A preliminary investigation into geopolymer cement mortar’s suitability for providing resilient highway solutions

Despite local and national road authorities striving to provide motorists with a durable and safe infrastructure environment, one in six UK roads are 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 focused 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. A metakaolin/alkali silicate-based geopolymer cementitious mix design investigation is initially reported, providing key fresh and mechanical material properties such as setting time and compressive/flexural strength. Using favourable mix designs, the paper presents an assessment of geopolymer cement mortar’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 mortar-based artificial aggregate as a cost-effective alternative to calcined bauxite for high friction surfacing applications. The results of this phase of the work show potential for geopolymer application, although ongoing optimisation research is required.