Characterization of filler fraction from the production of recycled sand from construction and demolition waste

Abstract

The concept of circular economy envisages that the highest utility and value of a material can be achieved through proper management along its all life cycle. Therefore reducing waste, through increased reuse and recycling, is a major driver to close the loop. Within this framework, construction and demolition waste, which constitutes up to 30% of world waste generation, is a priority in order to achieve a high level of resource efficiency in the construction sector. In general, it is noticed that the fine fraction from traditional CDW processing, representing from 40 to 60% mass of the CDW mineral phases, is not suitable to be used as a secondary material for manufacture of concrete where high mechanical performance is required. Moreover, the filler fraction produced on recycling processes is rarely considered for recycling due to its high surface area and irregular shape. Filler properties depend on previous construction material composition and mineral processing applied for recycling. This paper aims to characterize the filler fraction from the production of recycled sand from construction and demolition waste processing, by particle size distribution, chemical and mineralogical composition and specific density and highlights some drawbacks related to their application as filler in cementitious building materials.