Paving the Way: Best Practices in Asphalt Production
Organisation: John Wainwright and Company is an end-to-end supplier of premium aggregate, asphalt and contracting services. It is committed to driving efficiency across operations – supporting its journey to reducing carbon emissions and achieving sustainability targets.
Location: Unit 2 & Unit 3 Rockingham Park, Smoke Ln, Bristol BS11 0YA
The Challenge
Asphalt is a material primarily composed of a mixture of bitumen and aggregates. It has a wide range of applications including in the creation of roads, footways, car parks and construction works. With the right expertise, asphalt can be 100% recyclable.
A market Intelligence report in 2022 estimated the asphalt market to be nearly 28 million tonnes in the UK. The energy consumption, emissions and waste associated with the industry are high, but can be significantly reduced (up to 61,000 tonnes of CO2e a year) through process efficiencies.
The Innovation
Wainwright is continually focused on increasing Recycled Asphalt (RA) content in its asphalt mixes. This includes material removed from old road surfaces, as well as waste or excess asphalt produced by clients or in its asphalt plants. The RA content in Wainwright’s asphalt doubled from 2021/22 to 2023/2024. This reduces the use of virgin aggregates and facilitates bitumen recovery – a fossil-derived product that can be recovered from recycled materials and re-used. Extending a post-consumer recycling option has been central to the company’s pursuit of a circular economy.
The increased use of RA content is a result of Wainwright significantly upgrading its asphalt plants to make use of the latest technology. Its plant in Avonmouth was built in 2016 and designed from the outset to make efficient use of recycled asphalt.
Challenges associated with achieving these targets include managing gas usage during production, maintaining quality and consistency, and finessing the use of additive to maintain workability of the materials produced.
Wainwright is also focused on energy efficiency and renewable energy use as part of it’s target to reach Net Zero emissions by 2040. At its Avonmouth site most of its roof space is covered in solar panels, accounting for 14% of its total on-site electricity.
Further, through an initiative with the BEIS Industrial Heat Recovery Support (IHRS) programme in 2019, it implemented heat recovery from its processes. This reduced gas consumption by approximately 385 MWh and cut emissions by 71 tCO2e annually.
In Phase 1, fuel demand was reduced by ducting hot air from the compressor exhaust. In Phase 2, heat was recovered from the plant exhaust using heat exchangers to preheat the primary air supply for the asphalt plant burner. In future, other focus areas for Wainwright are optimising processes, establishing carbon footprints per product, reusing grey water, reviewing lower-carbon bitumen innovations, and non-asphalt recycled options – all of which will facilitate greater circularity impact.
This case study draws on insights gained from Chloe Hart, Sustainability Manager at John Wainwright and Company Ltd.