The other benefits of sustainable building materials

As the construction industry strives to make its operations meet Net Zero commitments, research suggests that doing so does not have to come at the expense of economic goals. Indeed, a recent case study from Transport for London (TfL) shows how the benefits of sustainable building materials extend beyond their environmental credentials.

Better performance

In 2016, contractor FM Conway trialled a mix of 50% recycled asphalt planings (RAP) on a pavement section of the A1. To test the performance of the innovative material, two lanes were laid with a 50% RAP mix and a third lane was set with a standard mix.

A decade later, the results are in: the greener choice outperformed traditional asphalt on durability and longevity. Specifically, the 50% RAP mix had better rutting resistance (1.2 mm ruts after wheel track testing vs 1.6 mm for the regular mix) and stiffness (3,033 MPa vs 4,488 MPa).

A full spectrum of benefits

While this is only one result, the finding is supported by academic research. A research paper by Tagamud Tazmeen and Fasil Qayoom Mir published in ‘Results in Surfaces and Interfaces’, for example, set out “verifiable proof” of the viability of environmentally friendly materials in terms of economic and health benefits.

On the economic advantages, the authors emphasise the direct and indirect effects for economic growth, environmental preservation and human health. “Lower operating expenses, higher capital values, and more rental revenue are all advantages of a green building,” they write. “Eco-friendly structures improve not just the health of the building’s inhabitants, but also their productivity, marketability, and public perception as a whole.”

Circular economy

Achieving economic and environmental goals in tandem has, at times, seemed like the sticking point for the adoption of greener materials. Higher initial costs have been seen as a barrier to making the switch to recycled and eco-friendly building practices.

Aligning financial viability and sustainability therefore offers great promise. If implemented successfully, recycled asphalt and other sustainable materials could create a circular economy in UK infrastructure: with better durability and longevity, the maintenance burden would drop dramatically, further pushing greenhouse gas emissions downwards.

Regulatory blocks

At present, the scenario tested by TfL cannot be rolled out across the UK, as National Highways only permits 20% of recycled materials in road surfaces. “The use of high levels of recycled asphalt has grown significantly but there’s still a long way to go to making it standard practice,” notes Mark Flint, Technical Director at FM Conway.

To unlock the potential of sustainable building materials, more ambitious legal and political engagement might be required.