By Abbas Nazil
Nigeria faces a major infrastructure challenge as the government estimates the country needs an additional 200,000 kilometres of durable roads, costing around ₦18 trillion or US$12.2 billion.
The high costs of construction materials such as cement, bitumen, and aggregates, along with environmental and terrain challenges, have made road building extremely expensive, especially in rural areas where access to schools, hospitals, and markets depends on good roads.
Most Nigerian roads are built on lateritic clay soil, which swells and shrinks with moisture changes, making it unstable and prone to damage.
Traditionally, engineers use cement and lime to stabilise such soil, but these materials are costly and harmful to the environment, with cement production responsible for about 8% of global greenhouse gas emissions.
In search of a greener alternative, a research team led by civil engineer Ifeyinwa Ijeoma Obianyo from Nile University of Nigeria experimented with using shredded plastic waste as a soil stabiliser.
Laboratory tests revealed that adding just 2 percent of shredded plastic bottles to laterite soil improved its density and load-bearing capacity, making it more suitable for road construction.
The plastic acted as a filler, reducing the need for cement and lime while transforming waste into a useful resource.
The study found that at 2 percent plastic, the soil was denser, while at 10 percent, it achieved optimal moisture balance—creating a lighter, sustainable material.
The next step, according to the researchers, is real-world testing through pilot projects and government-funded trials to validate the findings.
They also called for new policies promoting plastic recycling and the use of recycled materials in infrastructure, including extended producer responsibility laws, tax incentives, and bans on single-use plastics.
Experts believe adopting this innovation could help Nigeria build stronger, greener, and more affordable roads while reducing plastic waste and cutting carbon emissions.
