Today, let’s talk about the national standard red brick

### **1. Specific gravity (density) of red bricks**
The density (specific gravity) of red bricks is usually between 1.6-1.8 grams per cubic centimeter (1600-1800 kilograms per cubic meter), depending on the compactness of the raw materials (clay, shale, or coal gangue) and sintering process.

### **2. The weight of a standard red brick**
-* * Standard size * *: The Chinese standard brick size is * * 240mm × 115mm × 53mm * * (volume approximately * * 0.00146 cubic meters * *). One cubic meter of national standard red bricks is about 684 pieces.
-* * Single piece weight * *: Calculated based on a density of 1.7 grams per cubic centimeter, the single piece weight is approximately * * 2.5 kilograms * * (actual range * * 2.2~2.8 kilograms * *). About 402 pieces of national standard red bricks per ton
(Note: Hollow bricks or lightweight bricks may be lighter and need to be adjusted according to the specific type.)
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### **3. The cost of red bricks**
-* * Unit price range * *: The price of each red brick is approximately * * 0.3~0.8 RMB * *, affected by the following factors:
-Regional differences: Regions with strict environmental policies (such as big cities) have higher costs.
-* * Raw material type * *: Clay bricks are gradually being phased out due to environmental restrictions, while shale or coal gangue bricks are more common.
-Production scale: Large scale production can reduce costs.
-Suggestion: Consult directly with the local tile factory or building materials market for real-time quotes.

### **4. National Standard for Sintered Bricks (GB/T 5101-2017)**
The current standard in China is * * “GB/T 5101-2017 Sintered Ordinary Bricks” * *, and the main technical requirements include:
-Size and appearance: allowable size deviation of ± 2mm, without serious defects such as missing edges, corners, cracks, etc.
-Strength grade: divided into five levels: MU30, MU25, MU20, MU15, and MU10 (for example, MU15 represents an average compressive strength of ≥ 15MPa).
-Durability: It must meet the requirements of frost resistance (no damage after freeze-thaw cycles), water absorption rate (generally ≤ 20%), and lime cracking (no harmful cracking).
-Environmental requirements: Must comply with the limits for heavy metals and radioactive pollutants in GB 29620-2013.
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###* * Precautions**
-Environmentally friendly alternative: Clay red bricks are restricted from use due to damage to farmland, and it is recommended to choose sludge bricks. Sintered bricks made from solid waste such as coal mine slag bricks, shale bricks, and coal gangue bricks.
-* * Engineering acceptance * *: During procurement, it is necessary to inspect the factory certificate and inspection report of the bricks to ensure compliance with national standards.