Design of mixes and development of prototypes of concrete blocks and pavers using construction and demolition waste (CDW) materials

Abstract

The acceleration of population growth and urban expansion has intensified the consumption of natural resources and the generation of construction and demolition waste (CDW), posing significant environmental challenges. This study evaluates the technical and environmental feasibility of using CDW in the production of sustainable construction materials, aligning with circular economy principles and the current Colombian regulations. The studied mixtures were incorporated with concrete, ceramic, crushed glass, and inactive carbon residues derived from construction activities and other productive sectors. The experimental methodology included the collection, classification, crushing, and characterization of the materials, followed by the formulation of ten mixtures containing varying proportions of CDW and other commonly used construction materials. Cylindrical specimens were subjected to compressive strength tests. Results demonstrated that the formulations meet standards for structural and non-structural applications based on generally accepted regulations, enabling the production of blocks, pavers, and concrete with compressive strengths up to 21 MPa. An environmental impact analysis was conducted using commercial life cycle assessment software, revealing that blocks made with recycled materials reduce the environmental footprint compared to industrially processed virgin materials. However, for pavers, the environmental footprint of recycled materials was higher which is an issue to be considered in recycled material initiatives. Besides reducing landfill waste accumulation, this proposal fosters sustainability by reusing materials and minimizing virgin resource extraction. This approach not only complies with Colombian regulations but also supports a sustainable development model in the construction sector, providing innovative solutions to the environmental and social challenges associated with urban growth and CDW generation.