MANAGEMENT OF CONSTRUCTION AND DEMOLITION WASTE AND ITS USE FOR ROAD CONSTRUCTION IN A SOUTH AFRICAN MUNICIPALITY

摘要

The management of Construction and Demolition (C&D) waste material plays a relevant social, economic and ecological role in contemporary world. Due to lack of space in the disposal sites, reuse of potentially recyclable material is vital. Finding alternative usage for waste materials is a challenge for municipalities that want to decrease the volume in landfill sites and also a challenge for scientists who want to reduce the environmental impact of these waste materials by promoting alternative uses. An effort in this direction will help and encourage a new economy in equilibrium with the growing necessity of environmental preservation. Moreover, the natural aggregates that are needed for construction purposes have reached inadequate levels today and the establishment of new quarries is discouraged by administrations. This paper is specifically focused on the C&D waste stream produced in Durban Metropolitan Area, South Africa, with suggestions for its management and recycling. Origin and quality of this material disposed at the Bisasar Road landfill site were investigated and tested to determine its suitability for road pavement uses. The replacement of natural soils with unconventional waste materials is strongly recommended to minimize the use of open quarries for natural aggregates. The alternative material studied in this research attains the same mechanical performance as natural aggregates despite having different physical characteristics, demonstrating that C&D waste can replace natural aggregates when specific management procedures are performed to mitigate the intrinsic heterogeneity observed in the material. The results obtained from this study demonstrated good performance of the C&D material as base, sub-base, or subgrade material depending on the road category.