Application of Industrial Waste (Saw-Dust Ash) in the Production of Self-Compacting Concrete

This research study studies the use of sawdust ash as a Pozzolan in the production of concrete. It also proceeded as far as investigating 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 saw-dust ash (SDA). Slump and compacting factor tests were carried out on the fresh concrete and compressive strength test on hardened concrete was performed and found satisfactory though varying considerably. The concrete cubes were also tested at the ages of 7, 14, 21, and 28 days. From the result, the value obtained from the slump test corresponds to the designed slump range of 25mm-100. The slump, which increases from the control sample with a value of 60mm to 10% sawdust ash replacement and then decreases to 47mm for 25% replacement. Furthermore, there were increases in the self-compacting concrete shown in the concrete slump test 0%, 5%, 10%, 15%, 20% and 25% replacement of saw-dust ash slump at 3.5, 4.5, 6.5, 8.0, 11.5 and 18.0secs with the control having the least value of 3.5 seconds and the highest value coming from 25 percent replacement of sawdust ash. This shows that 25% replacement takes more time for slump to fail than others which was as a result of the more fiber bond between the cement material and sawdust which was still workable, but has high plasticity than that of the control showing that it serve as plasticizer and makes concrete for substructure work and rebar possible. It was also noted that the control sample has quite lower water absorption followed by 5% SDA has an average value of 0.82, 1.06, 1.84, 1.91, 2.05, and 2.23 which shows the total increase of 60% from 0% to 50% SDA indicating a high rate of sawdust ash absorption. It is recommended that the 5% and 10% ash replacement should be used in casting slabs, beams and columns due to its strength and surface texture.