Taronga Zoo goes wild for Hymix shortcrete

Name of project:

Taronga Zoo





Project details:

Taronga Zoo kick-started a $41 million redevelopment plan in 2007. The large project included the construction of a new base for the zoo’s Australian Marine Mammal Research Centre, a 950-seat seal amphitheatre, underwater viewing areas, an educational centre and within each animal enclosure, new rock caves, boulders, grassy basins and sea pools.


The sheer size of the project and its combination of pooling, landscaping and architectural challenges meant when it came to choosing a concrete supplier, the zoo needed a business with a strong track record in all three areas and who could provide a high-strength concrete that met the zoo’s stringent standards for quality, durability and versatility. This made Hymix’s shotcrete a natural fit for the project.


Maximum shaping possibilities

Over 1500m3 of Hymix’s shotcrete was used throughout the zoo, predominantly to create a variety of realistic ‘mock-rock’ terrains and aquatic areas. The shotcrete was applied using an injection system that offered a smooth spray and a high level of workability. This meant Hymix was able to offer the zoo maximum shape possibilities and was able to easily manipulate the shotcrete into the rock ledges, overhanging rock formations, caves, waterfalls and habitat pools as required by the zoo.


The shotcrete used a specific combination of small aggregates. This provided Taronga’s mock-rock with a convincingly grainy and coarse texture, only without the stone. After being sprayed on, this rock was then coloured, carved and in many areas, also further softened with native plants, grasslands and wild vegetation. This gave each enclosure a striking visual impact and a realistic home away from home for the animals.



Integrating with other landscaping feature

The high workability of Hymix’s shotcrete meant it was flexible enough to accommodate the zoo’s structural necessities including metal hand rails along pathways and look out areas, over-head shade cloths both within and outside the animal enclosures and a large glass viewing wall in the penguin enclosure.


The shotcrete was not only used to produce sculpted rock features and pool areas for the zoo. In fact, over 600m3 of shotcrete was used in the for the seal amphitheatre. It seats 950 audience members and included the construction of a simulated Submarine Research Station for the zoo’s collection of Australian sea-lions, furseals, leopard seals, penguins and pelicans.


A hardwearing and long-lasting concrete solution

Strength and durability were major concerns for the zoo and for the projects developers, Reed Construction. The concrete used needed to withstand constant exposure to the natural elements and the surface stress caused by animals weighing up to six tonnes each.



For the pool areas, the concrete also needed the durability to withstand exposure to ongoing salt-water erosion. Because shotcrete offers high engineering capabilities, it was specially mixed by Hymix to ensure each surface had the requisite compressive strength. This maximised crack-control and impact resistance and also lowered the likelihood of shrinkage. For the aquatic areas, the shotcrete was waterproofed and steel reinforcement was used to provide additional tensile strength. Through this, Hymix was able to address all strength concerns held by the zoo and ensure it gets maximum life out of its shotcrete pools.


All of the new enclosures and precincts were unveiled in July this year, offering the visitors to Taronga Zoo an increasingly breathtaking insight into the animal kingdom and its habitats. In meeting all of Taronga Zoo’s specifications for the project and being used for such a broad range of pooling, landscaping and architectural applications, Hymix has shown the versatility of its high-performance shotcrete and provided a premium level of service and support.


Contractors: Environmental Images