Abstract:
Against the backdrop of escalating infrastructure budgets worldwide, a notable portion—up
to 45%—is allocated to maintenance endeavors rather than innovative infrastructure development.
A substantial fraction of this maintenance commitment involves combatting concrete degradation
due to microbial attacks. In response, this study endeavors to propose a remedial strategy employing
nano metals and repurposed materials within cement mortar. The methodology entails
the adsorption onto eggshell membranes (ESM) of silver nitrate (ESM/AgNO3) or silver nanoparticles
(ESM/AgNPs) yielding silver–eggshell membrane composites. Subsequently, the resulting
silver–eggshell membrane composites were introduced in different proportions to replace cement,
resulting in the formulation of ten distinct mortar compositions. A thorough analysis encompassing
a range of techniques, such as spectrophotometry, scanning electron microscopy, thermogravimetric
analysis, X-ray fluorescence analysis, X-ray diffraction (XRD), and MTT assay, was performed on
these composite blends. Additionally, evaluations of both compressive and tensile strengths were
carried out. The mortar blends 3, 5, and 6, characterized by 2% ESM/AgNO3, 1% ESM/AgNPs,
and 2% ESM/AgNPs cement replacement, respectively, exhibited remarkable antimicrobial efficacy,
manifesting in substantial reduction in microbial cell viability (up to 50%) of typical waste activated
sludge. Concurrently, a marginal reduction of approximately 10% in compressive strength was
noted, juxtaposed with an insignificant change in tensile strength. This investigation sheds light
on a promising avenue for addressing concrete deterioration while navigating the balance between
material performance and structural integrity.
