The Asphalt pavement is usually used as the pavement surface layer of the asphalt road, which is directly affected by vehicle load and atmospheric factors. At the same time, the physical and mechanical properties of the asphalt mixture are greatly affected by climate factors and time factors. Provide stable and durable service. The asphalt pavement must have the following important characteristics:
1. Asphalt road has high-temperature stability.
High-temperature stability refers to the ability of asphalt pavement to resist flow deformation. Since the strength and stiffness of the asphalt pavement decrease significantly with the increase of temperature, in order to better ensure that the asphalt pavement will not produce diseases such as waves, shifting, rutting, and wrapping under the repeated action of driving loads in high-temperature seasons, the asphalt pavement should have good high-temperature stability.
2. Asphalt road has low-temperature crack resistance.
Low-temperature crack resistance refers to the ability of asphalt road to resist low-temperature shrinkage cracks. As the asphalt pavement decreases with temperature, its stiffness increases, and its expansion capacity decreases. Under the action of external load, part of the stress has no time to relax, and the stress gradually accumulates. When the accumulated stress exceeds the tensile strength of the material, cracking will occur, which will lead to the destruction of the pavement. Therefore, the asphalt pavement should have a lower stiffness at low temperatures. And the greater anti-deformation ability to meet low-temperature crack resistance.
3. Asphalt pavement has water stability.
Water stability refers to the ability of the asphalt pavement to resist the erosion of water and gradually cause the asphalt film to peel off, drop grains, loosen, and be damaged by potholes. This is because the existence of moisture reduces the cohesive force of asphalt itself on the one hand, and at the same time destroys the cohesive force between asphalt and mineral aggregates in the asphalt pavement, thus accelerating the peeling phenomenon and causing water damage to the road. Therefore, asphalt pavement must have water stability, so as to ensure its durability of the pavement.
4. Asphalt pavement should have fatigue resistance.
Fatigue resistance refers to the ability of an asphalt road to resist damage under repeated loads. It is due to the fact that the asphalt pavement is repeatedly subjected to wheel loads during use, and is in a state of overlapping stress and strain for a long time, resulting in a gradual decline in the structural strength of the pavement. When the load is repeated more than a certain number of times, the stress generated in the pavement under the load will exceed the structural resistance after the strength drops, causing cracks on the pavement and fatigue fracture damage. Therefore, the asphalt pavement should have fatigue resistance.