Going green with geosynthetics

A manufacturer in Albury, New South Wales is recycling plastic bottles into green geotextile materials for use within major infrastructure projects to aid with anything from separation, filtration, drainage and cushioning; meet Geofabrics.

Geofabrics turns Australian waste plastic into a viable and beneficial geotextile for rail construction through its local manufacturing facilities.

For over 40 years Geofabrics has been providing the infrastructure sector with tailored geotextile solutions. It all began in the 1970’s when the ‘to-be’ owners of Geofabrics came across geotextiles being used for road construction in Europe.

In 1978, Geofabrics got its start in Melbourne and expanded quickly across the country. There are now two Geofabrics manufacturing sites in Australia, one in NSW and one in Queensland.

The Albury factory in NSW is home to all of the company’s rail infrastructure construction industry geotextiles. While Geofabrics has a wide range of different products for construction, its newest fabric made with recycled plastic is bidim Green.

Bidim Green is made from Australian recyclable materials and Peter Tzelepis, executive director of sales and business development at Geofabrics says it can be applied across nearly every civil engineering construction project.

The fabric can be used in the track base to provide separation and filtration under below rail construction materials such as ballast.

“The idea for bidim Green came from the issues around circular economy and waste. One of our key sectors for Geofabrics is waste management services and over the last two to three years we have seen this issue develop and we know there is a real need to do something with our waste plastic,” Tzelepis said.

“Our vision was that our product will go into the ground to serve a purpose, it’s not going into a landfill. We simply saw it as a great opportunity to support the circular economy.”

Locally made and sourced materials, such as the recycled plastic, are an important factor in the manufacturing process for all Geofabrics products. The company has a specific technical department and innovation sector that works with Australian companies to provide solutions tailored to local conditions.

“Australian conditions are quite unique, from isolation to UV exposure, even rock sizes in road construction can vary in different parts of the country and there might not always be a quarry nearby to provide materials for every rail project,” Tzelepis said.

“Geofabrics and its products like bidim Green, which is placed underneath the rail formation, are there to reduce the amount of excavation and virgin materials needed on these major infrastructure projects.”

“Another uniquely Australian challenge is the UV exposure. When looking at a UV radiation map of Australia different places have varied exposure to UV which can degrade a geotextile if left exposed for a period of time,” he said.

“To ensure we can provide the right solution we have real time testing on bidim Green at our offices all over Australia to see how it performs with different exposure. We are building the performance of our product to the climatic and environmental changes in different Australian regions.”

The bidim Green range has been rigorously tested at our Geosynthetic Research, Innovation and Design (GRID) laboratory located in Queensland for durability performance. The durability of any geotextile is important so that it can resist damage during the construction phase. During this phase, the geotextile can be punctured by very angular rocks – such as ballast – or heavy machinery pushing into the soft capping layer under the track. The geotextile to be selected must have multi directional strength and bidim Green offers that benefit. The GRID laboratory simulates performance of a geotextile for specific project situations and is available to Geofabrics Australia’s customers.

Geofabrics are currently working through a process with the Infrastructure Sustainability Council of Australia to certify bidim Green, to facilitate wider use on Australia’s infrastructure projects.

With demand from governments to use recycled products in infrastructure projects, such as Victoria’s Recycled First program and NSW’s Waste and Recycling Infrastructure Fund, Tzelepis said bidim Green is another product contractors can consider to make their projects environmentally friendly.

“We know we have to make our materials sustainable, I take my recycling bin out to the kerb every second week, if I know my recycling is going to be picked up and used on projects like my road, that is fantastic.”

Recycled First building future rail projects

The Victorian government is taking a new approach to the incorporation of recycled materials in major infrastructure projects.

In February 2020, the Victorian government announced its major new waste policy, Recycling Victoria: A new economy. Covering all waste from household, commercial, to industrial, the announcement was swiftly followed by an update from the Major Transport Infrastructure Authority, applying the goals of the program to Victoria’s Big Build, than 100 major road and rail projects around the state.

Combined, the two policies signalled a new approach to waste management and resource recovery in major infrastructure works. Instead of using recycled or reused materials in an ‘ad hoc’ manner, Recycled First applied a uniform approach across the infrastructure sector, and hopes to not only drive change within the way that Victoria manages and uses its resources, but alter sector-wide construction practices.

Announcing the initiative, Minister for Transport Infrastructure Jacinta Allan highlighted that the size of Victoria’s construction pipeline means that an initiative such as this can have wider effects.

“Recycled First will boost the demand for reused materials right across our construction sector – driving innovation in sustainable materials and changing the way we think about waste products.”

Prior to the initiative, recycled materials had been in use in some rail projects in Victoria. A trial of sleepers made from recycled plastics is already underway at Richmond, the first time these sleepers had been used outside of low-volume tourist railways. Additionally, excavated soil from the Metro Tunnel site was repurposed to be employed as pavement layers on roads in Point Cook, a suburb south-west of Melbourne. These specific programs come in addition to other works, such as site-won earthworks and the re-use of rails, said Alexis Davison, director, program services and engineer, Major Road Projects Victoria.

“Rails and sleepers are already reused in rail projects along with recycled glass sand, rubber and steel – Recycled First takes this further by supporting research to identify emerging markets.”

The rollout of Recycled First aims to take  this a step further. So far, the program has taken a collaborative approach and has consulted with industry on its implementation. Rather than mandating a one-size fits all threshold or target for recycled content used in projects or waste that avoids landfill, the project takes a case-by-case approach.

When applied to major rail projects, the Recycled First policy will ask tenderers to ascertain what opportunities there are to maximise the use of recycled and reused Victorian materials, and once underway, report on the types, applications, volume, and source of the materials.

By flexibly implementing the policy, hopes are to stimulate innovation in the application of recycled materials and increase the quality of those products used.

“Victoria will benefit immensely from incorporating recycled content into our road and rail projects, by keeping waste out of landfill, reducing reliance on virgin materials and curbing greenhouse gas emissions,” said Davidson.

While the Recycled First initiative will apply to future projects, some of those under the mandate of MTIA have established a pathway for further innovation. On the Caufield to Dandenong Level Crossing Removal Project, 50,000 tonnes of recycled crushed concrete was used and rail barriers were made out of recycled plastic content.

Recycled glass sand was used in the Koroit Creek level crossing removal and the Wyndham Vale Stabling Yard. Completed in April, the stabling yard further trialled 120 recycled plastic sleepers, the same as those being trialled at Richmond station.

In future, the project could also expand to maintenance works on transport infrastructure, providing a larger market for the use of recycled materials.

At the launch of Recycled First, Allan highlighted that the shape and implementation of the project now will lead to the sustainable infrastructure of tomorrow.

“We’re paving a greener future for Victoria’s infrastructure, turning waste into vital materials for our huge transport agenda and getting rubbish out of landfills.”

Recycled

Recycled materials in use at multiple transport projects

Recycled materials are being used on transport projects in Victoria and NSW, making the most of the many infrastructure projects currently underway.

In Melbourne, the newly opened Kananook Train Storage Facility, located in Seaford, used over 11,000 tonnes of recycled rail ballast. The ballast was previously in use on the Melbourne train network and was extracted during the Carrum Level Crossing Removal Project. Instead of going to waste, the ballast was used to build the new storage facility.

The re-use of materials such as ballast reduces the use of raw materials and cuts associated energy used in the mining and transportation of these materials. The project’s environmental impact was also improved by the installation of solar panels on the building’s roof.

The Kananook Train Storage Facility will allow for more trains to run on the Frankston line. A signal control centre at the same site will also help to minimise disruptions by centrally managing train movements. The site includes room for further train storage or a train maintenance facility if required in the future.

In NSW, the Parramatta Light Rail project, which is partly following the former Carlingford Line corridor, has maximised the retention of rail infrastructure from the former line.

Over 15,000 metres of single rail, 13,650 rail sleepers, 13,000 metres of overhead wire and the existing track ballast will be reused on the new light rail line.

Across the entire 12km light rail route, which travels from Westmead, via the Parramatta CBD to Camellia and finishes in Carlingford, recycled components will provide around 30 per cent of the track.