Innovative Mixtures Can Reduce Life Cycle Costs in Concrete Pavement Repair
Many transportation agencies in North America require rapid setting materials for repair of concrete pavement to accelerate opening the road to traffic. While numerous high early-strength cementitious repair materials are commercially available, many of them are susceptible to premature deterioration, resulting in significant economic and social losses.
Extensive research on the use of supplementary cementitious materials (SCMs) such as fly ash, by-product of burning coal in power plants, showed that incorporation of Class F (low calcium oxide) fly ash generally improves the long-term performance and durability of concrete. Despite the environmental and engineering benefits of fly ash concrete, practical limitations remain unresolved in field applications. The delay in setting time, strength gain and microstructural development at early-age of fly ash concrete are considered to be the major issues, which deter its wider acceptance as a repair material.