Casein as a foaming agent in cement-treated soil for lightweight embankments

Construction of lightweight foamed cement banking embankments usually requires temporary sites for air-pressure machinery. This study proposes casein, a milk protein, as an additive in cement-treated soils for constructing lightweight embankments to reduce milk waste and the necessity for air pressure machinery. The effects of mixing time, casein content (0%–8%), and cement quantity (100 and 150 kg/m³) on the dry density, unconfined compressive strength, and coefficient of permeability of cement-treated soils were determined. Furthermore, the durability of the cement-treated soils mixed with casein to wet and dry cycles and its impact on the pH of water was determined. It was established that adding 5% of casein to cement-treated soils and mixing for 10 min produced lightweight embankment materials with complaint strength (>300 kPa), durability and permeability (10⁻³ cm/s), minimal environmental impact, and promoted sustainability.