By Marvin Joles III
Let’s face it: as asphalt maintenance contractors, we would much rather they just have us cut and replace with hot-mix, infrared or even skim patch a spot. But when they want the “cheapest” solution to fix a hole or broken spot, it’s cold-mix. Yes, it has its place, and most of the time that’s in roadways where the traffic will do the compaction work and there aren’t any risks of real sinking, marring issues or complaints.
It contains a lot of oils so that it doesn’t cure while it sits in piles, bags or buckets. The stone is mostly large rock and all one size, so it has some structure but is hard to compress. Lastly, it just doesn’t look pretty and doesn’t look better after we sealcoat it. It is hard to get packed in, especially well enough so that it doesn’t move and does its job.
So, I’m going to give you some things to remember to give you the best shot when aiming to compact cold-mix asphalt. Let’s jump into it:
Temperature: Ensure the cold-mix is at the right temperature for optimal workability. Warmer is always better. While it doesn’t need to be hot like hot-mix asphalt, it should be warm enough to spread and compact effectively.
Moisture: The surface should be clean and free from debris, oil or water. Excess moisture can hinder adhesion and compaction. Just like crack-sealing, water is going to create a bonding barrier.
Layer Thickness: Apply the cold-mix in layers. If you need to do these spaced apart by days, do it. Ideally, each layer is no thicker than two inches to allow for proper compaction. More than two layers is too much.
Compaction Method: If you can, use a drum roller. It’s your best shot at the ultimate compaction you can achieve with this stuff. Second best is a plate compactor. That’s what we use at Wis-Coat 80% of the time. Lastly, a hand tamper will do, but try to upgrade as soon as possible.
Compaction Timing: Compact the mix immediately after placing it to ensure proper binding and to minimize the risk of settling or displacement.
Edge Feathering: Feather the edges of the patch, with a lute, if possible, to create a smooth transition to the surrounding pavement, which helps prevent tripping hazards.
Curing Time: Allow sufficient time for the patch to cure before exposing it to traffic, if possible. Check manufacturer recommendations for specific curing times, as some patches are “water activated” and can cure quickly after compaction.
Regular Maintenance: Monitor the patch after compaction for any signs of cracking or settling and address any issues promptly.
By keeping these things in mind and putting them into action, you can achieve a durable and effective cold-mix asphalt patch. Feel free to ask me about compaction, cold-mix and more if you see me at any conferences, expos or events this winter and stay safe out there, ladies and gents.
As always, if you have any insight or criticisms about this article or anything in it, please feel free to email me at marvin@blacktopbanter.com, and of course, reach out to us at Blacktop Banter on any form of social media. You can listen to the Blacktop Banter Podcast anywhere podcasts are available, and the video versions are always posted to the Blacktop Banter YouTube Channel.
Marvin Joles III, Owner of Wis-Coat Asphalt Maintenance and host of Blacktop Banter podcast. You can listen to and watch Blacktop Banter podcasts by visiting https://blacktopbanter.com
