With autumn’s official arrival last week, frosty mornings and brisk evenings are not far away.
While chilly days might be good news for fans of pumpkin spice lattes, cold weather can cause problems for workers on road projects around Frederick County.
Projects will continue for several weeks, but the lower temperatures can make it difficult for work involving paving and concrete, which need consistently higher temperatures to set properly.
Base asphalt generally needs temperatures of 40 degrees or higher, while surface asphalt usually requires 50 degrees, said State Highway Administration spokesman Charlie Gischlar.
Crews will keep working well into October or November, and possibly later if the temperatures hold, he said.
There are several SHA projects in Frederick County that are expected to continue into the spring, Gischlar said. They include
- The bridge on U.S. 15 over Md. 26: Crews continue to backfill abutments and are setting structural steel. Once the steel has been set, crews will begin working on the new concrete bridge deck.
- Reconstruction of Md. 140 between Creamery Road and Timbermill Run in Emmitsburg: Sidewalk and concrete curb and gutter replacement continues on eastbound Md. 140 up to Patterson Street.
- Reconstruction on Alternate U.S. 40 in Middletown between Ivy Hill Drive and Middletown Parkway: Crews continue to replace the waterline throughout town, as well as curbs, gutters and sidewalks on the west side of town.
- Replacement of bridge on Md. 140 over Flat Run in Emmitsburg, and installation of sidewalk from North Avenue to Silo Hill Road: The contractor is in the beginning stage of the bridge demolition.
- Work on the U.S. 15 interchange at Monocacy Boulevard in Frederick: The contractor is installing bridge parapets on Monocacy Bridge over U.S. 15, while crews also continue the reconstruction of the Tuscarora River Bridge, working on stormwater management areas around the interchange and grading for the future park-and-ride lot.
Much of determining when work can be done is dependent on when the asphalt plants used by contractors decide to shut down for the season, Gischlar said.
If the temperatures stay high enough, plants can continue to operate well into the fall and winter months.
The scheduling of projects can be difficult, because crews don’t want to start a project that they won’t be able to finish, Gischlar said.
For instance, they won’t leave a road that has had its surface layer removed to sit over the winter because of the damage it would receive from snow plow blades and other equipment.
Concrete is also temperature-sensitive, but it can be covered and heated so that it sets.
Contractors have to decide whether that’s something they want to do, depending on the project, said Jason Stitt, chief of Frederick County’s Office of Transportation Engineering.
Temperatures can also affect other aspects of projects, such as pavement striping.
Both the pavement and the air have to be warm enough to allow the permanent striping material to stick to the road, Stitt said.
Crews can put down temporary tape until the weather is warm enough for permanent stripes to be laid, but those can be pulled up by snow plows and other equipment, he said.
While trying to gauge temperatures for work in the fall can be difficult, making decisions on projects in the spring can also be tough because the weather can vary so much, Gischlar said.
But even if crews can’t lay pavement as the weather gets colder, they can usually find other things to do to keep the project moving along, such as drainage work, excavating or laying foundations for signs and other parts of a project, Gischlar said.
Still, Stitt said crews will be working the next few weeks knowing that their windows for getting much asphalt work done is closing.
“We don’t bank on much after Thanksgiving, expecting to get any paving done,” he said.