Development of a Recycling System Policy for Construction and Demolition Waste Materials with Applications in Libya towards Sustainable Development

摘要

Construction and Demolition Waste (CDW) materials are presently put in landfills (henceforth, Landfill-Designated Waste). At the same time, many developing countries, particularly in Africa, suffer from a lack of proper management of suitable materials for road construction, mainly old concrete, brick, asphalt, gravel, and angular sand. CDW is significant because it may be fully or at least partially reused in new construction projects, saving valuable and non-renewable resources. In addition to the depletion of natural resources, the disposal of CDW causes clogging of disposal sites. Due to the absence of a recycling and reusing policy, there are no alternatives to these disposal sites where CDW piles up. The three challenges to recycling are: 1) landfill space which is cheap or free; 2) social norms and education surrounding recycling; and 3) waste is perceived as garbage, and therefore of lesser quality. By quantifying how landfilling CDW represents an increase in environmental liability and a problem for the future, this research discusses the waste of the potential value of the material and how existing and scarce resources might be protected. Thus, CDW is a liability that can be turned into a valuable resource by using System Dynamics (SD) concepts. In addition, SD presents a convenient framework to monetize the value of the recycled waste. This framework is based by characterizing CDW and then on reusing it. The results of the model provide an innovative needs-based recycling policy to manage CDW. The scope of the study is at the national level, focused on Libya but generalizable to developing countries with comparable climatic, social and cultural features. Validation in this study relies on three things: 1) verifying that the units that are input into the model are correct; 2) comparing the results with successful previous studies; 3) using one specific and very common building design. This needs-based approach regarding required construction materials relies on estimates of future material needs, from either new or recycled sources, for both new and rehabilitation projects. This assessment is based on infrastructure needs, population growth rates, GDP, and cement production and consumption.