By Doug Lindner
SOLON– From the moment the dust settled, Solon Public Works director Scott Kleppe knew he wasn’t happy with the asphalt on Main Street.
Now the city has some ammunition to back him up.
At last week’s city council meeting, representatives from Terracon, an Iowa City engineering and consulting company, reported samples of asphalt from the Main Street paving failed to meet the project’s required specifications in a number of ways.
The report confirmed something the city had suspected for a long time.
Shortly after the substantial completion of the project, Kleppe said, city officials noticed a number of troubling signs– the surface of the asphalt was unraveling, there was excessive sand in the street gutters, large aggregate had risen to the top of the street and voids appeared where a person could scrape off the surface with a shoe.
Asphalt is the term for the petroleum byproduct commonly used to bind aggregates such as gravel and sand into a material which can be laid in a hot mix for road construction.
Kleppe said even during construction of the Main Street project last year, there were warning signs about some of the practices used by the subcontractor, Hansen Asphalt of Iowa City.
“We were kind of concerned about the quality of the job right from the get-go,” he noted.
So much so that it was brought to the attention of the general contractor for the Main Street overhaul, All American Concrete of West Liberty, and approximately $45,000 in payments for the $900,000 undertaking were withheld by the city.
The contractor provided test samples which were just within the parameters set out by the city, but members of the Solon City Council subsequently granted Kleppe permission to seek an independent assessment.
And that’s what brought Terracon civil engineers Justin Widdel and Tom Lisi to the Solon City Council meeting last Wednesday (Sept. 18).
The city contracted with Terracon to evaluate the Main Street asphalt at a cost of just over $6,800, and according to the report, Solon’s new surface doesn’t appear to make the grade.
The project had certain specifications as far as compaction, the amount of void space allowed within the asphalt mat, Widdel said. The greater the void, the weaker the structure of the pavement.
“We took core samples, we measured the density of the samples and a majority did not meet the 94 percent compaction,” he noted.
In fact, five of the six samples taken did not meet the minimums required by the city.
Based on conversations with a senior engineer who reviewed the report, Widdel said it was possible half the pavement did not meet the standard, and were at eight percent void, “which is a number you would want to stay away from.”
Lisi clarified Terracon did not take random samples, but for the most part targeted problem areas identified with Kleppe’s help. Numerous additional random samples would be needed to verify the actual percentage of unacceptable asphalt.
In addition, Widdel said while the amount of sand and gravel was within specifications, the tested samples were shy of the required percentage of asphalt, the material that binds the aggregate. The pavement wasn’t as thick as it was supposed to be in some areas, and thicker in others.
Solon Mayor Cami Rasmussen thanked the two for the report.
“As a council, we have already decided this project is unacceptable,” Rasmussen said. “We now have something to back that up.”
The next step will be to go back to the contractor and seek a resolution, said city engineer Dave Schechinger. The contractor might want to do additional testing, he said, but the city will present the evidence that the work was unacceptable in a variety of ways, and entertain recommendations from the contractor regarding remedial measures.
Council members informally consented to have a letter sent to the contractor.