In 2020, Australia built more than 90% of a road project from recycled waste; five million bottles went into a job that cost no more than a standard build

In 2020, Australia built more than 90% of a road project from recycled waste; five million bottles went into a job that cost no more than a standard build. The project was carried out by Central Coast Council in Wyongah and covered the main elements of a road upgrade. Recycled material was used for the road base, road surface, kerb, guttering, footpaths and drainage. The council said more than five million glass bottles, 270 kilograms of plastic and thousands of tonnes of used concrete and road gravel were recycled for the project. Construction methods also helped reduce carbon emissions while keeping the project within the cost and time of a standard road build.

How the recycled road project was built?

The Central Coast Council project in Wyongah was designed to show that a road could be built with more than 90 percent recycled material.


The project did not use recycled products only for one part of the road. Recycled materials were used across the construction process, including:

• Road base
• Road surface
• Kerb and guttering
• Footpaths
• Drainage
• Trench backfills
• Sub-base materials

The council sourced most of the materials from recycled household and construction products.

This included glass bottles, plastic, used concrete and road gravel. More than five million glass bottles were recycled as part of the project. The project also used 270 kilograms of plastic and thousands of tonnes of used concrete and road gravel. The approach meant waste materials could be used as inputs for a road rather than being sent to landfill or left unused.

Five million glass bottles were used in the road

One of the main materials used in the project was recycled glass. According to Central Coast Council Director Roads Transport Drainage and Waste Boris Bolgoff, the construction process started from the bottom of the road and moved upwards. Instead of using virgin sand, the council used recycled glass for trench backfills and the sub-base of the road.

The road base was made from recycled crushed concrete and material recovered from the existing road pavement. This approach allowed materials from existing infrastructure to be reused in the new project. It also reduced the need to obtain new raw materials for construction. The project therefore combined waste recovery with road construction rather than treating the two activities as separate processes.

Recycled materials were used in concrete and reinforcement

The recycled approach continued above the road base. The council used what it described as “Green concrete” for the kerb, guttering and footpath. The concrete contained fly ash and recycled glass sand. Fly ash is a by-product of coal-fired power stations. Recycled plastic was also used for reinforcement.

The council said this use of recycled plastic saved the equivalent of 50,000 plastic bags. This meant several waste streams were incorporated into different parts of the same road project. Glass was used in the lower layers and concrete materials. Plastic was used in reinforcement. Recycled concrete and existing road pavement were used for the road base.

The project also reduced carbon emissions

Recycling materials was not the only part of the environmental approach. The council used construction techniques that helped reduce carbon dioxide emissions. According to Bolgoff, the techniques saved more than 6,000 kilograms of carbon dioxide from entering the atmosphere. The council compared this reduction with a 25,000-kilometre car trip.

The project was therefore intended to reduce the environmental impact associated with both materials and construction methods. Bolgoff said the council wanted to build a road predominantly from recycled material without reducing quality or increasing the cost compared with a standard road project. The council said it achieved that objective.

The cost and construction time were not increased

A key part of the project was its cost. The council wanted to demonstrate that using recycled material did not have to mean spending more money. The project was completed without costing more than a standard road project. The council also said the use of recycled materials did not affect the time required to complete the work.

Mayor Lisa Matthews said the project showed that roads could be delivered with a reduced impact on the environment without affecting either cost or construction time. This point is important because recycling in infrastructure often depends on whether recovered materials can meet technical requirements while remaining practical for large projects. The Wyongah project was presented as an example of how recycled products and construction methods could be incorporated into normal road work.

Materials and methods to be used again

Central Coast Council said the materials and technology developed for the project would be used across its wider road construction program. The Central Coast has a road network of about 2,200 kilometres. The council said applying these methods across its road program could produce environmental savings each year.

This means the project was not intended as a one-time demonstration. The council planned to use the experience gained from the project in future road construction and maintenance. The approach also connected waste management with infrastructure planning. Instead of treating household and construction waste only as material that needs disposal, some of it could be processed and used in road construction.

Other road recycling methods used by the council

The Wyongah project was part of a wider effort by Central Coast Council to use new products and construction techniques for its road network. One example was an Australian-first “road train” technology used to lay foamed bitumen.

The method was designed to reduce construction time and increase the amount of recycled road pavement used during construction. It also aimed to reduce greenhouse gas emissions and produce a more consistent road surface. Another product used by the council was Reconophalt.

Reconophalt is a road surfacing product made using several waste materials. These include plastic bags, glass bottles, used printer cartridges and reclaimed road asphalt. The use of these materials gives waste products another purpose within road construction.

Schools also supplied waste for road materials

The council also sourced waste from local primary schools for recycling into Reconophalt. The collected materials included chip packets, muesli bar wrappers and sandwich bags. This created a connection between local waste collection and infrastructure construction.

Materials generated by students and schools could be collected and processed rather than being treated as ordinary waste. The use of school waste also formed part of the council's wider approach to recycling road materials.

What the project showed about recycled infrastructure?

The Wyongah road project demonstrated that recycled material could be used throughout a road project rather than only in selected components. The council used recycled glass in trench backfills and the road sub-base. Recycled crushed concrete and existing pavement were used for the road base. Green concrete containing fly ash and recycled glass sand was used for kerbs, gutters and footpaths. Recycled plastic was used for reinforcement.

The project also used construction techniques that reduced carbon dioxide emissions. The council said the project used more than 90 percent recycled material while maintaining the cost and construction time of a standard road project. For the Central Coast, the next step was to apply the materials and methods across its wider road program.

Key figures from the project

• More than 90%: Share of recycled material used across the road project.
• Five million-plus: Glass bottles recycled for the project.
• 270 kilograms: Plastic used in the project.
• Thousands of tonnes: Used concrete and road gravel incorporated into construction.
• 50,000 plastic bags: Equivalent plastic saving from recycled reinforcement.
• More than 6,000 kilograms: Carbon dioxide emissions saved through construction techniques.
• 25,000 kilometres: Car-trip equivalent used by the council to describe the carbon reduction.
• 2,200 kilometres: Approximate length of the Central Coast Council road network.

Why recycled materials matter in road construction?

Road construction requires large quantities of materials. Traditional projects can depend heavily on newly sourced sand, aggregate and other construction inputs. The Central Coast project showed another approach.

Waste products from households, construction sites, schools and other sources can be processed and incorporated into road infrastructure when they meet the required standards. The project also showed that different types of waste can have different uses.

Glass can be used in road layers and concrete. Reclaimed concrete and pavement can form part of the road base. Plastic can be used in reinforcement. Other waste products can become part of road surfacing products such as Reconophalt. The council's stated aim was to combine sustainability with normal infrastructure delivery.