Seismic Rehabilitation of Existing Buildings

Behaviour of beam–column joints made of recycled-aggregate concrete under cyclic loading

https://www.tpbin.com/Uploads/Subjects/f679e157-1668-4b5b-b64d-7db23229dd85.pdf

A new model to simulate joint shear behavior of poorly detailed beam–column connections in RC structures under seismic loads, Part I: Exterior joints

Premature brittle failures because of seismic actions strongly affect the behavior of existing reinforced concrete (RC) structural systems. They commonly involve exterior beam-column joints of structures designed without transverse reinforcement. This paper investigates the behavior of unconfined joints that do not conform to current seismic codes and the effectiveness of externally bonded fiber-reinforced polymers (FRPs) as a strengthening technique. It presents an experimental program carried out on six full-scale RC corner joints under constant axial load and transverse cyclic loading in the as-built and FRP-strengthened configuration. After describing the specimen design strategy and test setup, seismic performance is compared. Particular attention is paid to comparing the experimental capacity of as-built joints and the capacity, which can be predicted on the basis of models available in the literature. Finally, a discussion on the effectiveness of different FRP-strengthening layouts is reported.

Experimental Investigation of Exterior RC Beam-Column Joints Retrofitted with FRP Systems

Study of the seismic behavior of external RC beam–column joints through experimental tests and numerical simulations

Key influence parameters for the joint shear behaviour of reinforced concrete (RC) beam–column connections

An extensive database has been constructed of reinforced concrete (RC) beam-column connection tests subjected to cyclic lateral loading. All cases within the database experienced joint shear failure, either in conjunction with or without yielding of longitudinal beam reinforcement. Using the experimental database, envelope curves of joint shear stress vs. joint shear strain behavior have been created by connecting key points such as cracking, yielding, and peak loading. Various prediction approaches for RC joint shear behavior are discussed using the constructed experimental database. RC joint shear strength and deformation models are first presented using the database in conjunction with a Bayesian parameter estimation method, and then a complete model applicable to the full range of RC joint shear behavior is suggested. An RC joint shear prediction model following a U.S. standard is next summarized and evaluated. Finally, a particular joint shear prediction model using basic joint shear resistance mechanisms is described and for the first time critically assessed.

https://www.koreascience.or.kr:443/article/JAKO201120956423778.pdf

Joint Shear Behavior Prediction for RC Beam-Column Connections

This paper constructs an extensive experimental database that includes all the types of reinforced concrete (RC) beam-column connections found in the literature to have experimental joint shear failure. Three kinds of RC joint shear strength models are developed using this database in conjunction with a Bayesian parameter estimation method. The improved performance of the developed joint shear strength models is evaluated by comparison with other deterministic RC joint shear strength models from the literature and codes. A modified ACI 352R-02 joint shear strength definition for design, with adjusted joint shear strength factors for greater consistency, is suggested.

Probabilistic Joint Shear Strength Models for Design of RC Beam-Column Connections

An extensive experimental database of reinforced concrete (RC) beam-column connections subjected to cyclic lateral loading has been constructed. All cases within the database experienced joint shea...

A Simplified Approach to Joint Shear Behavior Prediction of RC Beam-Column Connections

Reinforced concrete (RC) joint shear strength models are constructed using an experimental database in conjunction with a Bayesian parameter estimation method. The experimental database consists of RC beam-column connection test subassemblies that maintained proper confinement within the joint panel. All included test subassemblies were subjected to quasi-static cyclic lateral loading and eventually experienced joint shear failure (either in conjunction with or without yielding of beam reinforcement); subassemblies with out-of-plane members and/or eccentricity between the beam(s) and the column are not included in this study. Three types of joint shear strength models are developed. The first model considers all possible influence parameters on joint shear strength. The second model contains those parameters left after a step-wise process that systematically identifies and removes the least important parameters affecting RC joint shear strength. The third model simplifies the second model for convenient application in practical design. All three models are unbiased and show similar levels of scatter. Finally, the improved performance of the simplified model for design is identified by comparison with the current ACI 352R-02 RC joint shear strength model.

Jaehong Kim

Papers

Key influence parameters for the joint shear behaviour of reinforced concrete (RC) beam–column connections

Joint Shear Behavior Prediction for RC Beam-Column Connections

Probabilistic Joint Shear Strength Models for Design of RC Beam-Column Connections

A Simplified Approach to Joint Shear Behavior Prediction of RC Beam-Column Connections

A new statistical approach for joint shear strength determination of RC beam-column connections subjected to lateral earthquake loading