structures iv lecture 12 timber

8/9/2019 Structures IV Lecture 12 Timber

1/46

1

Structures IV _STRU401

Lecture 12: Properties of Building

MterilsWood/Timber

!"e: Lawrence Ogunsanya

#"il : [email protected]


2/46

$ood ter"inolog%

&rd 'ood

Soft 'ood

&ert 'ood Sp 'ood

(ro't) rings

Plin *+t, s'n -urter s'n

Bord foot

2


3/46

&rd 'ood.Soft 'oods

/ll ntie species of trees re diided intot'o clsses Hard wood )e rod lees nd re

deciduous * "ple3 cci3 o, Soft woods re conifers *pine3 cedr3 5r,

3


4/46


5/46

&ert'ood nd sp'ood

5

Sapwoodis t)e outer portiont)t conducts sp nd )s t)eliing cells

; T)e t)icness 'ill r%3

ut usull% fro" 181


6/46

(ro't) rings

6

Becuse of t)e rte tree

gro's3 c)nges 'it) t)esesons3 cross section 'ills)o' distinctie rings

Springwood

; Inner prt of t)e gro't)

ring; Usull% lrger cities ndt)in 'lls

Summerwood

; =uter prt of t)e gro't)ring

; S"ller cells nd t)icer'lls

A tree grows one springwood andone summerwood ring each year.

Springwood

Summerwood


7/46

Seen 9)rcteristics


8/46

(rin =rienttion

!

"ood is stronger when #orces are

app$ied para$$e$ to the grain than

when #orce is app$ied perpendicu$ar

to the grain.


9/46

$ood 9)rcteristics8Sti>ness

Sti>ness is "esure of t)e "ount of de+ection t)toccurs ')en lod is pplied

Its deter"ined % t)e cross section s)pe of t)e "e"ernd t)e lod

T)e "ount of cceptle de+ection is di>erent for ec)uilding "e"er

%


10/46

Ti"er


11/46

11

Timber

$pplications


12/46


13/46

13

L"inted Veneer Lu"er *LVL,

T)in s)eets of ti"er re l"intedtoget)er under pressure3 using glue

7eep nd long sections possile &ig) strengt)

grain in all

laminates


14/46


15/46

15

Prticleord Mde % gluing 'ood c)ips toget)er *"inl% in

s)eet for", Mes good use of forest resources not suitle

for s'ing Rndo" c)ip directions crete )o"ogenous

strengt) in lengt) nd 'idt)

Mde for internl uses Min uses:

& 9inet construction eg itc)en cinets& Structurl +oor s)eeting


16/46

16

Mediu" 7ensit% Hire Bord Si"ilr pproc) to prticleord ut uses 'ood

5res not c)ips T)is proides "uc) s"oot)ersurfce 5nis) It cn lso e "oulded nd routed Mde to suit internl pplictions 'it) n e"p)sis

on proiding sustrte for decortie 5nis)es Min uses:

& 7oors in cinet construction& Internl 5t out eg sirtings3 tiles3 rc)itres3prtitions

& 7oor sins for )ollo' core doors


17/46

1

(lue l"inted ti"er *(lul", S"ll locs of s'n ti"er re glued toget)er to for"

deep "e"ers 7efects nd 'enesses in indiidul pieces "ini"ised 9n e used to crete cured rc)itecturl structures


18/46

1!

IJ Be"s I8e"s re "de fro" solid ti"er +nges3 'it) pl%'ood or steel

'es

Lig)t'eig)t3

Suitle for "ultiple "ediu" spns e"pplictions

9 l i t d ti *9LT,


19/46

1%

()* is a digita$$y designed and manu#actured +ui$ding materia$ that can +e

used in p$ace o# con,entiona$ materia$s such as concrete.

*im+er +oards are stacked in $ayers at right ang$es and g$ued together with

non-toic adhesi,es +e#ore +eing hydrau$ica$$y pressed to make so$id wood

pane$s/ creating a product with a high #ire-resistance/ good therma$ insu$ationproperties and impro,ed strength.

9ross l"inted ti"er *9LT,


20/46

2'

S'n products Inoles cutting logs into lengt)s 'it) s"ll cross

sectionl pro5les

T)e resulting pieces )e di>erent properties inlengt)3 'idt) nd dept)

T)e s'n ti"er is strong long t)e lengt) *t)e

direction of t)e grin, !ot prticulrl% strong or stle cross t)e 'idt)

$e generll% "e use of ti"er long its lengt)*'it) t)e grin,


21/46

21

S'n products

S'ing


22/46

S'ing7irection

22

!lain sawn &*lat sawn(

; Bord is s'ed prllelJ to gro't)rings

& 0ost common +oards.

1uarter sawn

; Log is 5rst Gurtered

; Bords re cut

perpendiculrJ to t)egrin

& sua$$y must +e specia$

ordered.


23/46

23

Timber

#efects 2 *ailures


24/46

24

$ood: /gents of /ttcs

*ungi &decay(3 )oisture4 high temperatures4ade5uate o6ygen.

7estro%ing fungi

7is5guring fungi

nsects Beetles

Ter"ites

+acteria

Weathering 0hemicals3 Strong acids and alalis

Heat

)echanical forces3 7nbalanced forces 2stresses causing permanent deformation.


25/46

25

$ood 7efects

Shaes

Tendenc% of 'ood to split if it is put under stress fro" rpid

dr%ing3 poor felling or de8l"intion of t)e gro't) rings


26/46

26

$ood 7efects

Split

Is seprtion of t)e 'ood due to tering prt of 'ood cells

Split is usull% due to lrge ritions in te"perture


27/46

2

$ood 7efects

+lue stain

/ decolourtion penetrting t)e sp'ood cused % fungi

T)ere re t'o t%pesK log lue present in t)e log efore it iss'n3 %rd nd iln lue colour fter s'ing


28/46

2!

$ood 7efects

)ould

/ 5ne egetle gro't)3 or "ilde'3 t)t for"s on 'ood in d"p

stgnnt t"osp)eres It is t)e lest )r"ful t%pe of fungus nd is usull% con5ned to t)e

surfce of 'ood


29/46

2%

$ood 7efects

Weathering

Resisting lternte 'et nd dr% conditions

9)e"icl nd "ec)nicl decolourtion nd disintegrtion of'ood surfces occur due to e6posure to 'et)er3 dust3 lig)t

/lso 5re c)nge "% occur due to ried "oisture content


30/46

3'

$ood 7efects

#ry 8ot

7r% rot refers to 'ood dec% cused % certin species of

fungi3 lso no'n s True 7r% Rot3 t)t digests prts of t)e'ood ')ic) gie t)e 'ood strengt) nd sti>ness


31/46

31

$ood 7efects


32/46

$ood 7efects nsect attac

T%pes of insects t)t cuse deteriortion of 'ood:

crpenter nts3 eetles3 nd ter"ites

9rpenter nts prefer )ig)er "oisture content nd softer 'oodt)t )s egun to dec%

$)ile po'der post eetles prefer lo' "oisture content in ot)soft'oods nd )rd'oods


33/46

$ood 7efects

33

Warping

$ood 'rping is deition fro" +tness s result of

stresses nd s)ringe fro" t)e uneen dr%ing of ti"er T)e 5e "For t%pes of 'rp re cup3 o'3 croo3 t'ist nd

di"onding


34/46

$ood 7efects

34

9ross grin crc

S)e

$ne *Br,

Split

Slopinggrin

Cnot


35/46

35

$ood Presertion !etroleum9based solutions

9ol8tr creosote3 petroleu" creosote3pentc)lorop)enol

Waterborne preser%ati%es

/""onicl copper rsente

9)ro"ted copper rsente /""onicl copper inc rsente

/dntges oer oil ; clenliness3 ilit% to epinted

7isdntges ; dngerous to )u"ns


36/46

36

/dntges of $ood $ood is t)e "ost eniron"entll% responsile uilding

"teril Ti"er )s lo' production energ% reGuire"entsnd is net cron sorer Ti"er is rene'le resource

$ood is redil% ille

$ood is strong3 lig)t nd relile "ing ti"er constructionsi"pler nd sfer t)n steel or concrete construction

T)e lig)t'eig)t structures possile in 'ood confer +o'8ondntges in ter"s of reduced foundtion costs3 reducedert)Gue loding nd esier trnsport

$ooden uilding co"ponents nd co"plete constructionsre si"ple nd sfe to erect3

nd c)eper to deconstruct or reuse t t)e end of uildings life

$ood )s lo' to6icit% nd t)erefore reGuires no specilsfet% precutions to 'or 'it) it3 ot)er t)n nor"lprotection fro" dusts nd splinters


37/46

3

/dntges of $ood

9o"prtie studies of t)e econo"ics of di>erent 'llfr"ing s%ste"s indicte t)t3 in ter"s of direct uildinge6penses3 ti"er fr"es re consistentl% t)e "ost cost8e>ectie solution

(ood detiling3 coting nd "intennce ensure t)tti"er structures re durle nd lst for lifeti"es

/ prticulr feture of 'ood is t)e +e6iilit% of designfor"s nd 5nis)es t)t cn e used

T)is +e6iilit% lso e6tends to t)e ese 'it) ')ic)e6isting uildings cn e dded to or "odi5ed to suitc)nging circu"stnces

$ell8designed Ti"er structures re co"fortle to liein ll %er round no "tter ')ere %ou re

$ooden structures )e )ig) leels of t)er"linsultion3 reducing )eting costs nd conseringenerg%


38/46

3!

Ti"er structures


39/46

3%

Ti"er structures


40/46

4'

Ti"er structures

Ti"er Structures


41/46

41

Ti"er Structures

0etropo$ araso$/ Se,i$$e/ Spain

Ti"er Structures


42/46

42

Ti"er Structures

Ti"er Structures


43/46

43

Ti"er Structures


44/46


45/46


46/46

-uestions

structures iv lecture 12 timber

Documents