混凝土材料损伤机理.pdf

《混凝土材料损伤机理.pdf》由会员上传分享，免费在线阅读，更多相关内容在应用文档-天天文库。

1、第30卷第2期材料科学与工程学报总第136期Vo1．30NO．2JournalofMaterialsScience&EngineeringApr．2012ArticleID：1673-2812(2012)02—0182—07．DamageMechanismofConcreteZHANGShi—pingI，DENGMin2，TANGMing-shn2(1．DepartmentofArchitectureCivilEngineering，NanjingInstituteofTechnology，Nanjing2111

2、67，China；2．CollegeofMaterialsScience&Engineering，NanjingUniversityofTechnology，Nanjing210094，China)[Abstract]Thedamagecauseofanairportrunwayshoulderhasbeenexploredbothinfieldandinlaboratory．Seriouscrackingandspallingappeareduponsurfaceoftherunwayshouldershort

3、lyaftertheairportwasputintoservice．Bothofalkali—aggregatereactionandfreeze-thawcyclesmayresultinsimilarvisiblecrackingandspalling．Thepossibilityofalkali—aggregatereactionwasexcludedbyfieldsurveyand1~oexaminationsuchasX—raydiffractometry，petrographicanalysisan

4、ddeterminationofalkalireactivityofaggregates．Freeze—thawcycleswereidentifiedtobethemaincauseforthedamageoftherunwayshoulder，accordingtorapidfreezingmethod．Microstructureofdamagedconcretewasexaminedbyopticalmicroscopyandmercuryintrusionporosimetry(MIP)inordert

5、oexplainthemechanismofthedamage．Newapproachestomitigatethedamageofconcreteusedundersevereenvironmentalconditionswerealsodiscussed．[Keywords]concrete；alkali—aggregatereaction；frostresistance；microstructureCLCnumber：TU528．07DocumentCode：A混凝土材料损伤机理张士萍，邓敏，唐明述(1．南

6、京工程学院建筑工程学院。江苏南京211167；2．南京工业大学材料科学与工程学院，江苏南京210009)【摘要】本文分别在现场以及试验室内研究了某机场跑道混凝土出现严重的开裂和剥落现象的原因。碱集料反应以及冻融循环均会导致开裂和剥落，通过XRD、岩相分析以及集料的碱活性检测排除了发生碱集料反应的可能性。采用快冻法测试了机场跑道现场钻取的芯样混凝土的抗冻性。同时借助于显微镜、SEM、MIP分析了损伤混凝土的微观结构，揭示出跑道混凝土的损伤与抗冻性较差有关，并讨论了改善严酷地区混凝土耐久性的措施。【关键词】混凝土；碱

7、集料反应；抗冻性；微观结构causedbyvariousenvironmental，physicaland1Introducti0nchemica1factorssuchascorrosionofreinforcementbarsduetocarbonationorchlorideingress，freezing—Concretestructuresarebuilttoprovideaservicethawingaction，sulfateattack，alkaliaggregateduringalimitedt

8、imeperiodand，insomecases，thereaction(AAR)，etc．~z-63．Theresistanceagainstneedformaintenanceisforeseen[．However。thesechemicalerosionsandphysicaldeteriorationsrecentlydurabilityofconcretehas