The new roundabout at the entrance to picturesque Busselton provides an example of Holcim 's desire and ability to undertake and complete even the trickiest of architectural projects.
The Shire of Busselton wished to create an entry statement to the town that both addressed a major road and traffic issue as well as depict the Noongar stories of travelling from the south west hills to the coast through the various Aboriginal seasons and linking these six Aboriginal seasons to the traditional four western seasons.
The solution was to change the intersection to a roundabout, allowing the Shire of Busselton and the south west Noongar community to create a visual representation of the Noongar seasons at a major traffic roundabout in central Busselton. An artist was hired and concept plans and drawings were conceived.
The Holcim team undertook to match the swathe of colours from the original artwork not only in colour but also in texture. Holcim’s first step was to experiment with the mixing of various coloured oxides until they could exactly match all of the numerous colours and in total there were more then 20 different colours and textures of decorative concrete developed for the project. The roundabout required exposed aggregate concrete areas, trafficable kerbing and outer surfaces as well as adjacent footpaths and pram ramps.
The roundabout design was to reflect the Noongar people's travels from the hills to the ocean and a limestone and gravel exposed aggregate mix coincidentally already named "Ocean to Earth" was chosen as the foundation mix for the various ochre colours that would represent this travel path. Two of these colours were specifically developed for this project and now form part of the Holcim Concept range in Vasse and Meelup (sub-regions of Western Australia). These travels were aligned to the now little known six Noongar seasons and the roundabout visually represents these seasons against the western seasons of summer, autumn, winter and spring.
The Holcim needed to produce a patchwork quilt of wet concrete colours and faced a further challenge in that the entire project had to be completed at night in the cold of winter. This presented a problem for the Holcim team as concrete requires heat to enable the process of hydration or the setting and curing of the concrete to occur.
Holcim hired Russell Lines' Jetline Paving and kerbing to build the initial outer kerbs and later complete all the adjoining footpath areas. This was a challenge as each piece of coloured kerb only travelled a couple of metres before it completely changed colour and each concrete truck could only carry one particular colour at a time.
Completion of the major part of the jigsaw puzzle, the various pie shaped textured and exposed concrete aggregate sections was undertaken by Greg Higgins' Westec Concrete. This task meant spending each day planning and preparing for the evening and then that night, pouring and exposing aggregate until around 6:00am.
Thanks to the enthusiasm of both the Jetline and Westec grano teams, the complete project was achieved over just six nights, quicker than the Holcim team's original estimation.