Stirling’s waterproof bridge

Stirling Lloyd has combined its Eliminator waterproofing membrane and Gussasphalt surfacing to successfully replace the road surface of the Avonmouth Bridge on the M5 motorway in the UK.

The 1,4 km long steel box girder bridge features a 16000 m2 steel decked central span and two 16000 m2 concrete approach spans, all of which needed resurfacing during the winter months of 2008 and 2009 to avoid impacting on tourism in the area.

Work began in September 2008 on the southbound carriageway with the Eliminator liquid spray membrane being applied. Once the membrane was in place, Aeschlimann International were sub-contracted to apply the dense mastic Gussasphalt surfacing that is almost impervious and is self-compacting when laid.

Gussasphalt is spread using a paver that runs on pre-positioned rails to achieve the required thickness with a tolerance of just +/- 2 mm. Applied in two 17 m wide runs, to minimise the number of joints, the Gussasphalt was laid to a depth of 50 mm on the steel sections and 60 mm on the concrete.

Following the successful rehabilitation of the southbound carriageway, the northbound carriageway is scheduled for completion this month.