Nehbandan Astan Granite Stone is extracted from the mines of South Khorasan province in the city of Nehbandan and has a light background with gray, cream and orange themes, which is considered as a cotton flower granite.
Granite is a group of igneous rocks that is one of the heaviest building stones in Iran in terms of density. Granite is a symbol of hardness, strength and durability.
This stone has a larger granulation than similar stones and the lower grades of this stone have black and gray spots and belong to the white granite family. Proper grinding mode, high compressive and abrasion resistance and low water absorption are the inherent features of this stone. This stone has good resistance to atmospheric factors such as acid rain, cold and heat, alkalis, impact and pressure.
Nehbandan Granite Stone is one of the stones that is very strong and resistant due to its volcanic particles. It has low water absorption power and high compressive strength, and therefore in places where there is a lot of traffic or is exposed to moisture and chemicals, this stone is the most suitable choice among granite stones.
Usages of Nehbandan Granite Stone:
Nehbandan granite is one of the most suitable options for use in the exterior of the building. The high resistance of this stone against high pressure, cold and heat, rain and frost, and… has caused it to always be used in the external environments of the building.
Nehbandan Astan granite is generally used in the following cases:
- Interior and exterior stone of buildings and structures
- Sidewalks, street tables and decorating development plans
- Structural components with stable dimensions
- Separation of slope and retaining walls
Grading of granite types:
Grading (sorting) of granite stones in the stone market is classified into three grades: super, excellent and one grade. The parameters that determine the grading of granite stone are:
- Type of stone
- Lack of tubers and paddy
- Accurate grading and minimal color play
- Stone diameter
- The size of the stone
- Grinding mode
- The lips of the stones should be full
Features of Nehbandan Astan granite:
- Very high density
- Extraordinary strength
- Proper grinding mode
- Suitable abrasion resistance
- Very high compressive strength
- Lack of absorption and permeability of water and moisture
- Very reasonable price
Nehbandan granite physical requirements according to national standard:
- The minimum compressive strength, flexural strength and fracture coefficient must be greater than the minimum average strength.
- Granite must be sound, durable, and free of debris, cracks, open veins, cavities, or other defects that may damage the structural cohesion of the intended use.
- Granite must be free of minerals that, under normal conditions of consumption, may appear as undesirable stains.
- Optimal texture and color, with acceptable natural differences.
Good resistance to cold and heat
Relatively low water absorption
High compressive and abrasion resistance
Proper grinding mode
Analysis of granite according to the standard of building stones:
|Row||Title||Iranian standard code||Min||Max||granite|
|2||Water absorption rate||ISIRI 5699||0.03||1.50||1%|
|3||Mega Pascal compressive resistance||ISIRI 5698||600||2200||2000|
|4||Abrasion Resistance||ISIRI 5700||2.20||6||6|
|5||Special Weight||ISIRI 5699||1.80||2.80||2.6|