Effects of municipal solid waste incineration bottom ash on corrosion resistance of cement mortar

Studies show that municipal solid waste incineration (MSWI) effectively reduces and treats municipal waste environmentally. Therefore, it is crucial to use bottom ash (BA) from MSWI as efficiently as possible. This study explores the macroscopic properties of cement mortar, in which MSWI BA partially replaces fine aggregate, over time in different corrosion solutions. These properties include flexural strength, compressive strength, mass variation, and appearance degradation. Moreover, the corrosion products and mechanisms influencing corrosion resistance were explored using X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), and scanning electron microscopy (SEM). The effects of various corrosion solutions on flexural and compressive strengths of cement mortar with different BA replacement rates were explored, compared to hydration in clean water as a control group. Flexural and compressive corrosion resistance coefficients were also determined. Results indicated that replacing fine aggregates with BA enhanced the corrosion resistance of cement mortar across different corrosion solutions, with resistance increasing proportionally with the BA replacement rate. In the Na ₂SO ₄ solution, the specimen showed the highest level of corrosion resistance effect. By the 450th day, the flexural corrosion resistance coefficient of the specimen with the maximum replacement rate of 75% had a flexural corrosion resistance coefficient of 1.26, which was an impressive 9 times greater than the coefficient of 0.14 observed in the specimen with a 0% replacement rate. This study contributes to the efficient use of BA and promotes sustainable waste management techniques while decreasing resource consumption and environmental degradation related to MSWI.