Cullet Surge Bunkers— Visy Yatala Glass

At a Glance

The Project

Visy's Largest Ever Investment

Visy's new glass plant at Stapylton, between Brisbane and the Gold Coast, is the company's largest ever investment. When it's fully running it will make around one billion glass containers a year. More than 600 people worked on the build.

At the front of the plant sits a new cullet plant. It takes in used glass, sorts it down to pieces as small as 3mm, and separates it by colour into amber, green and flint. It can handle up to 40 tonnes of glass an hour.

The surge bunkers sit behind the cullet plant. They hold a buffer of processed glass so production keeps moving. Cullet weighs 1,150 to 1,350kg per cubic metre, so the walls had to carry real load every day.

Early Engagement

Three Years Before the Bunkers Were Built

Envirocon was involved early. Visy's engineering team first worked through Interbloc bunker designs with us in 2019, and the first conversation about Yatala came in 2022, three years before the bunkers were built.

That early start meant we could help shape the design, not just quote on a finished drawing. We worked directly with Build Run Repair, Visy's in-house team, as plans for the cullet plant developed. Over two years we designed options for five different bunker structures across the site.

Each round balanced what the engineering required, how much storage the plant needed and what the budget allowed. Wall heights were adjusted, the bay layout was redrawn, and the scope was refined to the surge bunkers the plant needed first. The final design landed at around 1,000 blocks, with walls at 3.6m and 4.2m.

Being in early also meant we could build in room to grow. Visy wanted the option of more height later, so the bunkers were designed from day one to take it. Precast panels and poured walls can't offer that.

The Solution

A Groutless Reinforcing System

Interbloc's groutless reinforcing system holds each wall to the slab with RB32 Reidbar that runs through the blocks and is tensioned from the top. Because nothing is grouted in, the blocks can be added to, reconfigured or lifted off and reused at any time. Visy can raise the walls for more capacity, change bay sizes, or move the bunkers if the plant layout changes. Flat-top blocks already sit on the top course, ready for a roof.

The same standard blocks build every wall, whether it's 3.6m or 4.2m. A design change means a new drawing, not new moulds or new panels.

The Install

Built on a Live Plant Site

The bunkers went in on an active construction site, alongside concreters, gas line installers, silo crews and other trades. Our crew mobilised in July 2025 with the first blocks arriving just days later. The delivery plan ran up to four semi-trailer loads a day, with blocks going straight into the wall, so there was no big stockpile taking up room on a tight site.

• No specialist equipment. Every block was placed with forklifts.
• When other trades were working in some bays, the crew moved to the bays that were free. Delivering extreme flexibility to match a changing construction schedule.
• When the slab didn't quite match the wall layout, we repositioned the wall to match.

What This Means for Your Site

Built to Change With Your Plant

The final walk-through and sign-off with Visy took place just under eight weeks after we arrived, and across three swings.

If you store glass, aggregates, fertiliser or other bulk materials, and your plant is still changing, Interbloc gives you:

• Walls that go in with a small crew and forklifts, no crane
• A design that can change right up to install
• Bunkers you can raise, extend or relocate later