Effect of elevated temperature on the structural performance of reinforced high volume fly ash concrete

Abstract

The present investigation delves into a critical examination of the structural performance of high-volume fly ash (HVFA) concrete, both plain and reinforced, under elevated temperatures. A partial cement replacement with 40% and 50% fly ash was employed. Concrete mixes were cast into plain and reinforced concrete (RC) cylinders of 100 × 200 mm (diameter × height). After 28-day curing, the specimens underwent compression testing under ambient conditions and after exposure to a single heating–cooling cycle of 300 °C and 600 °C temperature. The heating rate was 5 °C/min for two hours under unstressed and stressed conditions. Plain concrete exhibited more significant weight loss than fly ash concrete. The residual load-carrying capacity of fly ash concrete was superior under stressed conditions compared to unstressed conditions. Statistical model analyses such as Artificial Neural Network (ANN), Decision Tree (DT), and Random Forest (RF) were formulated. Finite element analysis (FEA) was also performed on plain and reinforced HVFA concrete at ambient and elevated temperatures utilizing the ABAQUS solver. The results predicted from statistical and FE analysis exhibited satisfactory agreement with the experimental tests. The results of this study bear significance for the design of short reinforced HVFA concrete compression members, specifically for pedestals used in industrial machine foundations.