When laying down pavement there is more to it than just pouring asphalt and flattening it out to make a smooth road or driveway. There is a lot more to laying or installing pavement. One critical aspect of laying pavement is the drainage system. If the drainage system isn’t properly done then the road or pavement can develop a number of different problems that will reduce the life of the asphalt. Andersen Asphalt & Striping will share how pavement pumping occurs, how it is repaired, and why a proper drainage system can prevent this common problem.
What is Water Bleeding & Asphalt Pumping
Water bleeding occurs when water seeps out of joints or cracks in asphalt pavement whereas pumping occurs when water and fine material is ejected from underlying layers through cracks. Identifying asphalt pumping can be tricky and it can look very different from case to case. However, asphalt pumping will have large area cracks, with some that can span long distances. They can run in multiple directions. At times they can look like alligator skin cracking or it appears as flag stones. To properly identify asphalt pumping, often the contractor will need to inspect the pavement’s underlying layers. If the underlying layers are compromised, this is a classic case of asphalt pumping.
What Causes Asphalt Pumping Pavement Distress?
Asphalt pumping is essentially the result of the underlying layers being compromised. When the underlying layer has been weakened or compromised, this will allow the upper surface or the asphalt to move around and shift. As the asphalt moves, it will crack and even begin to break apart. However, the main question is what will cause the underlying layer to weaken? The underlying layer can be effected by a few different things. One can be simply due to a bad mix. If the asphalt and the underlying layer are of poor quality, they will tend to break down fairly quickly. In other cases the asphalt was simply mixed wrong. The other major culprit is water. In some areas, the ground water content is very high and the underlying layer is effected from the ground up. However, in the south western part of the U.S., the ground water content isn’t that high or is super saturated. Nevertheless this area does get rain and even snow. When heavy rains hit the the pavement, there must be proper drainage. Along with rain, the heat can also cause the road to contract very quickly which contributes to asphalt damages. In some cases asphalt pumping is due to a poor drainage design or installation.
Repair of Asphalt Pavement Failures
In order to repair asphalt pumping, the contractor will need to first determine the cause for the damages. In some cases, a better drainage system will need to be put in place. In other cases the entire road will need to be removed, the drainage system redone, or installing a better underlying layer. In other situations, the road surface can be repaired which will extend the need to redo the pavement for a few years. In areas with heavier rain or regions prone to snow, the drainage system is key in preventing asphalt pumping.