How to Prevent a Pocked Mat
BY John Ball
When the paving crew discovers divots in the mat immediately behind the paver, the first place to look for problems is under the screed. While the best time to prevent a pocked or marred asphalt mat is before the shift begins, sometimes routine maintenance misses the buildup of material under the screed or strikeoff plate. We’re all human; mistakes happen. Let’s look at how to fix the problem.
Determine whether or not you can knock the material loose and scoop it up without harming the equipment. If mix has built up, you may need to heat up the screed to warm the material from the underside, and use a putty knife to scrape the mix away. Depending on how much material has accumulated, you may need to add heat from the outside of the mass as well as from the underside. When applying heat with a propane torch, you have extra safety measures to consider.
The first thing to do is ensure workers wear their PPE. Safety goggles are important because the asphalt will sputter and spatter as it heats. You want long sleeves, thermal gloves and safety goggles between your skin and the heating material.
Next, make sure the propane tank and torch has a regulator on it to prevent any gas from going back into the tank. That’s a recipe for disaster. Use common sense with the torch also, keeping the torch low to the ground and away from personnel.
Follow other propane torch manufacturer’s recommendations and your company’s safety plan.
The best way to get a smooth mat with no pocks or divots is to have a clean, smooth metal screed plate floating over it. When the screed is hot at the end of the shift, clean the endgates and check the screed for build-up. Wipe the mix away while it’s easy to do. This ensures a smoother start to the next shift.
John Ball is the proprietor of Top Quality Paving, Manchester, New Hampshire. He provides personal, on-site paving consulting services around the United States and into Canada. For more information, contact him at (603) 493-1458 or email@example.com.