Abstract:
Bottom ash emerges as a by-product from the combustion of municipal solid waste in energy
generation plants. The global predicament surrounding the management and disposal of bottom
ash, an aftermath of waste-to-energy facilities, remains significant. The use of improper
disposal methods has engendered substantial health and environmental predicaments,
necessitating pragmatic solutions. This research scrutinises the plausibility of harnessing
bottom ash as a substitute for fine aggregate, specifically in the context of cement block
fabrication. The study meticulously probes into the mechanical, thermal, and durability
characteristics of cement blocks that incorporate bottom ash, all while meticulously adhering
to guidelines. Establishing a consistent mixture is pivotal; it entails maintaining a volume ratio
of 1:6:3 for cement, fine aggregates, and quarry chips, steadfastly retaining a cement-to-water
ratio of 0.8. Central to the investigation is the precise crafting of solid cement blocks measuring
300 mm x 100 mm x 150 mm, accomplished through the conventional table vibratory
compaction method. The primary thrust of the study involves methodically incorporating
varying percentages of bottom ash into the block matrix, progressing incrementally in steps of
10% across a range spanning from 0% to 60%.
Critical evaluations of the cement blocks' compressive strength and water absorption
capabilities were meticulously undertaken at predefined intervals of 7, 28, and 56 days.
Conspicuous trends surfaced, unequivocally establishing a direct correlation: higher
proportions of bottom ash invariably led to a commensurate reduction in the density,
compressive strength, durability, and specific heat capacity of the resultant cement blocks.
Counteractively, water absorption capacity exhibited an incremental rise in tandem with
augmented proportions of bottom ash. The findings of the research emphatically suggest that
within the purview of modest and intermediate-scale cement block production, tailored for
load-bearing walls within residential structures not exceeding four stories, the substitution of a
substantial fraction of conventional fine aggregate with scrupulously sieved bottom ash from
waste-to-energy plants is thoroughly conceivable. The specific mix proportions meticulously
examined within the ambit of this investigation convincingly advocate for the replacement of
up to 50% of the fine aggregate with bottom ash.
In summative essence, this investigation profoundly underscores the latent potential of
repurposing bottom ash a seemingly intricate waste byproduct as a prized resource within the
expansive domain of the construction industry. Notably, this approach does not merely address
the challenges entailed in inadequately handling bottom ash but also tangibly contributes to
sustainable construction practices by effectively mitigating the demand for traditional fine
aggregates. While the parameters of this inquiry are judiciously delimited, they form the
underpinning for the possibility of wide-ranging future research and innovation, engendering
the conscientious utilisation of waste byproducts in forging ecologically attuned construction
materials.