Question

Distinguish between hot mix asphalt patching and crack seal used for the maintenance treatment for flexible pavements.

Answer 1

Hot Mix Asphalt is used as patching or maintenance of pavement having pot holes and cracks developed in them. It is produced at a very high temperature of 300-350° C. It is used for a location of temperature of about 40°C or more, so it is highly weather resistant. It can cools down very quickly to allow minimum road interference time. Hot Mix Asphalt patching is most durable grade of paving asphalt, hence it is suitable for high traffic volume roads. It has high flexibility as they don't break but bend. But cost of treatment is slight high. It is done mostly all over the world pavement maintenance.

Crack sealing is that process inwhich hot sealants is applied to crack to prevent entry of water and dust. Usually crack sealant materials are rubberized asphalt or Sandy slurry. Generally crack sealing is perform in moderate temperature and this sealing is most effective when crack is developed immediately. Average life span of this treatment is about 5.6 years. Crack sealing is done for limited edge deterioration. Cost for treatment is less compared to hot Mix Asphalt patching.