This research is aimed to use two different waste materials; calcium carbide residue (CCR) and Alum Sludge Ash (ASA) for the stabilization of a fine-grained soil. Different dosages of CCR were used (3, 6, and 9% by the soil dry mass) and mixed with different percentages of ASA (1.5, 3, 4.5, and 6%) at different proportion to produce 13 mixtures of soil-binder along with control mixture; untreated virgin soil. The Atterberg limits, standard compaction and unconfined compressive strength (UCS) tests were utilized to evaluate the geotechnical properties. Specimens experienced by UCS test were cured at different periods; 7, 28, and 56 days. Additionally, scanning electron microscopy (SEM) testing was conducting for microstructural investigation. Experimental results revealed significant improvement in Atterberg limits particularly after the inclusion of ASA in the used binder, which recorded 50% reduction of plasticity index. UCS increased for both soils treated with CCR and treated with binary binders recording a highest value for the binder comprises 9% and 4.5% by the soil dry mass of CCR and ASA respectively which showed strength about 10 times of that for the untreated soil. SEM testing revealed considerable developments in microstructure of the selected binder through the age of curing confirming the gradual production of cementitious gel such as C-S-H. hence, the more dense and coherent structure contributes to strength development of the treated soil.