Subbase (pavement)

Mass concrete is used where exceptional loads are expected, with thickness usually 100 to 150 millimetres (4 to 6 in), and optional reinforcement with steel mesh or polymer fibers.

In the UK, the specification for aggregate used as a subbase in the construction of driveways and roads includes MOT Type 1 Stone.

Low quality subbase material, including large pieces of rock and concrete, which was hardly acceptable heretofore, can now be re-used when crushed in-situ with conventional milling machines to obtain a homogenous grain size.

The subgrade or base course is properly prepared for the required grade and camber of WBM road.

The potholes and the depressions on the surface of the road are properly filled up and compacted.

Layers in the construction of a mortarless pavement: A.) Subgrade B.) Subbase C.) Base course D.) Paver base E.) Pavers F.) Fine-grained sand