What is granular sub base?

Granular sub base is a layer of coarse aggregate material used in road construction and civil engineering to provide structural support and drainage for the pavement above. It typically consists of crushed stone, gravel, or other granular materials that are well-graded to ensure stability and minimize settlement. This layer helps distribute loads from the pavement to the subgrade, improving durability and extending the lifespan of the roadway. Proper compaction and moisture control during installation are essential for its effectiveness.