REVOLUTIONIZING SUSTAINABLE CONSTRUCTION THROUGH RECYCLED CONCRETE AGGREGATE PRODUCTION: A SYSTEMIC REVIEW OF CODES, STANDARDS AND GUIDELINES

The significant rise in the production of construction and demolition (C&D) waste has increased dramatically in recent years, resulting in the entry of tons of concrete waste into the environment. Recycling and reusing C&D waste as a partial replacement for aggregate in building construction is practiced in other nations as a possible solution and waste management. However, few studies have identified how C&D waste can be utilized in the Ethiopian Construction Industry (ECI). In addition, the application of recycled concrete aggregate (RCA) in Ethiopia is limited owing to a lack of well-established standards and guidelines. Thus, the focus of this research is to investigate the opportunities and limitations of recycled concrete building materials based on legal design codes, standards, and government guidelines for utilizing recycled concrete waste as aggregates. This study systematically reviewed existing norms and standards for the potential use of recycled concrete aggregates and identified opportunities and limitations by incorporating them into current design and construction practices. This study evaluates the current state and utilization practices of RCA in economically comparable developing countries, drawing comparisons with Ethiopia. The findings revealed inconsistencies in the national standards concerning the permissible substitution of natural aggregates with recycled alternatives. Furthermore, the existing standards lack crucial parameters, such as the precise influence of the source concrete grade on the recycled material properties and the impact of service life on its characteristics. To address these shortcomings, it is essential to develop local design codes, laws, and standards, specifically for RCA in developing countries. Such measures will bolster stakeholder confidence in the sector’s applicability, utilization, commercialization, and promotion of this sustainable material. This study is expected to contribute to the standardization of recycled concrete in Ethiopia and similar developing countries where such guidelines or standards do not exist.