In this experiment, the role of admixtures on the strength of red soil (RS) and black cotton soil (BCS) are studied. Many researchers have used different admixtures like cement, nanomaterials, bagasse ash, polypropylene fibers, palm oil, zeolites, bio-enzyme, Alccofine etc. to stabilize the soil. Each admixture has shown considerable enhancement in the strength of the soil. However, there was a lag in literature with a combination of Alccofine and polypropylene fibers and, comparison between two types of soil. Hence, identifying this research gap, the authors attempted to investigate the engineering properties of RS and BCS by adding an admixture like Alccofine and polypropylene fibers. Alccofine are added in varying percentages such as 0, 5, 10, 15, 20, 25, and 30% with fixed 1% of polypropylene fibers. The basic tests of soil such as specific gravity, sieve analysis, water content, Atterberg’s limit tests are performed along with strength test. A standard compaction test is carried out to assess the ideal moisture content (MC) and the maximum dry density (MDD) of a soil. Unconfined compressive strength (UCS) test and California bearing ratio (CBR) test are conducted to determine the soil strength. Inclusion of these admixtures in the soil has improved the strength and stability of the soil against the absorption of moisture content. An increment in the strength with an increase of Alccofine content was observed. Maximum strength is found to be at 20% addition of Alccofine, there after we noticed a decline in the strength of soil. Also, the CBR value in both soaked and unsoaked conditions of both the soil has improved the strength by more than 20% compared to nominal soil strength value. Reduction in Atterberg limits has shown that a decrease in water absorption as Alccofine stabilizes the soil and results in a minimum water content requirement for soil. Finally, the test results are compared, and an optimum percentage of Alccofine with constant polypropylene fibers for obtaining maximum strength of soil is identified. Thus, the significance of using Alccofine and polypropylene fibers as an admixture to attain maximum strength is concluded, proving it as an economical and sustainable approach in improving the clayey soil strength.