Development and Operation Model of Plant-derived Soil Additives for Road Disaster Reduction on Problematic Soil

This SATREPS project was originally planned for the five-year period beginning in the 2019 academic year. However, its end was extended by one year due to impact of the COVID-19 response.

Expansion of road networks is thought to be an important path forward for sub-Saharan Africa. Roads enable access to markets hospitals and schools, contributing not only to boosting economic development but also to the promotion of health and welfare and securing equitable and high-quality education. Unfortunately, vast areas of Africa are characterized by “black cotton soil”, a distensible, cohesive soil that swells in the rainy season and shrinks in the dry season, complicating road building, management and maintenance.

In this project, our aim was to create an operational model for counteracting special soils based on local production and consumption, through the development of plant-based soil stabilization additives to improve the soil. Applying the mechanisms of soil conditioners previously commercialized in Japan, we developed a method of producing a cellulose soil conditioner made from local plants while analyzing the characteristics of local special soils. Based on this technology, we are planning the construction of an operational model for a road construction method that uses this local-plant-based soil conditioner.