As pavement preservation budgets tighten and road agencies seek maximum value from every dollar, cold in-place recycling (CIR) has emerged as a proven, cost-effective alternative to traditional mill-and-fill rehabilitation. Unlike conventional methods that require hauling recycled asphalt pavement (RAP) to a hot plant for processing and then returning it to the job site, CIR processes material directly on the roadway. This approach cuts costs, reduces carbon emissions, and produces durable pavements that meet strict government specifications. For a deeper look at how this technology has been applied in challenging terrain, see How Prs Used Cold in Place Recycling to restore forest roads in the Sierra Nevada.
Why Road Agencies Are Turning to Cold In-Place Recycling
The economics of cold in-place recycling are compelling. Canadian road agencies, facing the dual pressures of aging infrastructure and shrinking budgets, have been among the early adopters. Cruickshank Construction Inc., based in Kingston, Ontario, invested $2.5 million Canadian dollars in a complete CIR train, betting that the provincial market would support the equipment. The calculation was straightforward: CIR costs roughly 60 percent of a conventional mill-and-overlay operation.
Direct Cost Comparisons
Cost savings come from eliminating multiple haul cycles. In a typical mill-and-fill operation, the contractor must:
- Mill the existing asphalt surface
- Haul the RAP to a hot-mix plant
- Process and recycle the material at the plant
- Haul the new mix back to the road site
- Place and compact the fresh overlay
With cold in-place recycling, steps two through four are eliminated entirely. The milling machine feeds RAP directly into a mobile processing and mixing train that treats the material and places it back on the road in a single continuous operation. The Nevada Department of Transportation estimated that CIR with a chip seal surface treatment can rehabilitate a low-volume road at roughly half the cost of a 2-inch hot-mix overlay with surface treatment.
Budget Pressures Driving Adoption
David Semley, business development manager at Cruickshank, notes that government stimulus funds are running out, forcing road agencies to stretch their dollars further. This fiscal reality is pushing agencies in Ontario and elsewhere to embrace CIR as a standard rehabilitation tool rather than a niche experiment. The province alone represents an estimated 5 to 6 million square meters of CIR work annually.
For contractors considering entry into this market, understanding the equipment and process is essential. The article Cold in Place Recycling for Full Depth Reclamation offers additional case studies and best practices for pavement contractors evaluating this method.
Inside the CIR Train: Equipment and Process
A modern cold in-place recycling train is a coordinated sequence of specialized equipment that mills, processes, mixes, and places recycled pavement in one pass. Cruickshank selected a Roadtec train that includes four key components working in concert.
Components of the Recycling Train
- Milling Machine: A Roadtec RX-900 with a standard cutting width of 12 feet, 6 inches. It operates in down-cutting mode, milling 100 millimeters (3.9 inches) deep at rates of 260 to 270 tons per hour.
- Mixing Trailer: The RT-500 receives RAP from the mill via conveyor. It houses a JCI double-deck screen measuring 5 feet by 14 feet that sieves 100 percent of material to 37.5 millimeters (1.5 inches) minus.
- Crusher: A Telsmith impact crusher processes any oversize material that fails the initial screen. A return circuit sends crushed RAP back over the screen for quality assurance.
- Pugmill Mixer: A Kolberg-Pioneer pugmill mixes the screened RAP with liquid additives. A weigh bridge on the 48-inch belt measures material mass and sends signals to a blending computer that adjusts additive flow in real time.
Weight-Based Additive Control
One distinguishing feature of the Roadtec train is its use of mass-based measurement for liquid additives. The belt scale system provides accuracy within plus or minus 1 percent. This matters because the Ontario Ministry of Transportation (MTO) specifications require weight-based measurement. Systems that calculate additive volumes based on theoretical volume do not meet these specifications. After mixing, the rejuvenated RAP is discharged onto the roadway as a windrow. A Carlson windrow pickup machine then feeds the material into a Roadtec RP 195 paver for final placement.
For a detailed breakdown of how recycling trains operate on full-depth reclamation projects, see Using Cold in Place Recycling Trains for Full depth reclamation work.
Real-World Project Performance With Cold In-Place Recycling
The true test of any pavement rehabilitation method is how it performs under real-world conditions. Cruickshank’s first two CIR projects demonstrate the capabilities and learning curve associated with this technology.
Highway 140, Port Colborne, Ontario
Cruickshank’s first CIR project was on Highway 140 north of Port Colborne. The 5.5-kilometer section involved approximately 45,000 square meters of recycling work. The RX-900 milled 100 millimeters deep at production rates between 260 and 270 tons per hour. The project required two passes on the two-lane road, with a 1-meter-wide milling machine working in echelon ahead of the larger RX-900. The smaller mill windrowed RAP into the path of the larger machine for pickup and processing. The entire project was completed in just eight working days.
Aviation Parkway, Ottawa, Ontario
The second project was larger: 55,000 square meters on Ottawa’s Aviation Parkway. This job introduced additional complexity because the roadway width varied up to 16 meters and cutting depths ranged up to 175 millimeters. Cruickshank crushed RAP to the 37.5-millimeter specification and added liquid binder at rates between 1.5 and 2.8 percent by weight.
Key Project Metrics
| Metric | Highway 140 Project | Aviation Parkway Project |
|---|---|---|
| Location | Port Colborne, Ontario | Ottawa, Ontario |
| Project Size | 45,000 sq m | 55,000 sq m |
| Roadway Length | 5.5 km | Variable width up to 16 m |
| Milling Depth | 100 mm | Up to 175 mm |
| Production Rate | 260-270 tons/hour | Not specified |
| Binder Addition | By weight per MTO spec | 1.5-2.8% by weight |
| Duration | 8 working days | Late July start, rest of season |
Working Within Government Specifications
All CIR work in Canada is awarded through the low-bid system, which puts a premium on cost efficiency and quality control. One of the critical requirements for provincial projects in Ontario is mandatory gradation control. The Roadtec train’s integrated screen and crusher system ensures that 100 percent of material passes the 37.5-millimeter specification. As Steve Cruickshank, president of the company, notes, not every CIR system provides this capability. The ability to control gradation directly on site is a significant advantage when working to MTO standards.
Lessons from highway-scale CIR applications continue to inform best practices. The project team documented their experience on Cold in Place Asphalt Recycling On Californias I-80, demonstrating that CIR methods developed in Canada translate effectively to major US highway corridors.
The Road Ahead: Market Growth and Environmental Benefits
The case for cold in-place recycling extends beyond immediate cost savings. Two additional factors are driving broader adoption: environmental performance and expanding market opportunities.
Environmental Advantages
The carbon footprint of CIR is approximately half that of a mill-and-fill operation. This reduction comes from eliminating truck haul cycles to and from the hot plant, reducing fuel consumption and associated greenhouse gas emissions across the project lifecycle. Semley describes this as an increasingly important consideration for both contractors and project owners. As sustainability requirements find their way into more transportation contracts, the environmental case for CIR becomes a competitive differentiator.
Steve Cruickshank puts it plainly: “Environmentally speaking, cold in-place recycling is the way to go. Quite often, when you have environmental solutions, they are more expensive than the conventional method. But in this case, the environmentally friendly solution is lower in cost than the mill-and-pave method of reconstruction.”
Expanding Applications
CIR is no longer limited to low-volume secondary roads. In Ontario, controlled-access highways (the province’s equivalent of interstate freeways) began seeing CIR projects in 2010. This represents a significant expansion of the addressable market. As more agencies gain confidence in the technology and more contractors invest in capable equipment, the range of applications continues to grow.
Key factors driving market expansion include:
- Budget constraints at all levels of government pushing agencies toward lower-cost rehabilitation options
- Proven track records from early adopters that demonstrate both quality and durability
- Environmental regulations and sustainability targets that favor methods with lower carbon footprints
- Equipment advances that improve gradation control, additive accuracy, and production rates
- Growing availability of experienced crews and contractors who can deliver CIR projects on time and on budget
Investing in the Right Equipment
For contractors considering entering the CIR market, the Cruickshank experience offers a useful template. The company spent five years evaluating the opportunity before committing, waited for the right experienced manager to become available, built a detailed business case, and then selected equipment that matched both market requirements and specification demands. The result is a recycling train capable of meeting MTO standards and competing successfully in the low-bid environment.
As more road agencies discover the cost and environmental advantages of cold in-place recycling, the contractors who invest in the right equipment and expertise today will be well positioned to capture this growing market. The technology works, the savings are real, and the window of opportunity is open.