Decorative coloured surface for a coastal promenade

As part of a project to replace and upgrade the sea wall at Morecambe Bay, the client, Lancaster City Council required a new surface for the promenade that would complement the development. The existing surface was an old HRA which was suffering from a longitudinal crack running down the centre of the promenade. Given the importance of the site to the local tourist industry, the client was keen to choose an aesthetic material that suited the clean, modern design of the new sea wall. The chosen material also needed to provide an accessible, trip-free surface and offer a long service life with minimal requirement for ongoing maintenance.

After discussions with the client and delivery partner VBA, Tarmac proposed ULTICOLOUR, their durable coloured asphalt. Samples were provided to help the client make the correct choice of colour. ULTICOLOUR uses a clear polymer modified binder, pigment and colour matched aggregates that resist surface wear and maintain a long lasting appearance. The chosen material was a 6mm ULTICOLOUR buff coloured asphalt. It was established that the reflective cracking on the site was caused by differential movement between the concrete sea defence and the adjacent ground. To resist cracking in the new surface, ULTILAYER SAMI, Tarmac’s innovative stress absorbing membrane interlayer would be used. ULTILAYER SAMI is designed to provide exceptional resistance to cracking in asphalt overlays caused by movement in underlying layers.

In total, 561 tonnes of ULTILAYER SAMI was laid on the site in a 25mm interlayer and 592 tonnes of ULTICOLOUR 6mm was laid as a 30mm surface course. ULTILAYER can be laid quickly using conventional paving techniques. This allowed the client to use a single surfacing contractor and avoided the additional time and logistical requirements of employing a separate contractor to install a geogrid. The client was delighted with the finish which perfectly complemented the new sea wall, constructed using Tarmac’s TOPTINT pigmented concrete. After being shown evidence of the performance of ULTICOLOUR and ULTILAYER SAMI on other sites, they were also confident of the long term durability of the new pavement.