Asphalt Additives for Seal Coat Asphalts
Some aggregates have a strong electro-chemical make-up and tend to repel the asphalt, particularly in the presence of water. Under these conditions, the asphalt strips from the rock and the rock loses its bond. This is where the anti-strip additive may prove benefi cial, particularly for paving grades and cutbacks. Most of the emulsifi ers in asphalt emulsions are an anti-strip additive.
A polymer can be blended with an asphalt to alter the physical characteristics of the asphalt. It must be an individual decision as to the need, benefi ts, and additional cost justifi cation of the polymer.
Seasonal Protection Seal Coats
Seal coats, as with all asphalt pavements, should be protected during the time of year when bases are weakened. This weakness occurs when frost is coming out. Weight restrictions should be posted as necessary and enforced to preserve the seal coat surface. Excessive pressure applied to the plow blade during snow removal can result in the loss of seal coat rock.