Simulation study on static pressure crushing performance of demolished reinforced concrete beams for recycling

A highly efficient, low-carbon crushing technology is urgently needed for recycling demolished reinforced concrete (RC) components. Static pressure crushing (SPC), based on fragmentation theory, is a proposed solution. This paper presents a numerical model and a corresponding quantitative analysis method for the SPC of RC components. The model was developed based on a full-scale crushing application of an RC beam, wherein the failure of concrete and steel was characterized by the traditional finite element method (FEM) and the "erosion algorithm". A volume reduction-based crushing ratio was suggested and proven feasible for the quantitative evaluation of SPC. Subsequently, the effects of component length, boundary conditions, and top die shape on crushing performance were numerically investigated. The results show that the established model effectively simulates the crushing behavior of RC beams, influenced by boundary conditions and top die shape. Furthermore, modifying the top die shape can significantly enhance crushing performance. A crushing ratio of 49.8 % was achieved using the cross-shaped top die. This study provides a practical quantitative analysis paradigm for SPC process optimization.