Elastic and Dissipative Properties of Concrete under Impact Loads

Abstract

Concrete structures during their service life are subjected to vibrations and impact loads in addition to static forces. Just these loads are more often responsible for their critical state. Mathematical simulation of the vibration and impact processes in concrete is based on the viscoelastic constitutive relations. Information for the correct and reliable evaluation of the parameters of these models can be obtained from the experiments where the character of testing load corresponds to the real operating conditions of the structure.In this paper a theoretical and experimental approach is proposed to determinate elastic and dissipative characteristics of concrete. In the framework of viscoelastic model, the deformation response of a concrete specimen to an impact load is analyzed. Based on the results of numerical experiments, a structural scheme of experiments has been obtained to determine the elastic and dissipative properties of concrete.A series of physical experiments was performed to study the deformation behavior of a concrete sample, which experienced free vibrations. The elastic and dissipative characteristics of the material were obtained by applying an iterative procedure ensuring the agreement between the results of experimental measurements and calculated data. Estimation of the dependence of the material properties on the vibration frequency was made. The proposed approach to determining the properties of concrete provides high sensitivity of the vibrodiagnostic procedure to the appearance and development of defects in concrete structures.