Effect of Date Palm Seed Ash as a Supplementary Cementitious Material in Concrete

Abstract

This study investigates the effect of Date Palm Seed Ash (DPSA) as a pozzolan on the workability, compressive strength and water absorption capacity of concrete. Temperature regulated kiln was used to burn the Date Palm Seed (DPS) into DPSA in two stages: it was first burned for eight hours at an optimum temperature of 590oC and then cooled for two days. It was again burned for three hours at an optimum temperature of 630oC for eight hours and was air cooled again for three days. The ash obtained was sieved through 75um sieve and then used for this research. The mineral oxide composition of the DPSA was analysed using X-ray fluorescence (XRF) procedures and DoE mix design method was used to produce concrete ingredients for grade 30N/mm2. The paste and concrete produced using DPSA to partially replace cement at 0%, 2.5%, 5%, 7.5%, 10%, 15% and 20% DPSA were tested for consistency, workability, compressive strength and water absorption. Findings revealed that the use of DPSA in concrete reduces the workability of fresh DPSA concrete and the water absorption capacity of the hardened concrete as analysis showed that the water absorption of concrete at 20% cement replacement with DPSA was 11% lower than the control concrete. Results also indicates an increase in the consistency of cement-DPSA paste when cement is replaced with DPSA. Finally, the concrete specimens made using 2.5-10% DPSA content have at least 1.5% higher Compressive strength than the control concrete at 56 days. The replacement of cement with DPSA up to 10% gave promising and positive effects on the compressive strength and water absorption capacity of concrete and hence is recommended for use in concrete production.