Nano-Modified Fly Ash Concrete: A Repair Option for Concrete Pavements

Abstract

Efficient repair of concrete pavements typically requires a rapid-setting material to accelerate opening the road to traffic. While numerous high-early-strength cementitious repair materials are commercially available, many of them are vulnerable to premature deterioration. On the other hand, despite its improved long-term performance, concrete incorporating fly ash is rarely used as a repair material due to the delay in setting time, strength gain, and microstructural development at early ages. Nevertheless, these performance limitations can be mitigated by incorporation of nanoparticles (for example, nanosilica) in fly ash concrete. In this study, an effort was made to develop nano-modified fly ash concrete as a repair material for concrete pavements. The performance of the newly developed mixtures was compared to that of two commercial cementitious products. The results indicate that the nano-modified fly ash concrete has balanced performance in terms of hardening time, strength development, bonding with substrate concrete, and resistance to infiltration of fluids and salt-frost scaling.