Application of Bender Elements Technique in Testing of Anthropogenic Soil—Recycled Concrete Aggregate and Its Mixture with Rubber Chips

Abstract

This paper discusses the application of piezoceramic bender elements (BEs) for measurement of shear wave velocity in the time and frequency domain in a triaxial cell under different isotropic confinement. Different interpretation methods were used in the tests and their results were finally compared with each other. Two types of anthropogenic material were tested: pure Recycled Concrete Aggregate (RCA) and RCA-rubber chips mixtures (15% of rubber addition). Presented study is an attempt to describe dynamic properties, in terms of shear wave velocity (VS), of the aforementioned anthropogenic material using the technique commonly applied for natural soil. Although some research is currently being carried out, in order to evaluate physical, chemical and mechanical properties of RCA and rubber-soil mixtures, still little is known of their dynamic properties. Hence, this work will provide the experimental results of shear wave velocity of RCA and its modified version. The results show that tires chips significantly decrease the VS values of modified RCA. They help to reduce the near field effect, but the received parameters are more incoherent. The VS values were found to be influenced by interpretation technique, mean effective stress and wave’s propagation period. The maximum VS values were obtained mostly from the frequency domain method, although time domain analysis gives the results that are more coherent.

Keywords

• anthropogenic soil dynamics
• bender elements tests
• shear wave velocity
• recycled concrete aggregate
• rubber chips