Steel fibre reinforced concrete
The 125 year old Blackpool tram infrastructure, which runs along an 11 mile, beachfront stretch between Star Gate and Fleetwood was in a state of deterioration, leading Blackpool Council to make a bold decision to carry out a £100 million refurbishment and totally revitalise the route. With new accessibility regulations taking effect from 2019, it was also decided to upgrade the tramcars that are used for regular day-to-day services.
16 new Bombadier Flexity 2 trams are now running regular 10 minute services along the Blackpool seafront, but 16 of the older ‘vintage’ vehicles have also been retained, including the famous illuminated trams, some of which will have new doors fitted to comply with new accessibility requirements.
The total upgrade also includes overhead supply renewal, new substation equipment, raised platforms, tram priority traffic signals and a new depot.
A concrete base for the new tracks was required, capable of being drilled in order to take the new track fixings. Using conventional steel reinforcement in the laying of the concrete base for the new track could have caused major problems, with the uncertainty that the steel mesh could have moved during the pouring of the concrete, which could then have interfered with the drilling of holes for the fitting of the new track.
It was therefore decided to include steel fibres as a replacement for the steel mesh. Adding steel fibres to the mix sped up construction, firstly by obviating the need for steel mesh placement and secondly, because of their small physical size and even distribution throughout the concrete, allowed drilling into the concrete structure without interference.
Hanson Concrete supplied 2,500 cubic metres of fibre reinforced concrete during the construction of the new track base. The use of Sika® ViscoCrete®superplasticiser concrete admixture and steel fibres produced a strong, durable concrete base with maximum resistance to withstand heavy loads.