Client: National Highways (South East Alliance), PDF2 Framework
Role: Principal Contractor and delivery contractor (full asphalt surfacing self-delivery including material production)
INTRODUCTION
In Q4 2025, Roadways delivered Clause 948 cold asphalt binder as a direct replacement for conventional AC20 binder on the National Highways strategic road network, across the A26 Beddingham and A259 Winchelsea schemes.
Roadways acted as principal contractor, material producer and installer, providing complete self-delivery from early technical engagement through to installation on site, anchored in the South East. The works represent the first use of Clause 948 cold bitumen emulsion based asphalt on the strategic road network as a binder course, providing a direct AC20 replacement and with no departures from specification. The material was manufactured using cold bitumen emulsion based asphalt, fully in accordance with the operative Specification for Highway Works – including legacy Clause 948.
1,300 tonnes of cold binder course were produced, supplied, and laid by Roadways teams under controlled road closures, followed by the application of a hot asphalt surface course as the final running layer.
THE CHALLENGE
National Highways schemes traditionally specify warm-mix AC20 binder for resurfacing works. While compliant and familiar, hot or warm asphalt binders carry inherent delivery risks related to temperature control, logistical resilience, and exposure to heat-related site hazards. They also rely heavily on virgin aggregates and energy-intensive production processes. Additionally, heating the bitumen to temperatures of up to 180°C to ensure adequate coating can increase the risk of brittleness in the asphalt and reduce its life-cycle performance.
The challenge was to demonstrate that a lower-carbon, lower-risk alternative could be delivered on the strategic road network without changing pavement design or layer thickness, introducing departures, trials or bespoke approvals, or increasing delivery or performance risk.
THE ROADWAYS SOLUTION
Roadways identified an opportunity to replace conventional AC20 binder through a technical query and early design discussion. Roadways then initiated and led technical engagement with National Highways and the scheme designers to confirm that Clause 948 cold recycled asphalt could be used as a direct binder replacement.
Roadways took full responsibility for mix design, material production, quality assurance, logistics, delivery and laying on site. The binder course was produced off-site using bitumen cold emulsion (not foamed bitumen) to achieve consistent coating, controlled stiffness and repeatable performance aligned with Clause 948 grading requirements.
Materials were processed and produced at Roadways’ fully-computerised recycling facility in Sussex, supporting efficient delivery across the South East of England. In addition, Roadways provided early technical support and know-how, particularly in the use of cold asphalt on the strategic road network, helping the client to adopt lower-carbon, lower-risk solutions with confidence.
DELIVERY OUTCOMES
1300 tonnes of Clause 948 cold bitumen emulsion asphalt binder successfully delivered for the first time as a direct AC20 replacement on the SRN
COMMERCIAL AND PROGRAMME PERFORMANCE
- Full self-delivery by Roadways as principal contractor, material producer and installer
- Reduced delivery risk through cold production and laying
- Elimination of temperature-loss risk during transport and installation
- Improved logistics resilience, including flexible delivery windows
- Ability to plan back-haul movements
- Reduced exposure to heat-related hazards during material production and on site
CARBON AND RESOURCE OUTCOMES
- Approximately 23-25 tonnes of CO 2 saved across 1,300 tonnes of binder production and laying in comparison to the warm mix AC20
- Additional ~2.4 tonnes of CO 2 saved through back-haulage and elimination of empty loads
- 100% recycled aggregate content within the binder layer
- Zero virgin aggregate used
- Closed-loop delivery achieved, with planings returned to Roadways’ Sussex plant and reused as cold bitumen binder on subsequent shifts
- Reduced haulage mileage, double handling and programme risk through circular material use
The A26 Beddingham and A259 Winchelsea schemes demonstrate that Clause 948 cold bitumen emulsion based asphalt binder can be delivered on the strategic road network as a fully standards-led, low-risk alternative to conventional AC20 – without changing standards, pavement design or delivery expectations.
By combining early technical engagement, full self-delivery and controlled ex-situ production, Roadways proved that cold asphalt is not an experimental solution, but a commercially credible, scalable option that improves programme resilience while delivering measurable carbon and resource benefits.
This approach relies on existing specifications, established construction techniques and intelligent logistics by removing temperature sensitivity from production and delivery while maintaining consistent quality and performance. Roadways continues to show that applying
standards intelligently can reduce risk, improve outcomes and support lower-carbon infrastructure at scale in the South East.
Roadways can support Tier 1 contractors, local authorities and groundworks through a range of flexible delivery options, including full delivery as principal contractor with product and installation, supply and install of material plus installation, or material supply only.
ABOUT ROADWAYS
Roadways is a highways and civil engineering contractor with Tier 1 principal contractor and full self-delivery capability, operating across the South East.
We deliver highways maintenance, resurfacing, civil engineering and road recycling schemes for National Highways, local authorities, Tier 1 contractors and private clients. Roadways designs, produces and installs its own materials — including Cold bitumen emulsion based asphalt and Hydraulically Bound Materials (HBM / CBGM) — giving direct control over quality, programme certainty and commercial risk.
By applying the operative Specification for Highway Works more intelligently, Roadways delivers lower-risk, specification-compliant infrastructure without departures or experimental methods.