As with other materials, asphalt is not impervious to adverse weather and other conditions. Properly identifying the problem is essential in order to come up with the best solution when it comes to pavement flaws. Here are a couple of common pavement problems that your pavement contractor should easily spot.
- Alligator Cracking: This type of problem is associated with structural failure that can be due to weakness in the surface, base or sub grade; a surface or base that is too thin; poor drainage or the combination of all three. It initially starts in the wheel path as longitudinal cracking and ends up as alligator cracking after severe distress.
- Block Cracking: These look like rough and large interconnected rectangles that are caused by shrinkage of the asphalt pavement due to an inability of asphalt binder to expand and contract with temperature cycles. It can be that the mix was mixed and placed too dry, fine aggregate mix with low penetration asphalt & absorptive aggregates, poor choice of asphalt binder in the mix design, or aging dried out asphalt.
- Linear Cracking: As the name implies, these are longitudinal cracks that are parallel to the pavement centerline or lay down direction. It can be caused by pavement fatigue, reflective cracking, or poor joint construction.
- Transverse Cracking: These are single cracks perpendicular to the pavement’s centerline or lay-down direction. Transverse cracks can be caused by reflective cracks from an underlying layer, daily temperature cycles, and poor construction due to improper operation of the paver.
- Edge Cracks: These types of cracks travel in the inside edge of a pavement surface within a foot or two. The main reason behind this would be poor drainage conditions that can weaken the base materials. Heavy vegetation along the pavement edge and heavy traffic can also be the initiator of edge cracking.
- Joint Reflection Cracking: These cracks happen on asphalt pavements over concrete and affect the underlying rigid pavement joints.
- Slippage Cracks: These are crescent-shaped cracks in the surface layer of the asphalt where new material has slipped over the underlying course. Most probably, it is caused by lack of bonding between layers that can be sue to dirt, oil, or other contaminants preventing adhesion between the layers.