Use of some agricultural wastes to modify the engineering properties of subgrade soils: A review

The drive to diversify the economy in some developing countries have resulted in increased agricultural production and consequently increased agricultural waste. This study reviews some published research works on the reuse of some agricultural wastes for modifying soils with poor engineering properties. The review shows that some agricultural wastes, such as palm oil fuel ash, palm kernel shell ash, rice husk ash, seashell powder and sawdust ash, are effective modifiers of subgrade soil and become more effective when combined with traditional stabilizers. The use of stabilizers from agricultural wastes has the potential of reducing the amount of waste disposed of in landfills/dump sites, and at the same time reduce the carbon footprints caused by the use of traditional stabilizers like cement, and the cost of highway construction.