Building the Future with Recycled Materials
- Tahnia Miller
- 13 hours ago
- 6 min read
As pressure builds to reduce embodied carbon across infrastructure, attention is increasingly turning to how materials are sourced, specified and reused, and how sustainability can be embedded without compromising safety, durability or performance.
The conversation is no longer just about lower-carbon materials, but also about circular use of materials already within the construction system.
Challenging Perceptions Around Recycled Materials
According to Dr Brody Clark, Senior Engineer at SOLV Consulting and an award-winning Chartered Civil Engineer with over a decade of experience delivering major infrastructure projects across Australia, the issue is less about capability and more about perception.
“The most persistent misconception is the belief that recycled materials are inherently lower in quality or less reliable than virgin materials,” Dr Clark says. “Many practitioners still assume that recycled content introduces unacceptable variability, reduced durability, or long-term performance risks.”
This perception persists despite strong technical evidence.
“Modern processing methods, national specifications, and extensive performance data consistently show that recycled materials can meet or exceed the standards required for road and infrastructure applications. Many engineers and project managers are unaware that recycled materials are already permitted in numerous state and national specifications when used in the correct applications.”
This disconnect between what is technically possible and what is commonly practiced continues to slow broader uptake.
From Policy to Practice
While innovation and technical capability continue to advance, adoption often comes down to policy, procurement and organisational capacity, particularly at the local government level.
Pravin Menon, Director of MCAS Consulting Services and board member of Plastic Oceans Australasia, says recycled materials are already widely used, but not always prioritised.
“The use of recycled materials in construction and infrastructure is well established across Australia… however, it’s fair to say adoption as ‘materials of choice’ is still secondary to preferencing virgin materials.”
Even where specifications support recycled content, uptake can vary.
“While state government specifications already permit and, in some cases, encourage recycled content, the pace of adoption at the local level varies significantly.”
In practice, many councils are already incorporating recycled materials into everyday projects.
“The use of crushed glass and recycled construction and demolition material is almost standard practice in landfill construction. Many local government road projects also use reclaimed pavement materials for road profiling and resurfacing works.”
Keeping materials local is often key to making reuse viable.
“Recovered materials are stockpiled and reused in close proximity to where they are needed to provide cost-effective and efficient outcomes.”
Supply chain confidence also plays a role.
“Established procurement pathways for virgin materials provide confidence in availability, quality, and timing. Recycled materials, particularly newer ones, may lack this consistency.”
The ability to adopt recycled materials also varies between organisations.
“Larger councils are generally better positioned to adopt recycled materials due to their scale and resources… Smaller councils may face constraints in funding, staffing, and project scale.”
To move from trial to standard practice, Menon believes a more coordinated approach is needed.
“Embedding clear targets and performance measures related to recycled material use can help shift practices from optional to standard.”
“Ensuring that government procurement processes are aligned with broader organisational environmental objectives would encourage contractors to prioritise sustainable options.”
While policy and procurement set the direction, it’s often engineers on site who turn these opportunities into reality.
From Specification to Site
For engineers delivering projects on the ground, recycled materials are often identified through practical problem-solving rather than top-down directives.
Joshua Thompson, Project Engineer at CPB Contractors, says the push to reuse materials is often driven by both cost pressures and initiative from delivery teams.
“Recycling or repurposing materials is inevitably driven by clients and managers looking to reduce cost. Where opportunity arises is discovered by delivering engineers and site supervisors looking to repurpose materials for multiple tasks across the project.”
In many cases, reuse starts with simple, everyday decisions.
“Concreting forms are reused multiple times before they become too deteriorated for their original purpose but are still suitable for the backing of site signs or temporary work covers over penetrations.”
Some of the most effective outcomes come from planning ahead. On a recent project, Thompson identified an opportunity to repurpose materials before they left site.
“Once the crossing was no longer required, we had approximately 600 tonnes of high-quality rock destined for landfill. I had thought about the removal during the construction phase and thought maybe another team would be able to use it in a similar manner for subgrade improvement.”
That thinking led to a practical and cost-effective outcome.
“This led to a conversation, and then to 600 tonnes of material being used in a permanent state rather than filling a tip.”
Balancing Risk and Innovation
Even with clear opportunities, using recycled materials requires careful decision-making.
“Typically it’s a risk versus cost challenge when deciding to use recycled materials,” Thompson explains.
“Is there a major consequence for using a recycled product resulting in time and money to remove and replace, or do you accept the upfront cost of using virgin materials with a longer standing record?”
“Typically project managers and clients want the lowest cost and risk opportunity resulting in an unbalanced equation. Our jobs as construction professionals is striking the perfect balance while meeting both demands.”
Recycled materials can deliver strong outcomes, but they are not always straightforward.
“Recycled materials can have both positive and negative impacts on a scope of works. Like most things with a second life, they don’t always meet the demands like virgin material.”
However, ongoing innovation is improving confidence.
“As more time and energy is put into developing recycled materials, the quality continues to improve, making it more appealing by reducing the risk factor associated with repurposed materials.”
Engineering the Next Generation of Materials
While reuse on site plays a critical role, material design remains one of the most powerful levers for reducing environmental impact, particularly in concrete.
Dr Clark highlights that practical, proven approaches are already delivering results.
“The most realistic opportunity to achieve large carbon reductions in Australian concrete mixes without compromising durability comes from lowering the Portland cement content through greater use of supplementary cementitious materials such as fly ash, slag and calcined clays, supported by performance-based mix design.”
“Confidence in low-carbon concrete is definitely growing across Australia, but there is still noticeable hesitation, and both cost and material availability play a major role in that,” Dr Clark explains.
Supply chain limitations continue to influence adoption, particularly in regional areas.
“Availability is another major constraint, particularly in remote and regional parts of Australia where fly ash and slag supply is limited, transport distances are long, and local batching plants may not have the infrastructure to handle multiple binder streams.”
The Future of Infrastructure
Infrastructure delivery depends on vast quantities of materials, from aggregates and rock to concrete and asphalt. Finding ways to reuse, repurpose and reduce these materials will be critical to lowering the sector’s environmental footprint.
The shift toward recycled and lower-carbon materials is no longer just an environmental consideration. It is increasingly a commercial and procurement priority.
Dr Clark believes the industry is already moving in the right direction.
“What gives me the most optimism about the future of sustainable infrastructure in Australia is the way the industry is shifting from isolated trial projects to genuine mainstream adoption,” he says.
“The conversation has moved beyond whether sustainability is possible and into how to embed it at scale, which is a fundamental change in mindset.”
As policy frameworks strengthen and engineers continue identifying practical opportunities on site, recycled materials are set to become a standard part of infrastructure delivery.
For Thompson, the key is staying alert to those opportunities.
“Understand the opportunity. If there is a recycled product that meets the demands and requirements whilst saving on cost or time, it is always worth exploring.”
At a broader level, Menon emphasises that lasting change will depend on embedding these practices into how projects are planned and delivered.
“While the technical capability to use recycled materials in road construction is well established, broader adoption depends on having the right frameworks in place to preference their use as a standard component of infrastructure delivery."
Small decisions on individual projects, multiplied across the scale of Australia’s infrastructure pipeline, have the potential to reshape how the industry builds for the future.
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