Illinois tollway fast track project calls on Mt. Carmel to save time and money

High traffic and high profile project demands top quality work

(Rockford, IL; May, 2009)

In any given year, Mt. Carmel Stabilization Group will perform soil stabilization applications on hundreds of projects ranging from highway reconstruction, airport runways, subdivision roads, commercial building pads, drying operations on massgrading projects and many other miscellaneous project types. These projects can range in size from 1,500 to several million square yards. Each project presents a unique situation and subsequent challenges to success. This particular project is an addition to a senior living facility with residents and heavy traffic, in an urban area in North Indianapolis. The area that Mt. Carmel is treating is a relatively small buidling pad, roughly 4,700 square yards and it is considered to be an extremely dust sensitive site.

The Situation - Undercut or Lime Modification

During a major reconstruction in Northern Illinois, it is not uncommon to encounter such poor subgrade conditions once the old pavement has been removed. Over time, water works it’s way down and is absorbed by the subgrade layer. During the wet spring and fall seasons, in-situ moisture conditions can be over 30% which is well above a typical optimum moisture content of 13-18%. High moisture reveals the true colors of poor subgrade soils. On this project, the sandy, lean clay was extremely unstable and would have taken weeks or months to dry out conventionally. To complicate things, the problem was deeper than just the top 12”. Field testing revealed that 2’ to 4’ undercuts would be necessary to get to the bottom. All undercut soil would have to be removed and hauled off site and coarse aggregate would be brought in for backfill. On this project the total undercut volume would have amounted to over 50,000 cubic yards and it would have likely taken weeks to complete.

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