Simulation of the Attrition of Recycled Concrete Aggregates during Concrete Mixing
Author/s
Moreno-Juez, Jaime; Tavares, Luís Marcelo; Artoni, Riccardo; Carvalho, Rodrigo M. de; da Cunha, Emerson Reikdal; [et al.]Date
2021-06-01Keywords
Attrition
Concrete mixing
Discrete element method
Recycled concrete aggregates
Abstract
Concrete mixing can lead to mechanical degradation of aggregates, particularly when
dealing with recycled concrete aggregates. In this work, the attrition of such materials during mixing
is studied by means of experiments and simulations. The effect of the presence of fines, water
addition, flow configuration of the mixer (co- or counter-current) and impeller frequency is discussed.
Experiments were performed in a laboratory Eirich mixer. Discrete element numerical simulations
(DEM) were performed on the same geometry by mimicking the behaviour of the material and,
in particular, the cohesion induced by water and the cement paste using either Hertz–Mindlin or
Hertz–Mindlin with Johnson–Kendall–Roberts (JKR) contact laws. The combination of the collision
energy spectra extracted from the DEM simulations and an attrition model allowed the prediction
of the mass loss due to attrition in 1-min experiments. Semi-quantitative agreement was observed
between experiments and simulations, ...
Type
article