摘要:AbstractThe present study deals with the effect of Road Building International Grade 81 (RBI Grade 81) on strength characteristics of the clayey subgrade. A wide range of tests was conducted on various percentages of RBI Grade 81 subgrade mixtures such as Atterberg limits, compaction characteristics, California Bearing Ratio (CBR) and Unconfined Compression Strength tests (UCS). It can be noticed that the CBR of clayey subgrade has increased significantly with the addition of RBI Grade 81. Similarly, the maximum dry density (MDD) has decreased and the optimum moisture content (OMC) has increased with RBI Grade 81 addition to subgrade. The strength of clay subgrade at 8% of RBI Grade 81 has improved 3–3.5 times as compared to the natural clayey subgrade. Overall, it can be concluded that RBI Grade 81 is suggested as a potential stabilizing agent especially for clayey subgrades.