Static and fatigue responses of retrofitted RC beams with GGBS based UHPC strips

Abstract

The strengthening techniques are primarily studied and well documented for the monotonic responses of RC structures. Perhaps, the knowledge concerned about fatigue or cyclic responses of RC structures is limited in the literature. Hence, the static and fatigue responses of retrofitted RC beams with GGBS based ultra-high performance concrete strips (5, 10 and 15 mm thick) have been investigated in this study. The results illustrated that even a thin UHPC strip (5 mm) can significantly increase the static and fatigue performance of RC members. A finite element model has been developed to predict the numerical response of retrofitted RC beams subjected to static and fatigue loads. Numerical studies incorporated with crucial parameters such as concrete damage model, failure criteria, stress-crack relation and fracture properties are performed. The predicated numerical model correlates with the corresponding experiments with a little deviation of less than 12%. These deviations could be mainly attributed to the porosity of concrete, rebar slip, and experimental errors in testing the massive specimen under fatigue loading.