Stockport Interchange

The Stockport Interchange is an important project for the regeneration of Stockport. The interchange benefits the local community by providing an active travel hub and gateway to Stockport Town Centre. Curvature and exposed concrete are used to create a feeling of fluidity and openness, as long-span reinforced concrete beams house the bus station under and support 'Viaduct Park' over, with a central 'oculus' opening.

Judges' Comments:

Regeneration of Stockport town centre was key to this project, connecting the waterfront, railway, A6 highway, town centre and bus station. The rooftop park provides play areas, green space and community space for residents of Stockport, enhancing community engagement and well-being. The project had to deal with a difficult location, being next to a river and a Victorian viaduct, which presented challenges for levels with the park at carriageway height, but with sufficient clearance for double-decker buses.
Exposed concrete has been used throughout the project and was the material of choice for both structural, curvature of the cast elements and aesthetics. The detailing, workmanship, execution and surface finish are exceptional for the in-situ exposed concrete, which includes curved ring beams. The ceiling cladding (timber) sits slightly higher than the soffit of the beams, making them a feature that does not appear functional.
The project team embraced bespoke engineering and developed new software. Due to the shape of the design and unusual loading caused by the planting in the park, there were no standard details, with the engineer having to write bespoke software to estimate deflections.

Gull Wing Bridge, Lowestoft

The Gull Wing Bridge spans 350m across Lake Lothing, Lowestoft. Its centrepiece is a 38.5m rolling bascule bridge, the world's largest of its type, which required a meticulously balanced centre of gravity for operation. The design concept could only be realised by using a heavyweight concrete, overcoming numerous technical and practical challenges.

Judges' Comments:

From an engineering viewpoint, the project is first-class and the iconic beauty of Gull Wing Bridge is evident. Although the MagnaDense concrete played a crucial role within the envelope of the steel 'wings', it is concealed. The in-situ concrete used for the bridge piers and control room tower showed excellence in placement, with no visible honeycombing or blowholes. The heavyweight concrete used as the counterbalance was not visible as it was placed into the steel 'wings' of the bridge. However, the technicalities of designing this concrete to achieve +4000kg/m³ density were well documented.
The parapets for the road and railway sections of the bridge, and the bridge deck, were supplied as precast units and craned into position. The units were of excellent appearance.
A patterned profiled finish with chamfered edges was used for the bridge piers.
The control tower was cast in-situ with an exposed concrete finish and of a high standard, resulting in a very good finish with no obvious blemishes, as were the bridge piers and visible precast units.

Parson's Tunnel, Holcombe

This project provides resilience to coastal hazards such as rockfalls and landslides and protects the iconic coastal railway between Exeter and Newton Abbot. The design, using precast concrete, coloured in response to the local sandstone, also protects rail passengers' seaward view.

Judges' Comments:

This project is a key part of the Network Rail resilience programme for maintaining rail connectivity to the further south-west and a significant architectural addition to the iconic Brunel railway line. It was a complex project logistically, with a demanding programme and the location of the build incredibly constrained.
Locally sourced, red-coloured concrete was used to match the context of red sandstone rocks. Some 130 precast units provided a quality finish, ease of transportation and speed of erection. Concrete was chosen for its durability and ability to withstand the harsh coastal environment and protect the railway from falling rocks. No other material would have been able to compete with the service life. The precast mix design contained 30% cement replacement, lowering the carbon footprint. The precast units still look exemplary.
The 109m-long continuous uniform structure, with 'classical colonnade', comfortably knits within the surrounding geological red rock dramatic landscape and the open-sided structure maintains dramatic views of the South Devon coastline for rail passengers.

19-35 Baker Street, London

The 19-35 Baker Street redevelopment used precast concrete for columns, core walls, lattice slabs and cladding panels, ensuring a high-quality finish, including meticulous panelisation, bespoke shutters and uniform colour across precast shells. Enhanced architectural aesthetics were achieved through the use of precast and post-tensioned slabs.

Judges' Comments:

The use of precast has enabled high-quality finishes to be achieved and these finishes are exposed, showcasing the concrete and reducing the requirements for other finishes.
The majority of precast columns, soffits, lattice slabs, twin walls, stair cores and stairs were specified as 'Special finish', which has not been seen on a project of this size before. 'Special finish' was also achieved on PT slabs used on levels 9 and 10. Acid-etched/polished black stairs in building C were hung and the finish was exceptional.
The quality of the exposed finishes was excellent; there were flat finishes, acid-etched finishes, and polished black concrete. Even the in-situ concrete finishes were a high quality.
Visually, the precast brick cladding matches the surrounding historical listed brick buildings in accordance with the planning requirements. The stacked 12.5-tonne precast panels incorporating reconstituted stone and natural Limestone in building C are impressive.
The amount of 'Special finish' precast concrete used is impressive. Visually, concrete played an important role in both the design and the achieved architectural aesthetics.

Llyn Celyn PMF Flood Conveyance Scheme, North Wales

Llyn Celyn is the largest reservoir by volume in Wales, with a capacity of 81 million cubic metres. The £45m reservoir safety scheme is designed to protect the dam and communities along the River Dee, in the event of an extreme flood. The project features a new auxiliary spillway, including a culvert beneath the access road and precast concrete tipping gates.

Judges' Comments:

Based on the remote site and the weather conditions experienced to deliver the project on time and on budget is a testament to excellent teamwork and communication within the project team, and an example of how civil engineering projects can be delivered. Careful planning, considerable expertise in concrete and engineering, all ensured that the solution not only met the brief but went above and beyond.
As Llyn Celyn lies within Snowdonia National Park, the spillway has been carefully designed to blend in with its natural surroundings. All exposed concrete walls have either a patterned concrete finish or stone cladding. The care and attention taken over the formwork liners is commendable considering few people will look closely at the finish, and if they do, many will assume that it is stone block not formed concrete.
Most people will see just a glimpse of this project as they drive along the A4212. This is a real shame, as the attention to detail and quality of finish deserve to be appreciated by more than those who will have access to the site.

UCL East Marshgate, London

Marshgate's sculptural architectural form and richly textured surfaces create a bold identity that honours the site's industrial heritage. Internally, the flexible exposed concrete structure provides diverse spaces purposefully designed to foster collaboration and research.

Judges' Comments:

The palette of concrete in this building is awesome. From the hero elements, such as the pigmented board-marked concrete, to the quieter elements of the finish of the reveals, the floors and the stairs. The quality and consistency of finish are exemplary.
There is no doubt this is a concrete building; it has been expressed throughout the building, with very few other finishes. The aesthetic of the building could not have been achieved without using concrete.
The building has excellent concrete finishes, using a variety of textured finishes in a deliberate and aesthetically pleasing way. It includes board finishes, textured finishes, polished finishes, abraded finishes and smooth finishes. Attention to detail was excellent.
The concrete frame and facade are highly ambitious structurally, in terms of the varied high-quality finishes required, and represent an unusual level of challenge on a building of this scale.
Without doubt, this building is an exemplar for visual concrete; it uses exposed concrete finishes throughout and it would be hard to find another building that showcases visual concrete any better than this one.

Claire Ackerman, Chief Executive, The Concrete Society
Ian Evans, Principal Engineer, The Concrete Society
James Niland, Advisory Engineer, The Concrete Society
James Luckey, Editor, The Concrete Society
Steve Thorpe, Concrete Society President
Gareth Wake, MPA
Owen Brooker - Structronix
Enda McKenna, McFarland Consulting
Mark Daley - LHC Design