|CHARLESTON, WV – Although April is the cruelest month, February is worse for potholes. This year, West Virginia Division of Highways (WVDOH) has added a weapon in its fight against the freeze and thaw cycles that destroy the roads we share.
Potholes form when water gets into tiny cracks in the road, freezes, and rethaws. This makes tiny cracks into big cracks, and big cracks into potholes. By February, this constant cycle of freezing and thawing has taken its toll on the Mountain State’s roads.
Asphalt plants typically shut down in November and don’t reopen until March or April. During the winter it’s often too cold for asphalt to stick even if plants were open, but winter is when potholes form most frequently.
|This year, the West Virginia Division of Highways (WVDOH) has added a new weapon in its arsenal to battle potholes during cold weather.
“During the winter months, we use cold mix,” said WVDOH Chief Engineer of District Operations Joe Pack, P.E. “It’s a mixture of cold asphalt we can use to make temporary repairs. It’s not going to last as long, but it’s a temporary measure we can use until we can make permanent repairs in the spring.”
When making a temporary pothole patch, the WVDOH doesn’t just throw a shovel full of cold mix into a pothole and drive off. To make a proper wintertime pothole repair, Pack said crews first use tools to try to make the pothole as square as possible. They then remove all the old debris and heat the hole to make the cold mix stick better.
Finally, the cold mix is tamped down with hand tools or a roller. These repairs should last several months until asphalt plants reopen in the spring.
|This winter, WVDOH also has the ability to make a limited amount of hot asphalt even when asphalt plants are closed.
In District 1, which includes Kanawha, Boone, Clay, Mason, and Putnam counties, work crews have an asphalt recycling machine that takes old, ground up asphalt and reheats it in a big drum. Crews can tow the asphalt recycler to the site of a pothole and deliver hot asphalt on the spot.
“This will allow us to make permanent pothole repairs during the winter,” said WVDOH District 1 Manager Arlie Matney.
The machine now in use in District 1 allows work crews to make small batches of hot asphalt on the spot to make permanent pothole repairs even when asphalt plants are shut down. Matney said the machine is ideal for making emergency repairs or when crews can’t want to wait until spring for a permanent pothole repair.
“Where we can really use this is in our work zones,” Matney said. He said the machine can come in handy in places like Interstate 64, where heavy traffic typically wears out cold asphalt patches quickly.
District 1 bought 30 extra tons of asphalt before the asphalt plants closed and left it in a pile to use for emergency repairs over the winter. When they want to make a batch of hot asphalt, crews scoop up the chunks of hardened asphalt and dump into the asphalt machine to reheat.
|The machine has a spinning drum like a cement mixer. Two powerful burners then heat the chunks of asphalt to more than 200 degrees Fahrenheit.
Between the heat and the tumbling action of the drum, chunks of hard asphalt are quickly broken down and melted into a mixture just like it comes from the asphalt plant. It takes about 20 minutes to warm up the machine, but once up and running the asphalt recycler can turn out a new batch of asphalt every five or 10 minutes.
The machine can’t make large batches of asphalt, but it can be towed to trouble spots quickly for emergency patching or other small jobs. WVDOH hopes to expand use of the machine to provide one more tool in the fight against freeze and thaw.