Single Coat Seal
Primer seals are the most common surface treatment for low-volume roads. A primer seal is an application of bitumen followed by an aggregate cover. The bitumen is usually applied as a hot cutback bitumen. After the hot bitumen, cutback is applied to the pavement surface, aggregate is immediately applied over the asphalt before the hot bitumen cools. A pneumatic roller is used to reorient or seat the aggregate particles and tighten the rock matrix. After the bitumen cures, the excess aggregate is removed by booming.
A primer seal application corrects raveling and seals small cracks on the old pavement surface while providing a new skid resistant surface. Primer sealing may also be used following crack sealing.
Two Coat Primer Seal
Often more than one layer of a primer seal treatment is applied to a roadway. Two or three applications can be applied using the same equipment as a single coat seal treatment. When multiple layers are applied, the size of aggregate used in the first treatment is larger than the succeeding layers. Multiple coat seals are used to build up a thicker seal coat over an asphalt pavement, as a primed base course, or over a cement-treated base. The number of additional layers would determine the cost of the treatment as well as the life expectancy.
Contact us for more information about our spray seal services in Sydney.