The Sirius Building: A Testament to Brutalist Architecture and Modern Engineering

Over the past three years, Slabtec has played a pivotal role in transforming the Sirius building, one of Sydney’s most iconic structures. As one of the first subcontractors on the project, Slabtec’s involvement ranged from initial safety measures to extensive remedial repairs, ensuring the building’s structural integrity and aesthetic preservation.

Key Contributions by Slabtec

Extensive Man-Hours and Advanced Materials

• 12,000 man-hours: Slabtec dedicated approximately 12,000 hours of skilled labour to this project.
• Largest Carbon Fibre Project: Sika recognised Sirius as the largest Carbon Fibre Project globally at the time, marking a significant achievement.
• Carbon Fibre Installation: The project installed over 12 kilometres of Sika Carbon Fibre laminate across various sizes and stages.
• Application and Materials:
  • 2000 linear meters / 1000m² of Sika CarbonFibre Wrap.
  • 9 tonnes of epoxy for CarbonFibre installations.
  • 9.5 tonnes of concrete repair mortars for structural elements.

Project Partners

• Developer: JDH Capital
• Builder: Richard Crookes
• Architect: BVN

Background of the Sirius Building

The Sirius building in the Rocks district of Sydney is a prominent example of Brutalist architecture. Designed by Tao Gofers for the Housing Commission of New South Wales between 1978 and 1979, it holds historical significance and has been a subject of public interest.

Originally slated for demolition, the building was saved when JDH Capital acquired it for $150 million in 2019. The redevelopment has increased the total floor space by 27% to 8316 square meters, including new amenities such as a gym, pools, cafes, and commercial spaces. Converting the original 79 public housing flats into 75 high-end apartments, including a penthouse listed at $50 million, was an intricate and costly endeavour.

Concrete Spalling Investigation & Repair – Internal and External Challenges

The refurbishment required the removal of adjoining walls, necessitating substantial structural strengthening. Before applying the carbon fibre laminates, internal concrete spalling issues were meticulously addressed. Externally, the building had endured nearly 50 years of chloride attack from Sydney Harbour and carbonation from the nearby Cahill Expressway, resulting in significant concrete spalling that required repair.

Slabtec Innovation

Slabtec’s contribution to the Sirius building project exemplifies the company’s dedication to quality and innovation in structural strengthening and concrete repair. Their efforts have ensured that this iconic structure retains its historical and architectural significance while also meeting modern standards of safety and functionality.

The Sirius building is a testament to the successful collaboration between developers, builders, architects, and subcontractors in preserving Sydney’s architectural heritage.