Effect of Elevated Temperature on the Strength of Date Palm Fiber Reinforced Concrete Containing Silica Fume

Abstract

Date palm fiber (DPF) is an agricultural, organic, and fibrous material. Therefore, when used as fiber in concrete that is subjected to higher temperature, it can easily degrade and cause reduction in strength. Hence, there is a need to investigate the effect of elevated temperature on the weight loss and strengths of the DPF reinforced concrete. In this study, the fiber reinforced concrete was produced by adding different proportions of DPF at 0%, 1%, 2% and 3% by weight of cementitious materials. Cement was partially replaced with silica fume in proportions of 0%, 5%, 10% and 15% by volume. The concrete was subjected to elevated temperatures of 200 ℃, 400 ℃, 600 ℃ and 800 ℃ for 2 h. The weight loss and compressive strength after subjecting to high temperatures were investigated. The results showed that the weight loss escalated, and the compressive strength of the concrete decreased with the increment in the elevated temperature and DPF content. At a temperature above 600 ℃, the increment in weight loss and reduction in strength became more severe. The addition of silica fume as partial substitute to cement led to reduction in the weight loss and decrease in compressive strength of the DPF reinforced concrete when heated to a temperature up to 400 ℃., However, at higher temperature above 400 ℃, the addition of silica fume to the DPF reinforced concrete led to further escalation in weight loss and reduction in strength. The physical observation revealed that when the concrete was subjected to higher temperature, its surface color changed to light grey, some cracks were observed on the surface. The DPF reinforced concrete was able to withstand up to 400 ℃ temperature without spalling, after which severe spalling was observed with the DPF degraded.