DOT Type "A" Aggregate

Definition

A Department of Transportation (DOT) specified gradation of aggregate used under roadways and in pipe bedding applications.

Purpose

DOT Type "A" aggregate is used to provide a stable and supportive base for roadways and to ensure proper bedding for pipes. The specified gradation ensures that the aggregate has the necessary properties for load distribution, compaction, and drainage.

Examples of Use

1. Road Construction: Used as a base layer beneath asphalt or concrete pavements to provide stability and support.
2. Pipe Bedding: Ensures proper bedding for underground pipes, preventing shifting and providing adequate drainage.
3. Railroad Ballast: Sometimes used in railroad construction to support and stabilize tracks.

Related Terms

• Aggregate: A material composed of sand, gravel, crushed stone, or slag, used in construction.
• Gradation: The distribution of different sizes of particles within an aggregate.
• Subbase: The layer of material beneath the base course in a road pavement structure.

Notes

• The specific gradation and quality of DOT Type "A" aggregate are determined by the DOT to meet performance and safety standards.
• Proper compaction of the aggregate is crucial to ensure long-term performance and stability.