In a bid to improve sustainability in road construction and reduce the cost of road construction, there is a need for a
green alternative. This research improved the geotechnical properties of tropical lateritic soil using Bamboo Straw
Ash (BSA). The lateritic soil was stabilized with increasing percentage of BSA at 0%, 2%, 4%, 6%, 8%, 10%, and
12%. The index properties, Compaction (Maximum moisture content, Maximum dry Density), CBR, of the soil samples
with BSA were evaluated. Response Surface Analysis was used to model the mathematical relationship between the
atterberg limit and the CBR of the BSA stabilized soil sample. The plasticity index of the unstabilized soil sample was
14.01 upon the addition of 16% BSA, the plasticity index reduced to 10.73 which showed an improvement in the soil
index properties. The CBR increased from 26.38% to 30.2% at 0% and 8% respectively which signifies an improved
strength. From the Respons Surface Analysis, the highest plasticity index achievable with BSA stabilization is 27.18.
The model equation showed that the plasticity index and plasticity limit have a positive relationship with the CBR.
Ultimately, the use of BSA provides a cost-effective and green alternative to lateritic soil stabilization in road
construction
