Making Street and Road Funds Go Four Times Further, or Four Miles for the Price of One
Executing a road project via Full Depth Reclamation (FDR) and a double chip seal will cost the county approximately $51,380.67, compared to $246,189.33 for a traditional 3″ mill and overlay. Utilizing internal county personnel, equipment, and county-produced aggregate yields a massive direct savings of $194,808.66 per mile.
The total roadway surface area for 1 mile (5,280 feet) by 22 feet wide is 12,906.67 square yards.
Required Materials & Cost Breakdown (FDR & Double Chip Seal)
By performing a 9-inch FDR blend (3″ new AB-3 rock, 4″ existing rock, and 2″ underlying clay subgrade), you create a mechanical subgrade stabilization matrix. The material quantities and county-internal operating costs are calculated below:
AB-3 Base Rock (New Subgrade Addition)
Quantity Required: 1,559.56 tons (calculated at 3 inches deep over 12,906.67 sq. yd. at a standard compacted density of 1.45 tons per cubic yard).
Cost: $7,018.00 (estimated internal county quarry production rate of $4.50/ton for blasting, crushing, and fuel).
Emulsion (Bitumen for Double Chip Seal)
Quantity Required: 9,034.67 gallons (calculated using standard KDOT application rates of 0.40 gal/sq. yd. for the first lift and 0.30 gal/sq. yd. for the second lift, totaling 0.70 gal/sq. yd.).
Cost: $27,104.00 (estimated out-of-pocket material purchase cost of $3.00/gallon).
Chipseal Cover Aggregates (County Chips)
Quantity Required: 322.67 tons (calculated using standard application rates of 30 lbs/sq. yd. for the first layer and 20 lbs/sq. yd. for the second layer, totaling 50 lbs/sq. yd.).
Cost: $2,258.67 (estimated internal county quarry production rate of $7.00/ton).
Internal Personnel & Equipment Operating Cost
Cost: $15,000.00 (covers internal fuel consumption, grader blades, reclaimer teeth, and equipment wear for standard county machinery; fixed staff salaries are already accounted for in baseline county overhead).
Total FDR & Double Chip Seal Cost: $51,380.67
Financial Comparison: FDR vs. 3″ Mill & Overlay
Traditional 3″ mill and overlay requires importing Hot Mix Asphalt (HMA) and contracted milling services, which vastly escalates the cost structure:
| Cost Category | FDR & Double Chip Seal (Internal) | 3″ Mill & Overlay (Commercial/HMA) |
|---|---|---|
| Milling / Pulverization | Included in Equipment Wear ($15K) | $45,173.33 (avg. $3.50/sq. yd.) |
| Base Rock / Asphalt Mix | $7,018.00 (1,559 tons AB-3) | $181,016.00 (2,129 tons HMA @ $85/ton) |
| Surface Seal / Placement | $29,362.67 (Emulsion & Chips) | $20,000.00 (Paving equipment operations) |
| Fixed Equipment/Labor | $15,000.00 (County internal fuel/wear) | Included in contracted placement rates |
| Total Project Cost | $51,380.67 | $246,189.33 |
Benefits of Full Depth Reclamation (FDR) in This Scenario
Elimination of Subgrade Reflective Cracking: Bourbon County clay soils expand and contract severely with changing moisture levels. Laying a 3″ HMA overlay directly on top of an un-stabilized base will cause the underlying cracks to mirror up into the new asphalt within 1–3 years. FDR blends the components into a monolithic, homogenous 9-inch thick base slab that absorbs subgrade shifts seamlessly.
Mechanical Stabilization of Bourbon County Clay: By blending 2 inches of raw clay into 4 inches of old rock and 3 inches of new sharp-graded AB-3 aggregate, you alter the plastic index of the soil. The clay effectively acts as a natural binder filler inside the void structures of the crushed stone, yielding a highly compacted, rigid foundation layer.
100% On-Site Material Recycling: FDR transforms 100% of the road’s existing, deteriorating crushed aggregate into structural assets. It completely removes the need to haul away old road materials, saving thousands of dollars in trucking costs, commercial disposal fees, and fuel consumption.
Renewable and Cost-Effective Riding Surface: The double chip seal cap is highly flexible, weather-resistant, and entirely renewable. Instead of paying massive commercial premiums for hot asphalt down the line, the county can re-seal this exact surface every 5 to 7 years using its own chips and crews for a nominal cost.
Note: Full Depth Reclamation (FDR) is a cost-effective, long-lasting, greener alternative to deep rehabilitation or removal and replacement techniques. It is an engineered rehabilitation technique in which the full thickness of the asphalt pavement and a predetermined portion of the underlying materials (base, subbase and/or subgrade) is uniformly pulverized and blended to provide an upgraded, homogeneous material. The reclaimed materials may be improved and strengthened by using mechanical, chemical, or bituminous stabilization. FDR isn’t only for roads in poor condition — it is also a viable design process for increasing the structural capacity of a pavement in good condition.
— Pete Allen