Analytical and numerical model to predict the behavior of RC beams strengthened with UHPC jackets

In this present work, an analytical and numerical analysis was carried out to predict the flexural response of RC beams strengthened with Ultra-high-performance concrete (UHPC) jackets of varying thicknesses (5, 10 and 15 mm). The analytical models aimed to incorporate the geometric and material properties of the constituent components, such as Young's modulus, compressive strength and tensile strength of UHPC, Normal strength concrete (NSC), and steel. The momentcurvature and deformation behaviour of the composite RC beams was evaluated from the analytical model. Furthermore, the numerical analysis is performed using finite element tools to predict the same and compare it with the analytical model. The primary objective is to validate the developed analytical and numerical model with the results of the UHPC strip attached at the bottom of the beams available in the literature. The relative study of strengthened beams of varying thickness over control beams illustrated a significant increase in flexural response with an increase in the thickness of UHPC jacketing. The maximum increase in flexural capacity for UHPC jacketed beam (15 mm) is 45% compared to the reference beam. The deviation in results between the analytical and numerical models is less than 7.2% and closely match the existing experimental results. The outcome of this study provided essential insights into the effectiveness of UHPC jacketing as one of the strengthening solutions for damaged/distressed RC structures.