Evaluation of engineering properties and environmental effect of recycled gypsum stabilized soil in geotechnical engineering: A comprehensive review

The discard and landfill of by-product gypsum cause significant environmental problems. About 100-280 million tons of phosphogypsum and a large amount of waste plasterboard are produced every year in the world, but the utilization rate of phosphogypsum is about 10%. Most by-product gypsum is directly landfilled or discarded without treatment, only a small amount is recycled and reused. In the past decades, by-product gypsum has been used in different geotechnical engineering applications, such as subgrade filler, soft soil stabilization, expansive soil treatment, etc. This paper presents a comprehensive review of the engineering and environmental properties of recycled gypsum stabilized soil, which includes compaction characteristics, consistency, strength, deformation, compression, shear, expansion properties, and durability. Meanwhile, the environmental effect is also analyzed. In summary, the recycled gypsum in geotechnical engineering application is promising.