Road rehabilitation projects on active highways present unique challenges that demand meticulous planning, coordinated equipment staging, and real-time adaptability. The Wisconsin State Highway 14 rehabilitation project west of Madison exemplifies how a well-orchestrated production train can transform aging infrastructure while minimizing disruption to daily traffic. This case study examines how Rock Road Companies executed a 12.2-mile corridor upgrade using the “moving mile” approach, where construction crews advanced continuously within a one-mile work zone. Understanding the interplay between milling, rubblization, and paving operations in this project offers valuable insights for professionals managing roadway renewals. For a broader perspective on how such projects fit into overall project delivery, see Key Facts About Construction Project Life Cycle Phases.
Project Overview and Background
Wisconsin State Highway 14 serves as a major east/west artery in the southwestern part of the state, carrying both commercial trucking and commuter traffic between Madison and the Wisconsin River valley. The original Portland cement concrete road, built as a two-lane facility, received an asphalt overlay in the early 1980s. After 20 years of heavy traffic loads and the punishing freeze-thaw cycles of Wisconsin winters, the riding surface had deteriorated into an uneven, washboard-like condition requiring comprehensive rehabilitation.
Project Parameters and Contract Award
Rock Road Companies of Janesville, Wisconsin won the bid to rehabilitate a 12.2-mile segment of Highway 14 from Mazomanie west to the Wisconsin River. The contract value of $3.7 million reflected the complexity of widening the roadway while performing full-depth reclamation. The project scope included widening the existing 30-foot-wide road to a new 40-foot width, accommodating passing lanes at strategic locations along the corridor.
Key Stakeholders
- Rock Road Companies (Janesville, WI) – Prime contractor responsible for paving and overall project coordination
- Kraemer Company (Plain, WI) – Milling and grading subcontractor operating the production train
- Antigo Construction (Antigo, WI) – Pavement breaking specialist for concrete rubblization
- Wisconsin DOT – Client specifying mix designs and quality standards
The Milling and Rubblization Production Train
The rehabilitation strategy relied on a carefully sequenced production train that moved continuously along the corridor. Initial grading began in early June to prepare for the passing lanes. On July 14, the surface work commenced as milling and paving crews mobilized to transform the road.
Milling Operations
Kraemer Company deployed two milling machines operating in tandem to remove five inches of asphalt from the concrete road base: a Wirtgen W2000 and a Caterpillar PR 1000. The two machines deposited windrows of the milled material along the shoulder as they advanced. This material, totaling approximately 60,000 tons, was stockpiled for later use as part of the crushed base. The windrowing strategy eliminated the need for separate haul-off operations, keeping the production train moving efficiently.
Concrete Rubblization
After milling crews removed the asphalt layer, Antigo Construction mobilized to rubblize the underlying seven-inch-thick Portland cement concrete pavement. Rubblization fractures the existing concrete slab into small pieces without removing it, creating a granular base that can be compacted and paved over. This approach eliminates the cost of concrete removal and disposal while reusing the existing material as structural support. Antigo used Badger State Highway Equipment MHB Badger Breakers to deliver controlled impact energy that fractured the concrete into pieces smaller than fist-size while leaving the subgrade undisturbed.
Base Preparation
Once the concrete was rubblized, Kraemer grader operators spread the milled asphalt back over the crushed concrete base. This recycled asphalt pavement was graded to a uniform surface and compacted, creating a stable foundation for the new hot mix asphalt layers. The recycling approach eliminated the need to import virgin base material and placed the milled asphalt in a structurally beneficial location.
Mix Design Changes and Paving Operations
One of the most significant decisions on the project involved a change to the asphalt mat design. The original Wisconsin DOT specification called for three 1.75-inch-thick mats: a leveling course, a binder course, and a surface course. Rock Road Companies recommended a redesign based on traffic considerations and constructability concerns.
The Two-Lift Redesign
Rock Road proposed replacing the three-lift design with a two-lift system:
- A 3-inch leveling/binder mat as the first lift
- A 2.25-inch surface mat as the final wearing course
The contractor determined that a 1.75-inch leveling mat would not withstand the projected 9,400 vehicles per day, many of them heavy trucks, during the period between placement of the leveling course and the subsequent layers. By going to a thicker 3-inch combined leveling/binder mat, the road could handle traffic loads immediately. The total asphalt thickness remained unchanged at 5.25 inches.
Mix Specifications and Production
The Wisconsin DOT specified E3 mix design for both lifts with different aggregate gradations:
- Leveling/binder course: 0.75-inch maximum aggregate size providing structural strength
- Surface course: 0.625-inch maximum aggregate size delivering a smoother riding surface
Rock Road produced the virgin aggregate HMA at a portable Gencor 400-ton-per-hour plant set up at the job site. On-site production eliminated haul distances from a fixed plant and ensured consistent material temperature at the paver. The total HMA tonnage for the project reached 103,000 tons.
Paving Train Configuration
The paving train consisted of a Blaw Knox PF 5510 paver equipped with a Roadtec SB 2500C material transfer vehicle. The hopper and shuttle buggy combination provided a paving capacity of 35 tons, enabling continuous non-stop operation from 9:00 a.m. to 7:00 p.m. daily. The material transfer vehicle remixed the HMA to maintain uniform temperature and gradation while allowing trucks to discharge without stopping the paver.
Compaction requirements called for achieving 89.5 percent density, which Rock Road attained using an Ingersoll-Rand DD-130HF vibratory roller. The double-drum roller delivered the compaction energy needed to meet density specifications while keeping pace with the paver’s production rate.
Traffic Management and Lessons for Rehabilitation Projects
Safety and minimal disruption to the traveling public were critical throughout the project. Since Highway 14 was a two-lane road with no suitable detour routes, the team adopted a moving one-mile work zone strategy that became the project’s defining operational feature.
The Moving Mile Concept
The moving mile concept limited active construction to a one-mile segment at any given time. Within that mile, the full production train operated with milling machines at the front, rubblization equipment in the middle, and paving operations at the rear. Flaggers controlled traffic flow from both ends, allowing alternating one-way traffic through the active area. As each mile segment was completed, the entire operation advanced to the next mile.
| Production Element | Equipment Used | Quantity |
|---|---|---|
| Asphalt Milling | Wirtgen W2000, Caterpillar PR 1000 | 60,000 tons removed |
| Concrete Rubblization | MHB Badger Breakers | 12.2 miles, 7-inch slab |
| Base Grading | Kraemer graders | 40-ft roadway width |
| HMA Production | Gencor 400-tph portable plant | 103,000 tons |
| Paving | Blaw Knox PF 5510 + Roadtec SB 2500C | Two lifts, 5.25 inches total |
| Compaction | Ingersoll-Rand DD-130HF | 89.5% density target |
Bob Kennedy, vice president of Rock Road, noted that the milling, rubblizing, and paving crews advanced close to 1.5 miles in a 10-hour work day, with weather delays being the primary source of downtime. Factors contributing to this pace included equipment synchronization, the on-site asphalt plant, the material transfer vehicle, and experienced crew coordination across all three subcontractors.
Design Flexibility Improves Outcomes
Rock Road’s recommendation to change from three thin lifts to two thicker lifts demonstrates the value of contractor input during design. The contractor identified a risk the design engineer had not fully anticipated: the vulnerability of a thin leveling mat to traffic loading between lifts. By maintaining the same total thickness while changing the lift configuration, Rock Road improved durability during construction. This underscores why understanding the full Construction Project Life Cycle Phases in Life Cycle matters when planning major interventions.
Equipment Selection and Material Recycling
The project demonstrates how matching equipment to project requirements maximizes production. Two milling machines in tandem doubled daily output compared to single-machine passes. Specialized rubblization equipment handled concrete breaking faster than conventional demolition. And the material transfer vehicle sized to the paver’s capacity eliminated the stop-start cycle that reduces mat quality.
By rubblizing existing concrete in place and reusing milled asphalt as base material, the project avoided hauling tens of thousands of tons off-site. The 60,000 tons of milled RAP that would have required disposal became a structural asset. This reduced truck traffic, lowered material costs, and shortened the schedule.
Project Management in Practice
Coordinating three specialized subcontractors across a moving work zone, managing material production and delivery, maintaining quality control across 103,000 tons of HMA, and keeping traffic moving safely demanded disciplined management. For professionals working to improve their approach to project delivery, Construction Project Scheduling Methods Tools and Best Practices offers practical guidance on coordinating interdependent work streams. The habits that made Rock Road successful align with the approaches in 5 Habits of Successful Construction Project Managers Essential.
The moving mile approach to this Highway 14 rehabilitation shows that well-planned production trains with the right equipment mix, thoughtful design adaptations, and disciplined coordination can deliver high-quality roadway renewals efficiently. For contractors and agencies tackling similar projects, the lessons from this $3.7 million corridor upgrade provide a practical blueprint for maximizing productivity while maintaining safety and quality.