Circular Economy Assessment of Recycled Concrete with Life Cycle

Abstract

This research examines the life cycle costing (LCC) of concrete produced using recycled concrete aggregates (RCA) combined with sustainable fibers, including carbon nanofibers and natural sisal fibers, as substitutes for traditional natural aggregates. A series of concrete mixtures were formulated with RCA content levels of 0%, 50%, and 100%, incorporating various fiber combinations, while some mixtures were further enhanced with supplementary cementitious materials such as fly ash (FA) or silica fume (SF). The study included a thorough assessment of mechanical properties, including compressive strength, flexural strength, and split tensile strength, to evaluate the performance of these concrete mixtures. The findings indicated that the integration of sisal and carbon nanofibers significantly improved mechanical properties, suggesting that while using 100% RCA (Mix C9) resulted in a slight reduction in strength, it still outperformed conventional concrete. This research highlights the economic advantages of utilizing RCA and sustainable fibers in concrete formulations, demonstrating how life cycle costing can provide a framework for promoting sustainable construction practices that enhance resource efficiency and minimize overall project costs in the context of a circular economy.

Keywords

• circular economy
• life cycle assessment
• recycled