One of the most common materials used in roads, driveways and parking lots is asphalt. It is reputed to be long-lasting, economical, and well-polished and therefore a vital element of contemporary infrastructure. However, what is asphalt and why does it matter? This guide will simplify it into easy to comprehend terms.
Understanding Asphalt
Definition of Asphalt
Asphalt is a black sticky and very viscous substance mostly composed of bitumen which is a by product of crude oil refining. It is combined with other materials such as sand, gravel or crushed rocks to form what we normally refer to as asphalt concrete or simply asphalt. This mixture forms a very powerful and malleable surface that can be used in high-traffic zones.
History of Asphalt
Asphalt has been in use for thousands of years, although it gained popularity during the late 19th and early 20th centuries. The road that was used in the early times used to be made of gravel or cobblestone, which could not stand the modern vehicles. Asphalt was quickly adopted as the road material of choice because it had a smooth surface, was weather resistant and capable of supporting heavy traffic. More than 90 percent of paved roads today utilize asphalt.
Types of Asphalt
Asphalt has several types, which are used in a certain application. Knowledge of these types assists in the selection of the appropriate material in your project.
Hot Mix Asphalt
The most popular mix is Hot Mix Asphalt applied to roads and highways. It is applied with a high temperature (approximately 300degF) and is therefore easy to spread and compact. HMA offers a wear resistant and smooth surface that can withstand heavy traffic and severe weather conditions.
Warm Mix Asphalt
Warm Mix Asphalt is made at lower temperatures as compared to HMA, typically ranging between 200degF and 250degF. This minimizes the fuel usage and emissions in production and thus is a greener substitute. WMA suits well in medium traffic zones and where sustainability is an issue.
Cold Mix Asphalt
Cold Mix Asphalt is applied in temporary repairs, potholes and low traffic areas. It does not need heating and can be applied directly out of the bag as opposed to HMA and WMA. It is weaker than the hot mix asphalt but offers a fast and convenient answer to minor repairs.
Porous Asphalt
Asphalt that is porous permits the water to seep through the surface and in the process minimize runoff and floods. It is widely applied in the parking area, sidewalks, and minimal traffic roadways where stormwater control is necessary.
Components of Asphalt
Asphalt is more than just a black road surface.
Its strength and durability come from the combination of several key components:
Bitumen
The binding agent in asphalt is bitumen. It is a sticky thicker substance that is made out of crude oil which makes the aggregates sticky and gives it elasticity. Asphalt is also black in color due to bitumen.
Aggregates
Aggregates are minute grains of sand, gravel or ground rock. They give the asphalt mix strength, stability and texture. The quality and the size of aggregates may influence the durability and smoothness of the final surface.
Additives
In some cases, additives are added to the asphalt to improve performance. These may be flexibility polymers, anti-stripping agents to avoid water destruction, or fibers to enhance strength. Additives are particularly necessary in the regions of extreme temperatures or high traffic.
Benefits of Asphalt
Asphalt is not just popular like that. It is a favorite when it comes to projects of both public and private nature due to its advantages.
Durability
Well laid asphalt can withstand heavy traffic and last up to 15 to 20 years. Its lifespan can be increased with regular maintenance, such as closing cracks and repurposing.
Cost-Effectiveness
Asphalt is less costly to lay than concrete and therefore is a cost-effective material to use in road construction, driveways and parking lots. It also saves money in the long run because of its smooth surface which decreases vehicle wear and tear.
Quick Installation
The asphalt is relatively fast to install as opposed to other paving materials. The preps of roads and driveways can be completed within a day or two and cause minimal inconveniences.
Easy Maintenance and Repair
Maintenance is easy and cheap. The cracks, potholes and surface damage can be patched without taking away the pavement which is particularly crucial to busy roads and commercial locations.
Environmental Benefits
Asphalt can be recycled to 100% today, and this decreases the amount of waste and saves natural resources. Warm mix and porous asphalt are also used to reduce energy use and stormwater runoff and thus are more environmentally friendly.
Common Uses of Asphalt
Asphalt is very versatile and this is the reason why it finds a very great number of applications.
Roads and Highways
Most roads have asphalt paving. It has a smooth surface that means it is safer to drive in, has better traction and less noise than other materials.
Parking Lots
Commercial and residential parking areas are done using asphalt. It is solid, does not need much maintenance and can easily be marked to indicate traffic flow and parking spaces.
Driveways
Because of their smooth look, durability and the capacity to resist the seasonal variation in temperatures that is usually experienced in most parts of the U.S, homeowners like asphalt driveways.
Airports
Taxiways and runways in airports are usually constructed using asphalt due to its ability to support heavy aircraft traffic as well as the fact that it offers a smooth and safe surface to take off and land.
Recreational Areas
Asphalt is applied on bike paths, walking trails, tennis courts, and playgrounds because it has a smooth surface and does not need much maintenance.
Asphalt Maintenance Tips
The hardest asphalt needs some care in order to be in good condition.
Here are some simple tips:
Seal Coating: Seal Coating prevents water, UV ray and chemical damage by applying a seal coating after every 2-3 years.
Crack Filling: The timely filling of cracks helps stop the seeping in of water and formation of potholes.
Frequent Cleaning: Cleaning up the surface and eliminating debris and dirt make the surface safe and deterioration is avoided.
Proper Drainage: This is necessary to ensure that water drains off the asphalt and increases their life time.