2001
Ampthill, Bedfordshire
Bedfordshire County Council
Tarmac & Tarmac Johnson
Babtie Group
Road Mesh™ Pavement Reinforcement Solution for A507 Trunk Road
Unrolling the Road Mesh™ onto the planed surface
PTR rolling the Road MeshTM to conform it to planed surface
Asphalt being placed onto the Road Mesh™
Rolling the wearing course
Placing wearing course onto Road Mesh™ Transverse reinforcing rod Double twist
Rolling the wearing course
Schematic of Road Mesh™
Challenge
A section of the A507 trunk road bypassing Ampthill in Bedfordshire experienced significant pavement deterioration due to fatigue cracking within the existing road construction. Bedfordshire County Council (BCC) identified the need for a durable road resurfacing solution that would not only repair visible defects but also extend the overall pavement design life.
Traditional resurfacing methods alone were unlikely to prevent reflective cracking from reappearing, meaning a more advanced pavement engineering solution was required to improve long-term performance and reduce future maintenance costs.
Solution
Babtie Ltd, working on behalf of Bedfordshire County Council, implemented an innovative pavement reinforcement solution to enhance the structural integrity of the road. The design accounted for heavy traffic conditions, including axle loads of 90 kN per axle, ensuring suitability for long-term highway performance.
In collaboration with Maccaferri Ltd, Babtie utilised OLCrack pavement design software, developed by the University of Nottingham, to assess the effectiveness of reinforcement. The analysis confirmed that incorporating Road Mesh™ pavement reinforcement within the bound layers would significantly extend pavement life by reducing crack propagation and improving load distribution.
Prior to installation, the existing road surface was planed, and any weak or loose areas identified during scarification were repaired. This preparation ensured optimal bonding between the existing pavement and the new asphalt overlay.
Road Mesh™ is a high-performance steel pavement reinforcement system made from hexagonal woven steel wire mesh, with transverse steel bars integrated every 160 mm to provide additional stability. The steel is heavily galvanised in accordance with BS EN 10244-2 Class A, delivering a design life exceeding 60 years. Its open mesh structure allows excellent adhesion between pavement layers, ensuring the reinforcement does not compromise bonding performance.
During installation, the Road Mesh™ was unrolled onto the prepared surface and compacted using a pneumatic tyred roller to eliminate any residual curvature and ensure full surface contact. Fixing methods were adapted based on site conditions and contractor expertise, allowing flexibility in installation.
The use of Road Mesh™ pavement reinforcement on the A507 enabled Bedfordshire County Council to deliver a long-lasting road resurfacing solution. By strengthening the pavement structure and mitigating reflective cracking, the project successfully extended the service life of the highway while reducing the need for future repairs.
This project demonstrates the effectiveness of steel mesh pavement reinforcement in highway maintenance, offering a cost-effective and sustainable solution for road infrastructure upgrades.
