Arabian Journal for Science and Engineering (2019) 44:4095–4109 https://doi.org/10.1007/s13369-018-3281-4 RESEARCH ARTICLE - CIVIL ENGINEERING Seismic Behavior of Hybrid Post-Tensioned Cast in Place Concrete Shear Walls Anis Shatnawi 1 · Sara G. Abdallah 1 · Bashar Tarawneh 1 Received: 3 September 2017 / Accepted: 18 April 2018 / Published online: 26 April 2018 © King Fahd University of Petroleum & Minerals 2018 Abstract A hybrid concrete shear wall system is created by combining the conventional reinforced concrete construction with post- tensioning technology. Such hybrid shear wall with continuous mild steel combined with post-tensioned (PT) steel provides superior restoring, energy dissipation, and ductile behavior over larger lateral displacements. Hence, both mild steel and high-strength post-tensioning steel contribute to the flexural strength. This leads to a reduction in the total area of steel when compared to the conventional reinforced concrete shear wall. When using a hybrid system, the lateral load response varies based on the ratio of post-tensioning steel to the mild steel reinforcement. In this research, the seismic behavior of hybrid unbonded PT concrete shear walls is investigated. Finite element analysis using ABAQUS for multi-hybrid shear walls of different ratios of post-tensioning steel area to mild steel area is performed. Results show that the large nonlinear displacements in PT shear wall may be reduced by using more mild steel reinforcement in the hybrid unbonded PT system. The post-tensioning steel provides a restoring force that eliminates the permanent deformation after cyclic load and reduces the displacement peaks during a cycle. However, PT walls incorporating only post-tensioning bars do not provide a sufficient amount of energy dissipation to limit seismic displacement adequately. By increasing the mild steel reinforcement area concerning the post-tensioning steel area, seismic energy can be dissipated by the yielding of mild steel. Keywords Seismic · Shear wall · Hybrid · Post-tension 1 Introduction The benefit of the unbonded hybrid post-tensioned cast in place (PT-CIP) shear walls is that the unbonding allows the shear wall to undergo larger nonlinear displacement without yielding of PT bars. Moreover, the restoring force pro- vided by post-tensioning steel results in higher self-centering capacity upon unloading which eliminates residual deforma- tion after the seismic action. Consequently, the shear wall can experience larger lateral deformation without failure. The main criteria that a structural designer aims to satisfy when performing seismic design are stiffness, strength, and B Bashar Tarawneh btarawneh@ju.edu.jo Anis Shatnawi ashatnawi@ju.edu.jo Sara G. Abdallah Sara.G.Abdallah@gmail.com 1 Civil Engineering Department, The University of Jordan, Amman 11942, Jordan ductility. Concrete shear walls have proven their ability to provide nearly optimum means of achieving those objectives and have demonstrated an excellent seismic performance over the years [1]. For that reason, concrete shear walls have been used as the primary lateral load resistance system for different types of concrete structures. Smith et al. [2] investigated the potential use of precast walls as special reinforced concrete shear walls in high seis- mic regions. The behavior of the hybrid wall with Type II splices was also limited, which occurred because of the pull- out of the mild steel bars. In contrast, the hybrid wall with continuous mild steel bars showed better restoring, energy dissipation, and ductile behavior with larger lateral deforma- tion. Zhu and Guo [3] presented an experimental study on the emulative hybrid precast concrete shear walls. The emulative hybrid wall combined grouted vertical reinforcements with unbonded PT high-strength multi-strand tendons for lateral resistance, attempting to emulate the cast-in-place reinforced concrete. The reversed cyclic lateral loading experiments were conducted. The emulative hybrid wall specimens were 123