Gypsum board testing standard

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Gypsum board GB / t9775-2008 test report
Range
This standard specifies the terms and definitions, classification and marking, requirements, test methods, inspection rules, marks, packaging, storage and transportation of gypsum board.
This standard is applicable to the paper faced gypsum board used as non load-bearing internal partition wall and ceiling in buildings, as well as the base plate of decorative paper faced gypsum board that needs secondary finishing.
(2) normative references
The provisions in the following documents become the provisions of this standard through the reference of this standard. For dated reference documents, all subsequent amendments (excluding Corrigendum) or revisions are not applicable to this standard. However, parties reaching an agreement according to this standard are encouraged to study whether the latest version of these documents can be used. For undated references, the latest edition is applicable to this standard.
GB / T 1250 expression and determination of limit values
GB / T 9776 building gypsum
3 terms and definitions
The following terms and definitions are applicable to this standard.
3.1 edge
A longitudinal edge covered with paper.
3. 2 end
Cutting edge of vertical edge.
3. 3 front
The protective paper has no overlapping board surface at the edge.
3.4 back
The protective paper has overlapping board surface at the edge.
3. 5 face paper
Cover paper on the front of the plate.
3. 6 back paper
Cover paper on the back of the plate.
3.7 core material
A material covered with protective paper and mainly composed of dihydrate gypsum.
3. 8 length
Dimension of the plate parallel to the edge.
3. 9 width
Dimension of the plate perpendicular to the edge.
3.10 thickness
The vertical distance between the front and back of the plate.
3.11 gypsum plaster
Powdered cementitious materials conforming to GB / T 9776.
4 Classification and marking
4.1 classification
4.1.1 plate type and code
According to its functions, paper gypsum board can be divided into four types: ordinary paper gypsum board, water-resistant paper gypsum board, fire-resistant paper gypsum board and water-resistant and fire-resistant paper gypsum board.
4.1.1.1 plain paperboard (code P)
A building board with building gypsum as the main raw material, mixed with appropriate amount of fiber-reinforced materials and admixtures, poured between the face paper and the back paper of the protective paper after mixing with water, and firmly bonded with the protective paper.
4.1.1.2 water resistant paperboard (code s)
It is a building board with building gypsum as the main raw material, mixed with an appropriate amount of fiber reinforced materials and water-resistant admixtures, poured between the face paper and the back paper of the water-resistant protective paper after mixing with water, and firmly bonded with the water-resistant protective paper, aiming at improving the waterproof performance.
4.1.1.3 fire resistant paper faced stone with plate (code h)
Building gypsum is used as the main raw material, mixed with inorganic refractory fiber reinforced materials and admixtures, and mixed with water It is a building board poured between the face paper and the back paper of the protective paper and firmly bonded with the protective paper to improve the fire resistance
4. 1.1.4 water resistant and fire-resistant plasterboard (Code: SH)
It is a building board with building gypsum as the main raw material, mixed with water-resistant admixtures and inorganic fire-resistant fiber reinforced materials. After mixing with water, it is poured between the face paper and the back paper of the water-resistant protective paper, and firmly bonded with the water-resistant protective paper. It aims to improve waterproof performance and fire resistance.
4.1.2 edge shape and code
According to the edge shape, the paper faced gypsum board can be divided into four types: rectangular (code J), chamfered (code D), wedge (code c) and circular (code y)
(see Fig. 1-fig. 4), and other edge shaped plates can also be produced according to user requirements
4.1.3 specifications and dimensions
4.1.3.1 the nominal length of the plate is 1500 mm, 1800 mm, 2100 mm, 2400 mm, 440 mm
2 700 mm, 3 000 mm, 3 300 mm, 3 600 mm and 3 660 mm.
4. 1.3.2 the nominal width of the plate is 600 mm, 900 mm, 1200 mm and 1220 mm.
4.1.3.3 the nominal thickness of the plate is 9.5 mm, 12.0 mm, 15.0 mm, 18.0 mm, 21.0 mm and 25.0 mm.
4.2 marking
4.2.1 marking method
The order of marking is: product name, plate type code, edge shape code, length, width, thickness and the number of this standard.
4.2.2 marking examples
Examples of marking are as follows:
Example: ordinary gypsum board with a length of 3000 mm, a width of 1200 mm, a thickness of 12. 0 mm and a wedge edge shape, marked as: gypsum board pc 3000 × 1 200 × 12. 0 GB/T 9775-2008。
5 requirements
5.1 appearance quality
The surface of the paper gypsum board shall be flat and free from ripple, groove, material loss, material leakage, scratch, damage, stain and other defects that affect the use.
5.2 dimensional deviation
The dimensional deviation of the plate shall conform to the provisions in Table 1.
Table 1 dimensional deviation (unit: mm)
project
length
width
thickness
nine point five
≧12.0
Dimensional deviation
﹣6～0
﹣5～0
±0.5
±0.6
5.3 diagonal length difference
The plate shall be cut into a rectangle, and the length difference between the two diagonals shall not be more than 5 mm.
5. 4 wedge edge section size
For plates with wedge-shaped edges, the width of wedge-shaped edges shall be 30 mm, ~ 80 mm, and the depth of wedge-shaped edges shall be
0.6 mm～1.9 mm。
5.5 surface density
The surface density of the plate shall not be greater than that specified in Table 2.
GB/T9775-2008
Table 2 surface density
Plate thickness / mm
Surface density / (kg / ㎡)
nine point five
nine point five
twelve
twelve
fifteen
fifteen
eighteen
eighteen
twenty-one
twenty-one
twenty-five
twenty-five
5.6 breaking load
The breaking load of the plate shall not be less than that specified in Table 3.
Table 3 breaking load
Plate thickness
/mm
Breaking load / n
portrait
transverse
average value
minimum value
average value
minimum value
nine point five
four hundred
three hundred and sixty
one hundred and sixty
one hundred and forty
twelve
five hundred and twenty
four hundred and sixty
two hundred
one hundred and eighty
fifteen
six hundred and fifty
five hundred and eighty
two hundred and fifty
two hundred and twenty
eighteen
seven hundred and seventy
seven hundred
three hundred
two hundred and seventy
twenty-one
nine hundred
eight hundred and ten
three hundred and fifty
three hundred and twenty
twenty-five
one thousand and one hundred
nine hundred and seventy
four hundred and twenty
three hundred and eighty
5.7 hardness
The edge hardness and tip hardness of the plate shall not be less than 70 n
5.8 impact resistance
After impact, there shall be no radial cracks on the back of the plate.
5.9 adhesion between face paper and core material
The cover paper and the core material shall not be peeled off.
5.10 water absorption (only applicable to water-resistant plasterboard and water-resistant fire-resistant plasterboard)
The water absorption of the plate shall not be greater than 10%.
5.11 surface water absorption (only applicable to water-resistant paperboard and water-resistant fire-resistant paperboard gypsum board)
The surface water absorption of the plate shall not be greater than 160g / ㎡.
5.12 stability in case of fire (only applicable to fire-resistant paper faced gypsum board and water-resistant fire-resistant paper faced gypsum board)
The fire stability time of the plate shall not be less than 20 min.
5.13 damp deflection
It shall be agreed by both parties.
5.14 shear force
It shall be agreed by both parties.
6 test method
6.1 test equipment and instruments
6.1.1 steel tape: the maximum measuring range is 5000 mm, and the graduation value is 1 mm.
6.1.2 steel ruler: the maximum measuring range is 1000 mm and the graduation value is 1 mm.
6.1.3 plate thickness tester: the maximum range is 30 mm, and the graduation value is 0.01 mm.
6.1.4 wedge edge depth tester: the maximum range is 10 mm, and the graduation value is 0.01 mm.
6.1.5 electronic scale: 1g.
6.1.6 electronic balance: sensitivity 0.01g.
6.1.7 electric blast drying oven: the maximum temperature is 300 ℃, and the sensitivity of the temperature controller is ± 1 ℃.
6.1.8 plate bending resistance tester: the maximum range is 2000 n, and the accuracy is level 1.
6.1.9 pressure testing machine: the maximum range is 2000 n, and the accuracy is level 1.
6.1.10 impact resistance tester: the diameter of steel ball is 50 mm, and the mass of steel ball is 510g.
6.1.11 adhesion tester between cover paper and core material: load mass 3 kg.
6.1.12 paper surface absorption weight tester: inner diameter of cylinder is 113 mm.
6.1.13 fire stability tester: flame head diameter (40 ± 1) mm, flame hole diameter (2.5 ± 0.1) mm, maximum temperature
900 ℃, accuracy class 1.
6.1.14 damp deflection test chamber: adjustable to temperature (32 ± 2) ℃ and relative humidity (90 ± 3)%.
6.2 test conditions
The laboratory where the surface density, breaking load, hardness, impact resistance, adhesion between the cover paper and the core material and water absorption are measured shall meet the test environment conditions of temperature (25 ± 5) ℃ and relative humidity (50 ± 5)%. The laboratory for surface water absorption measurement shall meet the test environment conditions of temperature (25 ± 5) ℃ and relative humidity (50 ± 3)%.
6.3 samples and test pieces
Take five plates as a group of samples, measure the appearance quality, size deviation, diagonal length difference and wedge edge section size in sequence, and then cut the test pieces at the position more than 100 mm from the plate (except for the test pieces for end hardness and edge hardness measurement) according to the direction, size and quantity specified in Table 4, and number them for other tests.
For the test piece to be tested for end hardness, cut the test piece at either end of the plate according to the provisions in Table 4, but the distance from the edge shall be more than 100 mm. For the test piece to be tested for edge hardness, take one test piece on both edge sides of the plate according to the provisions in Table 4, but the distance from the end shall be greater than 100 MRN.
Table 4 specification of test piece
Purpose of test piece
Specimen code
Longitudinal dimension / mm
Lateral dimension / mm
Number of test pieces cut from each plate
Longitudinal breaking load (also used as area density)
Z
four hundred
three hundred
one
Transverse breaking load (also used as area density)
H
three hundred
four hundred
one
End hardness
T
seventy-five
three hundred
1 (1 at both ends)
Edge hardness
L
three hundred
seventy-five
2 (1 for each edge)
Impact resistance
K
three hundred
three hundred
one
Bonding of face paper and core material
M
one hundred and twenty
fifty
one
Bonding of backing paper and core material
D
one hundred and twenty
fifty
one
Fire stability
Y
three hundred
fifty
one
Water absorption
S
three hundred
three hundred
one
Surface water absorption
B
one hundred and twenty-five
one hundred and twenty-five
one
6.4 treatment of test piece
The test pieces used for the determination of breaking load (also used as surface density), hardness, impact resistance, adhesion between face paper and core material, water absorption and stability in case of fire shall be placed in an electric blast drying oven in advance, dried to constant weight under the temperature of (40 ± 2) ℃ (the mass change rate of the test pieces in 24 hours shall be less than 0.5%), and cooled to room temperature under the laboratory conditions of temperature (25 ± 5) ℃ and relative humidity (50 ± 5)% before measurement. The test piece used for the measurement of surface water absorption shall be placed in the electric blast drying oven in advance, dried to constant weight under the temperature of (40 ± 2) ℃ (the mass change rate of the test piece in 24 hours shall be less than 0.1%), and placed for 24 hours under the Laboratory environmental conditions of temperature (25 ± 5) ℃ and relative humidity (50 ± 3)% before measurement.
6.5 test steps
6.5.1 inspection of appearance quality
When the light is bright, conduct inspection 0.5 m away from the sample, record the appearance quality affecting the use of each plate, and take the most serious defect of the five plates as the appearance quality of this group of samples.
6.5.2 determination of length
Measure three length values on each plate. The measuring points are distributed 50 mm away from the edge and on the axis of symmetry (see Fig. 5). During measurement, the plate shall be placed flat and the steel tape shall be parallel to the edge of the plate.
Record the three length values on each plate, calculate the deviation between the measured length value and the nominal length value, and take the maximum deviation value of the five plates as the length deviation of this group of samples, accurate to 1 mm.
6.5.3 measurement of width
Measure three width values on each plate, and the measuring points are distributed at 30 mm from the end and on the axis of symmetry (see Fig. 6). During measurement, the plate shall be placed flat and the steel tape shall be perpendicular to the edge of the plate. If the plate has a chamfered edge shape, the width of the back of the plate shall be measured.
Record the three width values on each plate, calculate the deviation between the measured width value and the nominal width value, and take the maximum deviation value of the five plates as the width deviation of the group of samples, accurate to 1 mm.
6.5.4 thickness measurement
Six measuring points are arranged equidistantly in the width direction of any end of each plate, and the distance between the measuring points and the end of the plate is not less than 25 mm, and the distance between the measuring points and the edge of the plate is not less than 80 mm (see Fig. 7). Use a plate thickness meter to measure.
Record the six thickness values on each plate, calculate the deviation between the measured thickness value and the nominal thickness value respectively, and take the maximum deviation value of the five plates as the thickness deviation of this group of samples, accurate to 0.1 mm.
6.5.5 measurement of diagonal length difference
Use a steel tape to measure the length of the two diagonal lines on the plate, record the length values of the two diagonal lines on each plate, calculate the difference between the two diagonal lines, and take the maximum diagonal length difference among the five plates as the diagonal length difference of the group of samples, accurate to 1 mm.
6.5.6 measurement of wedge edge width
Measure four values on the edge side 300 mm from the end of the plate. Place the steel ruler horizontally on the front of the plate and make it perpendicular to the edge of the plate. The end of the steel ruler is aligned with the edge of the plate. Measure the distance between the edge of the plate and the contact point between the steel ruler and the front of the plate (see Fig. 8).
Record the four measured values on each plate, calculate the average value, and take the average value of the width of the maximum deviation from the middle value of the specified wedge edge width of the five plates as the wedge edge width of this group of samples. To the nearest 1 mm.
6.5.7 determination of wedge edge depth
Measure four values on the edge side 300 mm from the end of the plate. Place the wedge edge depth measuring instrument on the front of the plate. When the measuring head of the instrument is 10mm away from the edge of the plate, the data can be read from the instrument (see Fig. 9).
Record the four measured values on each plate, calculate the average value, and take the average value of the depth of the maximum deviation from the middle value of the specified wedge edge depth of the five plates as the wedge edge depth of this group of samples. To the nearest 0.1 mm.
6.5.8 determination of areal density
Place the 10 test pieces used to measure the breaking load that have been processed in 6.4 on the electronic scale for weighing. Calculate the average area density of two test pieces on each plate according to its area. Take the maximum of the average values of the five plates as the area density of the group of samples, accurate to 0.1 kg / ㎡.
6.5.9 determination of fracture load
Press 6.5