Utilization of Fly Ash and Bottom Ash as a Mixture for Making Paving Blocks

Abstract

PLTU Tanjung Jati-B Jepara produces waste from coal combustion in the form of fly ash and bottom ash. The accumulation of waste will cause many other problems, so innovation is needed to turn it into value-added materials. One of them is to make fly ash and bottom ash into a mixture for making paving blocks. In making paving blocks with fly ash and bottom ash materials will use a mixture of materials 1: 3 and 6 mix designs. The results showed that the use of fly ash and bottom ash can produce quality B paving blocks with compressive strength values of 18.73 MPa in mix design (1 S: 3 BA) and quality C paving blocks with 7.5% water absorption in mix design and ((0.5 S : 0.5 FA): 3 BA). From these results, it can be concluded that every addition to the percentage of fly ash will reduce the compressive strength value and reduce the water absorption of the paving block. While the use of bottom ash as a substitute for sand will reduce the compressive strength value but add water absorption of paving blocks.