Performance of a small-scale construction and demolition waste recycling unit: a case study in northeastern Brazil

Abstract

Environmental and operational performance of a full-scale small and decentralized construction and demolition waste (C&DW) recycling unit (SDRU) were evaluated. The SDRU was defined as having a production capacity of up to 5 m³ per hour, occupying up to 100 m². The operational and environmental performance indicators of the SDRU were obtained from the literature and validated by expert judgment. Subsequently, the values of these indicators were obtained from a real-scale SDRU in Bahia state, Brazil. The results showed that the SDRU presented lower levels of noise emission, very small water and energy consumption, and inhalable-particle concentration values lower than the requirements of Brazilian environmental legislation. It was observed that 90% of the C&DW in the storage area had recycling potential. The characteristics of the fine recycled aggregate make it suitable for use in road or sidewalk paving, and the coarse recycled aggregate is suitable for use in concrete without structural function. A Life Cycle Assessment (LCA) of the SDRU was also applied and it was concluded that the use of the recycled aggregate for manufacturing concrete without structural function reduced the environmental impact in all the categories considered, compared with the impact of natural sand and gravel extraction from nature. It was possible to conclude that the implementation of the SRDU in developing countries can provide an effective step towards reducing environmental impacts from the construction sector.