Using waste products to advance low-carbon construction

The industry is a major contributor to global emissions, with materials such as Portland cement alone responsible for around 8% of worldwide carbon dioxide output. At the same time, Wales must balance its net-zero ambitions with the need for resilient, affordable infrastructure. This has created an urgent need for new approaches which reduce environmental impact without compromising performance.

The research team is  leading research which reimagines waste materials as valuable construction resources. Their work demonstrates how industrial, agricultural, and even healthcare by-products can replace traditional, carbon-intensive materials. The by-products  include steel industry waste such as ground granulated blast-furnace slag, agricultural residues such as rice husk ash, and a wide range of recycled construction,  demolition, war, and earthquake waste materials.

A key feature of this research is the integration of artificial intelligence to optimise material design. AI-driven modelling allows the team to predict how different mixtures will behave, reducing the need for time-intensive testing and accelerating the development of new, low-carbon solutions. These tools could evolve into real-time digital systems capable of tracking material performance, durability, and carbon savings.

The team has demonstrated a series of innovative applications. These include geopolymer concretes which eliminate the need for traditional cement, recycled rubber and plastic aggregates which reduce reliance on natural resources, and high-strength, low-carbon footprint concrete mixes optimised for durability and cost-effectiveness. Other work focuses on stabilising challenging soils such as expansive sulphate-rich soils, using waste-derived materials to improve resilience in infrastructure built on such challenging  ground conditions.

One of the most pioneering initiatives, the MEDWAS project, explores how processed healthcare waste can be reused in construction materials. Working with industry partners, the team is testing materials such as nappy waste, plastics, fly ash and glass in concrete and mortar, demonstrating how complex waste streams can contribute to more sustainable building practices.

The impact of this research extends across Wales’ economy and environment. By reducing reliance on traditional materials and repurposing local waste streams, it supports the transition to a circular economy while lowering transport costs and emissions. At the same time, these innovations offer more durable and resilient infrastructure, particularly in areas with challenging ground conditions.

The research team is working with industry partners to validate the novel research materials and prepare them for large-scale use. This positions Wales as a leader in sustainable construction, combining material innovation with digital technologies to accelerate decarbonisation.

The researchers are also engaging with local authorities, developers, and infrastructure providers to pilot these solutions across housing and construction projects. By integrating waste valorisation with advanced modelling and monitoring tools, the work offers a clear pathway towards lower-carbon footprint and a more sustainable built environment.