Investigation into stress wave propagation across interlayers existing in roller compacted concrete (RCC) under impact loadings

摘要

The weak bonding interlayers in roller compacted concrete (RCC) have significant influence on the physical and mechanical behaviors for its layered structure. However, less attention has been paid to the stress wave propagation across interlayers under impact loadings. In this paper, the split Hopkinson Pressure Bar (SHPB) is used to investigate the stress wave propagation across RCC, characterized by reflection and transmission coefficients. It is found that the stress wave propagation across RCC is influenced by the interlayer and exhibits obvious strain-rate sensitivity under impact loadings. Furthermore, an equivalent viscoelastic medium model is suggested to analyze the stress wave propagation across RCC specimen, which verifies that the wave attenuation lies in the nonlinear deformation behavior of RCC. The theoretical transmission coefficient of stress wave in SHPB test is negatively related to relative wave impedance, wave attenuation coefficient and specimen length. Besides, much less wave attenuation will occur when RCC specimens are exposed to higher strain-rate loadings. This paper further interprets the mechanism for the dynamic behaviors of layered RCC in term of stress wave propagation and indicates the ability of interlayers to obstruct the wave propagation effectively. (C) 2018 Elsevier Ltd. All rights reserved.