Project: New Sydney Metro Martin Place integrated station development, Martin Place, Sydney
Contractor: Lend Lease
Period: June 2021 to June 2022
Product Used: Clayform Void Former
About the project:
This integrated project includes the underground metro station, pedestrian connections and two buildings above ground.
Key challenge:
The sandstone ground across Sydney is an iconic feature, but can be a challenge when doing deep excavations given its tendency to shift over time. With significant excavations occurring at the site of Sydney Metro Martin Place, Lend Lease required a solution to accommodate the natural movement of the sandstone so it would not jeopardise the integrity of the buildings. A gap of minimum 30mm was needed between the sandstone and buildings. However, this gap is too small for standard formwork that can be later removed, so a different solution was necessary.
Our Solution:
Lend Lease reached out to Lite Corp to see if we had a fix. We communicated regularly to understand their requirements, and Lend Lease then tested the Clayform product vigorously on-site to ensure its effectiveness (it worked perfectly).
Lite Corp supplied custom-length Clayform sheets for ease of installation at site. These were applied vertically against the excavated sandstone faces before the concrete was poured. Given the uneven nature of the sandstone excavations, the high-density core of the Clayform ensured a good structure to pour against and achieve the void required.
After the concrete had been poured, water was introduced to the Clayform to swiftly break the product down.
This principle is known as ‘vertical stress relief’ – safely accommodating the natural movement of the sandstone.
The Construction Manager for the project mentioned: “We have installed a lot of material and have poured against it with results being favourable.”
