Early Diseases of Drainage Asphalt Pavement

2023-08-15 15:55:07 ENUO

Pore blockage

Under the influence of the surrounding environment and vehicle tires, the voids in the drainage pavement are easily blocked by dust, gravel, soil and other foreign matter, which reduces the drainage and noise reduction functions of the pavement. This problem is especially serious on dusty road surfaces, low-speed roads and urban roads. Studies have shown that when the highway lane and pavement thickness is greater than 4cm and the porosity is greater than 22%, the problem of pore blockage is not obvious. However, the emergency lane is prone to blockage due to few vehicles, which not only reduces its own water permeability, but also hinders the lateral drainage of the road surface, thereby affecting the overall lateral drainage performance of the road surface. The blockage of the gap will also cause the weakening of the noise reduction function of the road surface.

Icing on the road surface

Although the problem of icing on the road surface only occurs in winter every year, the issue of road safety and maintenance is still a concern. France and the Netherlands have proved that the temperature of drained asphalt pavement is 1-2°C lower than that of densely graded asphalt pavement. Australia's research shows that drained asphalt pavement and densely graded asphalt pavement behave differently when the temperature is 0-5°C. The behavior is the same below -5°C. Scholars from different countries have obtained different conclusions in their comparative studies on the safety of drainage asphalt pavement and densely graded asphalt pavement when the pavement is icy, which has a lot to do with the structure of the pavement itself. Aggregate loosening problems in drained asphalt pavements usually begin in winter after icing occurs on the pavement.

missing aggregate

The contact between the aggregates of the drainage asphalt pavement is point contact, so under the coupling effect of environmental factors and vehicle loads, diseases such as asphalt spalling, loose aggregates, and loss of aggregates are prone to occur, and once the diseases occur, the pavement will often be destroyed in a short period and this is the main factor affecting the service life of the road. The main cause of aggregate loss disease is the aging of asphalt. The aging of asphalt in drained asphalt pavement occurs earlier than that of ordinary pavement, and because of its large voids, the surface and the bottom surface age equally. The aging of asphalt makes the binder become brittle, the viscosity increases, and the stress relaxation ability decreases, which leads to the accumulation of micro-damages in the internal structure of the pavement, and finally leads to the loss of aggregates.