Concrete strengthening for Quay Quarter Tower (QQT) – Sydney


Slabtec is proud to have been involved in this groundbreaking and multi-award-winning project. We thank the major stakeholders, AMP Capital, Multiplex, and BG&E for the opportunity.

Quay Quarter Tower is a $900M refurbishment of a 50-year-old building in Sydney’s famous Circular Quay.

The additional floors and significant footprint enlargement resulted in additional stress on the original concrete cores. Strengthening with a combination of both CFRP and steel plates was adopted, with CFRP shear strengthening and steel plates in the vertical directions installed in many of the header beams in the cores.

Slabtec also installed CFRP beam shear strengthening in a new plant area and notched/strengthened a new concrete transfer beam, which obstructed the façade system.

In a number of areas, steel plates up to 30mm thick were used to strengthen the cores with M24 bolt fixings and all plates were also bonded to the substrate with Sikadur 30 epoxy adhesive.

The significant existing reinforcement in the cores and the weight of the wall plates made for a challenging installation process.

The majority of the core wall strengthening was undertaken with vertical CFRP laminates.

A key challenge in the installation process was ensuring the flatness tolerances of the laminates were achieved on the 50-year-old cores. Anchorage into the foundations was also critical to ensure the CFRP laminates transferred the tensile forces into the footing elements as required.

The notch in the new transfer beam was required to avoid time delays in modifying the complex glass façade elements. The notch was cut out “over depth”, and strengthened with vertical shear bolts and flexural bars before the high-build mortar was used to make good the soffit in the notch. Significant CFRP flexural strengthening was also required in the main span of the beam.

CFRP fabrics were used to provide shear strengthening to accommodate an increase in applied loading.

The fire spray was first removed from the beam sides, which protected existing steel strengthening plates along the soffit of the beam, which was retained.

World Building of the Year Award

In November 2022, architects 3XN and BVN won the International High-Rise Award for Quay Quarter Tower, while in December of that year, the building won the World Building of the Year Award at the World Architecture Festival.

“Quay Quarter Tower’s architects 3XN and BVN, with developers AMP Capital, were singled out for “radical sustainability” that saved 7500 tonnes in carbon dioxide emissions, compared to the impact of demolishing and rebuilding on the site.”

American Concrete Institute 9th Annual Awards

The “Overall Excellence” award was presented to Quay Quarter Tower, located in Sydney, New South Wales, Australia. The winning concrete project also received first place in the repair and restoration structures category at the ACI Excellence in Concrete Construction Awards during the ACI Concrete Convention on Monday, October 30, 2023.

ACRA Remedial Industry Excellence Awards 2023

ACRA Strengthening AwardACRA was formed in 1991 with the aim of providing a forum to promote discussion and an exchange of views in the concrete repair and remedial building industry to advance the technology and practice in the remedial industry and associated activities.

ACRA present the annual Remedial Industry Excellence Awards. Slabtec entered the Quay Quarter Tower project (QQT) and is humbled to be named the winner of the Strengthening Category.

Congratulations to the other category winners, and a big thank you to ACRA for the work they do for the industry.

AMP Capital



  • Sika CarboDur
  • Sika CarboShear
  • SikaGrout Deep pour
  • Hilti RE500
  • Hilti HY200