材料的选择PPT课件

1、.,1,第三讲 材料的选择 Lesson 3: Selecting Materials,1,.,2,木材的类型 Types of wood,硬木（阔叶木）和软木（针叶木） Hardwoods and softwoods 树木通常被划分为两个种类：硬木和软木Trees are often divided into two classes: hardwoods and softwoods 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）These names can be misleading because some softwoods are harder than some ha

2、rdwoods (the reverse is also true),3,.,3,木材的类型 Types of wood,硬木和软木 Hardwoods and softwoods 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。Hardwood trees usually have broad leaves that, with some exceptions, are shed in autumn or winter in temperate climates 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。Softwood trees usually ha

3、ve needle or scale-like leaves that, in most cases, remain green and are retained year-round,4,.,4,木材的类型 Types of wood,硬木和软木 Hardwoods and softwoods 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） Hardwoods are used in construction mostly for flooringand interior woodwork (e.g. stairs, cabinetry, baseboards, tri

4、m around windows and doors, 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Softwoods are used for framing, sheathing, concrete forms, scaffolding and many other building components 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Some more durable species of softwood are used forexterior components such as roof and

5、wall shingles, window frames and exterior doors,5,.,5,软木材的制造 Manufacturing softwood lumber,制造过程始于伐树 Manufacturing process begins with harvesting trees 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Trees are cut down, stripped of branches and cut to length for transport by truck 这样形成的原木再被运往锯木厂Resulting logs are then sh

6、ipped to a sawmill 砍伐之后的区域将种上树苗使森林再生Harvested areas are replanted with tree seedlings to regenerate the forest,6,.,6,软木材的制造 Manufacturing softwood lumber,原木在锯木厂进行加工 The logs are processed by the sawmill 树皮在加工的过程中被去除Bark is removed from the logs 去掉树皮的木材将被锯成的初步的木板Debarked logs are sawn to into rough p

7、lanks 这些厚木板之后会被切边，重新切割成特定尺寸和长度These planks are then edged, resawn to specific dimensions and cut to standard lengths,7,.,7,软木材的制造 Manufacturing softwood lumber,之后把生材由垫块隔开堆放进行风干或者窑干 This green lumber is then stacked with spacers and either air-dried or kiln-dried 大多数软木是在窑内烘干而不是风干Most softwood lumber

8、is kiln-dried rather than air dried 尽管花费更大，但窑干更快速，过程更方便控制Although more costly, kiln drying lumber is a quicker and easier to control process,8,.,8,软木材的制造 Manufacturing softwood lumber,需将生材干燥的重要原因： There are several important reasons to dry green lumber: 减少收缩变形Reduces problems with shrinkage 减少变色、腐坏及

9、虫害Reduces susceptibility to staining, decay and insect damage 使得木材可以被防腐处理Enables wood to be treated with preservatives,9,.,9,软木材的制造 Manufacturing softwood lumber,需将生材干燥的重要原因： There are several important reasons to dry green lumber: 改善木材握钉及施胶能力Improves strength and the hold of nails, screws and glue

10、保证油漆和其他表面材料的更好的粘结力Allows paints and other finishes to adhere better 6. 使木材处理及运输更方便Makes it easier to handle and transport,10,.,10,软木材的制造 Manufacturing softwood lumber,干燥之后，木材被送过刨床，校直，磨平，统一尺寸 After drying, the lumber is put though a planer mill where it is straightened, smoothed and uniformly sized,1

11、1,.,11,软木材的制造 Manufacturing softwood lumber,木材制造的最后一个过程是将木材分等级 Final step in the manufacturing process is grading and sorting the lumber,12,.,12,软木材尺寸 Softwood lumber sizes,木材相关称呼： Lumber terminology:,13,边面 Edge,端面 End,宽度 Width or Depth,厚度 Thickness,正面 Side or Face,.,13,软木材尺寸 Softwood lumber sizes,木

12、材的厚度和宽度： Thickness and width of lumber is expressed in two ways: 名义尺寸-在进行干燥和最终处理之前的生材尺寸Nominal size Refers to the approximate size (in inches) of green lumber before it is dried and receives final processing in a planer mill 实际尺寸-进行干燥和刨光处理之后的实际尺寸Dressed size Refers to actual size of lumber after it

13、is driedand surfaced in a planer mill,14,.,14,软木材尺寸 Softwood lumber sizes,结构规格材常用的尺寸（厚度和宽度）: Common sizes (thickness and width) of framing lumber:,15,.,15,软木材尺寸 Softwood lumber sizes,结构用规格材的长度 Common lengths of framing lumber: 2.4米至7.2 米，其中以600 毫米递增的每一个长度2.4 to 7.2 m in 600 mm increments 中国内地能买到的最长材

14、料为6.1米Longest material available in China is 6.1 m 常见长度：Usual lengths:,16,.,16,含水率与变形 Moisture content and shrinkage,木材的含水率极为影响其表观及耐久性 Moisture content of lumber is an important factorin its performance and durability 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Moisture content is the weight of water contained in wood

15、expressed as a percentage of the weight of oven-dry wood 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Moisture content of wood will eventually equilibrium withthe surrounding air and then respond to changing conditions,17,.,17,含水率与变形 Moisture content and shrinkage,木材会干缩和湿胀 Wood shrinks when it dries and swells wh

16、en it is wet 生材干燥时会有明显的收缩Significant shrinkage occurs as green wood dries 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Wood does not shrink or expand equally in all directions- very little shrinkage/expansion along the grain (lengthwise)- significant shrinkage/expansion can occur across the grain 木材干燥过程中可能会有翘曲出现Wa

17、rping may also occur as wood dries,18,翘曲类型 Types of warps,翘弯 Bow,扭弯 Crook,扭曲 Twist,瓦弯 Cup,收缩现象 Shrinkage effects,.,18,含水率与变形 Moisture content and shrinkage,推荐的含水率： Recommended moisture content levels: 结构中的规格材在封板之前最高含水率不超过19%Dimension lumber for framing should have a maximum moisture content level of

18、 19% before it is enclosed 一般此时，木材平均含水率在15%，绝大部分收缩已经没有了At this level, the average wood moisture content will be lower (about 15%) and most shrinkage has already occurred 可用仪器测试木材的含水率A wood moisture meter can be used to measurethe moisture content of dimensional lumber,19,探针型木材含水率测试仪 Pin-type wood mo

19、isture,.,19,软木材分级 Softwood lumber grading,结构用材必须是经过分等级的 Lumber used for framing must be graded 方便设计师选择强度合适的木材Enables designers to specify lumber that has appropriate strength properties 方便订货商清楚所订货物为其所需Provides buyers with a reliable way to identify what they are buying 方便施工监理检查材料是否符合规范Allows buildin

20、g inspectors to verify that quality of lumber meets code requirements,20,.,20,软木材分级 Softwood lumber grading,大部分木材是根据其缺陷数量进行目测分级 Most lumber is visually graded based on number and types of defects 节疤的尺寸与位置Size and location of knots 斜纹理 Slope of grain 钝棱数量 Amount of wane 轮裂、端裂与干裂的尺寸Size of shakes, spl

21、its and checks,21,节疤 Knot,斜纹理 Slope of grain,干裂 Checks,钝棱 Wane,.,21,软木材分级 Softwood lumber grading,加拿大国家评级系统 Canadas national grading system 加拿大国家木材评级机构National Lumber Grades Authority (NLGA) 加拿大木材评级标准规定Standard Grading Rules for Canadian Lumber GB 50005-2003木结构设计规范的分级标准同加拿大标准一致Grading rules in China

22、s GB 50005-2003Code for Design of Timber Structuresare equivalent to the NLGAs,22,.,22,软木材分级 Softwood lumber grading,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 National Lumber Grade Authority (NLGA)is regulatory authority 加拿大共有约15家木材定级机构Approximately 15 Canadian grading agencies 所有木材厂家都是加拿大木材评级管理局下的成员All lu

23、mber manufacturers are membersof the NLGA,评级机构,.,23,评级机构,树种,软木材分级 Softwood lumber grading,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 Wood species with similar characteristicsare grouped together 花旗松-落叶松 (D.Fir-L) Douglas Fir Larch (D.FIR-L) 铁杉-冷杉 (Hem-fir) Hemlock Fir (Hem-fir) 云杉-松-冷杉 (SPF) Spruce Pine Fir

24、(SPF) 北方树种 (Northern) Northern Species (Northern),.,24,树种,等级,评级机构,软木材分级 Softwood lumber grading,26,含水率,制材厂编号,目测强度评级 Visual strength grades 特选结构级材 (SS)Select structural (SS) 一级与二级材 No.1, No.2（结构用材）No. 1 and No. 2 (used for framing) 三级材No. 3,.,25,含水率,评级机构,软木材分级 Softwood lumber grading,27,树种,等级,制材厂编号,含

25、水率 Moisture content 制材时的测定值Measured at time of milling 干材刨光 S-DryS-Dry (surfaced dry) 湿材刨光 S-GrnS Grn (surfaced green or wet),.,26,含水率,制材厂编号,评级机构,软木材分级 Softwood lumber grading,28,树种,等级,制材厂编号 Mill designation 代表制材厂的代号Code for mill where lumber was manufactured,.,27,软木材分级 Softwood lumber grading,另一种方法

26、是用机械测试每根木材来分级 Another grading method involves load testing each piece of lumberwith a special machine followed by visual grading 这种叫做机械分级木材This type of lumber is called Machine Stress Rated (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）MSR lumber is typically used in highly stressed components(e.g

27、. long span floor and trusses, chords for I-joists, glulam beams, 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 Engineered wood products,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 Engineered wood products are reconstitutedor assembled materials increasingly being usedas a substitute for dimensional lumbe

28、r 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They are manufactured by binding wood strandsof fibers, particles, veneers or dimensional lumberbonded together with adhesives 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These products are manufactured to precise specificationsand must meet a variety of industry st

29、andards for performance,30,.,29,工程木产品 Engineered wood products,与规格材比较工程木产品的优势 Advantages of engineered wood products compared to dimensional lumber: 更高、更准确的强度与刚度，增加了许用跨度Higher, more predictable strength and stiffness allows increased spans 更好的尺寸稳定性（更少的收缩，弯曲或者扭转）More dimensional stability (less shrin

30、kage, warping or twisting) 消耗更少木材并且能使用更小的，生长快速的树进行制造Consumes less wood and can be made from smaller, fast-growing trees 在不牺牲结构强度的情况下提供额外的设计选择Provides additional design options without sacrificing structural strength,31,.,30,工程木产品 Engineered wood products,指接材 Finger-jointed lumber 指接材是将短段的规格材通过端部的指结缝

31、施胶粘结起来形成的木材Finger-jointed lumber is made from short sections of dimensional lumber joined together end-to-end with interlocking fingers that are glued 用途：在某些情况下可以与通常的规格材交替使用Uses: With some exceptions, can be used interchangeably withregular dimensional lumber 指接木可利用之前被视作无用的短片规格材制作Finger-jointing all

32、ows manufactures to utilize short pieces ofdimensional lumber that would otherwise be unusable,32,指接木接头 Finger joint,.,31,工程木产品 Engineered wood products,单板层积材(LVL) Laminated veneer lumber (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LVL is a layered composite of wood veneers and waterproof adhesive simi

33、lar to plywood but thicker 用途：主梁，过梁，楼板封边板，工字梁翼缘，楼梯梁Uses: beams, headers, rim joists, flange members for I-joists, stair stringers 主梁可在现场拼装制作，减少过重的吊装Beams can be built-up on-site to reduce heavy lifting,33,.,32,工程木产品 Engineered wood products,平行木片胶合木（PSL） Parallel strand lumber (PSL) 将木片在压力下胶合在一起制成的高强

34、度的工程木制品PSL is a high strength structural composite product manufacturedby gluing strands of wood together under pressure. 用途：主梁，柱，过梁Uses: beams, columns, headers PSL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PSL is an attractive material suitable where finished appearanceis important and for concealed structur

35、al applications whereappearance is not a factor.,34,.,33,工程木产品 Engineered wood products,层叠木片胶合木 (LSL) Laminated strand lumber (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Similar to OSB, LSL is manufactured from thin strandsof fast growing species of wood bonded together underheat and pressure usin

36、g a waterproof adhesive 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, floor joists, wall studs, rim boards,stair stringers, sill plates LSL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）LSL wall studs can be used selectively where eithertall walls are required or the walls needs to very straight(e.g. k

37、itchen cabinet walls, tiled bathroom walls),35,.,34,工程木产品 Engineered wood products,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-joists are prefabricated wood joists made by gluing solid lumber or laminated veneer lumber flanges to a plywood or OSB web 用途：楼板搁栅，屋顶椽条及搁栅Uses: floor joists, roo

38、f rafters and joists 工字梁一致的刚度，强度及自重使其适合较大跨度The uniform stiffness, strength and light weight of I-joists make them well-suited for longer spans 腹板可以按照要求钻出管道孔Holes can be drilled in web for plumbing and electrical work but must located according to the manufacturers recommendations,36,翼缘 Flanges,腹板 We

39、b,.,35,工程木产品 Engineered wood products,胶合木 Glue laminated timber (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Glulam is a structural wood product manufactured by gluing together pieces of special grade dimensional lumber under controlled conditions 用途：主梁，过梁，桁架梁，柱，重型桁架Uses: beams, headers, girders, columns, h

40、eavy trusses 使用防水胶使其室内外皆可应用Manufactured with waterproof glue makes it suitablefor both interior and exterior applications,37,.,36,木基结构板 Structural wood-based panels,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Plywood is a panel built-up from several sheets of wood veneer glued together 用途：屋面板，墙面板，楼面基板，工字梁 腹板Us

41、es: roof, wall and floor sheathing, floor underlayment, I-joist webs 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Plywood used for floor sheathing often has tongue and groove (T&G) edges to interlock adjacent panels eliminating the need for blocking to support edges 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Plywood roof she

42、athing has square edges that are often supported withmetal H-shaped clips as an alternative to solid blocking to support edges,38,楼面胶合板 带企口Plywood floor sheathingwith T&G edges,屋面胶合板 用H形卡件Plywood roof sheathingwith metal H-clip,.,37,木基结构板 Structural wood-based panels,定向木片板（OSB板） Oriented strand boar

43、d (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OSB is a panel made from thin strands of fast growingspecies of wood bonded together under heat and pressureusing a waterproof adhesive 用处：屋面板，墙面板，楼面板，工字梁腹板Uses: roof, wall and floor sheathing, floor underlayment, I-joist webs 由于木片朝向的原因，OSB板强度和刚度沿长向比沿短向大OSB panel

44、s have greater strength and stiffness along their length than across the panel due to the way the wood strands are oriented 15.5毫米或更厚的OSB板长边有些带有企口，有些没有OSB 15.5 mm and thicker are manufactured either with asquare edge or tongue and groove along the long edges,39,.,38,术语表 Glossary of new terms,风干材-裸露在

45、自然大气条件下进行缓慢干燥得到的木材Air-dried Lumber that has been slowly dried by exposing it to natural atmospheric conditions. 干裂-木材径向小裂纹Checks Short separations in the wood along the grain. 实际尺寸-进行干燥和刨平切割之后的实际尺寸Dressed size Actual size of lumber after it is dried and surfaced in a planer mill. 切边材-一面以上切出来的木材Edged

46、 Lumber that has had one or more of its surfaces sawn or planed square. 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-jointed lumber Lumber is made from short sections of dimensional lumber joined togetherend-to-end with interlocking fingers that are glued. 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Glue laminated timb

47、er (Glulam) An engineered wood product manufactured by gluing togetherpieces of special grade dimensional lumber under controlled conditions.,46,.,39,术语表 Glossary of new terms,生材-未干燥之前的木材Green lumber Unseasoned lumber that has not been dried. 硬木-在秋季或冬季会落叶的阔叶树（部分例外）的木材。 Hardwood Wood from broad-leave

48、d trees that, with some exceptions, are shed in autumn or winterin temperate climates. 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-joists A prefabricated wood joist made by gluing solid lumber or laminated veneer lumber flanges toa plywood or OSB web. 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-dried Lumber that has been dried to a predetermined level by placing it in a chamber, applying carefully controlled levels of heat and humidity and circulating air with a fan.