Abstract:
This research considered the use of saw dust ash as a pozzolan in the production
of concrete. the study investigated the physical properties and chemical composition of saw dust ash (SDA) as well as the workability, and compressive strength properties of the concrete produced by replacing
5%, 10%, 15%, 20% and 25% by weight of ordinary Portland cement with SDA. Slump and compacting factor tests were carried out on the fresh concrete and compressive strength test on hardened concrete. The concrete cubes were tested at the ages of 3, 7, 28, 56 and 90 days. The results showed that SDA is a good pozzolan with combined SiO2, Al2O3 and Fe2O3 of 73.07%. The slump and compacting factor decreased as the SDA content increased indicating that concrete becomes less workable as the SDA content increased. The compressive strength decreased with increasing SDA replacement. The compressive strength of concrete with SDA was lower at early stages but improves significantly up to 90 days. An optimum value of 23.26N/mm2 at 90 days was obtained for concrete with 5% SDA replacement. It was concluded that 5% SDA substitution is adequate to enjoy maximum benefit of strength gain.
Keywords: Saw dust ash, Pozzolan, Workability,
Compressive strength
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