M25 BELL COMMON TUNNEL
PROJECT CASE STUDY JOURNEY
Costain / Capita wanted Asphalt Reinforcement Services to help shed light on a reflective cracking problem in the M25 Bell Common Tunnel. With the aid of ARCDESO® technology, a long lasting solution was provided with the aim of reducing costs – GlasGrid® CompoGridseal incorporating CG100 and Sealoflex SC-4 sprayed at 2kg/m².
Site: M25 Bell Common Tunnel
Contractor: Aggregate Industries
Product: GlasGrid® CompoGridseal incorporating CG100 and Sealoflex SC-4 sprayed at 2kg/m²
Date: July – November 2009
With tens of thousands of vehicles travelling daily, the M25 is constantly busy. This means there is constant pressure on its road surface. Working closely with the client, Asphalt Reinforcement Services wanted to find the best way to arrest development of reflection cracks in the Bell Common Tunnel on the M25. What they needed was a maintenance free solution that would reduce reactive maintenance costs.
That’s where Anti-Reflective Cracking Design Software (ARCDESO®) came in. The technology helped Capita in their design of a 95mm asphalt overlay of a continuously reinforced concrete pavement. Next, GlasGrid® CompoGrid CG100 was installed prior to the overlay, in order to arrest reflection cracks that could develop in the bituminous layers. The 22,000m² area of GlasGrid® CompoGrid CG100 was installed over 4 night shifts by specially trained operatives. They used purpose built applicators, specifically designed to pretension and install the reinforcement, free from any wrinkles or folds for a smooth finish.
The beauty of ARCDESO® was that the client was able to see a model of the lifetime performance of the pavement. The GlasGrid® CompoGridseal incorporating CG100 and Sealoflex SC-4 sprayed at 2kg/m² stood out as the most effective way to strengthen and prolong the pavement life.
Quote from client.
Andy Goodwin PM for Costains – “I was highly impressed by the speed and quality of the ARS installation operation. The CompoGrid treated areas in the tunnel are still crack free in April 2016.”
Product featured: GlasGrid® CompoGridseal incorporating CG100 and Sealoflex SC-4 sprayed at 2kg/m²
GlasGrid® is an exceptionally strong reinforcement grid structure that is able to control crack growth and increase load bearing capability. It can extend pavement life up to a factor of 5 and permits thinner pavement design, making it the best choice price wise, whilst reducing the carbon footprint.
Start – Consulting with Costain / Captia to identify the M25 Bell Common Tunnel issues
First step – Using (ARCDESO®) Technology to help decide the best solution
Hit the road – Working with Aggregate Industries and usingGlasGrid® CompoGridseal incorporating CG100 and Sealoflex SC-4 sprayed at 2kg/m²
Moving forward – Laying 22,000 m²GlasGrid® CompoGridseal incorporating CG100 and Sealoflex SC-4 sprayed at 2kg/m² over 4 nights
Staying on track – Work completed on time by Asphalt Reinforcement Services qualified team
Finish – With the pavement life extended up to a factor of 5, the tunnel’s future was looking bright
Longevity – Extending pavement life up to five times
Technology – By using ARCDESO® software, this enabled the client to forecast the effect of implementing the solution
Efficiency – Keeping disruption to a minimum by operating over 4 nights
Safety – Reducing road surface related accidents and collisions
Results – The CompoGridseal treated areas in the tunnel are still crack free nearly 7 years on
Environmental – Providing a greener solution by allowing a thinner pavement design to reduce carbon footprint