Separation studies of concrete and brick from construction and demolition waste

The quality of recycled aggregates from construction and demolition waste (CDW) is strictly related to the content of porous and low strength phases and is specifically related to the high content of brick particles, despite representing approximately 50 wt.% of the total recycled aggregates. This paper focus on air jigging separation studies for removing brick particles from recycled construction and demolition waste aggregates. The operational parameters were achieved by studying the aggregate movement trajectories based on the small specific density differences of 2.52 g/cm³ and 1.97 g/cm³. Separation tests were conducted with a binary mixture of concrete and brick particles ranging from 5 to 10 mm for three operational parameters. The attained results confirmed that the brick fraction increases the water absorption and compromises the consistency and strength of the recycled aggregates. The proposed air jigging separation method was effective at reducing brick particle content and producing significant recycled concrete aggregates with a purity of 95 wt.%, paving the way for greater use of recycled aggregates in high grade applications, such as concrete and pavement layers.