Validation of two different analysis techniques to obtain dynamic mechanical properties of concrete using a modified Hopkinson Bar

In the present work, two different approaches for obtaining dynamic fracture properties of concrete are analyzed. Spalling tests over cylindrical samples using a modified Hopkinson Bar were carried to measure the tensile strength and the fracture energy of conventional concrete. Results for strain rates ranging from 60 to 130 s are presented for both techniques and compared to the respective quasi-static values. Moreover, two different projectile shapes (cylindrical and conical) have also been evaluated. In this sense, a deep qualitative and quantitative analysis is also performed, regarding the variations in tensile stress evolution of the pulses. Validation of both methodologies is achieved by comparing the obtained results.