The association for the manufacturers of architectural cladding and structural precast concrete

Thorp Precast

Case Studies ›

Launched in 1993, Admiral – perhaps best known for the savings available with its multicar insurance and one of Wales’s greatest business success stories – is now leaving its mark in Cardiff. Having tripled its number of customers, its staff, and its stock market capitalisation in the past decade, it has now opened a new 245,000ft² 11 storey HQ building developed by Stoford, designed by architects Glenn Howells and 3D Reid, with Sir Robert McAlpine as the lead contractor and Arup as project engineer.

 

Following a competitive tender, Thorp Precast was selected to deliver the external envelope cladding package on a full design, manufacture, supply and erect basis. The brief was to provide white Portland architectural precast concrete cladding with a high-quality surface finish featuring slightly exposed natural limestone aggregates.

 

Endorsed by the Design Commission for Wales, the building will meet the BREEAM ‘excellent’ standard of environmental sustainability and energy efficiency. With this in mind, it features a series of pale reconstituted stone double-storey height vertical splayed mullions, with slender horizontal spandrel units, and large expanses of glass to allow maximum natural daylight infiltration to every floor. Steel moulds were deployed by Thorp for manufacturing individual units to help maintain clarity and high definition, with a good consistency of quality and finish throughout.

 

At the lower level, a tall, colonnaded walkway running down the west side of the building is formed by a series of white architectural concrete columns and long-span spandrel units. This area will feature public cafes and restaurants, while outside areas will be landscaped to offer places to sit and relax during lunch breaks, or on shopping trips in the neighbouring shopping centre.

 

The roof level sees a labyrinth of steelwork with sophisticated geometry and connection details clad in Thorp’s architectural precast concrete. The installation of more than 600 precast components over several visits required high levels of skill and precision to meet strict health and safety targets. Using BIM software, the company was able to meet the tight construction programme, sometimes employing two fixing gangs – but still only 8–10 men altogether – to ensure continuing progress during several periods of bad weather.

3D modelling played a vital part to ensure all builders works were incorporated into the primary structural frame to accommodate the safe and efficient installation of the PCC units, particularly when it came to sequencing specific site activities. This also applied to some of the ground-to-second floor columns where structural steel components were cast into the precast concrete columns with projecting connection details.

With the frame complete, Thorp returned to clad the steel structure to make it watertight with two tower cranes servicing the main elevations. As the building is on a small footprint close to the city centre, restricted storage space dictated just-in-time deliveries to minimise disruption to the general public, local businesses, and surrounding highways.

 

All the precast cladding work was carried out without the need for external scaffolding and without the use of wet trades, providing significant construction time savings and major benefits as regards health and safety.

 

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ASPA, part of British Precast.                                                                                                                                                                           www.britishprecast.org

British Precast is the trade association for the precast concrete industry                                                                                 E-mail: info@britishprecast.org

                                                                                                                                                                                                                                    Tel: (0116) 232 5170

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