材料的选择ppt课件

.,1,第三讲材料的选择Lesson3:SelectingMaterials,1,.,2,木材的类型Typesofwood,硬木（阔叶木）和软木（针叶木）Hardwoodsandsoftwoods树木通常被划分为两个种类：硬木和软木Treesareoftendividedintotwoclasses:hardwoodsandsoftwoods有些软木比硬木的硬度更大，所以其名字会被误解（反过来也一样）Thesenamescanbemisleadingbecausesomesoftwoodsareharderthansomehardwoods(thereverseisalsotrue),3,.,3,木材的类型Typesofwood,硬木和软木Hardwoodsandsoftwoods硬木树种通常都有较宽的树叶（部分例外），在秋季或冬季会落叶。Hardwoodtreesusuallyhavebroadleavesthat,withsomeexceptions,areshedinautumnorwinterintemperateclimates软木树种通常都有针状或鳞片状的树叶，一般情况下都是常绿的并且有年轮。Softwoodtreesusuallyhaveneedleorscale-likeleavesthat,inmostcases,remaingreenandareretainedyear-round,4,.,4,木材的类型Typesofwood,硬木和软木Hardwoodsandsoftwoods硬木在建筑中通常用于地板和内装工程（楼梯，壁橱，踢脚线，门窗线条等）Hardwoodsareusedinconstructionmostlyforflooringandinteriorwoodwork(e.g.stairs,cabinetry,baseboards,trimaroundwindowsanddoors,etc.)软木一般被用于结构框架，封板，混凝土支模，脚手架和其他建筑构件Softwoodsareusedforframing,sheathing,concreteforms,scaffoldingandmanyotherbuildingcomponents耐久性好的软木（比如西部红柏，花旗松）可用于屋面瓦，墙面外挂板，窗框和外门等外部构件Somemoredurablespeciesofsoftwoodareusedforexteriorcomponentssuchasroofandwallshingles,windowframesandexteriordoors,5,.,5,软木材的制造Manufacturingsoftwoodlumber,制造过程始于伐树Manufacturingprocessbeginswithharvestingtrees树木被砍下后，树枝先被去除，切割成一定长度方便卡车运送Treesarecutdown,strippedofbranchesandcuttolengthfortransportbytruck这样形成的原木再被运往锯木厂Resultinglogsarethenshippedtoasawmill砍伐之后的区域将种上树苗使森林再生Harvestedareasarereplantedwithtreeseedlingstoregeneratetheforest,6,.,6,软木材的制造Manufacturingsoftwoodlumber,原木在锯木厂进行加工Thelogsareprocessedbythesawmill树皮在加工的过程中被去除Barkisremovedfromthelogs去掉树皮的木材将被锯成的初步的木板Debarkedlogsaresawntointoroughplanks这些厚木板之后会被切边，重新切割成特定尺寸和长度Theseplanksarethenedged,resawntospecificdimensionsandcuttostandardlengths,7,.,7,软木材的制造Manufacturingsoftwoodlumber,之后把生材由垫块隔开堆放进行风干或者窑干Thisgreenlumberisthenstackedwithspacersandeitherair-driedorkiln-dried大多数软木是在窑内烘干而不是风干Mostsoftwoodlumberiskiln-driedratherthanairdried尽管花费更大，但窑干更快速，过程更方便控制Althoughmorecostly,kilndryinglumberisaquickerandeasiertocontrolprocess,8,.,8,软木材的制造Manufacturingsoftwoodlumber,需将生材干燥的重要原因：Thereareseveralimportantreasonstodrygreenlumber:减少收缩变形Reducesproblemswithshrinkage减少变色、腐坏及虫害Reducessusceptibilitytostaining,decayandinsectdamage使得木材可以被防腐处理Enableswoodtobetreatedwithpreservatives,9,.,9,软木材的制造Manufacturingsoftwoodlumber,需将生材干燥的重要原因：Thereareseveralimportantreasonstodrygreenlumber:改善木材握钉及施胶能力Improvesstrengthandtheholdofnails,screwsandglue保证油漆和其他表面材料的更好的粘结力Allowspaintsandotherfinishestoadherebetter6.使木材处理及运输更方便Makesiteasiertohandleandtransport,10,.,10,软木材的制造Manufacturingsoftwoodlumber,干燥之后，木材被送过刨床，校直，磨平，统一尺寸Afterdrying,thelumberisputthoughaplanermillwhereitisstraightened,smoothedanduniformlysized,11,.,11,软木材的制造Manufacturingsoftwoodlumber,木材制造的最后一个过程是将木材分等级Finalstepinthemanufacturingprocessisgradingandsortingthelumber,12,.,12,软木材尺寸Softwoodlumbersizes,木材相关称呼：Lumberterminology:,13,边面Edge,端面End,宽度WidthorDepth,厚度Thickness,正面SideorFace,.,13,软木材尺寸Softwoodlumbersizes,木材的厚度和宽度：Thicknessandwidthoflumberisexpressedintwoways:名义尺寸-在进行干燥和最终处理之前的生材尺寸NominalsizeReferstotheapproximatesize(ininches)ofgreenlumberbeforeitisdriedandreceivesfinalprocessinginaplanermill实际尺寸-进行干燥和刨光处理之后的实际尺寸DressedsizeReferstoactualsizeoflumberafteritisdriedandsurfacedinaplanermill,14,.,14,软木材尺寸Softwoodlumbersizes,结构规格材常用的尺寸（厚度和宽度）:Commonsizes(thicknessandwidth)offraminglumber:,15,.,15,软木材尺寸Softwoodlumbersizes,结构用规格材的长度Commonlengthsofframinglumber:2.4米至7.2米，其中以600毫米递增的每一个长度2.4to7.2min600mmincrements中国内地能买到的最长材料为6.1米LongestmaterialavailableinChinais6.1m常见长度：Usuallengths:,16,.,16,含水率与变形Moisturecontentandshrinkage,木材的含水率极为影响其表观及耐久性Moisturecontentoflumberisanimportantfactorinitsperformanceanddurability含水率是指木材内所含水分的质量占其烘干质量的百分比Moisturecontentistheweightofwatercontainedinwoodexpressedasapercentageoftheweightofoven-drywood木材的含水率会随着周围的空气稳定下来，但会随着环境的变化而变化Moisturecontentofwoodwilleventuallyequilibriumwiththesurroundingairandthenrespondtochangingconditions,17,.,17,含水率与变形Moisturecontentandshrinkage,木材会干缩和湿胀Woodshrinkswhenitdriesandswellswhenitiswet生材干燥时会有明显的收缩Significantshrinkageoccursasgreenwooddries木材各方向变形不一致-顺纹方向变形很小-横纹方向变形很大Wooddoesnotshrinkorexpandequallyinalldirections-verylittleshrinkage/expansionalongthegrain(lengthwise)-significantshrinkage/expansioncanoccuracrossthegrain木材干燥过程中可能会有翘曲出现Warpingmayalsooccuraswooddries,18,翘曲类型Typesofwarps,翘弯Bow,扭弯Crook,扭曲Twist,瓦弯Cup,收缩现象Shrinkageeffects,.,18,含水率与变形Moisturecontentandshrinkage,推荐的含水率：Recommendedmoisturecontentlevels:结构中的规格材在封板之前最高含水率不超过19%Dimensionlumberforframingshouldhaveamaximummoisturecontentlevelof19%beforeitisenclosed一般此时，木材平均含水率在15%，绝大部分收缩已经没有了Atthislevel,theaveragewoodmoisturecontentwillbelower(about15%)andmostshrinkagehasalreadyoccurred可用仪器测试木材的含水率Awoodmoisturemetercanbeusedtomeasurethemoisturecontentofdimensionallumber,19,探针型木材含水率测试仪Pin-typewoodmoisture,.,19,软木材分级Softwoodlumbergrading,结构用材必须是经过分等级的Lumberusedforframingmustbegraded方便设计师选择强度合适的木材Enablesdesignerstospecifylumberthathasappropriatestrengthproperties方便订货商清楚所订货物为其所需Providesbuyerswithareliablewaytoidentifywhattheyarebuying方便施工监理检查材料是否符合规范Allowsbuildinginspectorstoverifythatqualityoflumbermeetscoderequirements,20,.,20,软木材分级Softwoodlumbergrading,大部分木材是根据其缺陷数量进行目测分级Mostlumberisvisuallygradedbasedonnumberandtypesofdefects节疤的尺寸与位置Sizeandlocationofknots斜纹理Slopeofgrain钝棱数量Amountofwane轮裂、端裂与干裂的尺寸Sizeofshakes,splitsandchecks,21,节疤Knot,斜纹理Slopeofgrain,干裂Checks,钝棱Wane,.,21,软木材分级Softwoodlumbergrading,加拿大国家评级系统Canadasnationalgradingsystem加拿大国家木材评级机构NationalLumberGradesAuthority(NLGA)加拿大木材评级标准规定StandardGradingRulesforCanadianLumberGB50005-2003木结构设计规范的分级标准同加拿大标准一致GradingrulesinChinasGB50005-2003CodeforDesignofTimberStructuresareequivalenttotheNLGAs,22,.,22,软木材分级Softwoodlumbergrading,24,树种,等级,含水率,制材厂编号,加拿大木材评级管理局是管理机构NationalLumberGradeAuthority(NLGA)isregulatoryauthority加拿大共有约15家木材定级机构Approximately15Canadiangradingagencies所有木材厂家都是加拿大木材评级管理局下的成员AlllumbermanufacturersaremembersoftheNLGA,评级机构,.,23,评级机构,树种,软木材分级Softwoodlumbergrading,25,等级,含水率,制材厂编号,具有相似特性的木材种类被划分为一类Woodspecieswithsimilarcharacteristicsaregroupedtogether花旗松-落叶松(D.Fir-L)DouglasFirLarch(D.FIR-L)铁杉-冷杉(Hem-fir)HemlockFir(Hem-fir)云杉-松-冷杉(SPF)SprucePineFir(SPF)北方树种(Northern)NorthernSpecies(Northern),.,24,树种,等级,评级机构,软木材分级Softwoodlumbergrading,26,含水率,制材厂编号,目测强度评级Visualstrengthgrades特选结构级材(SS)Selectstructural(SS)一级与二级材No.1,No.2（结构用材）No.1andNo.2(usedforframing)三级材No.3,.,25,含水率,评级机构,软木材分级Softwoodlumbergrading,27,树种,等级,制材厂编号,含水率Moisturecontent制材时的测定值Measuredattimeofmilling干材刨光S-DryS-Dry(surfaceddry)湿材刨光S-GrnSGrn(surfacedgreenorwet),.,26,含水率,制材厂编号,评级机构,软木材分级Softwoodlumbergrading,28,树种,等级,制材厂编号Milldesignation代表制材厂的代号Codeformillwherelumberwasmanufactured,.,27,软木材分级Softwoodlumbergrading,另一种方法是用机械测试每根木材来分级Anothergradingmethodinvolvesloadtestingeachpieceoflumberwithaspecialmachinefollowedbyvisualgrading这种叫做机械分级木材ThistypeoflumberiscalledMachineStressRated(MSR)机械分级木材一般用于作高应力构件（比如跨度大的楼板搁栅，工字梁的上下弦，胶合木梁）MSRlumberistypicallyusedinhighlystressedcomponents(e.g.longspanfloorandtrusses,chordsforI-joists,glulambeams,etc.),29,定级机构树种含水率弹性系数计算预计最终弯曲度锯木厂编号,.,28,工程木产品Engineeredwoodproducts,工程木产品是一种再造的或组合而成的材料，逐渐被用来替代规格材Engineeredwoodproductsarereconstitutedorassembledmaterialsincreasinglybeingusedasasubstitutefordimensionallumber它们是通过使用粘合剂把木材的纤维，颗粒，薄木片或者粘合在一起的规格材制作而成Theyaremanufacturedbybindingwoodstrandsoffibers,particles,veneersordimensionallumberbondedtogetherwithadhesives这些材料在制造过程中遵循严格的质量指标，并且其性能必须满足各种各样的工业标准Theseproductsaremanufacturedtoprecisespecificationsandmustmeetavarietyofindustrystandardsforperformance,30,.,29,工程木产品Engineeredwoodproducts,与规格材比较工程木产品的优势Advantagesofengineeredwoodproductscomparedtodimensionallumber:更高、更准确的强度与刚度，增加了许用跨度Higher,morepredictablestrengthandstiffnessallowsincreasedspans更好的尺寸稳定性（更少的收缩，弯曲或者扭转）Moredimensionalstability(lessshrinkage,warpingortwisting)消耗更少木材并且能使用更小的，生长快速的树进行制造Consumeslesswoodandcanbemadefromsmaller,fast-growingtrees在不牺牲结构强度的情况下提供额外的设计选择Providesadditionaldesignoptionswithoutsacrificingstructuralstrength,31,.,30,工程木产品Engineeredwoodproducts,指接材Finger-jointedlumber指接材是将短段的规格材通过端部的指结缝施胶粘结起来形成的木材Finger-jointedlumberismadefromshortsectionsofdimensionallumberjoinedtogetherend-to-endwithinterlockingfingersthatareglued用途：在某些情况下可以与通常的规格材交替使用Uses:Withsomeexceptions,canbeusedinterchangeablywithregulardimensionallumber指接木可利用之前被视作无用的短片规格材制作Finger-jointingallowsmanufacturestoutilizeshortpiecesofdimensionallumberthatwouldotherwisebeunusable,32,指接木接头Fingerjoint,.,31,工程木产品Engineeredwoodproducts,单板层积材(LVL)Laminatedveneerlumber(LVL)将多层单板施加防水胶胶合在一起形成的工程木产品，和胶合板类似，但比它厚LVLisalayeredcompositeofwoodveneersandwaterproofadhesivesimilartoplywoodbutthicker用途：主梁，过梁，楼板封边板，工字梁翼缘，楼梯梁Uses:beams,headers,rimjoists,flangemembersforI-joists,stairstringers主梁可在现场拼装制作，减少过重的吊装Beamscanbebuilt-upon-sitetoreduceheavylifting,33,.,32,工程木产品Engineeredwoodproducts,平行木片胶合木（PSL）Parallelstrandlumber(PSL)将木片在压力下胶合在一起制成的高强度的工程木制品PSLisahighstrengthstructuralcompositeproductmanufacturedbygluingstrandsofwoodtogetherunderpressure.用途：主梁，柱，过梁Uses:beams,columns,headersPSL梁有漂亮外观，可用于裸露部分。其高强度同样可用于其他非裸露的地方PSLisanattractivematerialsuitablewherefinishedappearanceisimportantandforconcealedstructuralapplicationswhereappearanceisnotafactor.,34,.,33,工程木产品Engineeredwoodproducts,层叠木片胶合木(LSL)Laminatedstrandlumber(LSL)同OSB板制作类似，是将速生树种木片在压力下施加防水胶胶合在一起制成的工程木产品SimilartoOSB,LSLismanufacturedfromthinstrandsoffastgrowingspeciesofwoodbondedtogetherunderheatandpressureusingawaterproofadhesive用途：主梁，过梁，楼板搁栅，墙龙骨，楼板封边板，楼梯梁，地梁板Uses:beams,headers,floorjoists,wallstuds,rimboards,stairstringers,sillplatesLSL可用作墙体龙骨，用在很高或垂直度要求高的墙体（比如厨房橱柜墙或浴室贴砖墙）LSLwallstudscanbeusedselectivelywhereeithertallwallsarerequiredorthewallsneedstoverystraight(e.g.kitchencabinetwalls,tiledbathroomwalls),35,.,34,工程木产品Engineeredwoodproducts,工字梁I-joists工字梁是将规格材或单板层积材作翼缘，胶合板或OSB板作腹板胶合在一起制成的工程木I-joistsareprefabricatedwoodjoistsmadebygluingsolidlumberorlaminatedveneerlumberflangestoaplywoodorOSBweb用途：楼板搁栅，屋顶椽条及搁栅Uses:floorjoists,roofraftersandjoists工字梁一致的刚度，强度及自重使其适合较大跨度Theuniformstiffness,strengthandlightweightofI-joistsmakethemwell-suitedforlongerspans腹板可以按照要求钻出管道孔Holescanbedrilledinwebforplumbingandelectricalworkbutmustlocatedaccordingtothemanufacturersrecommendations,36,翼缘Flanges,腹板Web,.,35,工程木产品Engineeredwoodproducts,胶合木Gluelaminatedtimber(Glulam)在一定条件下将特殊等级的规格材胶合在一起制成的工程木产品Glulamisastructuralwoodproductmanufacturedbygluingtogetherpiecesofspecialgradedimensionallumberundercontrolledconditions用途：主梁，过梁，桁架梁，柱，重型桁架Uses:beams,headers,girders,columns,heavytrusses使用防水胶使其室内外皆可应用Manufacturedwithwaterproofgluemakesitsuitableforbothinteriorandexteriorapplications,37,.,36,木基结构板Structuralwood-basedpanels,胶合板Plywood胶合板由多层单板在一定温度和压力下胶合而成Plywoodisapanelbuilt-upfromseveralsheetsofwoodveneergluedtogether用途：屋面板，墙面板，楼面基板，工字梁腹板Uses:roof,wallandfloorsheathing,floorunderlayment,I-joistwebs楼面胶合板一般都有企口，可以互相咬合，所以接缝部位下面就可以不使用挡块支撑Plywoodusedforfloorsheathingoftenhastongueandgroove(T&G)edgestointerlockadjacentpanelseliminatingtheneedforblockingtosupportedges没带企口的胶合板是用安装在接缝处的H形卡件彼此咬合PlywoodroofsheathinghassquareedgesthatareoftensupportedwithmetalH-shapedclipsasanalternativetosolidblockingtosupportedges,38,楼面胶合板带企口PlywoodfloorsheathingwithT&Gedges,屋面胶合板用H形卡件PlywoodroofsheathingwithmetalH-clip,.,37,木基结构板Structuralwood-basedpanels,定向木片板（OSB板）Orientedstrandboard(OSB)OSB板是细木片按同一方向排列、分层并用胶粘合的结构木板OSBisapanelmadefromthinstrandsoffastgrowingspeciesofwoodbondedtogetherunderheatandpressureusingawaterproofadhesive用处：屋面板，墙面板，楼面板，工字梁腹板Uses:roof,wallandfloorsheathing,floorunderlayment,I-joistwebs由于木片朝向的原因，OSB板强度和刚度沿长向比沿短向大OSBpanelshavegreaterstrengthandstiffnessalongtheirlengththanacrossthepanelduetothewaythewoodstrandsareoriented15.5毫米或更厚的OSB板长边有些带有企口，有些没有OSB15.5mmandthickeraremanufacturedeitherwithasquareedgeortongueandgroovealongthelongedges,39,.,38,术语表Glossaryofnewterms,风干材-裸露在自然大气条件下进行缓慢干燥得到的木材Air-driedLumberthathasbeenslowlydriedbyexposingittonaturalatmosphericconditions.干裂-木材径向小裂纹ChecksShortseparationsinthewoodalongthegrain.实际尺寸-进行干燥和刨平切割之后的实际尺寸DressedsizeActualsizeoflumberafteritisdriedandsurfacedinaplanermill.切边材-一面以上切出来的木材EdgedLumberthathashadoneormoreofitssurfacessawnorplanedsquare.指接材-将短段的规格材通过端部的指结缝施胶粘结起来形成的木材Finger-jointedlumberLumberismadefromshortsectionsofdimensionallumberjoinedtogetherend-to-endwithinterlockingfingersthatareglued.胶合木-在一定条件下将特殊等级的规格材胶合在一起制成的工程木产品Gluelaminatedtimber(Glulam)Anengineeredwoodproductmanufacturedbygluingtogetherpiecesofspecialgradedimensionallumberundercontrolledconditions.,46,.,39,术语表Glossaryofnewterms,生材-未干燥之前的木材GreenlumberUnseasonedlumberthathasnotbeendried.硬木-在秋季或冬季会落叶的阔叶树（部分例外）的木材。HardwoodWoodfrombroad-leavedtreesthat,withsomeexceptions,areshedinautumnorwinterintemperateclimates.工字梁-将规格材或单板层积材作为翼缘，胶合板或OSB板作为腹板胶合在一起制成的工程木I-joistsAprefabricatedwoodjoistmadebygluingsolidlumberorlaminatedveneerlumberflangestoaplywoodorOSBweb.窑干材-将其放入窑中，控制在一定热量、湿度和风量中干燥得来的木材Kiln-driedLumberthathasbeendriedtoapredeterminedlevelbyplacingitinachamber,applyingcarefullycontrolledlevelsofheatandhumidityan