Hysteresis and damping properties of steel and polypropylene fiber reinforced recycled aggregate concrete under uniaxial low-cycle loadings

Abstract

To investigate the hysteresis and damping properties of fiber-reinforced recycled aggregate concrete (FRAC), a series of cyclic compressive tests of SF-reinforced natural aggregate concrete (SF-R-NAC), SF-reinforced RAC (SF-R-RAC), and PPF-reinforced RAC (PPF-R-RAC) with different fiber contents were carried out. The development law of residual strain was explored, and the relationship between residual strain and unloading strain was suggested. Also, a modified constitutive model of the stress–strain relationship was proposed. Variation of the hysteretic characteristics of FRAC including hysteretic strain energy and residual strain energy under cyclic compressive loadings was analyzed. An equivalent hysteretic viscous damping ratio was suggested and analyzed by using based on Jacobsen’s approach. Furthermore, a new hysteretic viscous damping model represented by residual strain was proposed accounting for the fiber content. Based on the modified constitutive model, the hysteretic viscous damping model is predicted and analyzed to verify the effectiveness and accuracy of the model.