Study on Screening Mechanism and Numerical Simulation for Crashed Concrete Particles by Using DEM

Abstract

Recycling waste concrete has become a large problem in developing countries. The aim of this work is to provide guidance for screening concrete particles and improving screening efficiency. First, the elastoplastic collision model is established for calculating the coefficient of restitution for concrete particles with different compressive strengths. Then, a bar circular vibrating screen is applied to simulate the screening process of concrete particles by using the discrete element method (DEM). The optimal vibrating parameters, which contain amplitude, frequency and inclination angles, is analyzed for the representative concrete particles containing C15, C45 and C80 by comparing the screening efficiency. The results show that the optimal screening parameters of amplitude and frequency is smaller with the increase in the compressive strength of the concrete particles. Appropriately, the large inclination angle is suitable for screening fine concrete particles with a gap vibrating screen. This work should be helpful for the screening process of concrete waste particles and provides a theoretical basis and simulation case for screening and recycling other particles, such as sand, stone, iron ore and copper ore. In the screening processes of construction wastes, the optimal screening parameters can be selected quickly by calculating the coefficient of restitution and adopting the DEM simulation.