Modeling of RC shear walls strengthened with ultra-high performance fiber reinforced concrete (UHPFRC) jackets

Abstract

Reinforced concrete (RC) shear walls are considered one of the main lateral resisting members in RC buildings. Recently, ultra-high performance fiber reinforced concrete (UHPFRC) is an advanced cement composite material, which is characterized by high tensile and compressive strength, ductility, durability and fracture toughness. Nevertheless, while extensive studies have shown the superior mechanical of UHPFRC at the material scale, there remain very few studies on the application of UHPFRC for retrofit/strengthening structural elements especially under lateral loading like earthquake. This paper numerically analyzed the behavior of strengthened RC shear walls by a UHPFRC and reinforced UHPFRC (R-UHPFRC) jacketing under lateral loading using a two-dimensional (2D) model and the bond stress-slip model was incorporated to the analysis to simulate the interfacial concrete-to-concrete bond. First, behavior of RC and UHPFRC shear walls subjected to lateral loading is investigated using the proposed 2D model. Validation of the model is done using the available experimental results. The validated model is utilized to study the behavior of RC shear walls strengthened by UHPFRC and R-UHPFRC jacketing under lateral loading. It is stated that the strengthening procedure improved diagonal tension shear strength of the reference weak RC wall. Finally, the effectiveness of the proposed procedure is shown by performing a comparison with the outcomes of numerical analysis of RC shear wall strengthened by external CFRP sheets available in the literature.