Mace has completed the concrete structure for the new advanced imaging centre known as the Extreme Photonics Applications Centre (EPAC) on behalf of the UK's Science and Technology Facilities Council (STFC).

Mace worked closely with a global concrete specialist to create a unique concrete mix design that will support the complex technical building’s requirements while reducing carbon.

The team used 7,500m3 of structural concrete with a composition of 75% Ground Granulated Blast Furnace Slag (GGBS) instead of traditional Portland Cement. A less carbon intensive alternative, this led to a 48% overall carbon reduction and a saving of 1,373 tonnes of carbon.


The composition of concrete mix was guided by specific experimental shielding properties that required the use of high density aggregates and a reduced cement content in order to minimise the risk of thermal cracks occurring as a result of the heat generated during the concrete curing process.

Due for completion in spring 2022, EPAC will house super-bright lasers that, over a few tens of seconds, can produce state-of-the-art high-contrast 3D images of the internal structure of complex objects from aircraft wings to bones.

The laser testing process will achieve temperatures of 50 million degrees Celsius, hotter than the centre of the sun. A single flash from the laser is 1 quadrillion watt which makes it 10,000 times more powerful than the whole of the UK national grid output. These extreme conditions meant the Mace team was facing a number of challenges to deliver a structure able to house them.

Attached to the chamber a complex arrangement of labyrinths create service and personnel access into the testing chambers. Utmost care has been taken to ensure that the internal dimensions of both chambers and the labyrinth will provide enough shielding and absorption required for future experiments.