Applications of Recycled Gypsum from Waste Drywalls in the Construction Industry: A Review

Reusing and recycling construction and demolition waste materials are one of the main approaches to reduce the environmental impacts of the construction industry. Waste gypsum drywalls from ever-growing renovation projects and scrap drywalls from new constructions have become a major issue for municipalities. Several researchers have studied the potential use of recycled gypsum from waste drywall as a second-raw construction material, especially for concrete construction. However, there is no comprehensive review study on the topic while it can identify research gaps and provide a direction for future studies. With this background, this review paper focuses on the applications of recycled gypsum drywall (RGD) in the construction industry and its environmental and economic benefits. Additionally, this paper proposes the best mixtures for the concrete containing RGD through the literature review. The cementitious composite of this mixture can be used in other introduced applications. To this end, applications of RGD in the construction industry were classified into seven groups, including supplementary materials in concrete materials, soil stabilization, ceramic industry, recycled aggregates, cement production, plaster, as well as blocks and walls, and new achievements in each group were discussed. Then, the most eco-friendly concrete mixture with acceptable mechanical strength was proposed, assisting researchers in future studies. The results illustrate that reusing RGD can significantly reduce the carbon dioxide emissions of the concrete and provide economic benefits. A combination of ordinary Portland cement, recycled gypsum, fly ash or perlite, and slag was proposed as the most appropriate cementitious concrete composite.