The 2nd stage of construction of the NINE by Mirvac residential development in Willoughby (NSW), Australia, comprising 214 units, was completed in June 2024. PENETRON ADMIX, a crystalline waterproofing admixture, was specified to protect key below-grade concrete structures from the high hydrostatic pressure of the region’s groundwater levels.
Willoughby is an upscale suburb situated in the Lower North Shore (NSW), only 5 miles (8 km) north of downtown Sydney, Australia. Predominantly a residential area and home to around 78,000 inhabitants, the city also features substantial industries, commercial areas, and parks.
The new AUD$785 million (US$ 510 million) NINE by Mirvac residential development occupies the 8-acre (3.2-hectare) site of the former Channel Nine television studios, a historic institution that broadcast stories of Sydney, Australia, and the world for more than 60 years.
The newly completed 2nd stage of construction comprises 214 apartments housed in five buildings, each 4-9 floors tall, as well as a community pavilion open to the public. Once all construction phases are completed by the end of 2025, NINE by Mirvac will offer a total of 442 residential units of one-, two- and three-bedroom apartments and penthouses (layouts of 58-126 m2 / 538-1,390 ft2) housed in 10 buildings. The project also includes a 1,000 m2 (11,000 ft2) retail and commercial building, and a 6,500 m2 (71,500 ft2) landscaped public park with sheltered BBQ courts and a children’s playground, which incorporates recycled materials from the landmark 233 m (770 ft) high transmission tower (dismantled as part of the development).
“Due to the region’s high groundwater levels and the almost two dozen concrete elevator pits and stair well structures, ADG, the project’s engineering company, required a concrete waterproofing solution that would optimize the durability of these structures,” clarifies Steve Hodkinson, General Manager of Penetron Australia.
PENETRON ADMIX, a crystalline waterproofing admixture, was ultimately specified as the most reliable concrete waterproofing solution. Holcim, the ready-mix concrete supplier, delivered several hundred cubic meters of concrete to the various parts of the construction site, which was placed by Azzurri Concrete.
Once mixed into the concrete, the proprietary chemicals in PENETRON ADMIX react with moisture and concrete minerals to form insoluble crystals throughout the concrete matrix. These crystals reduce concrete permeability, provide corrosion mitigation, and enable the concrete to self-heal (and seal) hairline cracks.
“The insoluble crystals generated by PENETRON ADMIX significantly increase the durability and extends the service life of concrete and also helps minimize the need for future concrete repairs of the below-grade structures at NINE by Mirvac,” concludes Steve Hodkinson.
Below-grade concrete structures protected by Penetron: The NINE by Mirvac residential development in Australia will comprise 442 units once the final stage of construction is completed in 2025.
