ATB 37.5 factory run stone mesh 25x38mm

ATB 37.5 (Aggregate Base Type B, Dmax 37.5 mm) is a crushed stone with the largest particle size (Dmax) of 37.5 mm, used in asphalt concrete structures (Asphalt Treated Base – ATB).

This is an important material in road construction, acting as the upper base layer or roadbed layer before covering with hot asphalt concrete (Asphalt Concrete – AC).

Composition and characteristics of ATB 37.5 stone

• Composition: Crushed from original rocks such as granite, basalt or limestone.
• Particle size: The largest particle ≤ 37.5 mm, small particles can be down to a few mm.
• Particle shape: Angular, helps increase adhesion to asphalt.
• Fine particle content: Usually controlled to not be too high to ensure drainage.

1. In cement concrete

• ATB 37.5 is often used as a base layer (Base) or subbase layer (Subbase) before spreading hot asphalt concrete.
• Helps bear the load from vehicles, distributing the force to the roadbed.

2. In construction foundations

• ATB 37.5 stone creates a solid cushion layer, helping to prevent subsidence and cracking for the asphalt layer above.
• Limits the phenomenon of cracking, rutting and wheel tracks.

3. In road construction

• Due to its large grain size, ATB 37.5 helps create porosity in the road structure, allowing water to drain easily, avoiding stagnation that can cause road damage.

1. Standard grain composition (TCVN 8819:2011)

2. Important physical and mechanical indicators

• TCVN 8819:2011 – Regulations on asphalt concrete.
• TCVN 8859:2011 – Standards for grading crushed stone for roadbed.
• ASTM D692/D692M – American standards for aggregates in asphalt concrete.

1. Advantages

• Good load-bearing capacity – High strength, withstands heavy loads from vehicles.
• Stabilizes the roadbed – Helps prevent the asphalt surface from cracking.
• Increases road life – Helps the asphalt concrete layer to withstand better load-bearing capacity.
• Waterproofing – Helps limit water stagnation that causes road damage.
  

2. Disadvantages

• Large weight, more difficult to construct than small-sized stones.
• Requires strict quality control to ensure uniform particle size.
• Not suitable for asphalt pavement layers, only used for base layers.

1. Selection criteria

• The stone has an angular shape, helping to increase adhesion to asphalt.
• The content of small particles is not too high, ensuring ventilation.
• High hardness, limiting breakage during construction.

2. Storage and transportation

• Avoid mixing with impurities such as mud, soil, sand.
• Pile in a dry area, do not let water seep in.
• Avoid mixing with other types of stone, ensuring the correct particle composition.

ATB 37.5 stone is an indispensable material in asphalt road structure, helping to create a solid foundation layer, increasing durability and load-bearing capacity for traffic roads.

• Main application: Foundation layer in asphalt concrete road surface structure.
• Applicable standards: TCVN 8819:2011, TCVN 8859:2011, ASTM D692/D692M.
• Notes when using: Ensure the quality of stone particles, check the cleanliness before construction.