On 15 October 2026, Clough reported that crews had completed Suburban Rail Loop East’s first structural pour using calcined clay concrete. The mix, developed with Boral, went into the slab and walls of a water treatment plant at Glen Waverley in Melbourne. The report confirms completion by 15 October. The exact placement date is unreported.
For a project team considering a new binder, the change is the job the concrete had to do. A test slab can show whether a mix can be batched, delivered and placed. At Glen Waverley, the team used it in elements designed to serve the plant. Clough’s footage of the pour
From test pours to structural work
The Glen Waverley mix uses heat-treated kaolinite clay as a supplementary cementitious material. Heating suitable clay changes its structure so it can contribute to the hardened binder. Replacing part of the conventional cement gives the supplier a way to reduce embodied carbon. The reduction for a particular mix depends on the materials, their processing and the baseline used for comparison.
Boral’s February 2026 development update described trials at its Maldon operations and an earlier North East Link test slab made using clay recovered from excavated soil. Those trials show how the supplier built experience with batching and placement. The October report identifies calcined kaolinite in the Glen Waverley mix. It gives no blend proportions or clay source, so the earlier test slab cannot establish the composition of the structural concrete.
In a September 2026 update, Brett reported a related development by UK supplier Capital Concrete for the Accelerating Concrete Decarbonisation Group. Two calcined clay blends were among three mixes batched at production scale for full-size wall, floor and roof demonstrators at Kilnbridge’s Canning Town facility. The demonstrators are being monitored. At Glen Waverley, the concrete was placed in elements that form part of the plant and had to meet the project’s own design and acceptance requirements.
What the pour establishes
The contractor’s account confirms delivery and placement in a structural application. Clough says the mix maintained the required performance. The public account gives no strength results, durability data or product-specific carbon declaration. It therefore gives practitioners a real reference project, with the evidence for specifying the mix on another job still to be established.
The reports establish that Boral could supply concrete for this Victorian project. They give no published price or lead time for the Glen Waverley formulation and no indication that it is a standard mix across Boral’s Australian network. For an estimator, the starting point would be a supply proposal for the plant that will actually serve the site, including the delivery radius and arrangements if the binder supply changes.
What to ask before specifying it
The useful questions differ for a slab and a wall. For a slab, the crew may need evidence of how long the mix stays workable through delivery, placement and finishing. For a wall, the team may need to check placing behaviour through the reinforcement and strength development against the intended formwork cycle. Where the element is designed to retain water, the designer’s crack and leakage criteria belong in the same discussion. These are matters for the project team’s acceptance plan and the proposed mix’s test evidence.
Austroads’ 2026 guidance for Australian and New Zealand transport agencies sets out a way to make the procurement comparison. Define the performance the element has to achieve, then compare embodied carbon using environmental product declarations on the same basis. A useful comparison pairs mixes that can meet the same exposure and service requirements and records which life-cycle stages the figures cover. That gives the buyer a way to assess the carbon claim alongside supply, programme and construction requirements.
Sources
15 October 2026 · Clough’s Glen Waverley structural pour update
16 February 2026 · Boral’s calcined clay concrete development and field trials
Victoria’s Big Build on the earlier road concrete trial
September 2026 · Brett’s account of the UK production-scale demonstrators
27 February 2026 · Austroads’ Carbon Reduction and the Use of Low Carbon Concrete, AP-R757-26 and implementation overview
Cover photograph shows concrete placement at New York’s 63rd Street rail ventilation facility in 2019. MTA Capital Construction Mega Projects · CC BY 2.0
