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This part is developed in accordance with the rules given in GB/T 1.1-2009.
JC/T 412 consists of two parts under the general title Fiber cement flat sheets:
——Part 1: Non-asbestos fiber cement flat sheets;
——Part 2: Asbestos fiber cement flat sheets.
This part is Part 1 of JC/T 412. In this part, the bending strength index is modified in relation to ISO 8336: 2009 Fibre-cement flat sheets; the type inspection rules are identical to those in ISO 390: 1993 Products in fibre-reinforced cement - sampling and inspection.
This part replaces JC/T 412.1-2006 Fiber cement flat sheets - Part 1: Non-asbestos fiber cement flat sheets. In addition to editorial changes, the following main technical changes have been made with respect to JC/T 412.1-2006:
——the scope is modified, specifying that this part is applicable to the non-asbestos sheets used as interior wall panels, exterior wall panels and suspended ceiling boards in buildings, clapboards in carriages, offshore buildings and vessels as well as composite insulation panels with fire-proof, heat insulation and moisture-proof requirements, and is also applicable to those used for other purposes such as home decoration (see Clause 1; Clause 1 of Edition 2006);
——the expressions of normative references are modified (see Clause 2; Clause 2 of Edition 2006).
——for the normative references, the year of GB/T 5464, GB/T 7109 and GB 8624 is modified, and nine standards, i.e., GB/T 10294-2008, GB/T 12954.1-2008, GB/T 23263-2009, GB/T 24321, JC/T 409, JC/T 414, JC/T 572, JC/T 622 and FZ/T 52023 are supplemented (see Clause 2; Clause 2 of Edition 2006);
——the definition of fiber cement flat sheets is modified as sheets manufactured through forming, pressurizing (or non-pressurizing) or high pressure steam (or non-high pressure steam) conservation with cement as cementitious material while organic synthetic fiber, inorganic mineral fiber or cellulose fiber as reinforcing material (see Clause 3; Clause 3 of Edition 2006);
——the definitions of sanding, the high pressure steam conservation, non-high pressure steam conservation, siliceous materials, textured sheets and saturated shear bond performance are added (see Clause 3);
——the specification and size are adjusted, wherein, the length is extended to 4880mm (see Table 2; Table 1 of Edition 2006);
——the non-asbestos sheets are classified into Classes A, B and C according to their purposes while classified into low shrinkage sheets and ordinary sheets according to the bulking factor; the labels of bending strength grade and impact strength grade are adjusted accordingly (see Clause 4; Clause 4 of Edition 2006);
——the standards for raw materials are supplemented (see Clause 5; Clause 5 of Edition 2006);
——the quality requirements for back and corner failure are added in the appearance quality requirements (see Table 3; 6.1 of Edition 2006);
——the shape deviation is tabulated separately, wherein, the edge verticality is deleted while the flatness is added, and different indexes are proposed for the thickness unevenness based on thickness and for the diagonal difference based on length (see Table 4; Table 2 of Edition 2006);
——the index requirements for size deviation are modified, wherein, different indexes are proposed for the length and width based on different intervals; sheets are classified into textured sheets and non-textured sheets based on thickness and are subjected to different indexes based on different thickness intervals (see Table 5; Table 2 of Edition 2006);
——the requirements for asbestos composition are added;
——the items and index requirements for physical properties are modified, wherein, the moisture content index is deleted, the apparent density is indicated in the quality document by the supplier, and the index requirements for heat conductivity coefficient, hot rain performance, hot water performance, soaking-drying performance and bending strength ratio index in freezing resistance test are added (see Table 6; Table 3 of Edition 2006);
——the codes of bending strength grades are modified as R1, R2, R3, R4 and R5; the bending strength index is modified; the longitudinal and horizontal strength ratio in the original standard is modified as the minimum strength of single piece, or as the strength index requirements for Classes A and B sheets at saturated state. Index requirements for three mechanical properties of impact strength, impact resistance and saturated shear bond performance are added (see Tables 7 and 8; Table 4 of Edition 2006);
——the expression of test method is modified, wherein, the test methods corresponding to each item are tabulated, and the inspection methods for the additional test items in this part are supplemented (see Table 9; Clause 7 of Edition 2006);
——water absorption is added as an end-of-manufacturing inspection item (see 8.2.1; 8.2.1 of Edition 2006);
——the type inspection conditions are modified (see 8.3.1; 8.1.2 of Edition 2006);
——the judgment rules for water absorption, hot rain performance, hot water performance, soaking-drying performance and bending strength ratio in freezing resistance test, impact strength, impact resistance and saturated shear bond performance are added (see 8.3.5);
——the raw materials are adjusted to Annex A as an informative annex (see Annex A; Clause 5 of Edition 2006);
——the Sampling diagram for physical and mechanical properties is added as an informative annex (see Annex B).
This part was proposed by China Building Materials Federation.
This part is under the jurisdiction of the National Technical Committee on Cement Products of Standardization Administration of China (SAC/TC 197).
The previous editions of this part are as follows:
——JC/T 412-1991(1996), JC/T 412.1-2006.
Fiber cement flat sheets - Part 1: Non-asbestos fiber cement flat sheets
1 Scope
This standard specifies the terms and definitions, classification, grades, specifications and labeling, raw materials, requirements, test methods, inspection rules, marking and certificate, transportation, packaging and storage of non-asbestos fiber cement flat sheets (hereinafter referred to as non-asbestos sheets).
This part is applicable to the non-asbestos sheets used as interior wall panels, exterior wall panels and suspended ceiling boards in buildings, clapboards in carriages, offshore buildings and vessels as well as composite insulation panels with fire-proof, heat insulation and moisture-proof requirements, and is also applicable to those used for other purposes such as home decoration.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB 175 Common Portland cement
GB/T 5464-2010 Non-combustibility test method for building materials
GB/T 7019-2014 Test methods for fiber cement products
GB 8624-2012 Classification for burning behavior of building materials and products
GB/T 10294-2008 Thermal insulation - Determination of steady-state thermal resistance and related properties - Guarded hot plate apparatus
GB/T 12954.1-2008 Testing methods for construction adhesives - Part 1: Test methods for ceramic tiles adhesives
GB/T 23263-2009 Determination of asbestos in products
GB/T 24321 Unbleached sulfate softwood pulp
FZ/T 52023 High tenacity and high modulus polyvinyl alcohol ultra-short fiber
JC/T 409 Fly ash for silicate building products
JC/T 414 Diatomite
JC/T 572 Alkali-resistant glass fiber roving
JC/T 622 Sand for silicate building products
JGJ 63 Standard of water for concrete
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
fiber cement flat sheets
sheets manufactured through forming, pressurizing (or non-pressurizing) or high pressure steam (or non-high pressure steam) conservation with cement as cementitious material while organic synthetic fiber, inorganic mineral fiber or cellulose fiber as reinforcing material
3.2
non-asbestos cement flat sheets
fiber cement flat sheets made with non-asbestos fiber as reinforcing material
3.3
sanding
the surface flattening process of sheets after conservation and hardening
3.4
the high pressure steam conservation
the process of placing the prepared blank into an autoclave for saturated steam conservation at about 0.8MPa~1.0MPa and 180℃ to stimulate the activity of siliceous and calcareous materials in the raw materials, promote hydration reaction and generate strength during sheet production
3.5
non-high pressure steam conservation
the process of making the cement in prepared blank generate strength by being subjected to hydration reaction in damp-heat environment with atmospheric pressure
3.6
siliceous materials
material with SiO2 as main composition
3.7
textured sheets
sheets with embossed pattern
3.8
saturated shear bond performance
the maximum breaking load per unit area on the composite interface between the adhesive and sheet when subjected to tangential stress at saturated state where the sheet used as the bottom plate of wall tile is adhered to the wall tile by adhesive
4 Classification, grades, specifications and labeling
4.1 Classification
4.1.1 Based on surface treatment state, the sheet is classified into raw sheet (code: YB), single-sided sanding sheet (code: DB) and double-sided sanding sheet (code: SB).
4.1.2 It is classified into three classes based on purpose:
——Class A: suitable for outdoor use and may bear direct sunshine, rain, snow or frost;
——Class B: suitable for environments where it may suffer from heat, dampness and occasional frost for a long time, e.g., underground facilities, alternate dampness and heat or outdoor indirect sunshine, rain, snow, frost, etc.;
——Class C: suitable for indoor use, may be subjected to heat or dampness rather than frost, e.g., interior wall, floor, tile lining sheet or bottom sheet.
Table 1 shows several typical purposes of flat sheets in common buildings.
Table 1 Classes and typical purposes of flat sheets
Class Purpose
Class A Exterior wall panel and composite insulation panel
Lapping wall panel or enclose wall panel
Lining sheet for exterior wall tile
Subfloor
Class B Bottom surface (cornice lining sheet)
Lining sheet for plaster layer or overlay
Rigid underlayer for roof or wall
Formwork or baffle
Wall panel and enclosure panel for underground buildings or damp-heat environment
Class C Bottom sheet of interior wall or floor tile
Ceiling sheet
Paint or wallpaper substrate of interior wall
Interior bottom substrate
Note: this table gives examples of application methods in general buildings; other application methods may be agreed through negotiation between the manufacturer and the purchaser.
4.1.3 Based on bulking factor, the sheet is classified into ordinary sheet (code: PS) and low shrinkage sheet (code: DS).
4.2 Grades
4.2.1 Based on bending strength, the sheet is classified into five grades: R1, R2, R3, R4 and R5.
4.2.2 Based on impact strength, the sheet is classified into five grades: C1, C2, C3, C4 and C5.
4.3 Specifications
See Table 2 for the specification/size.
Table 2 Specification/size In mm
Item Nominal size
Length L 600, 900, 1 200, 1 800, 2 400, 2 440, 3 000, 3 600, 4 800 and 4 880
Width H 600, 900, 1 200 and 1 220
Thickness e 4, 5, 6, 8, 9, 10, 12, 14, 16, 18, 20, 22, 25 and 30
Note: as required by the users, products of other specifications may be produced according to the contract requirements of the supplier and the purchaser.
4.4 Labeling
4.4.1 The product code of non-asbestos sheet is NAF.
4.4.2 Non-asbestos sheet shall be marked in the sequence of product code, class, bending strength grade, impact strength grade, bulking factor, surface treatment state, specification/size (L×H×e) and standard No.
Example: a Class A low shrinkage single-sided sanding non-asbestos sheet with bending strength grade of R3, impact strength grade of C2, length of 2440mm, width of 1220mm and thickness of 6mm is labeled as:
NAF A R3 C2 DS DB 2440×1220×6 JC/T 412.1-2018
5 Raw materials
The raw materials listed in Annex A are recommended.
6 Requirements
6.1 Asbestos composition
Asbestos composition shall not be detected in non-asbestos sheet.
6.2 Appearance quality
Appearance quality shall meet those specified in Table 3.
Table 3 Appearance quality
Item Quality requirements
Front surface No crack, delamination or peeling is allowed
Back
Corner failure Length ≤20mm, width ≤10mm; ≤1 for one sheet
Edge failure Edge failure depth ≤5mm
Note: the quality of sanding surface is agreed between the supplier and the purchaser.
6.3 Shape deviation
Shape deviation shall meet those specified in Table 4.
Table 4 Shape deviation
Item Shape deviation
Thickness unevenness e≤10mm ≤6%
10mm20mm ≤4%
Edge straightness ≤2mm/m
Diagonal difference L≤1 220mm ≤3mm
1 220mm< L< 2 440mm ≤4mm
L≥2 440mm ≤5mm
Flatness Sanding surface ≤0.3mm
6.4 Size deviation
Size deviation shall meet those specified in Table 5.
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Table 5 Size deviation In mm
Item Size deviation
Length L (width H) L (or H) ≤ 1 220 ±3
1 22020 ±5%e
Textured sheet e≤6 ±0.6
620 +3
-2
6.5 Physical property
Physical property shall meet those specified in Table 6.
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Table 6 Physical property
Item Class A Class B Class C
Apparent density/(g/cm3) Not less than the specified value indicated in the manufacturer's document
Heat conductivity coefficient/[W/(m·K)] ≤0.45 ≤0.35 ≤0.25
Water absorption/% ≤28 ≤40 —
Bulking factor/% DS sheet ≤0.25; PS sheet ≤0.50
Noninflammability Grade A noninflammability specified in GB 8624
Watertightness After 24h-inspection, the bottom surface of sheet may show signs of moisture but shall be free from water drops —
Freezing resistance
test Freezing resistance Classes A and B subjected to 100 and 25 freezing-thawing cycles respectively shall be free from crack or delamination —
Bending strength ratio ≥70%
Hot rain performance Classes A and B subjected to 50 and 25 cycle tests respectively shall be free from crack or delamination affecting normal use —
Hot water performance Bending strength ratio≥60% —
Soaking-drying performance Bending strength ratio of Classes A and B subjected to 50 and 25 cycle tests respectively ≥70% —
Notes:
1 Freezing resistance test may not be conducted in the region with hot summer and warm winter.
2 The test pieces of test group and those of control group are in saturated state where the freezing resistance test, hot water performance and soaking-drying performance are conducted for bending strength ratio test.
6.6 Mechanical property
Mechanical property shall meet those specified in Tables 7 and 8.
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Table 7 Bending strength
Strength grade Bending strength R
MPa Minimum strength of single piece
Classes A and B Class C
Water saturation strength Drying strength
R1 4 4 The minimum strength of single piece shall not be less than 70% of the index
R2 7 7
R3 13 10
R4 18 16
R5 24 22
Notes:
1 The indexes listed in this table refer to the minimum requirements that must be met by the non-asbestos delivered; the test results shall indicate whether the sheet is coated with overlay.
2 The bending strength listed in this table is the arithmetic average of the longitudinal and transverse bending strengths of the non-asbestos sheet.
3 The bending strength indexes listed in this table are the standard low limits ( ) for the evaluation on mechanical property in Table 11.
4 The minimum strength of single piece refers to the minimum bending strength of any sample in any direction.
Table 8 Other mechanical properties
Strength grade Impact strength P
kJ/m2 Impact resistance Saturated shear bond performance a
e≤14mm e>14mm
C1 ≥1.0 The sheet surface is free of through crack after impacted once in falling-ball method test ≥345 kPa
C2 ≥1.4
C3 ≥1.8
C4 ≥2.2
C5 ≥2.6
a Only when non-asbestos sheet is used as the bottom plate of wall tile, shall the saturated shear bond performance test be conducted.
7 Test methods
See Table 9 for the test methods.
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Table 9 Test methods adopted for each property
S.N. Property Test item Test method
1 Asbestos composition Asbestos GB/T 23263-2009
2 Appearance quality Front surface GB/T 7019-2014
3 Back
4 Edge failure
5 Corner failure
6 Shape deviation Thickness unevenness
7 Edge straightness
8 Diagonal difference
9 Flatness
10 Size deviation Length
11 Width
12 Thickness
13 Physical property Apparent density
14 Heat conductivity coefficient GB/T 10294-2008
15 Water absorption GB/T 7019-2014
16 Bulking factor
17 Noninflammability GB/T 5464-2010
18 Watertightness GB/T 7019-2014
19 Freezing resistance test a
20 Hot rain performance
21 Hot water performance
22 Soaking-drying performance
23 Mechanical property Bending strength
24 Impact strength
25 Impact resistance
26 Saturated shear bond performance b GB/T 12954.1-2008
a The bending strength ratio test method in freezing resistance test may refer to the freezing-thawing strength loss rate in GB/T 7019-2014.
b Class D paste emulsion adhesive in GB/T 12954.1-2008 may be used for saturated shear bond performance test.
8 Inspection rules
8.1 Inspection classification
Inspection is classified into end-of-manufacturing inspection and type inspection.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Classification, grades, specifications and labeling
5 Raw materials
6 Requirements
7 Test methods
8 Inspection rules
9 Marking and quality certificate
10 Transportation, packaging and storage
Annex A (Informative) Raw materials
Annex B (Informative) Sampling diagram for physical and mechanical properties
