Micromechanical Modeling for Material Design of Durable Infrastructural Materials: The Influence of Aggregate and Matrix Modification on Elastic Behavior of Mortars

Abstract

This paper reports the fundamental difference in microstress distributions in traditional hardened cement paste with quartz inclusions and a cement paste with lightweight aggregate (LWA) inclusions using microstructurebased numerical simulation involving finite element method with periodic boundary conditions. Variation of relative stress distributions under varying component material properties and varying microstructural features in both the systems is elucidated for a comprehensive understanding. The presented microstructure-based numerical technique accurately captures the stress concentrations inside microheterogeneous systems, which is otherwise not detectible using analytical homogenization schemes. Numerical simulations reveal that strengthening and stiffening of matrix and interfacial transition zone (ITZ) with silica fume incorporation as cement replacement in LWA incorporated cementitious systems has a detrimental effect in terms of overall strength of the material, contrary to traditional quartz-based cement mortar system. Proper selection of stiffness and strength of LWA inclusions is critical towards performance of such materials. This paper links the microstructure with mechanical behavior of two different microheterogeneous materials and provides valuable input towards material design of such non-traditional cementitious systems with different inclusions.

A Peridynamics-Based Micromechanical Modeling Approach for Random Heterogeneous Structural Materials

“…Thus, the final states of the particles in the representative geometry are obtained. The representative unit cells are periodic in nature [43][44][45][46][47] implying material continuity at the boundaries. The information pertaining to the final particle radii and their locations along with their orientations are passed as input parameters to the discretization module.…”

Microstructure-guided numerical simulation to evaluate the influence of phase change materials (PCMs) on the freeze-thaw response of concrete pavements

“…Periodic boundary conditions (PBC) [33][34][35][36] are applied on the RVE. Periodicity provides higher computational efficiency in smaller analysis domain and thus facilitates faster convergence [27].…”

“…Periodic boundary conditions (PBC) ensure continuity of temperature and heat flux at the boarder of neighboring unit cells. PBCs have been applied successfully towards prediction of effective properties of heterogeneous composites [26] and are detailed adequately in [33][34][35][36]. Figure 2 presents the microstructures generated for multi-scale homogenization.…”

Influence of microencapsulated phase change materials (PCMs) on the chloride ion diffusivity of concretes exposed to Freeze-thaw cycles: Insights from multiscale numerical simulations

“…The numerical homogenization approach is schematically illustrated in Figure 2. The approach involves: (1) representative unit cell generation implementing the known microstructural features of the material, (2) application of periodic boundary conditions (PBCs) [29][30][31][32] and (3) implementation of a post-processing module that yields effective properties as explained in the forthcoming sub-sections.…”

“…Detailed formulations of the iterative process where particles change positions in the bounding box, collide and grow to achieve the desired volume fraction are mentioned elsewhere [37]. Periodic boundary conditions (PBC) [29][30][31][32] are applied to the generated unit cells. Such boundary conditions are computationally efficient and therefore suited for faster convergence in smaller analysis domains.…”