Development of resilient and environmentally responsible highway infrastructure solutions using geopolymer cement concrete

Despite local and national road authorities striving to provide motorists with a durable and safe infrastructure environment, one in six UK roads is currently classed as being in poor condition. In terms of safety, Department for Transport statistics continue to report high numbers of road fatalities; 1,780 in 2015, representing a 3% increase from the previous year. As such, research focussed on developing resilient and cost effective planned/preventative highway maintenance solutions remains highly topical. Reported in this paper is research aimed at developing high performance, low impact solutions for both highway repair and skid resistance enhancement. Based on a metakaolin/alkali silicate-based geopolymer cementitious material, a mix optimisation investigation is initially reported, providing key fresh and mechanical material properties such as setting time and compressive/flexural strength. Using optimum mix designs, the paper then presents an assessment of geopolymer cement concrete’s suitability as a highway repair material. To this end, wear and skidding resistance characteristics of potholes repaired with geopolymer cement concrete is reported, with initial findings suggesting excellent performance levels. Finally, the paper examines the potential use of a geopolymer cement-based artificial aggregate as a cost effective alternative to calcined bauxite for high friction surfacing applications. Initial production trials of aggregate will be discussed, together with effects of accelerated trafficking on texture depth retention.