Prairie Material has signed initial contracts with the city of Chicago's Bureau of Streets to provide back fill for its vaulted sidewalks rehabilitation program. The vaulted sidewalks are a remnant of Chicago's past when the streets and sidewalks throughout the city were raised to be at the same number of feet above sea level and to accommodate modern utilities. In some neighborhoods that meant raising the street more than six feet, creating a void under the sidewalks. The city is slowly filling in the voids, while raising the sewer lines and gas lines closer to the street surface. The standard procedure has been to bring in truckloads of granular fill and place them in 18" lifts, compacting and testing between each lift. In the past, the entire process took a minimum of three days per vault, a crew of three or more workers and required the use of expensive compacting equipment.

Initial testing proved to the Bureau of Streets that Prairie's proprietary, self-leveling Redi-Fill™ mix met design expectations, increased crew efficiency, and eliminated the need for granular fill and compacting equipment. The void could now be filled in three hours rather than three days.

Prairie Material has used a different form of Redi-Fill for more than 7 years in the Indianapolis area to backfill street cuts, pipe trenches, underground tanks and foundation walls. During that time, there have been no reported failures and the savings in manpower, time and annoyance have been outstanding.