Study on use of bottom ash from waste to energy plant in manufacturing cement blocks

Abstract

This research explores the feasibility of utilizing bottom ash, a residue from municipal solid waste incineration, as a substitute for fine aggregate in cement blocks. Inadequate disposal methods for bottom ash pose health and environmental risks. The study examines bottom ash characteristics and assesses resulting cement block properties following established standards. Solid cement blocks measuring 300 mm x 100 mm x 150 mm were produced using a mixture comprising 1:6:3 cement: fine aggregate: quarry chips volume ratio with a constant water/cement ratio of 0.8. Using conventional table vibratory compaction, blocks are fabricated with varying proportions of bottom ash ranging from 0% to 60% by volume in increments of 10%. After 7, 28, and 56 days, the compressive strength and water absorption of the cement blocks are tested. The findings indicate that increasing the proportion of bottom ash reduces the density, compressive strength, durability, and specific heat capacity of the blocks while increasing water absorption. Based on the limited analysis, replacing up to 50% of the fine aggregate with sieved waste-to-energy plant bottom ash is feasible in conventional cement block production for load-bearing walls in residential buildings up to four stories, using the mix proportions examined in this study.