A novel numerical algorithm for 2D and 3D modelling of recycled aggregate with different geometries

Abstract

The establishment of an aggregate model that better matches the actual situation is one of the prerequisites to studying the mechanical properties of concrete materials. Previous models focused on aggregates with more regular shapes, which differed from the morphology of the aggregates, particularly recycled aggregate. Due to the presence of adhered mortar, recycled aggregate has more complex structural characteristics than natural aggregates. Therefore, it is difficult to model the recycled aggregate, especially the distribution of irregular angles and sharp corners on the surface. In this paper, a modeling method based on the compression of circular and sphere shapes is proposed to obtain the aggregates of circular, elliptical, convex polygonal shapes in 2D and sphere, ellipsoidal, convex polyhedral shapes in 3D. The compression method has excellent scalability and applies to both natural and recycled aggregate in 2D and 3D. By using the proposed compression modeling method, the aspect ratio, sharp corners, flakes, edges, and needles of the recycled and natural aggregate can be characterized. The random aggregate models show that the compression modeling method can construct the 2D and 3D geometric models of natural aggregate concrete and recycled aggregate concrete with desirable aggregate distribution and aggregate morphological characteristics.