Investigation of aggregate size effects on the compressive behavior of concrete by electromechanical and mechanical impedance spectroscopy

Concrete is a composite material that is composed of cement mortar and aggregate. The size of the aggregates in the internal structure of concrete affects the mechanical properties and compressive strength of the concrete. In this study, three-dimensional concrete models are created by idealizing the material properties such as modulus of elasticity and mass density which were experimentally acquired in order to investigate the effect of varying size of the aggregates on the compressive strength of concrete cubes in the age of 28 days. Piezoelectric ceramic patches (PZT) are embedded in the core of the concrete cube models with aggregates in fine, medium, and coarse sizes and the harmonic analyses are simulated in commercial software, ABAQUS® using the multi-physics finite element method (MP-FEA). Eventually, electromechanical impedance spectroscopy (EMIS) results as well as mechanical impedance spectroscopy (MIS) results are obtained to highlight the relative changes in the impedance results depending on the aggregate sizes. Thus, EMIS and MIS simulation results are employed in order to predict the effects of varying aggregate sizes on the compressive strengths of the concrete models.