STUDY OF PARAMETERS AFFECTING HYSTERETIC BEHAVIOR OF EXTERIOR BEAM-COLUMN JOINT

• Main Author: Itharani Ulkhaq, Rafie
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/70772
• Institution: Institut Teknologi Bandung

required to avoid shear failure of the beam-column joint. In the ACI 318-14 requirements, joint shear strength is only affected by geometry, effective joint area and concrete compressive strenght. Joint hoops doesn’t affect joint shear strenght, while the ACI 318-14 requirements for adequate joint hoops is follows the column confinement requirements. The requirements of this confinement increases with increasing axial load and concrete compressive strenght. In addition to the ACI 318-14 requirements, the joint shear strength can also be calculated using the Softened Strut-and-Tie (SST) model and Park and Paulay method. The SST model suggests that joint hoops is more important in resisting shear, so the required amount of joint hoops can be reduced. This difference of opinion raises the question of parameters affecting joint shear strength and how it affects the deformability of joint. This research is a study of parameters affecting hysteretic behavior of exterior beam-column joint. These parameters are concrete compressive strength, yield strength of the beam reinforcement, joint hoops ratio and axial load ratio of the column. Fifty exterior beam-column joint specimens were used as the database in this study, which were collected from specimen testing in the previous studies. Statistical analysis was carried out using the Pearson Product Moment (PPM) method on the entire database to determine the correlation of each parameter to the joint hysteretic behavior. The hysteretic behavior studied in this study are joint shear strength and the deformability of the joint. After knowing the parameters affecting joint shear strength, an evaluation of the accuracy of the three formulations of joint shear strength is carried out. Based on the result of this study, for beam failure specimens, parameters affecting joint shear strength are concrete compressive strength and yield strength of the beam reinforcement with a positive correlation. Meanwhile, the parameter affecting deformability of the joint is the yield strength of the beam reinforcement with a negative correlation. For beam failure specimens, joint hoops ratio doesn’t affect joint shear strenght and deformability of the joint. Thus, it is possible that the requirements for joint hoops can be optimized as long as the beam and column iv design satisfied the ACI 318-14 design requirements which require that the columnbeam moment strength ratio be greater than 1.2 to reach strong-column weak-beam behavior. Furthermore, for joint failure specimens, parameters affecting joint shear strength are concrete compressive strength and joint hoops ratio with a positive correlation. Meanwhile, the parameter affecting deformability of the joint is concrete compressive strength with a negative correlation. For joint failure specimens, joint hoops ratio is very important to the joint shear strength. After evaluating the joint shear strength formulation, the SST model provides a more accurate shear strength with an average Vtest/Vn value of 1.43 and a covariance of 0.25.