Construct - Issue 50

Innovation

TESTING THE USE OF BIO-MATERIALS IN BINDER MIXES TO EXTEND THE LIFESPAN AND DUCTILITY OF STRATEGIC ROADS BIO-BOOSTING OUR ROADS

FM Conway is working with National Highways to increase the longevity and elasticity of roads using bio-materials in recycled asphalt product (RAP). By keeping roads in use for longer, this innovation helps to lower carbon emissions, minimise disruption for users, and reduce reactive maintenance costs over the long term. FM Conway’s trials have shown that recycled asphalt can match if not surpass virgin materials in terms of performance. We know that it works, but the business is now asking: how can we make it even better? Over the course of a road’s life, it faces plenty of stressors, from the harsh sun and UV rays, to rainfall and freeze-thaw cycles, not to mention traffic load. All of these serve to make asphalt hard and brittle – which is where bio-rejuvenators come in. Derived from waste cooking materials, these have the potential to preserve the strength and flexibility of asphalt, reducing the growth of cracks and slowing the unravelling of the asphalt surface.

Operators like National Highways are looking at ways to improve our strategic road networks while balancing rising costs, quality and carbon emissions – no easy task. The operator is conducting nationwide trials with varying percentages of RAP and bio enhanced surface binders for different types of roads. One of these experiments was conducted in partnership with FM Conway, repaving six sections of the A21 as part of the trial. The A21 is a major road connecting Greater London to parts of Kent and East Sussex – a vital artery for commuters and link between the towns and villages along its path. The goal of the trial was to test how additives like bio-rejuvenators affect the performance of materials containing high RAP content. The trial covered six patches, two that were resurfaced with traditional mix as a control, two with 50% RAP and two others with 50% RAP and bio-rejuvenator for robust comparison.

The goal of the trial was to test how additives like bio rejuvenators affect the performance of materials containing high RAP content.

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