Validation and Investigation on the Mechanical Behavior of Concrete Using a Novel 3D Mesoscale Method

Abstract

The mechanical performance of concrete is strongly influenced by the geometry and properties of its components (namely aggregate, mortar, and Interfacial Transitional Zone (ITZ)) from the mesoscale viewpoint, and analyzing the material at that level should be a powerful tool for understanding macroscopic behavior. In this paper, a simple and highly efficient method is proposed for constructing realistic mesostructures of concrete. A shrinking process based on 3D Voronoi tessellation was employed to generate aggregates with random polyhedron and grading size, and reversely, an extending procedure was applied for ITZ generation. 3D mesoscale numerical simulation was conducted under a quasi-static load using an implicit solver which demonstrated the good robustness and feasibility of the presented model. The simulated results resembled favorably the corresponding experiments both in stress–strain curves and failure modes. Damage evolution analysis showed that the ITZ phase has profound influence on the damage behavior of concrete as damage initially develops from here and propagates to mortar. In addition, it was found that tensile damage is the principal factor of mortar failure while compressive damage is the principal factor of ITZ failure under compression.

Realistic modeling of cemented granular materials with a lattice spring model by developing a digital 3D reconstruction approach

“…Due to the horizontal development of tensile stress in the uniaxial compression test, cracks tend to extend vertically, which is opposite to the transverse propagation of cracks in the tensile test. This observation is consistent with the previous work 33,38 . Moreover, there are 4–7 main macro cracks in each side face for the UCT, in which cracks prefer to almost vertically propagate along the edges of the specimen for both numerical and experimental tests.…”

“…This observation is consistent with the previous work. 33,38 Moreover, there are 4-7 main macro cracks in each side face for the UCT, in which cracks prefer to almost vertically propagate along the edges of the specimen for both numerical and experimental tests. Meanwhile, there are one or two inclined cracks with greater than 60 • in the middle of each side face.…”

Mesoscale Modelling of Concretes Subjected to Triaxial Loadings: Mechanical Properties and Fracture Behaviour

“…Compared with coarse aggregates, the characteristic length of ITZ was very small. Taking into account both the accuracy and computational efficiency, an appropriate thickness of 0.1 mm was employed through an extending process [ 31 , 32 ] and the “free-falling” procedure was adopted to improve the aggregate content [ 33 ].…”

“…The compressive stresses or tensile stresses are applied in the horizontal direction according to the stress ratio σ 1 /σ 3 (along the directions of the X-axis (σ 1 ) and Y-axis (σ 3 )), and the displacement is applied along the vertical direction (the direction of the Z-axis (σ 2 )). The mesh convergence study was conducted before the loading analysis [ 32 ]. An element length of 1 mm was employed in the following analysis.…”

Numerical Study of Concrete Dynamic Splitting Based on 3D Realistic Aggregate Mesoscopic Model

“…The results show that the irregular shape of aggregate has an important effect on the crack propagation and final fracture morphology. Zhang et al [ 26 ] used mosaic of Voronoi to generate a random polyhedral aggregate model, and simulated the mechanical behaviors of concrete under quasi-static loading. The damage evolution showed that ITZ had a great influence on the failure of concrete, and the fracture started from ITZ and extended to mortar.…”