ABSTRACT
Reinforced concrete (RC) structures are subjected to a variety of levels of damage. In order to improve their performance, the authors propose an innovative concept, using prestressed ultra-high performance concrete (UHPC) layer to strengthen damaged RC structures. Finite element analyses were performed to investigate the flexural resistance, deformation characteristics, and failure modes of RC beams strengthened with prestressed UHPC layers. Also, parametric analyses were carried out to reveal the influence of the reinforcement ratio and prestressing level on the flexural capacity of the strengthened beams. The results indicate that prestressed UHPC layers significantly improve the stiffness, cracking and ultimate flexure capacity of RC beams. Also, increasing the prestressing level and reinforcement ratio in the UHPC layer could increase the cracking load and ultimate load, respectively. Thus, using prestressed UHPC layers might be an effective strengthening method to address issues such as insufficient bending capacity in seriously damaged RC members.
