CASE STUDY: Cook County, Orland Park

  • truck-loads
    98% - 99% Fewer
    Semi Truck Loads
  • icon-less-time
    20% - 60%
    Less Time
  • icon-cost-savings
    45% - 53%
    Cost Savings

Resurfacing of 2 miles (27,000 square yards) of 108th Avenue in Orland Park, Illinois

Cook County  recently made the decision to rebuild 2 miles of deteriorating roadway, representing 27,000 square yards of road surface in the city of Orland Park. The existing pozzolanic base was rigid and contributing to reflective cracking, which meant that a simple asphalt overlay would not provide the best long term outcome. Facing costs upwards of $800,000 to remove and replace the roadway, the city was anxious to find a more suitable and effective solution.

 

The Solution

After consideration of all the available options, full-depth reclamation was chosen over a more traditional remove and replace approach because it meant that deep underlying pavement problems could be resolved and structural performance targets met at a fraction of the cost.

The result was a significantly shorter project timeline, taking only 4 days to complete compared with 5-10 days for traditional methods, and a savings of between $310,000-$428,000, 45-53% of the cost of the original remove and replace specifications. In total, Full-Depth Reclamation required only 17 semi-truck loads of material to be hauled on-site, compared with 1,198-2,538 loads of material that would have been needed if traditional methods had been employed.

Throughout the project, the contractor retained quality control processes, had field representatives on-site, and used core samples obtained prior to construction to inform mix designs that addressed the challenges of the inconsistent existing roadbed (from areas of shallow clay to varying width). Additional sample testing taken during construction verified soil density and moisture levels. As a result, all structural property targets were verified upon completion of construction.

Advantages to full-depth reclamation:

  • Accelerated construction times by decreasing the amount of materials needing to be excavated and trucked off site
  • Existing unsuitable material or fill can be modified in multiple lifts (up to 16” per lift), limiting the amount of select fill needing to be imported onto the worksite

 

ROCK SOLID RESULTS

Traditional Approach

  • Mill & remove 8″ – 18″ existing HMA, aggregate base, and clay (27,000 SY)

  • Replace with 18″ CA-6 Aggregate Base or 8.5″ CA-6 BAM (27,000 SY)

Days:

5-10

Rock Solid Approach

  • Full Depth Reclamation of 10″ base (27,000 SY)

  • Apply CSS-1H emulsion (75,000 Gal)

Days:

4-5

Cost Comparison

Full Depth Reclamation

Bit. Materials 74,231 (GAL) $2.55 $189,289.05
FDR Base Course 10″ 27,415 (SY) $7.15 $196,017.25
Total $385,306.30

Mill and Remove 18″ of Existing and Replace with 18″ of CA-6

Mill & Remove 18″ Existing HMA, AGG BASE, CLAY 27,415 (SY) $11.52 $315,820.80
18″ CA-6 Agg Base 27,415 (SY) $13.86 $379,971.90
Total $695,792.70

Mill and Remove 8.5″ of Existing and Replace with 8.5″ of BAM

Mill & Remove 8.5″ Existing HMA, AGG BASE, CLAY 27,415 (SY) $5.44 $149,137.60
8.5″ CA-6 BAM 27,415 (SY) $24.23 $664,265.45
Total $813,403.05