Resilient Modulus of Lime-Bamboo Ash Stabilized Subgrade Soil with Different Compactive Energy

The resilient modulus (Mr) of natural subgrade materials have been extensively studied, however, for stabilized subgrade materials, the Mr requires adequate characterization to ascertain pragmatic performance. Furthermore, the soil Mr is known to be influenced by the soil physical state. A lime-modified expansive subgrade soil, admixed with varying percentages of bamboo ash (4, 8, 12, 16, and 20%) was understudied to determine its Mr with compaction attenuation. Two compactive energies, British standard heavy and British standard light were applied for determination of the stabilized soil Mr. The Mr was determined in accordance with AASHTO T307 guide. The results clearly showed that whilst Mr improved with additive content and increased deviator and confining stresses, the values diminished with compaction attenuation. A polynomial model relationship was developed for the Mr obtained using the two compactive energies. The results of the multiple regression analysis carried out using modified stress-based models from literature demonstrated the influence of compactive energy and additive content on the stabilized soil Mr.