Committee members differ on use of foam in street work
WILLMAR — Members of the Willmar City Council’s Public Works/Safety Committee differed last week on the benefit of using geo-form in street construction.
Committee Chair Ron Christianson said the city needs to look at making roads last longer. For the past couple of years, Christianson has advocated the use of concrete rather than asphalt and has advocated the use of geo-foam as a subsurface material in street reconstruction.
He told the committee last week that Germany has used foam since 1972. He said many local contractors use foam below sidewalks and driveways.
City Engineer Sean Christensen said he researched the question of foam usage. Based on 12 responses he received from other city engineers and from the Minnesota Department of Transportation, Christensen said he cannot recommend foam anywhere under a street.He said foam has many inherent problems based on its insulation characteristics. Besides the additional cost of putting it in, and the depth to install it, foam prevents moisture from going down into the soils as moisture would on a regular street.Christensen said the foam would hold the water below the road surface and potentially make the street fail sooner. He said it would create a problem called differential icing in which the temperature could be above freezing but create black ice on the road section where foam is located.Ron Christianson said Germany uses tile to remove the water problem. He said he’s read about the black ice problem, but said foam is used all over Europe.“I don’t know if the asphalt people have a union or something that’s pushing not to use because (of) more maintenance on the roads,’’ he said. “But sometime we need to look at making our roads last longer.’’He pointed out the concrete on the Highway 12 East project is being removed and replaced with asphalt, “which we know fails.’’ He also said concrete poured in 1983 on West Litchfield Avenue next to the Municipal Utilities Building looks like it was put in two years ago.Ron Christianson said the cost difference today between asphalt and concrete is really small.“That was my reason for asking you to look into it. I would say not to discount it. I think we should try it someplace,’’ he said.Committee member Audrey Nelsen said she understood the East Highway 12 work was bid for asphalt and concrete and MnDOT decided to use asphalt because they’ve had problems with the concrete.Christensen said concrete is great in certain circumstances like high and heavy traffic.“It’s not without its faults. There’s benefits to both,’’ he said.After Christianson said the committee had the discussion, Nelsen said she wanted to put the issue to rest “because it has gone on for two years.’’ Nelsen then offered a motion, seconded by Bruce DeBlieck, to support Christensen’s recommendation “so we don’t have to talk about foam anymore.’’Since committee member Steve Ahmann was absent, Christianson asked if either Tim Johnson or Jim Dokken, sitting in the audience, would sit at the table in place of Ahmann.Nelsen and DeBlieck objected, saying Christianson couldn’t bring somebody in the middle of a discussion. “It’s going to go to the City Council,’’ said Nelsen.The motion was approved 2-1 with Nelsen and DeBlieck in favor and Christianson against.