Compressive Strength of OPS based Self-compacting Concrete Incorporated with Fly Ash under Elevated Temperature

The application of organic lightweight aggregates (LWA) such as rice husk, coconut shell and oil palm shell in concrete are gaining popularity. However, organic substances are generally flammable under elevated temperature. As such, it is important to understand the strength performance of concrete with organic LWA under elevated temperature. To this end, this paper presents the compressive strength and mass loss of lightweight self-compacting concrete (LWSCC) when exposed to elevated temperature. In the research, comparison was made between the LWSCC samples of the control mix and mix with 40% of fly ash replacement. The compressive strengths of these mixes at 28-day were 31.35 MPa and 22.77 MPa respectively while at 90-day age, they were 33.27 MPa and 25.04 MPa respectively. Compressive strength of LWSCC samples were studied experimentally under different temperature of 26°C (room temperature), 100°C, 200°C and 300°C respectively. The experimental results showed that there is significant reduction in concrete compressive strength within the temperature range of 100°C- 200°C. When temperature was increased to 300°C, the concrete experienced strength reduction of nearly 84% and 79% at 28-day and 90-day age respectively for control mix. When 40% fly ash is incorporated, the concrete experienced strength reduction of nearly 72% and 66% at 28-day and 90-day age respectively.