Long Life Asphalt Pavements
Long life asphalt pavements are essential to maintaining good road infrastructure. These types of pavement are designed to provide stronger structures with durable bases that can last up to 50 years or more.
Roads like this are possible through improved technology, stronger materials and improved processes designed to strengthen base, pavement and the overall structure of the road. This type of build is ideal for highways, ports, industrial areas and airports. High-traffic areas can also benefit from this type of road structure.
High-impact long-life roads are designed with a three-layer asphalt pavement structure that consists of a 4″ to 6” asphalt pavement top layer, a middle layer known as the flexible base with granular content and a natural subgrade base. This design reduces the tensile strain impact on the road by distributing the load. This design helps prevent surface flaws like cracking or rutting due to improperly distributed weights.
This reduces the instances of fatigue failure to the pavement layers and can prevent design flaws like fault cracks or ruts. Smooth roads result in better driving experiences for motorists and can help prevent accidents.
In turn, this prevents fatal flaws that can lead to expensive road repairs. For example, the flexible base is often prone to deformation from the weight of the traffic above it. Normally, thicker asphalt mitigates this, so a well-maintained asphalt layer is needed to prevent this type of deformation. However, long life pavements are still susceptible to other forms of damage, such as thermal cracking from tectonic plate movement, water damage and flood/storm damage.
Long-lasting pavements are designed with safety in mind, with thick asphalt mixtures that use hot-mix recycling or warm-mix recycling for heavy-traffic roads and cold-mix recycling for low-traffic or rural roads. Nowadays, cost-effective techniques like warm-mix asphalt can produce similar, long-lasting results even with thinner paving. This means that maintenance crews focus on the asphalt, not the sublayers, when repairing. However, thinner asphalt pavements mean that the base and layers must be up to standard as they cannot mitigate flaws below the surface.
Long-lasting asphalt pavements help to prevent damage to the flexible road base and subgrade. This minimizes the need for repair and road rehabilitation, except to the asphalt pavement itself. These days, asphalt paving is fast, safe and economical. In turn, this minimizes the inconvenience for the American motorist.
Good roads make for good economies, as anyone who has been to a developing country knows. Roads made from substandard material and with inferior technology easily break down and make repairs a regular recurrence. With long-life asphalt paving, this can be easily prevented.