WINDHAM – An analysis of core pavement samples, taken by Maine Department of Transportation crews last month, revealed rut issues within a layer that sits five inches beneath the surface pavement applied by Pike Industries this summer, according to transportation department project manager, Denis Lovely.

“Everything was fine except for the intersection at [Route] 115,” Lovely said, when asked about the areas of concern.

The $1.1 million reconstruction project, along a 1.16-mile stretch of North Windham’s Route 302, from the routes 115/35 intersection to Whites Bridge Road, was completed by Pike Industries in mid-August. The project was overseen by the state.

Multiple calls made to Pike Industries were not returned by press time. Pike has been involved in other recent paving jobs that had to be redone, including the Naples Causeway.

Known as a “mill-and-fill project,” the Route 302 roadwork began July 14 and lasted six weeks with crews working at night in the middle of tourist season to replace the top layer of pavement. According to transportation department spokesman, Ted Talbot, the roadwork was badly needed due to ruts along much of the roadway and a washboard surface at the approaches to the intersections.

On Sept. 24, after Windham town staff notified the department about the reappearance of ruts on the newly paved road, state crews spent two hours working in a turning lane at the busy intersection of routes 115 and 35, digging up 15-inch-deep core samples of pavement to be sent to a laboratory for testing.

While the “asphalt content analysis” has not been completed as of last Friday, Lovely said, Pike Industries is slated to return to the intersection the week of Oct. 21 to remove and replace 6-7 inches of pavement from several areas of rutting in the intersection.

The work is expected to take about a week, depending on the weather, Lovely said.

According to Lovely, polyphosphoric acid was added to the liquid asphalt mixture that Pike Industries applied to Route 302 this summer, which is supposed to stiffen the mixture. The desired end result is fewer ruts, Lovely said in September.

“It’s always worked great for us in the past, and there is no reason to believe it wouldn’t work for us here,” Lovely said, frustrated that the recent repair was faulty.

The reappearance of ruts was noticed particularly at the approaches to intersections “where traffic stops and goes,” Lovely said.

Deformed

On Tuesday, Lovely said the analysis of the pavement samples taken by his crews revealed “plastic deformation” 5 inches below the surface layer, which is contributing to the remaining rutting issues, Lovely said.

According to Lovely, “plastic deformation describes what happens when the asphalt mix moves or deforms under traffic loads, and the material does not return to its previous shape, flat and smooth, after it deforms,” versus an elastic deformation, which “describes what happens when the asphalt mix moves or deforms under traffic loads, and the material does return to its previous shape.”

“Polymer mixes act more in an elastic manner, but can fail or deform if placed over a plastic layer,” Lovely said.

Paving projects statewide must be completed by mid-November due to weather, Talbot said, but the repairs should take no longer than a week.

Lovely said the project is expected to cause traffic delays. The widespread removal of pavement will be completed at night “as to not impact traffic any more than necessary,” Lovely said.

The areas that the department of transportation has identified as needing “extra depth milling” will be done during the day, he said.

“We no longer have desirable pavement temperatures at night,” Lovely said. “But the daytime closures will be [short] in length and will only impact one lane at a time.”

When asked in September whether core sampling is a typical follow-up procedure for state reconstruction projects, Lovely said the process was “uncommon.” Last week, however, after learning the results of the analysis, Lovely said the issues weren’t any worse than the department expected.

“It’s too bad that it happened, but we will be able to fix it and everything will be good,” Lovely said.

Maine Department of Transportation workers took a core sample in September of new pavement in North Windham, seen above. Subsequent tests determined the recent paving job by Pike Industries was faulty and needs to be replaced.