An Investigation into the Feasible Transport Distance for Repurposing Construction Rubble in Johannesburg, South Africa

Abstract

The increasing demand for construction materials, fueled by population growth and infrastructure development, presents significant environmental concerns due to the energy-intensive and carbon intensive processes involved in manufacturing aggregates. The study investigated the viability of recycled aggregates as a mitigation strategy, focusing on the proximal distance for repurposing demolition rubble in the Gauteng region, Johannesburg in particular, to minimize environmental impacts. A mixed-methods approach combining surveys and interviews with demolition contractors, recyclers, and quarries was employed to conduct a comparative material analysis. The results indicated that recycled aggregates incur higher energy costs, carbon dioxide emissions, and manufacturing costs compared to natural aggregates. Subsequently, the study revealed that there is no feasible transport distance for repurposing rubble in the Johannesburg region due to these increased costs. However, the research also discusses unquantified costs associated with quarrying, such as unreclaimable land degradation and ecosystem disruption, which significantly contribute to the overall environmental impact of natural aggregates. This study contributes to the understanding of construction and demolition waste material recycling, emphasizing the importance of considering both economic and environmental factors. The findings will help in informing policymakers, construction industry stakeholders, and environmental managers on the potential benefits and limitations of recycled aggregates in reducing the ecological footprint of construction materials. The research highlighted the necessity of integrating life-cycle assessment and environmental costing into aggregate production encouraging policy incentives for sustainable construction practices.