《材料员》课件-1-1混凝土概述

《材料员》MaterialClerk混凝土ConcreteCONTENTS01混凝土的定义Definitionofconcrete混凝土的分类Classificationofconcrete02混凝土的特点Characteristicsofconcrete0301PART.01混凝土的定义Definitionofconcrete01、混凝土的定义Definitionofconcrete混凝土是现代土木工程中用途最广、用量最大的建筑材料之一。从广义来讲，混凝土是由胶凝材料、粗细集料和水按适当比例配合、拌制而成的混合物，由具有一定可塑性的浆体经一定时间硬化而成具有一定强度的人造石材，统称混凝土。Concreteisoneofthemostversatileandheavilyusedbuildingmaterialsinmoderncivilengineering.Inabroadsense,concreteisamixtureofcementitiousmaterials,coarseandfineaggregatesandwaterintheappropriateproportions,mixedfromacertainplasticityofthepasteafteracertainperiodoftimetohardenintoacertainstrengthofman-madestone,collectivelyknownasconcrete.01、混凝土的定义Definitionofconcrete以水泥为胶凝材料砂石为骨料的混凝土称为水泥混凝土，在建筑工程中最为常用；以沥青为胶凝材料砂石为骨料的混凝土称为沥青混凝土，在道路工程中最为常用。Concretewithcementasthecementitiousmaterialsandandgravelastheaggregateiscalledcementconcreteandismostcommonlyusedinconstructionprojects;concretewithasphaltasthecementitiousmaterialsandandgravelastheaggregateiscalledasphaltconcreteandismostcommonlyusedinroadprojects.02PART.02混凝土的分类Classificationofconcrete02、混凝土的分类Classificationofconcrete混凝土的种类很多，可根据其组成、特性与功能等从不同角度进行分类。Therearemanytypesofconcrete,whichcanbeclassifiedfromdifferentanglesaccordingtotheircomposition,propertiesandfunctions.02、混凝土的分类Classificationofconcrete1.按表观密度分Dividedbyapparentdensity(1)普通混凝土。表观密度约为2400kg/m3（通常在2350～2500kg/m3之间波动），用天然或人工砂、石为集料配制而成的混凝土，是土建工程中最常用的混凝土，主要用作各类建筑的承重结构材料。(1)Ordinaryconcrete.Apparentdensityofabout2400kg/m3(usuallyfluctuatesbetween2350and2500kg/m3),withnaturalorartificialsandandstoneasaggregatesformulatedconcrete,isthemostcommonlyusedconcreteincivilengineering,mainlyusedasaload-bearingstructuralmaterialforvarioustypesofbuildings.普通混凝土Ordinaryconcrete(2)轻混凝土。表观密度可以轻达1900kg/m3，往往采用陶粒等轻质多孔的集料，或者掺入一定量的加气剂或泡沫剂，配制成多孔结构的轻混凝土。主要用作轻质结构材料和保温绝热材料。(2)Lightconcrete.Apparentdensitycanbeaslightas1900kg/m3,oftenusinglightweightporousaggregatessuchasceramicpellets,ormixedwithacertainamountofaeratororfoamagent,formulatedintoaporousstructureoflightconcrete.Itismainlyusedasalightweightstructuralmaterialandasathermalinsulationmaterial.(3)重混凝土。表观密度可达3200kg/m3，是用特别密实的集料（如钢屑、重晶石、铁矿石等）配制而成的混凝土，因其具有防辐射功能，又称防辐射混凝土。主要用作核能工程的屏蔽结构材料。(3)Heavyconcrete.Theapparentdensitycanreach3200kgm3.Itisaconcretemadeofspeciallydenseaggregates(suchassteelchips,Baryte,ironore,etc.).Becauseofitsradiationprotectionfunction,itisalsocalledradiationprotectionconcrete.Mainlyusedasashieldingstructuralmaterialfornuclearenergyengineering.(2)轻混凝土。表观密度可以轻达1900kg/m3，往往采用陶粒等轻质多孔的集料，或者掺入一定量的加气剂或泡沫剂，配制成多孔结构的轻混凝土。主要用作轻质结构材料和保温绝热材料。(2)Lightconcrete.Apparentdensitycanbeaslightas1900kg/m3,oftenusinglightweightporousaggregatessuchasceramicpellets,ormixedwithacertainamountofaeratororfoamagent,formulatedintoaporousstructureoflightconcrete.Itismainlyusedasalightweightstructuralmaterialandasathermalinsulationmaterial.2.按胶凝材料分Classifiedbycementitiousmaterials可以分为水泥混凝土、石膏混凝土、水玻璃混凝土、沥青混凝土、聚合物水泥混凝土、树脂混凝土等。Itcanbedividedintocementconcrete,gypsumconcrete,waterglassconcrete,asphaltconcrete,polymercementconcrete,resinconcrete,etc.3.按流动性分Dividedbyliquidity可分为干硬性混凝土、塑性混凝土、流动性混凝土及大流动性混凝土。Itcanbedividedintodryhardconcrete,plasticconcrete,flowconcrete,andhighflowconcrete.4.按用途分Classificationbypurpose可分为结构混凝土、大体积混凝土、加气混凝土、防水混凝土、耐热混凝土、膨胀混凝土、防辐射混凝土、道路混凝土等。Itcanbedividedintostructuralconcrete,massconcrete,aeratedconcrete,waterproofconcrete,heat-resistantconcrete,expansiveconcrete,radiationresistantconcrete,roadconcrete,etc.5.按生产和施工方法分Classificationbyproductionandconstructionmethods可分为预拌混凝土（商品混凝土）、现场搅拌混凝土、泵送混凝土、喷射混凝土、碾压混凝土、挤压混凝土、离心混凝土、压力灌浆混凝土等。Itcanbedividedintoready-mixedconcrete(commercialconcrete),on-sitemixedconcrete,pumpedconcrete,sprayedconcrete,rollercompactedconcrete,extrudedconcrete,centrifugalconcrete,pressuregroutingconcrete,etc.6.按抗压强度分Classificationbasedoncompressivestrength抗压强度小于30MPa；主要用于一些承受荷载较小的场合，如地面。Thecompressivestrengthislessthan30MPa;itismainlyusedinsomeapplicationswheretheloadislow,suchasfloors.低强混凝土lowstrengthconcrete6.按抗压强度分Classificationbasedoncompressivestrength抗压强度小于30MPa；主要用于一些承受荷载较小的场合，如地面。Thecompressivestrengthislessthan30MPa;itismainlyusedinsomeapplicationswheretheloadislow,suchasfloors.低强混凝土lowstrengthconcrete中强混凝土。抗压强度为30～60MPa；是现今土木工程中的主要混凝土类型，应用于各种工程中，如房屋、桥梁、路面等。Thecompressivestrengthis30-60MPa;Itisthemaintypeofconcreteincivilengineeringtodayandisusedinvariousprojects,suchashouses,bridges,roadsurfaces,etc.中强混凝土Mediumstrengthconcrete6.按抗压强度分Classificationbasedoncompressivestrength高强混凝土Highstrengthconcrete抗压强度大于60MPa；主要用于大荷载、抗震及对混凝土性能要求较高的场合，如高层建筑、大型桥梁等。Compressivestrengthgreaterthan60MPa;mainlyusedforlargeloads,seismicandhighrequirementsforconcreteperformance,suchashigh-risebuildings,largebridges,etc.6.按抗压强度分Classificationbasedoncompressivestrength高强混凝土Highstrengthconcrete抗压强度大于60MPa；主要用于大荷载、抗震及对混凝土性能要求较高的场合，如高层建筑、大型桥梁等。Compressivestrengthgreaterthan60MPa;mainlyusedforlargeloads,seismicandhighrequirementsforconcreteperformance,suchashigh-risebuildings,largebridges,etc.超高强混凝土SuperHighStrengthConcrete抗压强度大于100MPa。主要用于各种重要的大型工程，如高层气窍桩基、军事防爆工程、大型桥梁等。Thecompressivestrengthisgreaterthan100MPa,mainlyusedinvariousimportantlarge-scaleprojects,suchashigh-risegaspilefoundations,militaryexplosion-proofprojects,largebridges,etc.混凝土的品种虽然繁多，但在实践工程中还是以普通的水泥混凝土应用最为广泛，如果没有特殊说明，狭义上我们通常称其为混凝土，本章将做重点讲述。Althoughtherearemanyvarietiesofconcrete,inpracticalengineeringitisthecommoncementconcretethatismostwidelyused,andifnotspecificallystated,weusuallyrefertoitinanarrowsenseasconcrete,whichwillbethefocusofthischapter.03PART.03混凝土的特点Characteristicsofconcrete03、混凝土的特点Characteristicsofconcrete普通水泥混凝土的优点：Advantagesofplaincementconcrete:(1)可塑性。混凝土在凝结前具有良好的可塑性，可浇筑成各种形状和大小的构件和结构物，并可做各种饰面。(1)Plasticity.Concretehasgoodplasticitybeforesetting,andcanbepouredintovariousshapesandsizesofcomponentsandstructures,andcanbeusedforvariousfinishes.(2)安全性。硬化混凝土具有较高的力学强度，且与钢筋之间具有牢固的结合力、收缩膨胀率相近，可做成钢筋混凝土构件或结构物，长期承载，使结构的安全性得到充分保证。(2)Safety.Hardenedconcretehasahighmechanicalstrength,andwithastrongbondbetweenthesteel,shrinkageandexpansionrateissimilar,canbemadeintoreinforcedconcreteelementsorstructures,long-termload-bearing,sothatthesafetyofthestructureisfullyguaranteed.普通水泥混凝土的优点：Advantagesofplaincementconcrete:普通水泥混凝土的优点：Advantagesofplaincementconcrete:(3)经济性。同其他材料相比，混凝土组成材料中的砂石等地方性材料的用量很大，且价格较低，符合就地取材和经济实惠的原则，结构建成后的维护费用也较低。(3)Economical.Comparedwithothermaterials,theamountoflocalmaterialssuchassandandgravelintheconcretecompositionislargeandlessexpensive,inlinewiththeprincipleoflocalmaterialsandeconomy,andthemaintenancecostofthestructureaftercompletionisalsolower.普通水泥混凝土的优点：Advantagesofplaincementconcrete:(4)灵活性。混凝土在土木工程中适用于多种结构形式，满足多种施工要求。可现浇、可预制，也可加入各种外加剂，可以通过改变材料的组成配制不同的混凝土来满足不同工程的需求。(4)Flexibility.Concreteissuitableforavarietyofstructuralformsincivilengineeringtomeetavarietyofconstructionrequirements.Itcanbecast-in-place,prefabricatedorwithvariousadmixtures,andcanbeformulatedtomeettheneedsofdifferentprojectsbychangingthecompositionofthematerials.普通水泥混凝土的优点：Advantagesofplaincementconcrete:(5)耐火性。混凝土一般可有1～2h的防火时效，比钢铁安全得多，不会像钢结构建筑那样在高温下很快软化而造成坍塌。(5)Fireresistance.Concretecangenerallyhave1to2hoffireresistance,muchsaferthansteel,andwillnotcollapseasquicklyassteelbuildingssoftenathightemperatures.普通水泥混凝土的优点：Advantagesofplaincementconcrete:(5)耐火性。混凝土一般可有1～2h的防火时效，比钢铁安全得多，不会像钢结构建筑那样在高温下很快软化而造成坍塌。(5)Fireresistance.Concretecangenerallyhave1to2hoffireresistance,muchsaferthansteel,andwillnotcollapseasquicklyassteelbuildingssoftenathightemperatures.(6)耐久性。混凝土本来就是一种耐久性很好的材料，古罗马建筑经过几千年的风雨依然屹立不倒，这本身就昭示着混凝土应该"历久弥坚"。(6)Durability.Concreteisaverydurablematerial,andthefactthatRomanbuildingshaveremainedstandingafterthousandsofyearsofweatheringisitselfasignthatconcreteshould"lastforever".由于混凝土具有以上许多优点，因此它是一种主要的土木工程材料，广泛应用于工业与民用建筑、道桥工程、水利工程及地下工程、隧道工程、国防建设等，它在国家基本建设中占有重要地位。Asconcretehasmanyoftheaboveadvantages,itisamajorcivilengineeringmaterial,widelyusedinindustrialandcivilbuildings,roadandbridgeworks,waterconservancyworksandundergroundworks,tunnelworks,nationaldefenceconstruction,etc.Itoccupiesanimportantpositioninthenationalcapitalconstruction.普通水泥混凝土的缺点：Disadvantagesofplaincementconcrete:(1)抗拉强度低。混凝土的抗拉强度是抗压强度的1/10～1/15，是钢筋抗拉强度的1/100左右。(1)Lowtensilestrength.Thetensilestrengthofconcreteis1/10to1/15ofthecompressivestrength,andisabout1/100ofthetensilestrengthofreinforcingsteel.普通水泥混凝土的缺点：Disadvantagesofplaincementconcrete:(2)延展性不高。混凝土是一种脆性材料，抵抗变形能力较差，只能承受少量的张力变形，易开裂发生脆性破坏；抗冲击能力差，在冲击或震动荷载作用下容易产生脆断。(2)Ductilityisnothigh.Concreteisabrittlematerial,poorresistancetodeformation,canonlywithstandasmallamountoftensiondeformation,easytocrackbrittledamage;poorimpactresistance,easytoproducebrittlefractureundertheimpactorvibrationload.普通水泥混凝土的缺点：Disadvantagesofplaincementconcrete:(3)自重大，体积大，比强度低。给施工和使用均带来较大的不便，尤其对高层、大跨度建筑物要求材料在保证力学性质的前提下，以轻为宜。(3)Self-important,largevolume,lowspecificstrength.Totheconstructionanduseofbothbringgreaterinconvenience,especiallyforhigh-rise,large-spanbuildingsrequirematerialstoensurethemechanicalpropertiesofthepremise,inordertolightappropriate.普通水泥混凝土的缺点：Disadvantagesofplaincementconcrete:(4)