CHAPTER V WOOD QUALITY TEST A. Depreciation Wood 1. Objectives a. To determine the percentage of wood angle. b. To find out what happens to wood shrinkage from wet to dry. In this case the depreciation based on the shrinkage of the wood grain. 2. Basic Theory Determine the moisture content in wood timber volume, less water in the wood, it also decreases the volume of the timber. Because wood is a shrinkage of volume shrinkage, the shrinkage is happening in three directions dimensions: a.Shrinkage direction toward the center (radial) b.Directions shrinkage in the direction of the tangent line type (tangential) c.Direction shrinkage in the direction of the length of the rod (axial) 3. Materials used a.Wood samples of I (wood camphor) b.Wood samples II (wood meranti) 4. Apparatus a.Calipers b.Scale 95
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CHAPTER V
WOOD QUALITY TEST
A. Depreciation Wood
1. Objectives
a. To determine the percentage of wood angle.
b. To find out what happens to wood shrinkage from wet to dry. In this case
the depreciation based on the shrinkage of the wood grain.
2. Basic Theory
Determine the moisture content in wood timber volume, less water in
the wood, it also decreases the volume of the timber. Because wood is a
shrinkage of volume shrinkage, the shrinkage is happening in three directions
dimensions:
a. Shrinkage direction toward the center (radial)
b. Directions shrinkage in the direction of the tangent line type (tangential)
c. Direction shrinkage in the direction of the length of the rod (axial)
3. Materials used
a. Wood samples of I (wood camphor)
b. Wood samples II (wood meranti)
4. Apparatus
a. Calipers
b. Scale
c. Oven with a max temperature of 150 ° C made in Germany
5. Steps Work
a. Each sample was coded teams, parallel fiber = a, b = perpendicular fibers,
fiber direction = c.
b. Considering each sample timber.
c. Measure the length, width, and thickness of wood (tangential, radial, axial)
d. Incorporate wood into the oven for ± 24 hours.
e. The next day put into oxilator for ± 15 minutes, and then weighed.
f. Measuring wood shrinkage.
95
6. Workflow
Figure V.1 Workflow of Depreciation Wood
Preparing Apparatus and Materials :a. Wood samples of I (wood camphor)b. Wood samples of II (wood meranti)c. Calipersd. Scalee. Oven
Depreciation Wood
Start
Steps Work:a. Each sample was coded teams, parallel fiber = a, b =
perpendicular fibers, fiber direction = c.b. Considering each sample timber.c. Measure the length, width, and thickness of wood
(tangential, radial, axial)d. Incorporate wood into the oven for ± 24 hours.e. The next day put into oxilator for ± 15 minutes, and then
weighed.f. Measuring wood shrinkage.
Observing Test Results
Data Analysis
Finish
Conclusion
7. Observation Results.
Figure V.1 Steps Work Depreciation Wood
Informations Before oven After oven
Camphor Meranti Camphor Meranti
Length (cm)Wide (cm)High (cm)
10,86,84,9
10,26,94,7
10,76,44,6
106,74,5
Table V.2 Tables Wood Sample Observations
Samples
Weight (gram) Before oven After oven
Before oven
After oven
atangential
(cm)
Bradial(cm)
caxial(cm)
a’tangential
(cm)
b’radial(cm)
c’axial(cm)
Camphor (I)
285 265 5,2 4,2 10,8 5,1 3,9 10,7
Meranti (II)
230 210 5,8 3,6 10,2 5,7 3,5 10
8. Data Analysis
a. Sample I ( Wood Camphor )
Sringkage length woods
1) Direction axial = c – c’= 10,8 – 10,7= 0,1 cm
Large depresiation =
0,110,8 x
= 0.926 %2) Direction radial = b – b’
= 4,2 – 3,9 = 0,3 cm
Large depresiation =
0,34,2 x
= 7,143 %3) Direction tangential = a – a’ = 5,2 – 5,1 = 0,1 cm
Large depresiation =
0,15,2 x
= 1,923 % Water content of wood camphor
1) Weight of water = weight before oven – weight after oven = 285 – 265 = 20 gram
2) The water content of the dry weight =
weight waterweight after oven x 100%
=
20265 x
= 7,5471 %
3) The water content of the wet weight =
weight waterweight before oven x 100
=
20285 x
= 7,0175 %
The level of moisture
Formula : X =
(1,15 . 6 x )−6 kv6kv x 100 %
By : 6x = weight of the object before the oven
6kv = weight of the object after the oven
X = moisture content of wood
XKa =
(1,15 .285 )−265265 x
= 23,679 %
b. Sample II (Meranti wood)
The length of wood shrinkage
1) Direction axial = c – c’ = 10,2 – 10 = 0,2 cm
Large Depreciation =
0,210,2 x 100 %
= 1,96 % 2) Direction radial = b – b’ = 3,6 – 3,5 = 0,1 cm
Large Depreciation =
0,13,6 x 100 %
= 2,78 % 3) Direction tangential = a – a’ = 5,8 – 5,7 = 0,1 cm
Large Depreciation =
0,15,8 x 100 %
= 1,72 %
The water content of the wood1) Weight water = weight before oven – weight after oven = 230 – 210 = 20 gram
e. Camphor wood moisture content > Meranti wood moisture content
10. Suggestions
a. Pieces of wood should be flat and angled corners should, because it will
affect the measurement of the length of wood.
b. In the measurement, caution should be considered properly.
c. Timber should be examined first, whether cracked or not to affect wood
shrinkage.
B. Pressure Strong Test Wood
1. Objectives
To find the powerful urge to know the strength of the wood so that
the wood properly.
2. Basic Theory
Wood for building or construction should be a good and healthy.
Provided that all the attributes and shortcomings of existing, will not
damage or diminish the value of construction (building). In Indonesia
Timber Construction Regulations of 1961 stated that for some types of
wood, which allowed voltage taken rather low. But this rule may also be
given to the evidence of the investigation can be accounted for.
Table V.3 Wood Class Data Classification
Class DensityAbsolute bending strength (kg/cm³)
Compressive strength of absolute
(kg/cm³)IIIIIIIVV
> 11001100 – 750750 – 500500 – 360
< 360
> 11001100 – 750750 – 500500 – 360
< 360
> 600600 – 425425 – 300300 – 215
< 215
3. Materials Used
Table V.4 Material Test Data Urges Strong Wood
No Data Wood Wood camphor Wood Meranti
1.2.3.4.5.6.7.
Wood defectsLength ( p )Wide ( l )High (t )
Weight ( s )Volume ( v )Density ( Bj )
-30 cm6,6 cm4,9 cm
700 gram970,2 cm3
0,72 gr/cm3
-30 cm6,6 cm5 cm
510 gram990 cm3
0,52 gr/cm3
4. Apparatus
a. Scale
b. Ruler bracket
c. Sandpaper
d. Calipers
e. Saw
f. Test equipment demanded
5. Steps Work
a. Cutting wood with a length of ±30 cm, ± 4 cm wide and ±5 cm tall,
then measure the length, width and height are actually using calipers.
b. The weighing timber.
c. Wood insert into test equipment and records pressed wood shortening
occurs, starting from the moment the needle indicates the load 2.5 kN,
5 kN; 7.5 kN, and so on (multiplier 2.5 kN)..
d. Draw a sketch of timber damage caused by the load acting on the
timber.
6. Workflow
7.Start
Pressure Strong Test Wood
Steps Work:a. Measure the width of the test surface in the central part of the
sample length, in millimeters.b. Placing the sample on recording devices, so that the test surface
facing up. Placing the press (punch) at odds with the test sample. Place the test sample and recording devices in the test machine. Perform loading sample rate continuously with constant pressure or constant rate of movement of the loading head, simultaneously recording devices will record the load and deformation. The rate of increase in load should be such that the test length not less than 2 minutes.
c. Testing continued until the deformation reaches 2.5 mm. It can be seen from the diagram the pressure readings on the machine or deformation on the gauge. Expenses associated with the deformation fmax should be noted.
Observing Test Results
Preparing Apparatus and Materials :a. Scaleb. Ruler bracketc. Sandpaperd. Caliperse. Sawf. Test equipment demanded
Data Analysis
Conclusion
Finish
Figure V.2 Workflow of Pressure Strong Wood
7. Observation Results
Table V.5 Observation data pressure strong test camphor wood
No.Weight P
(kN)Depreciations
( ∆L ) cm
1 0.02 0.13 0.24 0.35 0.4
Table V.6 Stress and strain calculations camphor wood
No.Weight (P) Depreciations σ=P/A
ε=ΔL/L0
Correction
kN Kg ΔL (cm) (Kg/cm²)Analytic
( ε' )
Correction :
x+0 .333x + 1 . 000 =
376 . 81475 . 36
475.26 X + 159.42 = 185.51 X + 185.51292.75 X = 26.09