This afternoon was the first “proof roll” on Block 2 of the City’s downtown construction project. The proof roll involves bringing in a fully loaded dump truck and seeing if the dirt – which has been disked up and then compacted down – will hold up.
“Today, we saw the dirt pump and rut, which is not what we want,” explained Shawn Cole, Nevada’s building and zoning administrator.
The outcome isn’t surprising on a first proof roll. Cole said the contractor will now disk the dirt again, let it dry again, and then “beat it down” again for another proof roll, likely to happen next week.
The City must accept a proof roll before pavement can be laid.
Cole said, disking the dirt again and compacting it down again might work, but sometimes other methods are needed.
“On Block 1, we had to use a geogrid. This stabilized the rock and spread the weight out across the dirt for paving,” he said.
One thing is for sure about the process, Cole said. “The proof roll doesn’t lie; it tells you what you need to know.”
See a video clip from the proof roll on our City of Nevada, IA Facebook page.