Roe Highway Upgrade Tonkin Highway to Orrong Road

TerraHex and TerraTilt® precast capping units and parapets

Perth, WA, Australia
Main Roads WA
McConnell Dowell
May 2016 - Apr 2017

Main Roads Western Australia has progressively developed Roe Highway over more than 15 years as part of Perth’s strategic freight network. These upgrades and widening works have eased congestion and encouraged free-flowing traffic at a "pinch-point" close to Roe Highway and Tonkin Highway interchange.  More than 52,000 vehicles, including 6,000 heavy vehicles use this section of road daily. The project upgraded a two-kilometre section of Roe Highway from Tonkin Highway to Orrong Road.

Works included:

-     Widening the existing road with additional lanes in each direction

-     Installing a new bridge over the freight railway near Sheffield Road

-     Providing a new off-road shared path for cyclists and pedestrians

Project benefits will include:

-     Improved traffic times

-     Improved road safety

-     Better cycling and pedestrian options

-     Landscaping and vegetation works

The Reinforced Earth Company (RECO) was awarded the design and supply of the two abutment wall extensions, including segmental panel, full height return walls and precast capping units and parapets. The total Reinforced Earth® wall area equals 1,204sqm.  

The Reinforced Earth® walls were built to a maximum height of 8.9m sloping down to 2m at the lowest point.

-       Match the existing competitors’ wall features with segmental panels and make the finish continue to the full height section as well.

-       Confined space to fit the soil reinforcement while maintaining the existing road traffic flowing.

-       A 500T crane was required to setup on top of the MSE wall with additional loads of 122kPa

RECO needed to write project specific procedures to comply with: Project Management Professional Certification; Technical Specifications; Inspection and Test Plans and Precast Manuals.

The precasting was completed at the RECO precast facility located in Landsdale, Perth.   Twelve heavy duty segmental TerraHex moulds and two full height TerraTilt® moulds were used for the project.   MRWA specifies that concrete temperatures during casting must remain under 32°C and that ambient air temperature cannot exceed 38°C.   To achieve this, ice was added to the concrete mix to ensure that this requirement was met.

 Significant design checks were carried out to ensure the capacity of the MSE walls was adequate for the additional short-term crane loads imposed while installing the bridge beams.


The new MSE walls were all cast with panels that match the exposed aggregate finish and hexagonal pattern found on the original segmental panels.

By increasing the number of lanes in each direction and improving merge points, traffic flow has improved, leading to safer journeys for commuters, residents and the freight industry.  

Project Specifications

TerraHex and TerraTilt® precast capping units and parapets
2 Reinforced Earth® Bridge abutments
1,204 sqm (total)
8.9 m
Design Load
Design Life
100 years
Hexagonal features with exposed aggregates

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