What causes the asphalt to lift where it meets the concrete at my self-storage facility?
You will notice in the picture to the left the asphalt is 1" higher than the concrete
If your self-storage facility / portfolio is located in an area of the United States which experiences freezing temperatures, you may have noticed the asphalt in the drive isle has raised above the grade of the concrete threshold by ½” – 4.” Freeze thaw cycle is the main culprit behind the asphalt in the drive isle raising above the concrete threshold at the storage units.
What Causes Freeze Thaw Effect on Self Storage Drive Isles?
As your asphalt drive isles age, the asphalt begins to separate from the concrete. This is just an inevitability. Even the best installed asphalt pavement begins to break down at some point, typically around 3-5 years after paving. If you ignore these separating joints between the asphalt and concrete, your asphalt could fail prematurely, especially when water is allowed to penetrate these joints during the winter months.
The Freeze Thaw Effect on Self Storage Drive Isles?
(Top) Inverted Swale With Crack From Freeze Thaw
When water penetrates the asphalt / concrete joints in the winter, it freezes, expands, and widens the separation. This happens numerous times over the course of a winter, worsening each and every time and degrading your asphalt surface from the inside out. The Result: Premature pavement failure.
The last two winters have been especially rough on asphalt in the Mid-Atlantic and Northeast!
The constant temperature fluctuations of 50 degrees one day in January and then 10 degrees the next day, this is very hard on asphalt.
Water intrusion through the joints and cracks are just the beginning. Rapid freeze-thaw can lead to potholes and total surface failure. Self-Storage asphalt drive isles are typically built with an inverted swale down the middle to promote positive drainage. The cross slope from the storage building to the center of the drive isle typically has a high degree of pitch. As the water enters through the joint, gravity forces it to trickle under the pavement until it finds a point of zero pitch which is under the inverted swale. As the water sits in the center of the drive isle under the asphalt the freeze thaw works separately to reduce the integrity of the asphalt and subgrade. The end result- TOTAL SURFAE FAILURE for the entire drive lane.
Soil conditions will react differently, but essentially what happens is the top layer thaws while the soil stays frozen deeper down. You end up with moisture trapped between the frozen soil and the asphalt and as that drains, it makes the base unstable and you get potholes.
Battling Back against the Freeze Thaw Effect
How to prevent water intrusion is a very simple and cost effective approach. The joint are cleaned free of debris and a hot rubberized joint sealed compound is injected at 410 degrees Fahrenheit with a specialized crack / joint sealing melter. In some instances a foam back road may be installed if the current joints are deeper than 1”. In this author’s opinion, it is not recommended to use cold applied joint sealing products as they do not adhere properly. When the hot rubberized joint sealant is applied at 410 degrees Farenheight, it thermodynamically bonds to both the asphalt and concrete creating a 100% water tight seal.
What is the cost for asphalt / concrete hot rubberized joint sealing?
Depending on the depth of the joints, preparation work involved (Thoroughly cleaning the joint & removing grass or other debris) and amount of lineal footage expect to pay $1.00 - $2.50 per lineal foot. Most professional self storage paving contractors which offer this service will also have a minimum charge to cover labor, materials, mobilization and overhead. Average minimum charges typically run $1,500.00. At $1.00 per lineal foot if your self-storage facility only had 1,100 lineal feet, you would pay $1.00 per lineal foot or $1,500.00, whichever is greater.
Lifting Asphalt, Paving Companies, Paving Contractor