The £1.2 million Mamhead Slipway in Exmouth, a ‘major technical undertaking’ on behalf of East Devon District Council (EDDC), reintroduced maritime access to the River Exe in the hope of increasing visitor numbers to the town. The original structure was closed in 2012 and eventually demolished by contractors Raymond Brown Construction as part of the rebuilding process.
Following Environment Agency guidance, which stipulates minimal use of traditional steel fabric where practicable in marine and coastal concrete, EDDC, in conjunction with the contractors and structural engineers needed a product that would help extend the service life of the slipway and provide a safer, cost-effective and high-performance alternative to traditional steel reinforcement.
SikaFibre® Force comprises a range of macro synthetic fibres which can be extruded, embossed and cut for use in a range of concrete applications. The system enhances the toughness of concrete,
alleviating the need for steel mesh when used with the appropriate design. Simple to apply, as well as being easier and safer to handle than steel, SikaFibre® Force macro fibres offer a three-dimensional reinforcement solution which does not rust or corrode due to long-term exposure to seawater chloride.
Due to water level and tidal fluctuations, Mamhead Slipway works took place behind a cofferdam provided by interlocking sheet piles. This resulted in a highly-restricted working area with mobile plant operating alongside site operatives. However, significant health and safety hazards were eliminated for the workforce due to the availability of the SikaFibre® Force macro fibre.
Had welded steel mesh reinforcement been specified, a crane would have been required to lift it into position, leading to potential disruption for drivers and pedestrians as well as causing a danger for on-site construction teams.
The SikaFibre® Force macro fibre offered a far more practical alternative. It was poured directly into the slipway’s formwork, thus ensuring the reinforcement’s containment within the delivered concrete and resulting in a more efficient installation and reduced construction time. The slipway’s six-month construction programme was completed in September 2016. The 38 metre-long, 12-metre-wide feature was described by Exmouth Regeneration Board, chairman, Cllr Philip Skinner as a ‘larger, safer and more resilient facility for people to use for decades to come’.
The SikaFibre® Force macro fibre will not be able to hold the tides at bay, but it will nullify the water’s corrosive element and ensure Exmouth’s latest maritime facility doesn’t slip away to sea over time.