Effects of High Temperature on High-Performance Concrete Produced from Cement Partially Replaced with Sugarcane Bagasse Ash

Abstract

Conventional concrete deteriorates under fire, leading to strength loss, durability and reduction in performance of concretes. High-Performance Concrete (HPC) concrete mix designs are limited and constrained by the type of aggregates and Cementous materials used. There is a need to explore mix-design that can incorporate Sugar Cane Bagasse Ash (SCBA) and local aggregates as viable alternative for HPC with fire resistance properties. This study investigated the effect of elevated temperatures on the performance of High-Performance Concrete (HPC) with cement partially replaced with Sugar Cane Bagasse Ash (SCBA). HPC mixes for grades 50, 60, and 65 N/mm² were prepared with varying replacement levels of cement with SCBA up to 20%. The mix ratios used included grade 65 N/mm², 1:0.34:0.19:0.68 and 0.21% water by weight basis. A total of 162 concrete samples were cast and subsequently cured for 28 days, then exposed to fire in brick incinerator for 100 to 220 minutes. Weight loss, residual compressive strength, physical changes, and calcination time were evaluated. Results showed that fire exposure caused irreversible damage with losses increasing at higher concrete grades and SCBA levels. At 1000°C, concrete samples with 20% SCBA disintegrated into powder at slight touch. The maximum strength loss (81.46%) occurred for Grade 65 HPC with 20% SCBA. Control samples (0% SCBA) performed best with lowest strength losses. The study concluded that while SCBA was viable under ambient conditions, it did not enhance fire resistance. However, the predictive model could serve as a starting guide in the design of fire-prone concrete applications. The findings highlighted a significant limitation of SCBA in HPC intended for fire-prone applications.