Plasterboard GB/T9775-2008 inspection report

                                          Plasterboard GB/T9775-2008 inspection report

Range
This standard specifies the terms and definitions, classification and marking, requirements, test methods, inspection rules, marking, packaging, storage and transportation of gypsum board.
This standard is applicable to the gypsum plasterboard used as non load-bearing internal partition wall and ceiling in buildings, as well as the base plate of decorative gypsum plasterboard that needs secondary finishing processing.
2 normative references
The clauses in the following documents become the clauses of this standard through the reference of this standard. For dated references, all subsequent amendments (excluding Corrigendum) or revised versions of these documents are not applicable to this standard. However, parties to agreements based on this standard are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest edition is applicable to this standard.
Gb/t 1250 expression and determination method of limit value
Gb/t 9776 building gypsum
3 terms and definitions
The following terms and definitions apply to this standard.
3.1 edge
A longitudinal edge covered with paper.
3 . 2 end
Cutting edge of vertical edge.
3.3 front face
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
Protective paper on the front of the board.
3.6 back paper
Protective 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
The size of the plate parallel to the edge.
3.9 width
The size 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
Powdery cementitious material 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 common paper stone flush (code P)
It is a building board with building gypsum as the main raw material, mixed with an appropriate amount of fiber-reinforced materials and additives, poured between the face paper and the back paper of the face paper after mixing with water, and firmly bonded with the face paper.
4.1.1.2 water resistant paper stone flush plate (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 additives, poured between the surface paper and the back paper of the water-resistant face paper after mixing with water, and firmly bonded with the water-resistant face paper, in order to improve the waterproof performance.
4. 1.  1.3 fire resistant paper stone with board (code h)
The building gypsum is used as the main raw material, mixed with inorganic fire-resistant fiber reinforcement materials and additives, etc. after mixing with water 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 paper faced stone board (code SH)
It is a building board with building gypsum as the main raw material, mixed with water-resistant admixture and inorganic fire-resistant fiber reinforcement, poured between the surface paper and the back paper of the water-resistant face paper after mixing with water, and firmly bonded with the water-resistant face paper, in order to improve the waterproof performance and fire resistance.
4. 1.  2 edge shape and code
According to the shape of edges, gypsum plasterboard can be divided into four types: rectangle (code J), chamfer (code D), wedge (code c) and circle (code y)
(see Figure 1 and Figure 4), 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 plates is 1500 mm, 1800 mm, 2100 mm, 2400 mm, 2440 mm
2700 mm, 3000 mm, 3300 mm, 3600 mm and 3660 mm.
4. 1.3.2 the nominal width of plates is 600 mm, 900 mm, 200 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 code, edge shape code, length, width, thickness and the number of this standard.
4. 2.  2 marking example
Examples of markings are as follows:
Example: the length is 3000 mm, the width is 1200 mm, and the thickness is 12 0 mm ordinary gypsum board with 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 faced gypsum board shall be flat, and there shall be no 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 comply with the provisions of Table 1.
Table 1 dimension 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 plates shall be cut into rectangles, and the length difference between the two diagonals shall not be greater than 5 mm.
5.4 section size of wedge edge
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 area density
The area density of the plate shall not be greater than that specified in Table 2.
GB/T9775-2008
Table 2 areal density
Plate thickness /mm
Area 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 should be no radial cracks on the back of the plate.
5.9 adhesion between protective paper and core material
The protective paper and core material shall not be stripped.
5.10 water absorption (only applicable to water-resistant gypsum plaster board and water-resistant and fire-resistant gypsum plaster board)
The water absorption of the plate shall not be greater than 10%.
5.11 surface water absorption (only applicable to water-resistant gypsum plasterboard and water-resistant gypsum plasterboard)
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 gypsum board and water-resistant and fire-resistant gypsum board)
The stability time of the plate in case of fire shall not be less than 20 min.
5.13 damp deflection
It shall be negotiated by the supplier and the demander.
5.14 shear force
It shall be negotiated by the supplier and the demander.
6 test method
6.1 test equipment and instruments
6.1.1 steel tape: the maximum range is 5000 mm, and the graduation value is 1 mm.
6.1.2 steel ruler: the maximum range is 1000 mm, and the division value is 1 mm.
6.1.3 plate thickness tester: the maximum range is 30 mm, and the division value is 0.01mm.
6.1.4 wedge edge depth tester: the maximum range is 10 mm, and the division value is 0.01 mm.
6.1.5 electronic scale: sensitivity 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 temperature controller is ± 1 ℃.
6.1.8 plate bending 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: steel ball diameter 50 mm, steel ball mass 510g.
6.1.11 adhesion tester between protective paper and core material: load mass 3 kg.
6.1 . 12 paper surface absorption weight tester: the inner diameter of the cylinder is 113 mm.
6.1.13 fire stability tester: the diameter of the fire spout is (40 ± 1) mm, the diameter of the fire spout hole is (2.5 ± 0.1) mm, and the maximum temperature
900 ℃, accuracy level 1.
6.1.14 damp deflection test chamber: it can be adjusted to the temperature of (32 ± 2) ℃ and the relative humidity of (90 ± 3)%.
6.2 test conditions
The laboratory that carries out the determination of area density, breaking load, hardness, impact resistance, adhesion between protective paper and core material and water absorption shall meet the test environmental conditions of temperature (25 ± 5) ℃ and relative humidity (50 ± 5)%. The laboratory for measuring the surface water absorption shall meet the test environmental conditions of temperature (25 ± 5) ℃ and relative humidity (50 ± 3)%.
6.3 samples and test pieces
Taking five plates as a group of samples, after the appearance quality, size deviation, diagonal length difference and wedge edge section size are measured in turn, the test pieces are cut at a distance of more than 100 mm from the periphery of 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 numbered 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 of Table 4, but the distance from the edge shall be greater 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 of Table 4, but the distance from the end shall be greater than 100 MRN.
Table 4 specification of test piece
Purpose of test piece
Code of test piece
Longitudinal dimension /mm
Transverse dimension /mm
Number of test pieces cut from each plate / piece
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 (choose 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 between face paper and core material
M
one hundred and twenty
fifty
one
Bonding between backing paper and core material
D
one hundred and twenty
fifty
one
Stability in case of fire
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 pieces
The test pieces used for the determination of breaking load (also used as surface density), hardness, impact resistance, adhesion between protective paper and core material, water absorption and stability in case of fire should be placed in an electric heated blast drying oven in advance, dried to constant weight at a temperature of (40 ± 2) ℃ (the mass change rate of the test pieces in 24 hours should be less than 0.5%), and cooled to room temperature at a temperature of (25 ± 5) ℃ and a relative humidity of (50 ± 5)%, and then measured. The test pieces used for the determination of surface water absorption should be placed in an electric heated blast drying oven in advance, dried to constant weight at a temperature of (40 ± 2) ℃ (the mass change rate of the test pieces should be less than 0.1% in 24 hours), and placed for 24 hours at a temperature of (25 ± 5) ℃ and a relative humidity of (50 ± 3)%, and then measured.
6.5 test steps
6. 5.  1. Inspection of appearance quality
Under the condition of bright light, check at the place 0.5 m away from the sample, record the appearance quality of each plate that affects the use, and take the situation of the plate with the most serious defect among the five plates as the appearance quality of this group of samples.
6.5.2 length measurement
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 Figure 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 respectively, and take the maximum deviation value of five plates as the length deviation of this group of samples, accurate to 1 mm.
6.5.3 width measurement
Measure three width values on each plate, and the measuring points are distributed 30 mm away from the end and on the axis of symmetry (see Figure 6). When measuring, the plate shall be placed flatly, and the steel tape shall be perpendicular to the edge of the plate. If the plate is in the shape of chamfered edges, the width of the back of the plate should be measured.
Record the three width values on each plate, calculate the deviation between the measured width value and the nominal width value respectively, and take the maximum deviation value of five plates as the width deviation of this group of samples, accurate to 1 mm.
6.5.4 thickness measurement
Six measuring points are arranged equidistantly in the width direction of either 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 from the measuring points to the edge of the plate is not less than 80 mm (see Figure 7). Use the plate thickness tester to measure.
Record 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 five plates as the thickness deviation of this group of samples, accurate to 0 1 mm。
6. 5.  5 measurement of diagonal length difference
Measure the length of the two diagonals on the plate with a steel tape, record the length values of the two diagonals on each plate, calculate the difference between the two diagonals, and take the maximum difference between the diagonals of 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 side of the edge 300 mm away 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 Figure 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. Accurate to 1 mm.
6. 5.  7 measurement of wedge edge depth
Measure four values on the side of the edge 300 mm away 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 10 m away from the edge of the plateThe data can be read from the instrument (see Figure 9).
Record the four measured values on each plate, calculate the average value, and take the average 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. Accurate to 0 1 mm。
6. 5.  8 Determination of areal density
Place the 10 test pieces used to measure the breaking load treated 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. The maximum of the average value of five plates is taken as the area density of this group of samples, accurate to 0 1 kg/㎡。
6. 5.  9 Determination of breaking load
Determine the breaking load of 10 test pieces that have been measured according to 6.5.8. Place the test piece on the support of the plate bending tester. Among them, the longitudinal fracture load specimen (specimen code z) is placed face down; The transverse fracture load specimen (specimen code h) is placed face up. The center distance of support is 350 mm. At the center of the span, the load is applied by the loading roller in the direction parallel to the lower support, and the loading speed is controlled at (4.2 ± 0.8) n/s until the specimen breaks. Record the maximum plate load and calculate the average breaking load of five plates. The average value and minimum value of five plates are taken as the breaking load of this group of samples. Accurate to 1 n.
6. 5.  10 Determination of hardness
6. 5.  10.1 determination of end hardness
Erect the test piece treated in 6.4 horizontally and vertically, and then clamp it with a fixture. Arrange three measuring points on the thickness centerline of the test piece according to figure 10. Load the test piece through the steel needle (see Figure 11) at the loading speed of (4.2 ± 8) n/s by the pressure testing machine until the insertion depth of the steel needle reaches 13 mm. Record the three maximum hardness values of each test piece during the test, and take the average value of the maximum hardness values of the five test pieces as the end hardness value of this group of samples, accurate to 1 n.
6. 5.  10.2 determination of edge hardness
Remove the edge protective paper from the test piece treated in 6.4 on the three measuring points specified in Figure 10 to expose the edge core material. Then determine the maximum edge hardness of ten test pieces according to the method in 6.5.10.1. The average value of the maximum hardness of ten test pieces is taken as the edge hardness value of this group of samples, accurate to 1n.
6.5.11 determination of impact resistance
Sand with a fineness of 0.5mm is installed in the chassis of the impact resistance tester and scraped flat with a scraper ruler. Put the test piece treated in 6.4 face up and place it flat on the sand surface. Make the steel ball fall freely on the intersection of the two diagonals of the test piece from the height specified in Table 5 (see Figure 12). Take out the test piece, record the crack condition on the back of the test piece, and take the most serious condition of the five plates as the impact resistance result of this group of samples.
Table 5 steel ball height unit: mm
Plate thickness
Steel ball height h
nine point five
five hundred
twelve
six hundred
fifteen
seven hundred
eighteen
eight hundred
twenty-one
nine hundred
twenty-five
one thousand
6. 5.  12. Determination of adhesion between protective paper and core material
For the test piece treated in 6.4, a seam shall be cut at 20mm from the end longitudinally, but the protective paper on the other side shall not be damaged (see Figure 13). For the test piece (code m) measuring the adhesion between the face paper and the core material, cut and sew on the back of the test piece; For the test piece (code D) for determining the adhesion between the backing paper and the core material, cut the seam on the front of the test piece. Then fix the test piece in the upper fixture of the adhesive tester between protective paper and core material (see Figure 14). Screw on the lower clamp at the end of the specimen bent along the cutting seam, and gradually increase the load until the protective paper is torn off. Record the bonding condition between the face paper and back paper of each plate and the core material, and take the worst condition of five plates as the result of the bonding between the face paper and the core material of this group of samples.
6. 5.  13 determination of water absorption
After the test piece is treated in 6.4, weigh the mass of the test piece (G1) with an electronic scale, and then immerse it in water with a temperature of (25 ± 5) ℃. The test piece is suspended with a support, not close to the bottom of the water tank, and the upper surface of the test piece is 30 mm away from the water surface. After soaking for 2h, take out the test piece, use a semi wet towel to absorb the water attached to the surface of the test piece, and weigh the mass of the test piece (G2). Record the mass of each test piece before and after immersion, and calculate the water absorption according to formula (1). Take the maximum value of five test pieces as the water absorption of this group of samples, accurate to 1%.
W1=  × 100 ………………………（1）
Where:
W1 - water absorption,%;
G1 - mass of test piece before immersion, unit: G;
G2 - mass of the test piece after immersion in water, in grams (g).
6. 5.  14 determination of surface water absorption
The test piece passes 6 4 after treatment, in 6 2. Carry out the determination under the specified laboratory test conditions. Measure the surface water absorption on the front of the test piece. Weigh the mass of the test piece (G3) with an electronic balance, and then fix the test piece on the paper surface absorption weight tester. Inject water with a temperature of (25 ± 5) ℃ and a height of 25 mm into the cylinder of the paper surface absorption weight tester. Start timing when turning the cylinder, and let it stand for 2h. After turning the cylinder into a regular one, remove the test piece and absorb the attached water on the surface of the test piece with neutral filter paper. Then weigh the mass of the test piece (G4) on the electronic balance, accurate to 0.01 G. Record the mass of each test piece before and after surface water absorption, and calculate the surface water absorption according to formula (2). Take the maximum value of five test pieces as the surface water absorption of this group of samples, accurate to 1g/ ㎡.
W2= ………………………(2)
Where:
W2 - surface water absorption, in grams per square meter (g/ ㎡);
G3 - mass of test piece before surface water absorption, unit: G;
G4 - mass of the test piece after water absorption on the surface, in grams (g);
S - surface water absorption area, unit: square meter (㎡).
6. 5.  15 determination of stability in case of fire
The test piece is drilled as shown in Figure 15, and then passes through 6 4 handling. Hang the test piece vertically between the two fire spouts with a support rod, and the fire spout is perpendicular to the surface of the test piece. Liquefied petroleum gas is used as the heat source to supply gas to the two burners of the fire stability tester, and the distance between the burner nozzle and the plate surface is 30 mm. Hang the load at the lower end of the test piece (see Figure 16) according to the provisions of table 6, and ignite the burner. Use two nickel chromium nickel silicon thermocouples to measure the temperature 5 mm away from the plate surface. At the beginning of the test, the carbonized face paper falling on the thermocouple should be removed without shaking the test piece. Through adjustment, the temperature shall be controlled at (800 ± 30) ℃ within 3 minutes, and this temperature shall be maintained throughout the test. The time shall be counted from the time when the test piece encounters fire to the time when the test piece breaks. Record the burning time of each test piece, and take the minimum value of the five test pieces as the fire stability of this group of samples. Accurate to 1 min.
Table 6 suspended loads
Plate thickness /mm
Suspended load /n
nine point five
seven
twelve
ten
fifteen
twelve
eighteen
fifteen
twenty-one
seventeen
twenty-five
twenty
6. 5.  16 measurement of damp deflection
The moisture deflection shall be measured in accordance with the provisions of Annex B.
6. 5.  17 determination of shear force
The shear force shall be measured in accordance with the provisions of annex C.
7 inspection rules
7.1 delivery inspection
7.1.1 the products shall be subject to factory inspection before leaving the factory.
7.1.2 the delivery inspection items are: appearance quality, dimensional deviation, diagonal length difference, wedge edge section size, area density, breaking load, bonding between face paper and core material, water absorption, surface water absorption, and stability in case of fire.
7.2 type inspection
7.2.1 the items of type inspection are all requirements except moisture deflection and shear force
7.2.2 type inspection shall be carried out in case of one of the following conditions.
a) When new products are put into production or product type identification;
b) When the product is transferred to another factory for production;
c) Under normal circumstances, once a year;
d) After normal production, there are major changes in product design, process, production equipment, etc., which may affect product quality;
e) When the production is resumed after the product has been suspended for more than half a year.
f) There is a big difference between the delivery inspection and the last type test inspection;
g) When the national quality supervision institution puts forward the requirements for type inspection.
7.3 sampling
7. 3.  1. Every 2500 pieces of products of the same model and specification are considered as a batch, and less than 2500 pieces are also considered as a batch.
7. 3.  2 randomly select five plates from each batch of products as a group of samples.
7.4 judgment rules
7. 4.  1 the determination of single inspection results shall be carried out in accordance with the rounding off value comparison method in gb/t 1250.
7. 4.  2 for the appearance quality, size deviation, diagonal length difference, wedge edge section size, impact resistance, and the adhesion between the protective paper and the core material of the plate, if one of them is unqualified, it is the unqualified plate. If there is more than one unqualified plate in the five plates, the batch of products is judged as unqualified.
7.4.3 for the surface density, breaking load, hardness, water absorption, surface water absorption and fire stability index of the plates, all five plates must be qualified, otherwise the batch of products is judged as unqualified.
7.4.4 for according to 7 4.2 and 7 4.3 for the batch determined to be unqualified, it is allowed to re sample two groups of samples and re inspect the unqualified items. The determination rules of re inspection results are the same as those in 7.4.2 and 7.4.3. If the two groups of samples are qualified, the batch is determined to be qualified. If there is still a group of samples that are unqualified, the batch is determined to be unqualified.
8 marking, packaging, storage and transportation
8.1 signs
The following contents shall be marked on the product or package:
a) Name and detailed address of the manufacturer;
b) Product mark, product trademark and production date;
c) Package specification and quantity of products.
8.2 packaging
8. 2.  1. Moisture proof measures shall be taken when the product package leaves the factory;
8. 2.  2. The product certificate or inspection seal shall be attached to the package of the product;
8. 2.  3. The outer packaging materials shall be marked with graphic signs for packaging, storage and transportation, moisture-proof signs, marks for handling with care, etc.
8.3 storage
Plates are classified indoors and stacked horizontally according to different models and specifications. The stacking site should be solid, flat and dry. When stacking, use cushion strips to separate the plates from the ground, so as not to deform and damp the plates during stacking.
8.4 transportation
The products shall be protected from impact and damage during transportation, and the plates shall be protected from moisture.