Pre-demolition concrete waste stream identification

Pre-demolition concrete waste stream identification: classification framework

Nedeljković, Marija (TU Delft Materials and Environment; Rijkswaterstaat)
Tošić, Nikola (Universitat Politecnica de Catalunya)
Schlangen, E. (TU Delft Materials and Environment)
Fennis, Sonja (Rijkswaterstaat)

2023

Demand for high quality recycled concrete aggregates (RCA) to offset the use of primary materials is significantly rising due to circular economy goals and high-value reuse of concrete. The quality of RCA significantly affects their availability for new concrete production due to the variability of parent concrete streams. The optimization of recycling procedures is under development to improve the quality of RCA, however, the costs and energy efficiency of such processes are of practical concern. With this in mind, this paper presents a new framework for reducing the variability of RCA quality by identifying concrete members before their demolition. The goal of identifying demolished concrete members from a structure is to provide groups of concrete members with similar mechanical and chemical properties through a systematic classification of the structural members. The quality assessment of concrete structures and their mechanical and chemical (composition, contamination) properties prior to demolition is generally recognized as challenging due to the absence of guidelines and the lack of easy-to-use in situ characterization techniques. This paper proposes experimental approaches that can non-destructively determine the properties of concrete structures, with a major emphasis on the measurement of the chemical composition of concrete before demolition. Characteristic quality indicators to classify concrete members are first proposed and can be instrumental in setting up future studies. A new method is proposed for in situ chemical composition testing of existing concrete structures; assuming that no records about the parent concrete are available. Next, the challenging parameters for in situ, non-destructive measurements are outlined. The practical application of the proposed method and its uptake in industry can potentially unlock a huge potential for optimized material recovery and contribute greatly to a fully circular construction industry.

concrete quality
strength
composition
in situ non-destructive testing
characteristic quality indicators
handheld XRF

http://resolver.tudelft.nl/uuid:89d9bee9-b433-451e-94d5-3ab96677ac55

https://doi.org/10.5937/GRMK2301001N

2217-8139

Gradevinski Materijali i Konstrukcije, 66 (1), 1-24

Special thanks to Wim Ekkelenkamp, Erik Hoven, and Peter Broere for valuable discussions related to concrete demolition and recycling. Student Abdellah Hussein is acknowledged for his insights on the topic of concrete demolition.

Institutional Repository

journal article

© 2023 Marija Nedeljković, Nikola Tošić, E. Schlangen, Sonja Fennis