Asphalt pavements: How are they built and what are their benefits?
Asphalt pavement consists of stones and sand mixed with asphalt, a thick, viscous, dark liquid that is a petroleum product. Asphalt is sometimes referred to as bitumen, which is both produced from crude oil and valued due to its adhesive qualities and resistance to damage from water and oil. However, it should be noted that bitumen is not the same as asphalt. Asphalt is a composite mixture of aggregate (such as stones and sand), while bitumen is used as a binder. Typically, the composition of an asphalt pavement includes 90 to 95% aggregate and sand, with the remaining 5 to 10% asphalt or bitumen. The high viscosity of asphalt effectively binds aggregate and sand together while maintaining flexibility. As asphalt cools, it becomes less flexible. However, this adaptability is a key advantage, which allows the surface to respond to changes due to weather and constant shifting that comes with it. Asphalt pavement is widely recognized for durability and resilience, making it a popular choice in construction for various paved surfaces, such as driveways, parking lots, roadways, air strips, and more.
The steps involved in the production of asphalt pavement are as follows. After measuring the components, the belt weighing instrument records every component carefully within a silo. For example, the aggregate components are dried in the rotary drying drum, and any change in weight is noted. Once dry, the dried aggregate is sifted and then stored in silos. For example, the binding element, liquid asphalt, is heated and stored in separate tanks for preserving its liquid state. In the mixer, aggregate and asphalt are mixed together, where the entrance of the asphalt is put into careful control. When mixed, the hot asphalt mix is kept in a heated silo. The asphalt plants normally have several chambers to store different recipes. The asphalt is kept hot until it is transported by dump trucks to the job site.
To prepare the surface for the asphalt pavement to be laid, extensive preparation is necessary. Prior to placing the asphalt, the ground under the pavement must first be cleared, excavated, compacted, and graded. Although base materials can be either compacted stone or an asphalt base, each requires a high level of technical expertise. But that may be compromised if the ground is prepared inadequately. Once the ground is prepared, the asphalt is transported to the site, where it is being dumped into the area. The hot asphalt is then being rolled onto the ground so that proper adhesion and a smooth surface are achieved.