Influence of Fly Ash and GGBFS in Laterized Concrete Exposed to Elevated Temperatures

Abstract

Concrete made with laterite aggregate, a marginal material, is used for fire protection applications. Using mineral admixtures in laterized concrete makes it more sustainable. This paper studies the physical and mechanical properties of laterized concrete with fly ash and ground granulated blast furnace slag (GGBFS) as mineral admixtures after the concrete was exposed to elevated temperatures. Specimens were heated to 200°C, 400°C, and 600°C using an electrical furnace. The rate of increase in the furnace temperature was kept in line with the standard temperature rise—time curve. Specimens were cooled to room temperature through air cooling and water cooling and were tested at ambient temperature. The available equations to predict the compressive and flexural strength of concrete were observed not to apply to laterized concrete, particularly at temperatures higher than 400°C. Hence, lower bound equations were proposed to predict the strength properties of laterized concrete exposed to elevated temperatures. Thus, laterized concrete with mineral admixtures (fly ash and GGBFS) is a promising economical and sustainable material that shows better physical and mechanical properties at elevated temperatures as against conventional concrete and has resistance against the development of thermal cracks up to an exposure temperature of 800°C.