Sika concrete admixtures were essential in the various specialist concrete mixes that were supplied by Hanson Concrete, to the new Bridlington Pumping Station, part of a £40 million scheme by Yorkshire Water to improve the way that storm water is managed.
The scheme is designed to ensure that the quality of the sea water at both the North and South bathing beaches meet stricter European standards that are due to come into force in 2015, and reinstate them to ‘Blue Flag’ status.
The project, which started in October 2012 includes a new 800 metre long underground water storm tunnel, a new pumping station situated on the Spa Promenade, and a coastal pipeline which will carry pumped water more than a kilometre out to sea.
Piling works were carried out by sub-contractor Bachy Soletanche, who were dealing with difficult ground conditions, caused by the high water table, together with a concrete mix that had the potential to lose its workability. This was due to a high cement content and the inclusion of Ground Granulated Blast Furnace Slag (GGBS), which was included to increase durability of the concrete in the harsh marine environment.
Sika® PilePac®, a specially formulated concrete admixture that is incorporated in Hanson EasyPile for use in difficult piling conditions, was an ideal solution. It enhanced the viscosity of the concrete and prevented segregation of the concrete when in contact with the ground water.
Also included in the mix was Sika® Viscocrete®-35RM, a superplasticiser that allowed a significant water reduction and gave a high consistency and retained workability.
Aesthetically, the colours of the concrete supplied to the pumping station had to match the colours to those of the adjacent Spa building, the leading theatre and entertainment venue on the Yorkshire coast.
Hanson Concrete had previously supplied the Spa project, but difficulty in replicating the colours on the pumping station was caused by the durability requirement of the GGBS incorporated in the concrete mix.
Sika® ColorFlo® is a range of liquid coloured pigments that are an integral part of Hanson’s Colourcrete coloured concrete system which was used to successfully implement Yorkshire Waters strict requirements for colour accuracy.
In the Colourcrete process, the Sika® ColorFlo® is added in a unique automated process, which allows the exact dosage time after time, ensuring unrivalled colour accuracy and consistency. A selection of primary colours and nearly endless blending possibilities allow the designer to choose almost any shade of his choice. The coloured concrete produced was durable and sun, weather and fade resistant.
The completed scheme will reduce the chance of untreated water entering the sea during times of heavy and prolonged rainfall. Excess dilute waste water will be carried by the 800 metres long underground storm water tunnel to the new pumping station from where it will be safely pumped down the new coastal pipe over a kilometre out to sea.