wood

Question 1

whats type of wood has interwined growth , bamboo etc

Answer 1

endogenus

Question 2

what type of wood has outward groth

Answer 2

exogenus

Question 3

what is another name for hardwood

Answer 3

deciduous

Question 4

softwood?

Answer 4

evergreen

Question 5

examples of hard wood/deciduous

Answer 5

ash oak maple

Question 6

examples of softwood/evergreen

Answer 6

douglas fir, spruce, pine

Question 7

radiata pine facts

Answer 7

90 % of sawn timber
usa nartive
low durability

Question 8

douglas fr facts

Answer 8

usa native, pinkish brown, more durabke

Question 9

whats sapwood

Answer 9

near outside, (1/3) of radisu, takes moisture from roots, stores food.

Question 10

whats heart wood

Answer 10

inner core, non living cells, more resistanct to decay

Question 11

pith?

Answer 11

for the new shoot, growing tip of tree

Question 12

outer bark puprose

Answer 12

protect

Question 13

inner bark purpose

Answer 13

transport sap to growing plants of tree

Question 14

cambium

Answer 14

layer inbetween new wood and new bark, repeated subdivisio of cambium formns new wood and bark.

Question 15

spring wood (early wood)

Answer 15

rapid growth, large diameters

Question 16

summer wood (late wood)

Answer 16

slow growth , smaller D thick cell walls

Question 17

what are tracheids

Answer 17

longitudinally allinged cells, mechanical support, transport sap
s3 and s1 layers perpendicular to grain, but thin
s2 layer parallel to grain, thick

Question 18

cellulose

Answer 18

50% by weight, formed from glucoes

Question 19

lignin

Answer 19

33% soft wood 35% hard wood phenylpropen units. responsible for longitudinal shear stress

Question 20

hemicellulose

Answer 20

20% softwood 30 hard wood.

Question 21

extractives

Answer 21

tannins, oils, resin, colour odour taste decay resistamce, flamibility

Question 22

chemical compostiiong

Answer 22

c 50 O 44 H 6

Question 23

equation for strength after extended loading

Answer 23

%=91.5-7log(hours)

Question 24

moisture content of green wood

Answer 24

30-200%

Question 25

how is bound water bound

Answer 25

hydrogen bonding to cellulose

Question 26

where does the most shrinkage occur. and how much for the rest

Answer 26

most in tangential direction, about 2/3 in radial of transverse, very little longitudinal shrinkage

Question 27

lumber process

Answer 27

harvesting (400-800 mm diameter) sawing (live sawing (most economic) quarter (most prime cuts), combination) season-drying, kiln or air (different shrinkage in different directions creates bow twist crook cup surfacing (2.5 mm from each side)

Question 28

types of boards?

Answer 28

``` flat sawn (grain 45 from flat side) worst rift sawn (45-80) quarter sawn (vertical) ```

Question 29

7 types of bad things that can be in wood

Answer 29

knots, slopping grain, core wood, reaction wood, checks, shake, wane.

Question 30

whats slopping grain

Answer 30

- due to grain distrubuted locallly from branch | - log had fibres growing in a spiral direction

Question 31

core wood?

Answer 31

less dense, 5-10 grwoth rings from center

Question 32

reaction wood?

Answer 32

lower side of leaning trunk, has 30 5 more density, leads to warp

Question 33

checks

Answer 33

differential drying consequence, cracks basically

Question 34

shake

Answer 34

seperation between annual growht rings

Question 35

wane

Answer 35

lack of wood at corner

Question 36

types of grading

Answer 36

presorted (representivitve testing) strength vclass visual grading knote etc no more than 1/3 knot area

Question 37

types of machine grading used

Answer 37

``` constant load plank (deflection measured) constant deflection (load measured) joist grading (stiffness and strength at joist. defelection measured acoustic grader ```

Question 38

what do fungus need

Answer 38

moisture (below 20 % prohibits) wood. air (can bury wood) temp

Question 39

chemical you can use for fungacide?

Answer 39

chromated copper arsenate CCA copper and arsenate fungaside chromium=uv resistive

Question 40

another chemical ?

Answer 40

ACQ alkiline copper quartenary

Question 41

whats borates

Answer 41

odourless etc, non toxic, penetrates deep as it is water bourne, cant be applied to wood in contact with wATER

Question 42

how can you stop fire in wood

Answer 42

pressure impregnation with water soluabkle salts, fiure retardant chemicals sprayed on outside.

Question 43

what is CLT

Answer 43

cross laminated timber, has dimensional stability

Question 44

what is LVL

Answer 44

laminated veneer lumber

Question 45

how to make ply wood

Answer 45

heat and pressure, phenol somthing,

Question 46

how to make fibrboards

Answer 46

heat and pressure, polyurethane adhesive

Question 47

composite benifits

Answer 47

``` resource utilisation insect and fire damaged timber juvenile woood recylced plastic dimensional stability greater durability less variability ```

Question 48

composite drawbacks

Answer 48

emissions, mechanical properties, moisture /temp affects, manufacturing energy, resource competition.

Question 49

what are SLT bridges

Answer 49

stress laminated timber bridges, use of friction, shear transfer and load distributions, retensioning possible

Question 50

post tensioned timber frames advantages

Answer 50

``` reconstrucabkle fast and effecient cost effective high seismic resistance sustainable multistory ```