Update on Road Construction for Brookfield 4th Addition

The purpose of this update is to provide information to the Public Works Committee regarding several soft spots in the pavement in the new Brookfield 4th Addition.  If you recall  this spring was unusually wet, with rain persisting well into June. During the construction of 168th Ln, west of Kamicite St, substandard soil was found in the road bed.  Northern Technologies Inc. a geotechnical and materials engineering and testing firm, was consulted and their recommendation was to remove 4 feet of the substandard soil and replace with sand.  The length of the correction was 400 feet.  After that soil correction was made, 4 inches of granular base material was placed on the road surface and compacted.  As the frequent rains persisted, it was decided by the engineering staff who are responsible for on site inspection, that if we waited for ideal conditions, which would mean a completely dry base material, we would run the risk of losing the road base.  The risk would come from construction traffic driving on the soft base, mixing the base material with the subgrade and thus contaminating the base.  With some water trapped below the pavement, several soft spots appeared in the base layer of asphalt.

5 minutes

Several soft spots are still noticeable in the base asphalt layer, near the intersection of 168th Ln and Kamicite St. These spots will be cut out and re-paved this fall.  The base course of asphalt will remain over the winter and will be inspected again in the spring of 2015.  If any additional soft spots appear next spring they will be replaced as well, before the final wear course is paved in 2015.  Once the project is accepted by the city, there is a one year warranty period if additional problems should arise.

Case was prepared as part of staffs normal duties.

Informational only

No action by the Public Works Committee is required at this time.