The 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.

中文翻译：

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RBI等级81对黏土路基强度特性的影响

本研究探讨了国际道路建筑81级（RBI 81级）对黏土路基强度特性的影响。对各种百分比的RBI 81级路基混合物进行了广泛的测试，例如Atterberg极限，压实特性，加利福尼亚承载比（CBR）和无侧限抗压强度测试（UCS）。可以注意到，随着RBI等级81的添加，粘土基路基的CBR显着增加。同样，随着RBI等级81的添加，最大干密度（MDD）降低，最佳含水量（OMC）增加。与天然黏土路基相比，粘土路基的强度为RBI 81级的8％，提高了3-3.5倍。总体，