Things you may not know about stone

① Classification by cause:

② Classification according to specifications:

GRANITE GROUP

LIMESTONE GROUP

MARBLE GROUP

QUARTZ-BASED DIMENSION STONE GROUP

SLATE GROUP

OTHER GROUP

ASTM C119-16 Standard Terminology Relating to Dimension Stone

American Society for Testing and Materials: ASTM C119-16 Standard Terminology Relating to Dimension Stone.

Domestic standard: JCG/T 60001-2007 Technical Specification for Natural Stone Decoration Engineering

10.4.4 Panel thickness shall be determined by strength calculations. The thickness of the polished face slab shall not be less than 25mm for granite, 3mm for the fire slab, and not less than 35mm for other stones. For the facades of high-rise buildings, important buildings and buildings facing the street, the thickness of granite panels shall not be less than 30mm. The area of a single granite panel should not be greater than 1.5 ㎡, and the area of other stone panels should not be greater than 1.0 ㎡.

3.6.6 The thickness of stone panel shall meet the requirements in Table 3.6.6. The effective thickness of mirror plate and thin plate shall not be less than 25mm, and the thickness of thick plate shall be 3mm thicker than that of mirror plate and thin plate.

3.6.7 The effective thickness of granite panel with a height of more than 100m shall not be less than 30mm.

6.6.1 For stone panels connected by back bolts, the thickness of mirror panel and thin panel shall not be less than 30 mm, and the thickness of thick panel shall be 3 mm thicker than that of mirror panel and thin panel.

7.2.1.5 Stone panels shall conform to the requirements of Table 46.

7.2.1.6 For the stone panel with the standard value of bending strength less than 8.0 MPa, additional structural measures shall be taken to ensure the reliability of the panel.

7.2.1.7 In severe cold and cold regions, the frost resistance coefficient of stone for curtain wall shall not be less than 0.8.

7.2.1.8 Stone surface should be protected. For stone panels in serious air pollution or acid rain environment, appropriate protective products should be selected to protect the stone according to the type and degree of pollution of pollutants and the mineral chemical and physical properties of the stone.

Determination of sandstone thickness:

① Classified by category;

② Determine the thickness according to the bending strength corresponding to the classification.

5.3.1.1.2 The minimum thickness of the mirror plate for outdoor use is recommended according to the experience of high-quality engineering;

① Granite shall not be less than 25mm;

② Marble with good soundness, high-density limestone and travertine shall not be less than 30 mm;

③ Textured sandstone and medium-density limestone shall not be less than 50mm.

5.3.1.1.3 The minimum thickness of mirror stone used indoors shall not be less than 20mm.

5.3.1.1.4 The nominal thickness of the rough surface stone building board shall be increased by not less than 3mm on the basis of the thickness of the mirror surface board.

6.1.2 The area and minimum thickness of a single dry hanging stone shall meet the requirements in Table 2

3.4.1 Granite should be selected as stone. The stone panel shall conform to the provisions of the current national standard Natural Granite Building Slab (GB/T 18601), and the bending strength, water absorption, minimum thickness and single area of the stone panel shall conform to the provisions of Table 3.4.1.

Conclusion on thickness of cave rock and sandstone

1. When the bending strength of natural limestone (travertine) and sandstone is ≥ 8.0 MPa, the thickness shall be ≥ 35 mm; when the bending strength is ≥ 4.0 MPa and ≤ 8.0 MPa, the thickness shall be ≥ 40 mm.

2. Textured sandstone and medium density limestone (travertine) ≥ 50 mm.

3. Dry and water-saturated bending strength test must be carried out.

About the content of stone, this issue will first talk about "stone classification, stone surface processing technology, stone thickness" three aspects, the next issue we will continue to bring you "ore inspection, stone physical performance indicators, stone surface protection" three aspects of dry goods knowledge, please look forward to!