Study the Effect of Adding Nano Fly Ash and Nano Lime to Compressive Strength of Mortar

Abstract

This research is aimed to investigating the possibility of substituting cement with fly ash. Fly ash is a waste product of the coal burning process. Previous studies showed that the substitution of 20% - 40% in cement weight by fly ash increases the 60 days compressive strength of mortar. Fly ash contributes to the compressive strength because the content of silica oxide reacts with the free lime to enhance the cement hydration process while on the other hand provides a better density by acting as filler. Besides looking into the increases of fly ash percentage below the 20%, the influence of addition ofactive lime is also studied. The content of silica oxide will react with the free lime hydration products of cement and active lime added. In this study, applying the nano-technology to modify the size of the fly ash and lime in conducted. The procedure will result in nano-fly ash andnano-lime particles. The cement-to-nanofly ash ratio is 1:12.24 and nano lime-to-nano fly ash ratio is 1:1.11. This research includes the study of the effect of nano fly ash and lime percentage in the mortar, ranges from 0%, 2.5%, 5%, 7.5%, 10%, 12.5% to 15% to the control specimen. Cement-to-sand proportion is 1 to 1.70 with water-cement-ratio 0.49. 50×50×50mm specimens are tested to obtain their compression strength at the age of 7 days.