Driving the resource efficiency agenda

FM Conway's state-of-the-art Erith asphalt recycling plant.

The infrastructure sector must be at the forefront of making the transition to a circular economy. Tim Smith explains why.

There’s no denying that construction remains one of the worst offenders when it comes to resource use.  According to data from the Office for National Statistics, our sector consumes around 200 million tonnes of aggregates and other mineral products every year. We are also the UK’s largest producer of waste.  Statistics from the Department for Environment, Food and Rural Affairs (DEFRA) show that on average construction, demolition and excavation generate over half of the UK’s annual total waste. Some progress has been made to improve materials recovery within our industry – the UK is currently meeting EU targets to recover at least 70% of non-hazardous construction and demolition waste – but there is still work to be done.

The infrastructure sector is especially resource-intensive, with road construction works, for example, requiring thousands of tonnes of finite raw materials and crude-oil derivatives such as bitumen.  With a record £500bn of projects planned under the government’s infrastructure pipeline between now and 2020, this demand for resources looks only set to increase.

Adopting a more sustainable approach will be critical to fulfilling these material needs, while helping to minimise the environmental impact of projects. Crucially, we need to make the transition to a circular economy, where materials are kept in use for as long as possible and then recovered and regenerated at the end of their service life to be used again.

Towards a smarter, sustainable model of materials use 

The EU has long been championing a more circular approach to materials and in 2015 set out clear recommendations for supporting the recovery and re-use of materials by both consumers and industry in its ‘Circular Economy Package’. The UK government has echoed this sentiment more recently, advocating the benefits of a more resource-efficient economy in its industrial strategy green paper issued at the start of this year. The paper notes that increasing the efficiency of material use across the whole supply chain can deliver huge cost savings as well as improve the productivity of UK businesses.  

The highways sector is a case in point.  Demand for sand, gravel and crushed rock supplies, which make up around 95% of the road surface, continues to outstrip permissions granted for new reserves in the UK.  Meanwhile, technological advances in oil refinery production techniques are cutting the supply of another key component of our roads, bitumen, as refineries are able to increasingly focus their efforts on extracting higher-value fuels. Both aggregates and bitumen are imported by the highways sector to make up this shortfall in supply, making it vulnerable to the vagaries of currency fluctuation and potentially adding both time and costs to highway construction and maintenance schemes.

There is, therefore, a clear need to find an alternative resource stream for the sector.  Asphalt recovery and recycling can go a long way to filling this gap.  Asphalt recycling is not a new concept to the highways sector but to date we haven’t fully exploited its potential benefits.

Shifting recycling up a gear

It is not unusual for asphalt with 50% recycled content to be incorporated into the lower layers of our roads. However, many highways operators remain cautious about using material with a recycled content of more than 10% for the upper layer, or surface course, of our highways, especially on strategic routes.

We need to make recycling standard practice across both the strategic and local road networks as well as across all layers of our highways. Conservative estimates suggest that two billion tonnes of asphalt could be recovered from the UK’s roads and reused on our highways. Tapping into this underutilised resource will not only help us to reduce the environmental costs of building and maintaining our roads, but also unlock  significant financial savings.

Leading the charge 

With significant development projects planned for the UK over the next few years, now more than ever the construction industry needs to ramp up efforts to adopt a more sustainable approach to resources. There are clear benefits to the highways sector and the infrastructure industry as a whole leading the way in this regard.  As well as fulfilling a company’s duty to act responsibly and ethically, making the move to a circular economy also makes business sense; bringing reliability to materials supply chains while driving financial efficiencies for projects.

Tim Smith is head of technical services at FM Conway.