Bridge Scour Protection and Marine Reef Mats

PROJECT:

Bridge Piling Scour Protection – Fremantle Traffic Bridge, WA

As part of the Swan River Crossings project, Australian Concrete Mats manufactured customised Articulated Concrete Block Marine Reef Mats for underwater scour protection around the new Fremantle Traffic Bridge piles.

Installed on the riverbed, the interconnected concrete block mats provide engineered hard-armour protection against erosion and localised scour while incorporating eco-engineered surfaces designed for the marine environment.

LOCATION:

Fremantle, Perth, Western Australia.

PROJECT STATS:

Articulated Concrete Block Marine Reef Mats
Recycled oyster shells and eco-engineered surfaces
Bridge pile scour protection
Marine and underwater infrastructure
Marine habitat enhancement
Underwater installation
Swan River Crossings – Fremantle Traffic Bridge
Installer: Brady Marine and Civil
Project: Fremantle Bridges Alliance

OUR REF: ACM 4725

Underwater grouting of Articulated Concrete Block Mats around the Fremantle Traffic Bridge piles. Installation by Brady Marine and Civil. Video source: Master Builders Solutions ANZ.

View the Master Builders Solutions Fremantle Traffic Bridge project

Download Articulated Concrete Block Mat Product Information

MARINE REEF MATS – SCOUR PROTECTION AND MARINE HABITAT

Australian Concrete Mats manufactured customised Articulated Concrete Block Mats incorporating recycled oyster shells and eco-engineered concrete surfaces for underwater scour protection around the Fremantle Traffic Bridge piles.

The marine reef mats were designed with a pH closer to natural marine conditions to provide conditions more conducive to shellfish settlement while maintaining their engineered scour-protection function.

Main Roads Western Australia reports that the marine reef mats represent an Australian-first environmental scour protection innovation. According to its May 2026 project update, the mats have a pH of approximately 8, compared with approximately 13 for conventional concrete mats, and are designed to support native marine life, enable blue-carbon sequestration and reduce visual and hydrological impact.

Source: Main Roads Western Australia – Swan River Crossings Project Update, May 2026.
Read the Main Roads WA Swan River Crossings Project Update

PROJECT BACKGROUND AND CLIENT:

The Swan River Crossings project includes the replacement of the Fremantle Traffic Bridge with a new bridge across the Swan River.

Australian Concrete Mats manufactured customised marine reef mats for underwater scour protection around the new bridge piles. The mats were installed on the riverbed by Brady Marine and Civil, with underwater grouting undertaken between the scour mats and bridge piles.

The project demonstrates how customised Articulated Concrete Block Mats can combine engineered scour protection with project-specific environmental design for bridge foundations, marine infrastructure and other submerged applications.