Fly Ash Substitution in Lightweight Concrete for Rigid Pavement Construction on Low-Bearing-Capacity Soil

Abstract

Peatlands are more likely to be affected by intense precipitation and soil erosion, thus requiring modifications for stabilized soil and subgrade protection. This experimental study aimed to find a suitable pavement type using fly ash, an unutilized byproduct from coal burning processes, for peatland areas with a low bearing capacity. We designed lightweight concrete specimens using 15% fly ash substitution to be incorporated into rigid pavement construction. The concrete quality was assessed through compressive and flexural strength tests performed at the ages of 7, 14, and 28 days in order to shorten the project durations and prevent further traffic delay. The obtained results suggested that the substitution of fly ash in 15% of the lightweight concrete mixture can be taken into account to achieve a mixture of a lightweight concrete that meets the general specification criteria for cement-treated subbases (CTSBs). Furthermore, the utilization of fly ash as a new material is considered substantial in managing existing waste-related environmental problems, as well as soil stabilization and subgrade protection problems for low-bearing-capacity soil areas.