Experimental Analysis on Tensile Dynamic Behavioi of Existing Concrete under High Strain Rates

摘要

The presented research is part of a wider research project involving the study of the dynamic behavior under extreme loads of the Tenza Bridge, a concrete arch bridge located in southern Italy. The dynamic behavior of the concrete of the bridge under tensile loads is herein investigated. Several dynamic tensile tests under different strain rates were performed on concrete specimens at the DynaMat laboratory of the University of Applied Sciences of Southern Switzerland using modified Hopkinson bars. The results were then processed in terms of strength dynamic increase factor-strain rate relationships. These are fundamental to assess constitutive laws of concrete to be implemented in analytical models of the bridge under dynamic loads. The results are compared with existing analytical formulations that attempt to predict the dynamic tensile strength of concrete. The comparisons show that, even though tested concrete was taken from an existing structure, the relationships found in the literature accurately describe its tensile dynamic behavior.