APE May 2020 | Page 28

ASPHALT ANSWERS Proper compaction, whether static or vibratory, is essential to award winning jobs. Compaction Basics For Success E arly in my career, I was told a truth that has rung true for years. An experienced contactor said, “A good roller man can make a bad paving job look good, but a bad roller man can really mess up the best paving job.” There have been many innovations in compaction over the years, but the basics always ring true, achieve density and make the wa- ter run the right way. In this article I’m going to discuss a few tips and actors that are important to compaction ba- sics. Compaction starts behind the screed both tamping and vibratory. In its www.callape.com most basic form you are getting the air out of your asphalt mix in order to reach maximum performance of your mix. Operators have a short amount of time to maximize density from our as- phalt mix and road smoothness and is directly impacted by your compaction efforts. Air Voids The more air voids your asphalt mix has, the more it is compromised in terms of strength, durability, rutting, and moisture damage, all leading to a short life cycle for your pavement. The asphalt paving industry relies on [28] JOHN GREANEY compaction to increase the pavement density and extend the life of your pavement. The binder and aggregate particles mix, and are forced together through compaction thus increasing aggregate interlock and inter particle friction reducing the air voids with in your pavement. Vibration helps in this effort, but over vibrating can cause rideability issues. Temperature, Temperature, Temperature Asphalt mixtures cool quickly, so it is highly important to compact while the mix is hot. Typically asphalt comes from the plant around 300°, so you 1.800.210.5923