CPT are proud to introduce our new lunchtime seminar: ‘Preston Bus Station MSCP – An Award Winning Refurbishment’.
When Preston Bus Station Car Park opened in 1969 it was the largest bus station in Europe. Recently awarded Grade 2 status this brutalist structure incorporates eye catching curved balcony fronts and sweeping access ramps.
Like many car park structures of this vintage the reinforced concrete elements were exhibiting extensive damage due to reinforcement corrosion. Over time chloride salts deposited from cars had penetrated the concrete cover, aggressively attacking the steel reinforcement and generating expansive corrosion products. The result was extensive cracking and spalling, particularly to the decks, soffits and ramps.
Cover depth, chloride and half-cell potential survey techniques were employed to identify areas of corrosion risk. It was critical that areas of corrosion risk were addressed prior to the application of deck coatings, otherwise cracking and spalling of the concrete was likely to continue beneath the coatings. CPT designed a bespoke corrosion management solution which incorporated a variety of techniques.
An impressed current cathodic protection system, utilising titanium ribbon anodes, was installed to the three external access ramps whilst DuoGuard, an innovative hybrid anode system, was installed to the car park decks. The system is termed ‘hybrid’ because the same zinc-based anode is utilised in both impressed current and galvanic modes. The impressed current mode runs for approximately one week during which time the steel is strongly passivated. Thereafter the anodes self-generate a galvanic current to maintain steel passivity. This reduces the long-term maintenance requirement and associated monitoring and control costs.
Following concrete repair and corrosion control works, a decorative and protective coating was applied to the concrete decks. We are proud to say that this project picked up a coveted ‘Inspiration Award’ at the 2019 British Parking Awards.
To find out more about how Preston Bus Station Car Park has been preserved for future generations, use the form below and register your interest in our lunchtime seminars, arranged to take place at your offices at a time convenient for you.
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