BAKER — The contractor on a street overlay project completed last year has agreed to extend the warranty on its work because of concerns about “clay balls” in the paving material, a company representative said Thursday.
Barriere Construction Co. did overlay work on some 20 Baker streets and patched numerous others in a $1.25 million project completed Dec. 27.
In January, small balls of a clay-like material began to show up on the surfaces of some streets, and the project engineer, Professional Engineering Consultants, brought in a testing firm to study the problem.
Michael McGowan of Southern Earth Sciences Inc. said his company visually inspected all of the streets, took core samples, inspected Barriere’s asphalt plant and performed several types of tests on the samples.
“These clay balls are part of the material blended at the plant,” McGowan told City Council members Thursday.
Asphaltic concrete, the overlay material, is made by blending a mixture of aggregates, ranging from sand to small pieces of gravel, with asphalt.
McGowan said finding a clay ball in the material is not unusual, but the material used on some Baker streets contained more than is normally found.
The lumps near the surface may become visible if the asphaltic emulsion wears off, he said. The spots ranged in size from slightly smaller than a quarter to the diameter of a pencil, McGowan said.
Jim Breland, representing Barriere at the meeting, said the company now has a different source for the sand added to the asphalt mixture and changed its quality-control procedures in the field.
“We may have hit some clay and didn’t notice it,” Breland said, adding that the company blew out the resulting holes and filled them with an epoxy material to prevent water from collecting in them and causing damage to the roadway.
Breland said the company will extend the warranty on its work from one year to three years.
“That’s our way of showing good faith,” he said.
McGowan said the material used in the overlays met the minimum requirements of the contract, but the streets with a significant number of visible clay balls would have been subject to “raveling” if they were not filled.
Council members and Mayor Harold Rideau said they will accept the warranty extension at an upcoming council meeting. The Thursday meeting was an informational session to discuss the Southern Earth Sciences report.