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

Abstract

The resilient modulus ( $${\text{M}}_{\text{r}}$$ ) of natural subgrade materials have been extensively studied, however, for stabilized subgrade materials, the $${\text{M}}_{\text{r}}$$ requires adequate characterization to ascertain pragmatic performance. Furthermore, the soil $${\text{M}}_{\text{r}}$$ 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 $${\text{M}}_{\text{r}}$$ with compaction attenuation. Two compactive energies, British standard heavy and British standard light were applied for determination of the stabilized soil $${\text{M}}_{\text{r}}$$ . The $${\text{M}}_{\text{r}}$$ was determined in accordance with AASHTO T307 guide. The results clearly showed that whilst $${\text{M}}_{\text{r}}$$ improved with additive content and increased deviator and confining stresses, the values diminished with compaction attenuation. A polynomial model relationship was developed for the $${\text{M}}_{\text{r}}$$ 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 $${\text{M}}_{\text{r}}$$ .