Recycled aggregates produced from two different feedstock materials – Applied in ready-mixed concrete

Author(s): Hernan Mujica, Egil Velde, Christian J. Engelsen, Monica S. Nodland
Paper category: Proceedings
Book title: Proceedings of the International Conference on Sustainable Materials, Systems and Structures (SMSS2019) New Generation of Construction Materials
Editor(s): Marijana Serdar, Nina Štirmer, John Provis
ISBN: 978-2-35158-217-6,
Vol 1. ISBN: 978-2-35158-223-7
e-ISBN: 978-2-35158-218-3
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 296-303
Total Pages: 8
Language : English

Abstract: Construction and demolition waste (CDW) and waste excavation materials (WEM) from construction activities are important raw materials for new construction materials and products. Recycled concrete aggregates (RCA) from both waste streams are today not used in bound applications (e.g. ready-mixed concrete).
In this study, RCA was produced from a feedstock with 50% of each waste stream (WEM and CDW) and used in concrete pilot. The RCA replaced fully the natural aggregates in the concrete mix. It was found that the compressive strength complied to the requirements for C35/45 in NS-EN 206. Furthermore, the use of this type of RCA had no negative impact on the physical characteristics of the RCA and the concrete. Low content of cement paste was found in the RCA and resulted in low water absorption. This demonstrated the ability of the wet recycling process to remove significant quantities of the mortar in the CDW.
The total concentrations of inorganic and organic substances were found to be low and complied to the strict Norwegian soil quality criteria. Cr(total) exceeded the criteria. However, most of the chromium was present on the trivalent form, Cr(III), which has low solubility in the neutral to mildly basic pH region.

Online publication : 2019
Publication type : full_text
Public price (Euros) : 0.00