Fracture response of metallic particulate-reinforced cementitious composites: Insights from experiments and multiscale numerical simulations

Abstract

This paper presents an experimental and numerical investigation into the fracture response of mortars containing up to 30% waste iron powder by volume as OPC-replacement. The iron powdermodified mortars demonstrate significantly improved strength and fracture properties as compared to the control mortars due to presence of elongated iron particulates in the powder. With a view to develop a predictive tool towards materials design of such particulate-reinforced systems, fracture responses of iron powder-modified mortars are simulated using a multiscale numerical approach. The approach implements multi-scale numerical homogenization involving cohesive zone-based damage at the matrix-inclusion interface and isotropic damage in the matrix to obtain composite constitutive response and fracture energy. Consequently, these results serve as input to macro-scale XFEM-based three-point-bend simulations of notched mortar beams. The simulated macroscopic fracture behavior exhibit excellent match with the experimental results. Thus, the numerical approach links the material microstructure to macroscopic fracture parameters facilitating microstructure-guided material design.

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

“…In an iterative framework, the frequency of such collisions increases with increase in the size of the particles. The formulations of the iterative framework that terminates at a target volume fraction, as presented in [39], places the particles at various positions in the bounding box, which thereafter collide and grow so as to achieve the target volume fraction [42]. The iterative algorithm is terminated as the inclusions occupy the target volume fraction.…”

“…This section applies the aforementioned peridynamics-based framework towards performanceprediction of particulate-reinforced cementitious composite. Incorporation of waste iron powder replacing cement not only improves sustainability credentials of cementitious composite (due to reduction in cement-consumption) but also contributes towards enhanced mechanical behavior [38,39]. EAF (electric arc furnace) method of steel production and shot-blasting of structural steel sections generate a vast amount of the aforementioned waste iron powder which are landfilled at enormous environmental costs.…”

“…Use of analytical homogenization techniques resulting in closed form solutions to predict constitutive relationships for such heterogenous systems is rendered ineffective owing to the stiffness contrasts in the component phases. A finite element (FE)-based study governed by cohesive laws for the interfaces and progressive damage in the matrix has been carried out for the metallic particulate-reinforced cementitious composite in the authors' previous publication [39]. The damage law for the interface and the matrix in the FE study [39] are provided hereafter so as to provide insights into the merit of peridynamics application.…”

“…A finite element (FE)-based study governed by cohesive laws for the interfaces and progressive damage in the matrix has been carried out for the metallic particulate-reinforced cementitious composite in the authors' previous publication [39]. The damage law for the interface and the matrix in the FE study [39] are provided hereafter so as to provide insights into the merit of peridynamics application. The governing damage laws, used in the FE study, in the matrix are mentioned in Equation (16).…”

“…where σ c is the traction, λ is the separation, K p is the penalty stiffness, G F is the total fracture energy, f t is the tensile strength and λ 0 is the threshold limit of separation. The formulations are adequately detailed in [39]. Herein, employing peridynamics leads to a non-local method well suited for modeling solid bodies with stiffness-mismatch.…”