Partial Replacement of Cement with Municipal Solid Waste Incinerator Fly Ash in Concrete Production
No Thumbnail Available
Date
2025-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Fly ash resulting from municipal solid wastes incinerator (MSWI) can be potentially reused as cement replacement in concrete. However, several researchers suggest that fly ash requires pre-treatment due to its high chlorine content to be used as partial substitute for cement in concrete. Currently large amount of fly ash is generated in thermal power plant as waste material with an improper impact on environment and humans in Ethiopia. Fly ash waste generated by Reppie thermal power plant is as such a big environmental concern.
This research examines the potential of using treated and untreated MSWI fly ash as partial replacement of cement in concrete production for saving waste disposal cost, conserving natural resource and for mitigating the environmental impact of cement production. This study aim to investigate early and late age mechanical and durability properties of untreated and treated fly ash concrete. In this research, the fly ash was treated by washing with water only to reduce the chlorine and sulfur.
Concrete mixture containing 0%, 10%, 15%, and 20% dosage of untreated and treated fly ash by volume were proportioned. The compressive and flexural based tensile strength result at three, seven, twenty-eight and fifty-six days and also the water permeability data for twenty-eight days are determined. The experimental outcome indicates that the compressive strength of treated fly ash is lower compared to untreated fly ash, but still fall with in an acceptable range when compared to the control mix. The compressive strength of washed fly ash concrete with 10% and 15% replacement ratio exceed the control group’s 28th-day strength by 0.15% and 3.78% respectively. However, the flexural strength decreases as the level of both washed and unwashed fly ash increase. Still, the washed fly ash at 10% and 15% replacement level exhibits acceptable result when compared to the control group. Moreover, the 10% and 15% washed fly ash replaced concrete sample possess a better water tightness performance than the controlled sample. Based on the result, the treated FA can replace cement up to 15%.
Description
Keywords
Municipal solid waste incineration, Treated fly ash, Partial replacement, mechanical properties, durability.