Effect of Fly Ash Fineness and Nano Silica on Compressive Strengths and Workability of Mortar

Abstract

This research presents a study of the fly ash and nano silica. Affecting the compressive strength and the workability of mortar. With a mixture of Portland cement, water, sand, fly ash and nano silica. Replacement cement with coarse fly ash of 0, 20, 40 and 60 %, fine fly ash of 0, 20, 40 and 60 % and nano silica of 0, 1, 2 and 3 % by weight. Test results showed that the 28 days compressive strength of mortar of 30 – 46 MPa. And workability of mortar is 23.3 – 126.3 % The results indicated that the compressive strength was maximized by using coarse fly ash at 20%, fine fly ash at 40%, and nano silica at 2% by weight. Workability of mortar tended to increase with the higher content of course and fine fly ash. On the other hand, workability of mortar tends to decrease with the increasing amount of nano silica. Moreover, Improving the properties of fly ash to be finer. It can increase the use of fly ash. Which reduces the emissions of carbon dioxide (CO₂) into the atmosphere. This will reduce the occurrence of global warming sustainably.