Effect of steel and carbon fiber additions on the dynamic properties of concrete containing silica fume

Fiber reinforced concretes (FRC) are technologically important due to their combination of good structural properties, durability and multifunctional properties. The behavior of a structure under dynamic actions is determined by its dynamic mechanical properties and its total overall damping. In this work the influence of the steel fiber (SF) and carbon fiber (CF) additions on the mechanical properties of concrete containing silica fume has been studied, focusing on its passive material damping ability (damping ratio) and dynamic properties. According to the obtained results, under dynamic loads of low magnitude and high frequency, CF additions are more effective than SF additions for reducing vibrations, as they increase the damping ratio of concrete. In all cases, the dynamic elastic properties of concrete present higher values than their static counterparts. Both CF and SF additions lead to slight decreases of the compressive strength of concrete. For the same volumetric fraction, this fact is more significant in the concrete types containing SF.