Study on physical and geotechnical properties of Jana Manjung coal ash mixtures

Abstract

Most of coal-burning power plant produced residue by-product after burning process such as fly ash and bottom ash with approximate production ratio of 80% fly ash and 20% bottom ash. In the past, most of the coal burning especially the fly ash was not managed properly as it were dispersed through the air after it had been entrained in flue gases. Meanwhile, the bottom ash was dumped on land area without any treatment. A study has been conducted to explore the physical characteristics and geotechnical properties of fly ash and bottom ash mixtures. The physical characteristics that include the particle size distribution and compaction were tested for each mixture. Meanwhile, the geotechnical properties of the mixtures that include the unconfined compression test (UCT) had been studied at different curing periods to determine the impact on the geotechnical properties of the mixture. The results shows that mixtures with higher fly ash composition have higher value of well-graded and need lesser moisture to be compacted efficiently compared to those mixtures with higher bottom ash composition. Besides, the result also shows that mixtures with higher fly ash composition have less drainage characteristic but can be improved by prolonging the curing periods. Other than that, the equal composition of each fly ash and bottom ash in the mixture produced higher shear strength compared to other mixtures and significantly increased by enhancing the curing periods. Last but not least, from the tests conducted, it also have been proven that the mixtures with lower fly ash composition is more compressible compared to the mixtures with higher fly ash composition.