Thermal Resistance Evaluation of Raffia Palm Ash Concrete

This research attempts to empirically investigate the behavior of Raffia Palm Ash (RPA) concrete under elevated temperature of different percentages of RPA inclusion in the concrete. Raffia palm ash was obtained after the calcination of the raffia palm for 3 hours at 5500C. X-ray Florescence (XRF) analysis performed revealed that the sample of Raffia Palm Ash (RPA) is a Class C pozzolana, which contains 51.8% of (SiO_2 + Al_2O_3 + Fe_2O_3) and has a specific gravity of 2.8. The compressive strengths were determined at 0 ◦C, 718 ◦C and 821 ◦C at 0 minutes, 15 minutes and 30 minutes respectively. The result revealed that workability of the concrete declined with the increment in the percentage of raffia palm ash in the concrete. The compressive strength of the concrete cubes as well decreased with the rise in temperature for the entire samples tested. The average loss in strength of the control (0% RPA) is about 15.3% at 718◦C and 25.3% at 812◦C while for Raffia palm ash concrete with 5% (optimum replacement) gives a minimum loss in strength of about 21.3% at 718◦C and 28.5% at 812◦C, which is about 6% at 718◦C and 13.2% at 812◦C, more than the control. The Scanning Electronic Microscopy (SEM) imaging indicates that the concrete subjected to temperature of about 821◦C produces fewer flakes when compared to the concrete subjected to temperature of about 718◦C.