BEHAVIOR OF RCS (REINFORCED CONCRETE STEEL) BEAM-COLUMN CONNECTIONS UNDER CYCLIC LOAD

• Main Author: Herdiansah, Yudi
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46792
• Institution: Institut Teknologi Bandung

The RCS (Reinforced Concrete Steel) system is a structural system that has been developed in recent decades. The RCS system is a composite moment resisting frame, consisting of steel beams and reinforced concrete columns. RCS structures have advantages in terms of structural performance, construction cost efficiency, and ease of construction compared to conventional reinforced concrete and steel frame structures. The RCS structures combine the advantages of concrete and steel materials as structural components and form an efficient structure. The study of the RCS system applied in high seismic zones began in the early 1990s. The RCS beam-column connection details still developed to obtain connection details that have better performance and behavior due to the earthquakes and can apply in high seismic zones. Additionally, the direction of construction development towards precast systems encourages innovation in developing precast RCS systems. The main problem in RCS beam-column connections is constructability. The volumetric ratio of steel to concrete in the RCS connection area is quite large, due to the presence of beams which are installed continuously into the column, as well as longitudinal reinforcement and stirrups of the column. These conditions can cause problems during construction and decrease the quality of concrete in the connection area, especially in precast construction that emphasizes constructability. Removing most of the beam steel web in the connection area (void web) can reduce the potential for these problems. However, the void web has an impact on the loss contribution of the shear strength from the steel web panel in the connection area, which is an area with a high shear region. This research conducted to examine the RCS connection with the void web, combined with detail components that can mobilize concrete compressive strut on the joint panel, including additional bearing plates (ABP), band plates (BP), extended band plates (EBP), and stirrups in the connection area. The study was conducted through an experimental test of four specimens of RCS interior sub-assemblage beam-column joints, which subjected to cyclic load reversals. The proposed connection details are tested and compared with standard connection details without a void web developed by Liang and Parra-Montesinos (2004). The variables tested were the effects of the void web on RCS connections, as well as detail components of ABP, BP, EBP, and the number of stirrups in the connection area. The research was also carried out numerically through the analysis of three-dimensional finite element methods with the ANSYS 15.0 software, to obtain parameters that could not be obtained through experimental testing. The connection behavior is evaluated based on the parameters of strength, stiffness degradation, energy dissipation capacity, connection shear deformation, and stress distribution. The proposed RCS connection is also assessed based on ANSI/AISC 341-16 Seismic Provisions (2016) to determine its feasibility to applied in high earthquake risk zones. The results showed that web voids on RCS connections did not significantly affect on reducing joint shear strength. The compression strut of inner and outer concrete in the join panel effectively provide joint shear resistance. The EBP detail component is proven on increasing joint stiffness and reducing shear deformation effectively, to prevent damage due to joint shear failure. Additionally, EBP can mobilize concrete compressive struts on the outer concrete panel, and avoid strength degradation at drift ratios above 4.0%. The RCS connection with the void web and the proposed details can meet the deformation and strength requirements based on ANSI / AISC 341-10 as a Composite-Special Moment Resisting Frame System (C-SMRF), which applied in areas with high seismic zones. The joint shear strength equation based on the 1994 ASCE Guidelines and the Update Guidelines provides a conservative value for the design of RCS connections with the void web, for that the shear strength factors for inner and outer concrete in the connection panel are proposed in this study.