Experimental and numerical study on damage evaluation of hybrid fiber-reinforced concrete

Abstract

In this present study, static and dynamic properties of hybrid fiber-reinforced concrete (HFRC) were experimentally investigated. The mechanical properties accompanied by compressive strength, splitting tensile strength and flexural strength were evaluated for several combinations of mixtures containing hybrid fibers. In addition, dynamic properties such as damping ratio, mode shape and fundamental natural frequency have also been experimentally determined for the prismatic beams in free–free condition in order to evaluate the damage characteristics of HFRCs. Total fiber volume fractions of 0.25, 0.5 and 0.75% with different combinations of steel and polypropylene (PP) fibers have been considered in this investigation. Among various percentage additions of hybrid fibers, a mixture that contains 0.25% of total fiber volume fraction with the combination of 75% of steel and 25% of PP fibers has acquired the best performance. Furthermore, the natural frequencies of HFRC specimens decrease with the increase in fiber content as well as decrease with the increase in structural damage, whereas the damping ratio increases with the increase in fiber content and structural damage. Numerical modeling was also developed for control and HFRC specimens using ANSYS software to compare the experimental results with the analytical model prediction. It was also found that the HFRC with the combination of 75% of steel and 25% of PP fibers with total fiber volume fraction of 0.75% has the highest damping properties.