Influence of Boundary Conditions on Numerical Homogenization of High Performance Concrete.

Arkadiusz Denisiewicz,Mieczysław Kuczma,Krzysztof Kula,Tomasz Socha

doi:10.3390/ma14041009

Arkadiusz Denisiewicz, Mieczysław Kuczma + Show 2 more

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https://doi.org/10.3390/ma14041009

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Abstract

Concrete is the most widely used construction material nowadays. We are concerned with the computational modelling and laboratory testing of high-performance concrete (HPC). The idea of HPC is to enhance the functionality and sustainability of normal concrete, especially by its greater ductility as well as higher compressive, tensile, and flexural strengths. In this paper, the influence of three types (linear displacement, uniform traction, and periodic) of boundary conditions used in numerical homogenization on the calculated values of HPC properties is determined and compared with experimental data. We take into account the softening behavior of HPC due to the development of damage (micro-cracks), which finally leads to failure. The results of numerical simulations of the HPC samples were obtained by using the Abaqus package that we supplemented with our in-house finite element method (FEM) computer programs written in Python and the homogenization toolbox Homtools. This has allowed us to better account for the nonlinear response of concrete. In studying the microstructure of HPC, we considered a two-dimensional representative volume element using the finite element method. Because of the random character of the arrangement of concrete’s components, we utilized a stochastic method to generate the representative volume element (RVE) structure. Different constitutive models were used for the components of HPC: quartz sand—linear elastic, steel fibers—ideal elastic-plastic, and cement matrix—concrete damage plasticity. The numerical results obtained are compared with our own experimental data and those from the literature, and a good agreement can be observed.

Highlights

Significant progress in developing high-performance concrete (HPC) has been observed since the invention of a concrete from reactive powders (RPC) in the 1990s [1,2,3].Concretes of this type are characterized by a much higher compressive strength, flexural tensile strength, ductility, and resilience to an aggressive environment than traditional concrete
We restrict our numerical computations to the local boundary value problem (BVP) on the representative volume element (RVE) of high-performance concrete, checking the influence of different boundary conditions imposed on the boundary of RVE
The technique of numerical homogenization was used for determining the macroscopic response of high-performance concrete modelled as a nonhomogeneous multi-phase nonlinear composite

Summary

Introduction

Significant progress in developing high-performance concrete (HPC) has been observed since the invention of a concrete from reactive powders (RPC) in the 1990s [1,2,3]. Concretes of this type are characterized by a much higher compressive strength, flexural tensile strength, ductility, and resilience to an aggressive environment than traditional concrete. Publications about the properties of cement-based composites, a name that can be used for HPC, are concerned in most cases with experimental testing. One of the basic phenomena that significantly affect endurance of HPC is the formation and propagation of cracks in the microstructure of material [17,18,19]

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