Implications of Experiments on the Seismic Behavior of Gravity Load Designed RC Beam-to-Column Connections

1996 ◽  
Vol 12 (2) ◽  
pp. 185-198 ◽  
Author(s):  
Attila Beres ◽  
Stephen P. Pessiki ◽  
Richard N. White ◽  
Peter Gergely
Keyword(s):  
Reinforced Concrete ◽  
Seismic Behavior ◽  
Test Results ◽  
Joint Shear Strength ◽  
Cornell University ◽  
Gravity Load ◽  
Concrete Building ◽  
Load Effects ◽  
Definition Of ◽  
Reversed Cyclic

This paper summarizes recent experimental research at Cornell University conducted on the behavior of gravity load designed reinforced concrete building frame components subjected to reversing cyclic loads (simulated seismic effects). Reinforced concrete framing systems, designed primarily for gravity loads, with little or no attention given to lateral load effects, are typically characterized by non-ductile reinforcing details in the joint regions and in the members. The seismic response of connection regions for gravity load design (GLD) frames has received relatively little attention in earlier studies, thus making it difficult to reliably evaluate GLD frames and to properly plan repair or retrofit strategies. Thirty-four full scale bare interior and exterior beam-to-column joints have been tested under reversed cyclic bending to identify the different damage mechanisms and to study the effect of critical details on strength and deformations. The discussion of test results focuses on the definition of joint shear strength factors for GLD frames to complement those provided by ACI-ASCE Committee 352 for frames designed with better details.

Experimental Study on the Structural Performance of Beam-Column Joints in Old Buildings without Designed Shear Reinforcement under Earthquake

2017 ◽  
Vol 902 ◽  
pp. 33-40
Author(s):  
Cong Thuat Dang ◽  
Ngoc Hieu Dinh
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Shear Failure ◽  
Test Results ◽  
Shear Reinforcement ◽  
Reinforcing Bars ◽  
Reinforced Concrete Buildings ◽  
Concrete Buildings ◽  
Gravity Load ◽  
Load Beam

Old reinforced concrete buildings constructed around 1980’s in many developing countries have been designed against mainly gravity load. Beam-column joints in these buildings contain slightly or no shear reinforcement inside the panel zones due to the construction convenience, and are vulnerable to shear failure in beam-column joints under the action of earthquake loads, especially for the exterior beam-column joints. This experimental study aimed to investigate the seismic performance of five half-scale exterior beam-column joints simulating the joints in existing reinforced-concrete buildings with non-shear hoop details. The test results showed that the structural performances of the beam-column joints under earthquake including failure mode, load-drift ratio relationship, shear strain of the joints and energy dissipation are strongly affected by the amount of longitudinal reinforcing bars of beams.

Study on Seismic Behavior of Vertical Connection in Prefabricated Reinforced Concrete Structures

2011 ◽  
Vol 250-253 ◽  
pp. 1385-1394
Author(s):  
Guo Hua Song ◽  
Dong Wei Wang ◽  
Bing Kang Liu
Keyword(s):  
Reinforced Concrete ◽  
Seismic Behavior ◽  
Concrete Structures ◽  
Shear Resistance ◽  
Repeated Loading ◽  
Reinforced Concrete Structures ◽  
Test Results ◽  
Dowel Action ◽  
Cycle Loading ◽  
Good Agreement

The paper attempts to research the seismic behavior and mechanical mechanisms under repeated low-cycle loading of vertical connections in prefabricated reinforced concrete structures. Eighteen specimens were designed and tested, the test process and the mechanical mechanisms are studied, the seismic behavior of connections is analyzed, and the shear resistance formulas are proposed. The theoretical values based on proposed formulas are good agreement with test results. Under repeated loading, the shear resistance decreases, the connection ductility increases with connecting bar, but decreases with connection width. However, all the connections fail crisply with poor ductility. At sudden-cracking, the shear resistance increases with connecting bar, but changes nonlinearly with connection width. The resistance is composed of attributions of mechanism of diagonal-compressive column (MDCC) and mechanism of compressive friction action (MCFA). After sudden-cracking, the shear resistance is provided by weakened MDCC and dowel action of connecting bars (DACB). It increases with connecting bar and connection width.

Experimental Study on Seismic Behavior of High-Rise RC Shear Wall with Diagonal Web Reinforcement

2012 ◽  
Vol 446-449 ◽  
pp. 2305-2308
Author(s):  
Guang Qiang Zhou ◽  
Qing Yang Liu ◽  
De Yuan Zhou
Keyword(s):  
Reinforced Concrete ◽  
Axial Compression ◽  
Seismic Behavior ◽  
Shear Wall ◽  
Concrete Wall ◽  
High Rise ◽  
Web Reinforcement ◽  
Reinforced Concrete Wall ◽  
Rc Shear Wall ◽  
Reversed Cyclic

Based on the experiment of four models of reduced scale high-rise reinforced concrete wall under low-reversed cyclic loading, seismic behavior of reinforced concrete (RC) shear wall with diagonal web reinforcement under different ratio of axial compression is studied, in comparison to ordinary shear wall. The experiment result shows that diagonal bars affect the distribution of cracks and help to resist shear slip at the bottom of the wall. Seismic behavior of high-rise shear wall, which horizontal bars are replaced with the same amount diagonal bars in part can be obviously improved when the ratio of axial compression is high, but when the ratio of axial compression is low, the effect is not obvious.

scholarly journals Seismic Behavior of Rammed Earth Walls with Precast Concrete Tie Columns

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Xinlei Yang ◽  
Hailiang Wang
Keyword(s):  
Rural Areas ◽  
Seismic Behavior ◽  
Precast Concrete ◽  
Rammed Earth ◽  
Deformation Capacity ◽  
Test Results ◽  
Load Bearing ◽  
Displacement Ductility ◽  
Reversed Cyclic ◽  
Earth Walls

Rammed earth (RE) constructions are widespread in underdeveloped rural areas in developing countries. However, these RE constructions are often susceptible to earthquake damage due to their poor seismic performance. Precast concrete tie columns and ring beam (tie bars) were proposed to improve the seismic behavior of RE constructions. Four RE walls, including a traditional RE wall and three RE walls with precast concrete tie columns and ring beam (tie bars), were tested under reversed cyclic loading, and the seismic behavior of these tested specimens was evaluated in terms of failure pattern, energy dissipation, displacement ductility, and stiffness degradation. The results showed that a significant increase of the load-bearing and deformation capacity could be achieved with the application of precast concrete tie columns in combination with RE. The load-bearing capacity and deformation capacity of traditional RE wall were increased by an average of 113% and 417%, respectively. These test results could provide reference to the design and construction of the environmental-friendly structures in rural areas.

Experimental Research on the Seismic Behavior of the SRC Short-Pier Shear Wall with Layered Braces Structures

2011 ◽  
Vol 368-373 ◽  
pp. 2041-2044
Author(s):  
Wen Wu Lan ◽  
Xiu Ning Peng ◽  
Xiao Hua Huang ◽  
Yu Lei
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Seismic Performance ◽  
Axial Load ◽  
Seismic Behavior ◽  
Shear Wall ◽  
Displacement Ductility ◽  
Steel Reinforced Concrete ◽  
New Type ◽  
Reversed Cyclic

A new type of construction employing shaped steels as boundary elements and layered braces of RC(Reinforced Concrete) short-pier shear wall is put forward. The braces are in X shape and are erected in a multi-storied form. They are embedded in the boundary zone and the web of SRC (Steel Reinforced Concrete) short-pier shear wall respectively to make it possible to improve the bearing capacity and ductility of this shear wall and to improve its seismic performance. Three half-scale specimens of the SRC short-pier shear wall are tested under reversed cyclic loading. High design axial load radio of 0.5 is used. The failure processes and modes of the specimens are observed. The law about bearing capacity and displacement ductility of the specimens influenced by the layered braces structures is revealed. The experimental results show that the displacement ductility is closely related to the amount of stories of braces. The specimens with layered braces structures have better ductility and larger bearing capacity, and therefore the layered braces structures effectively improve the seismic performance of the SRC short-pier shear wall.

scholarly journals Seismic Behavior of Innovative Precast Superimposed Concrete Shear Walls with Spiral Hoop and Bolted Steel Connections

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Xi Wu ◽  
Meng-fu Wang ◽  
Ze-long Liu
Keyword(s):  
Seismic Performance ◽  
Seismic Behavior ◽  
Shear Walls ◽  
Test Results ◽  
Force Transmission ◽  
Steel Connections ◽  
Lateral Resistance ◽  
Reversed Cyclic ◽  
Strain Responses ◽  
Wall System

Owing to the desirable bond strength and excellent workability, spiral hoop and bolted steel connectors are introduced to enhance the connecting performance of superimposed reinforced concrete shear wall (SRCSW) system. In order to investigate the seismic performance of SRCSWs, applying such connecting methods under flexure-shear interaction and flexural dominated status, two groups of precast (PC) specimens were constructed: one-story and two-story specimens. Seismic behavior in terms of crack patterns, load-displacement response, ductility, stiffness degradation, strain response, and deformation results of SRCSWs is evaluated by the quasistatic cyclic test. It is shown that the wall specimens with the proposed connectors exhibited similar failure mode to that of the cast-in-place (CIP) walls and possessed adequate seismic performance such as lateral resistance, ultimate drift ratio, and lateral stiffness besides the ease of erection. The strain responses and deformation results of the PC specimens under reversed cyclic loading were presented to evaluate the effectiveness of the introduced connections. The test results indicated that the PC walls adopting bolted steel connectors behaved better in force transmission and exhibited greater integrity characteristic compared with the specimens having spiral hoop connectors. Lastly, simplified finite element models considering the nonlinear slip behavior within the connection joint of SRCSWs were established and verified, which could provide sufficient accuracy and efficiency to predict the seismic response of the proposed wall system.

Performance-Based Evaluation of Reinforced Concrete Building Exterior Joints for Seismic Excitation

2002 ◽  
Vol 18 (3) ◽  
pp. 449-480 ◽  
Author(s):  
Chris P. Pantelides ◽  
Chandra Clyde ◽  
Lawrence D. Reaveley
Keyword(s):  
Reinforced Concrete ◽  
Load Capacity ◽  
Load Reduction ◽  
Limit States ◽  
Joint Shear Strength ◽  
Seismic Rehabilitation ◽  
Specific Performance ◽  
Concrete Building ◽  
Current Design ◽  
Performance Based Evaluation

Beam-column joints of nonductile reinforced concrete buildings that were built prior to the current seismic code provisions have been investigated using several performance-based criteria. Four half-scale reinforced concrete exterior joints were tested to investigate their behavior in a shear-critical failure mode. The joints were subjected to quasi-static cyclic loading, and their performance was examined in terms of lateral load capacity, drift ratio, axial load reduction in the column at high drift ratios, joint shear strength, ductility, shear deformation angle of the joint, and residual strength. Two levels of axial compressive column load were investigated to determine how this variable might influence the performance of the joint. Specific performance levels for this type of reinforced concrete joint were established and a comparison was made to current design and rehabilitation standards. A limit states model was established, which could be used for performance evaluation or seismic rehabilitation.

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