علي حسني

With the rapid population growth and the increasing need for mass housing and fast construction execution, utilizing modern construction technologies has become an inevitable necessity in the building industry. One of these technologies is the permanent polymer formwork (RBS), which not only reduces construction time and costs but also enhances the final structural quality and improves seismic safety. However, given the use of these permanent formworks in structures, it is essential to conduct research and investigations into the behavior of the composite system consisting of RBS, concrete, and steel. These formworks appear to have a positive impact on the seismic performance of structures, yet more comprehensive studies are required to confirm this hypothesis. This study experimentally eva‎luates the seismic performance of reinforced concrete (RC) walls equipped with permanent polymer formwork (RBS) under full-scale cyclic lateral loading. For this purpose, two wall specimens with identical geometric dimensions and similar structural characteristics were constructed. The first specimen was a conventional RC wall with uniform reinforcement in both vertical and horizontal directions, while the second specimen was an RC wall with vertical reinforcement and permanent polymer formwork (RBS). The dimensions of these specimens were designed to enable a detailed examination of their structural behavior and to assess the impact of permanent formworks on stiffness, ductility, and ultimate strength. The walls were subjected to a standard cyclic lateral loading protocol to analyze their ultimate resistance, ductility, energy dissipation capacity, and hysteresis behavior. Additionally, tensile and mechanical characterization tests were conducted on the polymer formwork materials to eva‎luate their role in enhancing the structural performance of the walls. These analyses provided a deeper understanding of the influence of polymer formworks on nonlinear behavior and seismic resistance of RC walls. The results of this study demonstrated that RC walls equipped with RBS exhibited superior seismic performance compared to conventional RC walls. The RC wall with uniform reinforcement experienced sudden shear failure, accompanied by widespread diagonal cracking and a rapid reduction in load-bearing capacity. This type of failure indicated a brittle and less ductile behavior, along with a sudden loss of stiffness and strength in the final loading cycles. In contrast, the RC wall with permanent polymer formwork (RBS) exhibited a more gradual and ductile failure mechanism, characterized by evenly distributed flexural cracks along the height of the wall. The polymer formwork played a significant role in enhancing the bond between concrete and steel, preventing premature failure. Moreover, the experimental data analysis revealed that RBS walls had up to 10 times higher energy dissipation capacity and could withstand larger deformations. Examination of cyclic force-displacement curves and hysteresis loops indicated a gradual reduction in lateral stiffness while maintaining stable nonlinear behavior in the RBS walls. Additionally, these walls showed greater retention of load-bearing capacity under multiple cycles of lateral loading. The hysteresis envelope analysis confirmed that these walls not only had an adequate ultimate load-bearing capacity but also demonstrated superior lateral displacement resistance compared to conventional RC walls. These findings suggest that RBS formworks significantly improve the seismic behavior of structures and contribute to reducing earthquake-induced damage and enhancing structural durability. Overall, the findings of this research indicate that the use of permanent polymer formworks not only optimizes the construction process but also enhances ductility and energy absorption, making them a suitable option for improving the seismic performance of structures in earthquake-prone areas.

ديوار بتن آرمه با قالب پليمري ماندگار , RBS , رفتار لرزه اي , بار رفت و برگشتي , بار جانبي

Reinforced Concrete Wall with Permanent Polymer Formwork , RBS , Seismic Behavior , Cyclic Loading , Lateral Load

Ali Hassani

Dr. Mohsenali Shayanfar & Dr. Rasoul Ahmadi