Geopolymer Cement Concrete - An Emerging Technology for the Delivery of Resilient Highway Infrastructure Solutions

The 20th UK Annual Local Authority Road Maintenance survey has recently highlighted that, despite local authorities reporting an increase in overall maintenance expenditure, one in six roads in England and Wales are classed as being in poor condition. The estimated cost of rectifying this situation is £12 billion. As such, there has never been a more important time to identify resilient and cost effective planned/preventative highway maintenance solutions.Geopolymer cement concrete is generally regarded as an attractive alternative to Portland cement owing to environmental and performance benefits. Reported in this paper are preliminary findings of research undertaken to further interrogate its potential as a high-performance repair material for specific road defects, such as potholes. Undertaken collaboratively with local geopolymer cement producer Banah UK Ltd., metakaolin/alkali silicate-based geopolymer cement was assessed in this capacity. As part of a mix optimisation investigation, reported are key fresh and mechanical material properties including setting time, compressive/flexural strength and impact resistance. Indicative in situ performance, based on findings from accelerated road testing, is also discussed. On-going research to investigate composite material behaviour and optimisation of key material properties, such as bond, modulus of elasticity and abrasion resistance, is additionally reported.