To encounter the low bearing capacity, sudden shrinkage, and expansion of clayey soil at the starting stage of any new construction, an initial laboratory investigation is essential. For that, in this research, at the initial stage, a clay sample was taken as an oven-dry form having a silt content of 65.24% and clay content of 32.16%. The comparison properties such as UCC, Atterberg limits, and microstructural analysis using SEM of virgin soil partial additive with sodium bentonite (SB) stabilized with lime and the soil partial additive with SB treated with sodium-based alkaline geopolymer (GP) were studied under controlled conditions after stabilization, at various curing periods of 3, 7, 14, and 28 days, and 2 hours immediately after preparing the sample. The UCC samples were prepared and tested in untreated clay and the value obtained was about 343.8 kN/m². After stabilization at 28 days curing, the results show that lime stabilization achieved about 599.42 kN/m² at 5% SB content, and GP stabilized soil achieved a UCC value of about 1466.7 kN/m² at 5 molar solution @ 1% SB content @ 28 days of curing. The results show that a limited percentage of SB in geopolymer is enough to improve soil strength, but a larger amount is essential to enhance durability. The SEM results proved that texture alteration of clay contributed to closer particle contact with sodium bentonite admixed soil by geopolymer due to bonding between particles caused by gel formation and hardening when compared to lime stabilization. © 2020 Elsevier B.V., All rights reserved.