The curving concrete walls of the aquatics centre are one of its defining characteristics. They are first seen in the centre’s welcome area and provide a top and tail to the competition pools, as well as a stylish backdrop to television coverage of the diving.
The smooth curves and fine finish, even down to the neat rows of bolt plugs, are a source of obvious source of pride to the construction team. So how were they made?
“The curved parts of these walls required specialist formwork manufactured from phenolic ply in Germany,” reveals ZHA project architect Sara Klomps. In effect, they commissioned something akin to a giant toy construction set of formwork. “To keep costs down, we had to break down the design into straights, verticals, and forms for straight inclined, curved vertical, and curved inclined, as this allowed at least some re-use of formwork, especially as many sections are symmetrical.”
Though the corbelled curved walls sometimes give the impression of being double curvature like the roof, they are not. “If you cut a diagonal slice from a cylinder it can look this way but in fact, it’s single curvature.”
Morrisroe’s Tony Henry calls this “an incredible feat of carpentry and design,” and describes how the formwork was used to create the walls. “Because of the concave and convex shapes, there was an increased risk of trapped air creating voids, so we used a self-compacting mix and pumped the concrete into the forms from the bottom up. We had many meetings with the architect, engineer and contractor to work out the best mix and again, sample panels were made until we knew we could rely on the mix to flow effectively and also give the right appearance. It was all about attention to detail – for example, ensuring the bolt holes were all in a pattern and plugged with a proper colour-matched mix.”