What is the suitability of aggregate for use in asphalt construction?

The suitability of aggregates for use in asphalt construction is determined by evaluating the material in terms of: Size and Grading, Cleanlines, Surface texture, Absorption and Affinity for asphalt.

Coarse aggregates shall consists of crushed rock, crushed gravel or other hard material retained on the2.36mm sieve. They shall be clean, hard, durable, of cubical shape, free from dust and soft or friable matter, organic or other deletrious matter, Where the contractor's selected source of aggregate have poor affinity for bitumen, as a condition for the approval of that source, the bitumen shall be treated with approved anti stripping agents, as per the manufacturer's recommendations. Before approval of the source, the aggregate shall be tested for stripping.

Fine aggregates shall consists of crushed or naturall ocurring material or a combination of the two passing2.36mm sieve and retained on the75 micron sieve. They shall be clean, hard, durable, dry and free from dust and soft or friable matter, organic or other deleterious matter.