Effective scour protection for critical border bridge

Bridge on the NSW / Victorian border gets the mastaTEX Concrete treatment

The Project

Structures such as bridges can often be vulnerable to inundation flows in heavy rain events and floods. During these events, abutments and piers need to be adequately protected from erosion and damage.

Attributes such as inadequate elevation, insufficient protection from scour and insufficient rock armour can leave bridges vulnerable to severe damage from inundation, so authorities such as Transport for NSW frequently monitor and upgrade these assets to ensure they can withstand heavy rainfall and fast-flowing water.

In this instance, a bridge that crosses the Murray River separating Euston in NSW from the Victorian town of Robinvale needed additional scour protection.

The Challenges

The new Robinvale Bridge crossing was installed in 2006 and is crucial to the interaction of the two border communities. It was identified that the bridge required improved scour protection to ensure sediment such as sand and gravel from around bridge abutments would not be gradually removed by hydrodynamic forces.

TfNSW needed to ensure the integrity of the structure would not be compromised, and their contractors approached Polyfabrics for a geosynthetic solution.

Our Solution: mastaTEX® Concrete

mastaTEX Concrete is ideal for slope protection, swale drains and bridge abutment projects such as this. This geosynthetic cementitious composite mat (or GCCM) is a concrete impregnated geosynthetic fabric, supplied on rolls up to 5 metres wide.

Easy to install, it is flexible and can be easily manipulated into place, even on complex or variable contours. However, when it is hydrated with water, it creates a thin protective layer of concrete that adds structural stability to slopes.

A needle-punching process using long needles grabs fibres from the upper to lower non-woven geotextiles, through the cement mixture, creating a strong mechanical bond. When hydrated, the concrete is locked between the geotextile layers so that there is no risk of displacement. With its optimum sand/cement mix it offers up to 80 MPa strength and excellent chemical resistance when hydrated.

In contrast to traditional concreting processes, mastaTEX Concrete GCCM offers much faster installation and less wastage. GCCM composite mats are ideal for projects in remote locations, for both small and large treatment areas.

Combining the strength of concrete with the ease of transport and installation offered by a geosynthetic fabric, it provides excellent protection against scour.

The Solution: mastaTEX® Concrete

This alternative to shotcrete is also suitable for slope remediations caused by natural weathering, surface run-off and other environmental factors. For further technical assistance or specifications on our geosynthetic cementitious concrete mat products, contact Polyfabrics on 1300 287 484.