Rebuilding Blackpool's sea defence wall
After 100 years of wear and tear, Blackpool's 3.2km of sea defence wall have been renewed, in the town's largest ever civil engineering project. Over the last few years, our partners Blackpool Borough Council and contractor Birse Coastal have gradually replaced the old structure. This required over 103,900m3 of various high-performance concretes, all supplied by Tarmac.
Most of the construction work was completed within a tight daily time window, three hours either side of low tide. We addressed this challenge in two ways. First, we supplied 44,000m3 of precast concrete, which could be installed quickly. Then, for concrete that had to be poured in situ, we supplied 27,600m3 of Tarmac Topforce, our specialist fibre reinforced concrete. This material provides an ideal solution in a tough marine environment, because it contains fibre mesh instead of steel mesh, which would be at risk of salt water corrosion. It also gives increased resistance to impact and abrasion, reducing maintenance costs and increasing the concrete’s durability.
Topforce improved site safety because the team did not have to handle heavy steel wire. As the reinforcement is provided within the concrete, safety risks associated with conventional, steel-reinforced concrete, such as trips and falls, were also reduced.
This concrete is more sustainable because macro-synthetic fibres have less than 30% of the carbon footprint of conventional steel wire fabric and steel fibres. In the longer term, it also contributes to lower-carbon emissions because its durability extends the design life of the new sea walls.
Anthony Burgess, regional engineering manager at Birse, said: “Using Tarmac delivered both cost and time savings, because using steel mesh typically requires significant on-site preparation time. The product provided us with a viable material that could reach structural strength quickly, while remaining easy to work with.”