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WorksheetsBCM: Wood
Total questions: 10
Worksheet time: 8mins
Below are reasons why wood continues to be an
important construction material, except.
availability
fire resistance
relatively low cost
ease of use
durability
Select THREE (3) characteristics of good timber.
Narrow annual rings,
closer the rings, greater is
the strength.
No woolliness at fresh cut
surface.
When struck sonorous sound
is produced.
Variable texture.
Light weight
Defects in lumber may effect wood's appearance and mechanical properties.
Below are causes of defect in lumber, except ?
natural growth
of wood
wood
diseases
change in
weather
rapid
seasoning
animal
parasite
What is the type of lumber that cause by mishandling or seasoning
(a)
What is the type of lumber that cause the absent of material at the edge or bark
(a)
What is the type of lumber that cause due to
error during cutting or heavy winds.
(a)
What is the type of lumber that cause by
branch bases that incorporate into the tree trunk.
(a)
Below are correct statement about FUNGI, except.
Fungi may exist due to availability of food, proper range of temperature, moisture, & oxygen
Fungi can be avoided by proper handling in storage placement
Fungi growth in conducive temperature between 10°C to 40°C
FSP that suitable for fungi's' growth are more than 30%
Below are correct statements about INSECTS, except.
Proper seasoning can prevent wood-attacking insects
Termites enter structures through wood that is close to the ground
Application of sealing compounds layering onto wood surface may prohibit entry of insects
Poorly ventilated or wet environment leads to existence of termites in wood structures
Beetles and termites are the most common wood-attacking insects
Below are correct statements about BACTERIA, except.
Rapid storage of wood that have contact with soils leads to bacteria growth
Bacteria cause wet wood where the water-soaked condition occupies the stem centers of living trees.
Bacteria cause the softening of wood skin due to excessive shrinkages during re-dried process
Black heartwood causing by bacteria at the stem center that turn dark brown or black in color.
