scholarly journals Quasi-Static Cyclic Tests on Masonry Spandrels

2012 ◽  
Vol 28 (3) ◽  
pp. 907-929 ◽  
Author(s):  
Katrin Beyer ◽  
Alessandro Dazio
Keyword(s):  
Cyclic Loading ◽  
Mechanical Model ◽  
Axial Load ◽  
Failure Mechanisms ◽  
Cyclic Tests ◽  
Masonry Arch ◽  
Test Setup ◽  
Experimental Campaign ◽  
Constant Axial Load ◽  
Deformation Hysteresis

This paper presents the results of an experimental campaign on masonry spandrels. Within this campaign, four masonry spandrels were subjected to quasi-static cyclic loading. Two different spandrel configurations were tested. The first configuration comprised a masonry spandrel with a timber lintel, and the second configuration, a masonry spandrel on a shallow masonry arch. For each configuration, two specimens were tested. The first was tested with a constant axial load in the spandrel, while for the second specimen, the axial load in the spandrel depended on the axial elongation of the spandrel. This paper summarizes the properties of the four test units, the test setup, and the most important results from the experiments, documenting the failure mechanisms that developed and the force-deformation hysteresis of the spandrel elements. The paper also presents a mechanical model for estimating the peak strength of masonry spandrels.

Failure mechanisms of magnesia alumina spinel abradable coatings under thermal cyclic loading

2013 ◽  
Vol 33 (15-16) ◽  
pp. 3335-3343 ◽  
Author(s):  
Svenja Ebert ◽  
Robert Mücke ◽  
Daniel Mack ◽  
Robert Vaßen ◽  
Detlev Stöver ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Failure Mechanisms ◽  
Abradable Coatings

SEISMIC PERFORMANCE OF GFRP-RC RECTANGULAR COLUMNS: NUMERICAL STUDY

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ehab El-Salakawy ◽  
Fangxin Ye ◽  
Yasser Mostafa Selmy
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Axial Load ◽  
Numerical Study ◽  
Concrete Strength ◽  
Weight Ratio ◽  
Concrete Columns ◽  
Load Level ◽  
Reinforced Concrete Columns ◽  
Rectangular Columns

Composite materials like glass fiber-reinforced polymer (GFRP) is becoming widely acceptable to be used as a reinforcing material due to its high ultimate tensile strength-to-weight ratio and excellent resistance to corrosion. However, the seismic behavior of GFRP-reinforced concrete columns has not been fully investigated yet. This paper presents the results of a numerical analysis of full-size GFRP-RC rectangular columns under cyclic loading. The simulated column depicts the lower part of a building column between the foundation and the point of contra-flexure at the mid-height of the column. GFRP reinforcement properties and concrete modeling based on fracture energy have been incorporated in the numerical model. Experimental validation has been used to examine the accuracy of the constructed finite element models (FEMs) using a commercially available software. The validated FEM was used to perform a parametric study, considering several concrete strength values and axial load levels, to study its influence on the performance of the GFRP-reinforced concrete columns under cyclic loading. It was concluded that the hysteretic dissipation capacity deteriorates under high axial load level due to severe softening of the concrete. The FE results showed a substantial improvement of the lateral load-carrying capacities by increasing concrete compressive strength.

Exterior RC joints subjected to monotonic and cyclic loading

2020 ◽  
Vol 37 (7) ◽  
pp. 2319-2336 ◽  
Author(s):  
Yasmin Murad ◽  
Haneen Abdel-Jabar ◽  
Amjad Diab ◽  
Husam Abu Hajar
Keyword(s):  
Shear Strength ◽  
Cyclic Loading ◽  
Axial Load ◽  
Monotonic Loading ◽  
Concrete Compressive Strength ◽  
Joint Shear Strength ◽  
Content Type ◽  
Loading Case ◽  
Joint Shear ◽  
Test Points

Purpose The purpose of this study is to develop two empirical models that predict the shear strength of exterior beam-column joints exposed to monotonic and cyclic loading using Gene expression programming (GEP). Design/methodology/approach The GEP model developed for the monotonic loading case is trained and validated using 81 data test points and that for cyclic loading case is trained and validated using 159 data test points that collected from different 9 and 39 experimental programs, respectively. The parameters that are selected to develop the cyclic GEP model are concrete compressive strength, joint aspect ratio, column axial load and joint transverse reinforcement. The monotonic GEP model is developed using concrete compressive strength, column depth, joint width and column axial load. Findings GEP models are proposed in this paper to predict the joint shear strength of beam-column joints under cyclic and monotonic loading. The predicted results obtained using the GEP models are compared to those calculated using the ACI-352 code formulations. A sensitivity analysis is also performed to further validate the GEP models. Originality/value The proposed GEP models provide an accurate prediction for joint shear strength of beam-column joints under cyclic and monotonic loading that is more fitting to the experimental database than the ACI-352 predictions where the GEP models have higher R2 value than the code formulations.

scholarly journals Gravity Load Collapse Behavior of Nonengineered Reinforced Concrete Columns

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Chichaya Boonmee ◽  
Kittipoom Rodsin ◽  
Krissachai Sriboonma
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Axial Load ◽  
Concrete Columns ◽  
Poor Quality ◽  
Load Level ◽  
Longitudinal Reinforcement ◽  
Reinforced Concrete Columns ◽  
Gravity Load ◽  
Collapse Behavior

This paper aims at investigating gravity load collapse behavior of extremely poor quality reinforced concrete columns under cyclic loading. Such columns were usually constructed by local people and may not be designed to meet any of the standards. It was found that their concrete strength may be as low as 5 MPa and the amount of longitudinal reinforcement may be lower than 1%. This type of column is deliberately defined as “nonengineered reinforced concrete column,” or NRCC. During earthquake, the gravity load collapse of the NRCC columns caused a large number of death tolls around the world. In this study, four columns as representative of existing NRCC were tested under cyclic loading. The compressive strength of concrete in order of 5 MPa was used to be representative of columns with poor quality concrete. Two axial load levels of 6 and 18 tons were used to study the influence of axial load level on maximum drift at gravity load collapse. To investigate the effect of bar types on drift capacity, 9 mm round bars were used in two specimens and 12 mm deformed bars were used for the rest of the specimens. The maximum drift before gravity load collapse was very dependent on the axial load level. The maximum drift of the specimens subjected to high axial load (18 tons) was extremely low at approximately 1.75% drifts. The use of deformed bars (associated with larger amount of longitudinal reinforcement) caused the damage to severely dissipate all over the height of the columns. Such damage caused columns to collapse at a lower drift compared to those using round bars. Finally, the plastic hinge model was used to predict the maximum drift of the low strength columns. It was found that the model overly underestimates the drift at gravity load collapse.

Seismic Behavior of RC Beam to Partially Steel Tubed Concrete (PSTC) Column Joints Under High Axial Load and Cyclic Loading

2016 ◽  
Vol 16 (01) ◽  
pp. 1640015 ◽  
Author(s):  
Yun Tian Wu ◽  
Yu Shan Fu ◽  
Chong-Ming Dai
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Axial Load ◽  
Deformation Energy ◽  
Rc Beam ◽  
Weak Beam ◽  
Column Joint ◽  
Energy Dissipation Capacity ◽  
Beam Mechanism ◽  
Strength And Stiffness

A new type of partially steel tubed concrete (PSTC) column is proposed that is suitable to be used in new high rise reinforced concrete (RC) buildings. Three exterior joint specimens consisting of RC beams and PSTC columns and two exterior RC joint specimens were designed and tested under high axial load and cyclic loading to investigate the joint behavior in terms of failure pattern, hysteresis response, deformation, energy dissipation capacity and degradation of strength and stiffness. Test results indicate that the PSTC column can benefit the performance of the joint in terms of strength, ductility and energy dissipation capacity and can partly compensate for the unfavorable effect induced by slab. The strong column–weak beam mechanism can also be ensured in RC beam to PSTC column joint.

Experimental Behavior of Nonconforming RC Columns with Plain Bars under Constant Axial Load and Biaxial Bending

2013 ◽  
Vol 139 (6) ◽  
pp. 897-914 ◽  
Author(s):  
M. Di Ludovico ◽  
G. M. Verderame ◽  
A. Prota ◽  
G. Manfredi ◽  
E. Cosenza
Keyword(s):  
Axial Load ◽  
Biaxial Bending ◽  
Rc Columns ◽  
Experimental Behavior ◽  
Plain Bars ◽  
Constant Axial Load

Seismic Evaluation of Existing Reinforced Concrete Building Columns

1996 ◽  
Vol 12 (4) ◽  
pp. 715-739 ◽  
Author(s):  
Abraham C. Lynn ◽  
Jack P. Moehle ◽  
Stephen A. Mahin ◽  
William T. Holmes
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Lateral Displacement ◽  
Concrete Columns ◽  
Vertical Load ◽  
Seismic Evaluation ◽  
Severe Damage ◽  
Reinforced Concrete Columns ◽  
Concrete Building ◽  
Constant Axial Load

Past earthquakes have emphasized the vulnerability of reinforced concrete columns having details typical of those built before the mid-1970's. These columns are susceptible to axial-flexural, shear, and bond failures, which subsequently may lead to severe damage or collapse of the building. Research was undertaken to investigate the lateral and vertical load-resisting behavior of reinforced concrete columns typical of pre-1970's construction. Eight full-scale specimens were constructed and were loaded with constant axial load and increasing cyclic lateral displacement increments until failure. Test data are presented and compared with behavior estimated by using various evaluation methods.

Towards an understanding of the loosening characteristics of prevailing torque nuts

2010 ◽  
Vol 224 (2) ◽  
pp. 483-495 ◽  
Author(s):  
W Eccles ◽  
I Sherrington ◽  
R D Arnell
Keyword(s):  
Axial Load ◽  
Axial Loading ◽  
Transverse Displacement ◽  
Test Machine ◽  
Transverse Joint ◽  
Metal Type ◽  
Prevailing Torque ◽  
Transverse Movement ◽  
Complete Detachment ◽  
Constant Axial Load

Prevailing torque nuts are an extremely popular method of providing resistance to vibration-induced self-loosening of fasteners. Such nuts have a self-contained prevailing torque feature that provides a degree of resistance to rotation. Although such nuts are frequently used, it is not widely realized that they can occasionally come completely detached from bolts. The mechanism by which this can occur has hitherto been unidentified since it has not been possible to replicate detachment under laboratory testing. This article identifies a general condition that can result in the complete loosening and detachment of prevailing torque type nuts. This mechanism involves the application of an axial load when transverse joint slip is occurring. This article describes a modified Junker test machine that allows the application of axial loading to a joint while experiencing transverse displacement. Tests have been completed using an intermittent as well as a constant axial load. Loading in both modes has been demonstrated to result in the complete detachment of this nut type. Based on this investigation, if the magnitude of the axial loading exceeds the residual preload in the bolt retained from sustaining transverse movement alone, the all-metal type of prevailing torque nut can completely detach. Applications that involve shear and axial loading being simultaneously applied to a joint are numerous in engineering.

STRUCTURAL PERFORMANCE OF DAMAGED OPEN-WEB TYPE SRC BEAM-COLUMNS WITH BOLT-CONNECTED BATTEN STEEL PLATES AFTER RETROFITTING

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Takahiro Kume ◽  
Takashi Fujinaga ◽  
Yuping Sun
Keyword(s):  
Axial Load ◽  
Steel Plates ◽  
Analytical Models ◽  
Structural Performance ◽  
Test Results ◽  
Beam Columns ◽  
Cyclic Lateral Load ◽  
Load Carrying ◽  
Lower Load ◽  
Constant Axial Load

In this paper, structural performance of damaged SRC beam-columns with open-web type of batten steel plate after retrofitting was investigated. Three open-web type SRC beam-columns with bolt-connected batten steel plates were fabricated and tested under combined constant axial load and cyclic lateral load. At first, each beam-column was　cyclically loaded to the targeted displacement. After the first loading, the test columns were retrofitted and reloaded till large deformation or failure. The damaged portion of each column was retrofitted with the polymer cement mortar and epoxy resin was injected into the cracks. The measured stiffness of retrofitted columns varied between 71.4% and 85.5% of the initial one. And, test results also indicated that the column which experienced the larger displacement and higher axial load showed lower load carrying capacity, but the others showed approximately the same capacities as the initial columns. Numerical analysis was also conducted to explain the retrofitted columns. Analytical results predicted the experimental behavior fairly well, which verifies the validity of the analytical models in low axial load.

Sign in / Sign up

Export Citation Format

Share Document