When construction demand outpaces production capacity, asphalt producers face a critical decision: upgrade or lose the opportunity. For Ajax Paving Industries, the catalyst came in the form of a 30-mile widening and resurfacing project on Interstate 75 between Naples and Fort Myers, Florida. The approximately 500,000 tons of hot mix asphalt required to complete the design-build project demanded production capabilities far beyond what the company’s existing portable plant could reliably deliver. The solution was a completely new 400-ton-per-hour Dillman counterflow drum mixer plant installed in just 19 days, demonstrating what is possible when careful planning, equipment selection, and contractor coordination align. For asphalt producers contemplating similar upgrades, the lessons from this rapid installation offer practical guidance on plant modernization, equipment configuration, and production optimization. Understanding how to scale asphalt production capacity efficiently has become increasingly important as infrastructure projects grow in size and complexity. For more on modernizing plant equipment, see our guide on upgrading asphalt plant drum systems for enhanced performance.
The Business Case for Plant Upgrades
The decision to invest in a new asphalt plant rarely happens in isolation. For Ajax Paving, the trigger was a specific project opportunity that exposed the limitations of existing equipment.
Market-Driven Capacity Requirements
Ajax had been running a portable 1984 Cedarapids 160-tph Standard Havens Low Rider plant in the South Fort Myers area since 1999. The plant operated six days a week without interruption, a testament to Florida’s year-round construction climate. However, the nonstop production schedule made maintenance nearly impossible to schedule. When the I-75 widening project came up for bid as a joint venture between Anderson Columbia and Ajax, the anticipated tonnage requirements made it clear that a more substantial plant was necessary. Lane closure restrictions on the interstate project meant that production could not afford delays, and the 500,000-ton demand would stretch the old plant far beyond its reliable capacity.
Evaluating Manufacturer Partnerships
Ajax took a systematic approach to selecting equipment manufacturers. The company already had experience working with Meeker Equipment on specialized hot mix storage tanks, including a custom 30,000-gallon AC tank designed for rubber-modified and polymer-modified asphalt blends. This existing relationship influenced the decision to build the new plant around Meeker’s liquid asphalt system. For the plant itself, Ajax evaluated multiple manufacturers before selecting Dillman Equipment Inc. According to Vince L. Hafeli, vice president of plants and manufacturing for Ajax, the deciding factor was not just equipment specifications but organizational culture. Dillman and Meeker demonstrated a willingness to collaborate closely with Ajax through every phase, from design to commissioning, rather than simply delivering equipment and walking away.
Plant Configuration and Equipment Specifications
The new plant was built around a Dillman 400-tph skid-mounted Unified counterflow drum mixer, configured to handle the high moisture content typical of Florida aggregates while maintaining production targets.
Cold Feed and Recycle Systems
The plant includes a seven-bin virgin cold feed system with 10-foot by 16-foot bins, a 36-inch self-contained collector conveyor, and a 5-foot by 14-foot Deister double-deck aggregate screen. For recycled asphalt pavement, a dedicated two-bin recycle system with a 10-foot by 15-foot bin configuration, a 5-foot by 10-foot Deister single-deck screen, and a 30-inch by 80-inch bicycle scale conveyor allows precise control over RAP introduction. This dual-system design gives the plant flexibility to handle varying material blends without cross-contamination.
Drum Mixer and Burner
The centerpiece is a 10-foot 6-inch by 60-foot Dillman Unified counterflow drum mixer equipped with a Hauck EcoStar ESII-175 burner rated at 175 million BTUs, capable of running on oil or natural gas. The counterflow design improves heat transfer efficiency and reduces fuel consumption compared to parallel-flow configurations, particularly important when processing materials with the 15 percent moisture content Ajax routinely encounters.
Emission Control and Storage
A 120,000-cfm four-module reverse pulse baghouse with a variable frequency drive fan handles particulate control. Dust is managed through a primary 14-inch by 36-inch auger and secondary 14-inch by 24-inch auger system. For liquid asphalt storage, three 30,000-gallon Meeker AC tanks were installed, featuring a proprietary non-fin coil heating system that can be removed for cleaning by sliding the coil through a bottom manhole. This design supports high-volume circulation to keep particles such as crumb rubber suspended in the liquid AC, preventing settling.
| Component | Specification |
|---|---|
| Drum Mixer | Dillman Unified counterflow, 10 ft 6 in x 60 ft |
| Burner | Hauck EcoStar ESII-175, 175 million BTUs |
| Rated Capacity | 400 tons per hour |
| Baghouse | 120,000 cfm, four-module reverse pulse |
| Liquid AC Storage | Three 30,000-gallon Meeker tanks |
| Mix Storage | Three 300-ton silos |
| RAP Capability | Up to 50 percent in mix design |
Control and Blending Systems
A 12-foot by 36-foot Model 123610 two-room split control module houses the WEM Total Controls blending system, giving operators precise command over mix formulations. The mix handling system includes three 300-ton silos paired with a 400-tph by 112-foot slat conveyor featuring a remote-controlled reject gate, and a 400-tph by 32-foot three-way horizontal transfer conveyor. This configuration provides 900 tons of storage capacity, enough to stage multiple mix designs for simultaneous project supply.
The 19-Day Installation Process
Perhaps the most impressive aspect of the project was the installation timeline. Ajax allotted just 21 days to remove the old Standard Havens plant and erect the new Dillman plant on the same footprint. The existing plant remained operational until noon on September 21, meaning there was zero overlap between old production and new construction.
Pre-Shutdown Preparation
Critical to the success was pre-positioning equipment well ahead of the shutdown. Meeker shipped all liquid asphalt components two months before the switch-out date, allowing the new AC tanks to be connected to the old plant for operational testing. This early setup also enabled the removal of old AC tanks to make room for the new baghouse. Dillman supplied six service personnel to assist with both disassembly and erection. By the time the old plant shut down, significant portions of the new infrastructure were already in place around the existing equipment.
Sequential Disassembly and Erection
On the day of the shutdown, the pace was relentless. Three old silos and a slat conveyor were removed and three new silos were erected before the end of the same day. The project followed a synchronized removal-and-replacement sequence: as each old component came out, its new counterpart went in immediately. At peak activity, nearly 30 workers were on site simultaneously. Bulger of Dillman noted that the sequencing of component deliveries was essential, as there was no space for staging large amounts of equipment onsite.
Commissioning Results
On October 10, just 19 days after shutdown, the new plant was fired up and began producing mix. Quality control testing on the first batch exceeded expectations. In the first seven weeks of operation, the plant produced over 105,000 tons of mix. Under the Florida Department of Transportation’s Percent Within Limits specification, Ajax was delivering mix quality that earned in excess of 100 percent pay factor on the I-75 project. The rapid ramp-up validated the pre-planning effort and demonstrated that an aggressive installation schedule can work when manufacturers, contractors, and plant personnel coordinate effectively. For producers facing similar tight timelines, understanding best practices for asphalt plant seasonal startup can help avoid common pitfalls.
Operational Benefits and Long-Term Positioning
Beyond satisfying the immediate demands of the I-75 project, the new plant positioned Ajax for sustained growth in the Southwest Florida market.
RAP Integration for Cost-Effective Production
The Dillman plant is capable of handling mixes with up to 50 percent reclaimed asphalt pavement. Ajax initially designed mixes with up to 25 percent RAP, giving the company significant flexibility in material costs and sustainability credentials. Using more RAP reduces virgin binder consumption and lowers the carbon footprint of each ton of mix produced. As state DOTs increasingly encourage or mandate higher RAP content, having a plant designed for high RAP rates gives Ajax a competitive advantage in bidding future projects. For contractors seeking to improve their own operations, maximizing RAP production in asphalt plants offers practical strategies drawn from state agency successes.
Flexible Mix Design and Supply Capabilities
With 900 tons of silo storage, the plant can accommodate three to four different mix designs during a single day. This flexibility allows Ajax to supply its own paving crews working on state projects while simultaneously serving independent contractors and other customers. Nighttime production shifts are used to build inventory for the I-75 project, producing 1,800 to 2,000 tons per night. Robert Ray, Ajax’s asphalt plant manager, noted that this dual-mode operation, daytime custom mix supply and nighttime bulk production, maximizes plant utilization and revenue potential.
Market Growth Positioning
Approximately 65 percent of the plant’s output supplies Ajax crews on state projects, with the remaining 35 percent going to external customers. This balanced production model reduces the risk associated with relying solely on internal project demand. The plant’s location in the growing Southwest Florida corridor positions Ajax to serve both public infrastructure projects and private development as the region continues to expand. The ability to quickly scale production, switch between mix designs, and maintain consistent quality gives the company a platform for winning additional work. For contractors evaluating their own capacity needs, the lessons from Ajax’s experience, particularly the value of manufacturer collaboration and aggressive scheduling, offer a blueprint for successful plant modernization.