Stabilization of weak subgrade soil with wood ash and cement for road construction: a case study along Arba Minch town – Sille road

Cement is one of the components of construction material which plays a significant role in the implementation of construction projects. More so, it is considered as one of the most expensive and environmentally unfriendly construction material. Therefore, the requirements for economical and environmentally-friendly cementing ingredients have given interest to other cementing compounds which is contained in other materials that can be used as partial replacement of the ordinary Portland cement. In case of Arba Minch town – Sille Road, most parts of the existing road section were heavily damaged and that is why this research study was focussed on the stabilization of subgrade soil using wood ash as partial replacement of cement in weak subgrade soil for road construction. To achieve the objectives of the study, primary data conducted directly in the field, through field observation and identifying the sections where to extract samples in the study area. The results revealed that Wood Ash found and partially can replace cement in weak subgrade soil stabilization. Plasticity index decreased slightly, maximum dry density (MDD) increased for all pits than control mix while moisture content decreased, CBR also showed a slight incremental change compared with the normal soil sample.