山灰效应发挥不明显,也不能促进砂浆抵御酸雨的侵蚀。在模拟酸雨环境中浸泡98d后,25%矿渣掺量的砂浆质量损失率最小仅为-38.2‰,且后期下降趋势最为平缓;对于抗压强度和抗折强度,在酸雨侵蚀条件下分别呈现不同的变化趋势,对于抗压强度的强化效果应控制矿粉的掺量不小于25%,而对于抗折强度,则应控制掺量不大于30%。综合考虑抗压强度和抗折强度,25%掺量最能强化砂浆抗酸雨侵蚀的性能;在SEM显微分析中可以观察到,矿粉砂浆较空白砂浆结构密实,微裂纹少。矿粉使水泥浆体的孔隙率明显下降,强化了集料界面黏结力,并减少了最大孔径的尺寸,大幅度提高混凝土的密实度,也就能更好地抵御酸雨离子的侵入。The chinese sulfate types acid rain＇s Condition is simulated, taking ordinary portland cement blank mortar to be the eontrastive system;using slag micro-fine powders to improve the concrete property of resisting acid rain is researched;the law of the properties are studied through mass loss rate, compressive strength loss, flexural strength loss and SEM microanalysis.The results show that,in our experiment＇s condition,slag micro-fine powders existed the best doping interval ,taking for 20%-30% as the best mixing amount.When the doping amount is over 30% ,the mortar cannot form enough C-S-H gel ,the structure is more loose.The internal micro-crack did not filled by new hydrated product to be compacting,H^＋ and SO4^2- were more easily to enter the slurry＇s internal area and result in more seriously corrosion damage.When the doping amount is less than 20% ,the volcanic ash effects played non-obviously and also cannot promote mortar resisting the erosion of acid rain.After soaking in the simulated acid rain environment 98 d,25% of slag mortar＇s mass loss rate was minimum,which was only -38.2%0 ,and the later downward trend is the most gentle.Taking the compressive strength loss and flexural strength loss, it has the different gentle.To be the compressive strength, the strengthen effect should be not less than 25%, and to be the ftexural strength loss,it should be less than 30%.Comprehensive considering the compressive strength and flexural strength,the 25% doping is the best.From SEM mieroanalysis,the slag mortar compared to the blank mortar is more compacting, the micro-crack is few.Slag makes the cement mortar＇s porosity significantly decreased, and reduced the large pore size, greatly increased concrete＇s density, also can improve resistance to acid rain ions＇ invasion.

关 键 词：磨细矿粉 酸雨 质量损失率 抗压强度损失 抗折强度损失 SEM显微分析 

分 类 号：TU528.041[建筑科学—建筑技术科学]