In recent years, tack coats have garnered a lot of attention from the asphalt paving industry. Many state transportation departments have conducted extensive research on the topic or are currently conducting test projects. Research has shown that tack coat can reduce pavement failure when used correctly.
When is tack coat used with asphalt?
Tack coat is almost always used when a new course of asphalt is being applied to an existing asphalt or concrete pavement. Tack coat is also seeing increased use between the courses of asphalt in new pavement construction.
Why is tack coat beneficial?
Tack coat provides several benefits. First, it improves the bond strength between the layers. This makes it less likely that one layer will slide or slip atop the one beneath it. Second, thanks to the enhanced bond, the load stresses are transferred to multiple layers of the pavement, improving the pavement’s durability. Third, the new surface will be less susceptible to shoving or pushing. Fourth, the stronger bond reduces the likelihood of top-down cracking.
Is tack coat just asphalt glue?
No, tack coat is an asphalt-based product that is sprayed onto the pavement. Although there are many products that can be used for tack coat, the most common are asphalt emulsion and asphalt binder. Asphalt binder is typically the same material used in the paving mix. Asphalt emulsion contains asphalt binder, a stabilizing agent and the appropriate amount of water.
How to prepare asphalt for tack coat?
For maximum bonding, the surface needs to be clean and dry. Milling the existing surface can enhance the bond strength, but the contractor must make sure that the dust created by the milling process is thoroughly removed. If the tack coat is being applied between layers of fresh asphalt, it is not normally necessary to clean before tacking; if the new pavement has become dirty, however, the contractor will likely sweep or wash it.
About tack coat...
Tack coat should be applied in an even layer that covers at least 90 percent of the pavement’s surface. However, the amount of tack coat needed is not the same for all applications. New asphalt pavement requires a thinner layer of tack coat, while aged pavement will need a thicker layer. A thicker layer of tack coat may be needed if applying asphalt over concrete or if the temperature is below approximately 60 degrees Fahrenheit. In mountainous terrain, it is normally advisable to use slightly less tack coat as the pavement will be subjected to shear stresses from traffic traveling on a steep grade.
Tack coat adds little to the price of a paving project. When constructing new pavement or having an overlay installed, the small investment in tack coat can have a significant return in the form of a more durable pavement that will also look better for longer. In many cases, the reduced repair costs more than offset the cost of the tack coat.
When you need an exceptional Kentucky asphalt contractor
APM is a paving company in Lexington with over 35 years of experience in the asphalt industry. We offer a full range of asphalt maintenance services to a variety of customers in Lexington, Louisville, and Central Kentucky. Our services include asphalt paving and asphalt resurfacing, pavement reinforcement, asphalt patching, milling and reclamation, sealcoating, parking lot striping, curbing, parking lot signs, site work and storm water management. We offer affordable prices, extraordinary workmanship and superior customer service. If you would like to request a quote, call us at (859) 299-8111 or fill out the form located on our website.
