SELECTIVE COMMINUTION OF CONCRETE WASTE AND RECOVERY OF THE CONCRETE CONSTITUENTS IN A GRINDING-DRYING PROCESS

Author(s): André Bätz, Holger Wulfert, Paul Erwerth, Andreas Schiffers, Andreas Jungmann, Dirk van Mechelen
Book Title: III Progress of Recycling in the Built Environment
Editor: I. Martins, C. Ulsen and S. C. Angulo
e-ISBN: 978-2-35158-158-2
Publisher: RILEM Publications SARL
Publication year: 2015
Pages: 15-26
Total Pages: 10
Language: English

Abstract: This article describes a new process for the separate recovery of the constituents of concrete waste by means of selective comminution in combination with dry separation by density. The process is based on a Loesche roller mill, which liberates the gravel and sand fractions in a non-destructive manner. Post-separation of the coarse fraction using an air jigging machine and/or a dry fluidized bed separation ultimately produces a recyclate of such a good quality that it can be used to completely replace the natural rock fraction. It can be demonstrated that under equal concrete manufacturing conditions the obtained recyclates (recycled gravel, sand and filler) are all just as good as, if not superior to, the natural rock fraction. Moreover, utilisation of filler consisting mainly of ground hardened cement paste fraction promises residual reactivity. This process also enables the alternate grinding of very different primary and secondary raw materials, such as steel slag, granulated blast furnace slag, clinker and concrete in a single plant, operated in campaigns.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00