New Methodology For Reinforced Concrete Beam-Column Cyclic Test
Rita Giao
Carlos Chastre
Válter Lúcio
Válter Lúcio
Sign up for access to the world's latest research
checkGet notified about relevant papers
checkSave papers to use in your research
checkJoin the discussion with peers
checkTrack your impact
Abstract
The aim of the present communication is to present an analysis of the gravity load influence on the hysteretic behaviour of a beam-column connection. For this purpose, in the experimental campaign a new procedure for RC cyclic tests is presented in order to reproduce closer demands on the beam critical zone than the traditional procedures. The Experimental campaign included cyclic tests of the specimens according with the ECCS recommendation and an innovate procedure. The test results are presented, compared and analysed.
Related papers
Assessing the behaviour of RC beams subject to significant gravity loads under cyclic loads
2014
Gravity loads can affect a reinforced concrete structure's response to seismic actions, however, traditional procedures for testing the beam behaviour do not take this effect into consideration.
Numerical modelling for monitoring the hysteretic behaviour of CFRP-retrofitted RC exterior beam-column joints
This paper presents the results of a study on the capability of nonlinear quasi-static finite element modelling in simulating the hysteretic behaviour of CFRP and GFRP-retrofitted RC exterior : beaan-column joints under cyclic loads Four specimens including two plain and two CFRP/GFRP-}strengthened beam-column joints tested by and other researchers are modelled ::using ANSYS. Concrete in compression is defined by the modified Hognestad model and anisotropic multi-linear model is employed for modelling the stress-strain relations in reinforcing bars while plasticity is considered for the FRP composite. Both concrete and FRP are modelled using solid elements whereas space link elements are used for steel bars considering a perfect bond between A step by step load increment procedure to simulate the cyclic loading regime employed in the testing. An automatically reforming stiffness matrix strategy is used in order to simulate the actual seismic : performance of the RC concrete after cracking, steel yielding and concrete crashing during the push and ull loading cycles. The results show that the hysteretic simulation for all specimens is satisfactory and :: therefore suggest that the numerical model can be used as an inexpensive tool to design of FRP-Strengthened Re beam-column joints under cyclic loads. reinforced concrete; joints; strengthening; fibre reinforced plastics; finite element method; nonlinear analysis; cyclic loads.
Hysteretic cyclic response of concrete columns reinforced with smooth bars
Bulletin of Earthquake Engineering, 2013
The application of smooth (plain) bars in reinforced concrete (RC) construction has been abandoned since the 1970s; however, there are many old reinforced concrete buildings in the world whose construction is based on this old style that are now in need of structural seismic rehabilitation according to the requirements of present day seismic rehabilitation codes. The focus of this study concerns the investigation of the hysteretic cyclic response of RC columns with smooth bars. The results of six column specimens having a variety of details for overlapping splices of longitudinal bars while experiencing two different levels of axial loads under cyclic loading reversals are presented. Through analysis of test observations and the obtained experimental results, it is attempted to clarify major aspects of hysteretic response for RC columns with smooth bars, from a seismic assessment point of view. The hysteretic force-drift responses of columns are deeply investigated and a new concept explaining the flag shape form of the hysteretic response is presented. Furthermore, the rocking response of columns is predicted with a new formulation that assumes an internal compression strut inside the column body as a consequence of rocking that originated from high base rotations. Finally, a simple hysteresis rule is proposed which is the result of considering the combination of two springs in parallel to provide the total hysteretic response as the summation of rocking hysteretic and bottom anchor (smooth bar) hysteretic responses.
Experimental Study on Behavior of Reinforced Concrete Beam Subjected to Cyclic Loading
2017
Experimental investigations that have been conducted by a number of researchers have shown that the confinement of concrete using an appropriate arrangement of transverse reinforcement results in a significant increase in both the strength and ductility of confined concrete. The increase of strength and ductility of concrete due to confinement have a significant impact on the load-bearing capacity and ductility of reinforced concrete elements subjected to bending. The experimental testing includes twelve beams reinforced with same longitudinal reinforcement and different transverse confining reinforcement. The aim of this research was to investigate the effects of confinement on strength and ductility of the beam under cyclic loading. The experiments resulted in hysteresis loops showing the force-displacement dependence. Beams with different constitutive laws for concrete and reinforcement and with differently defined cross-sections were modeled using SAP 2000 software. Results of t...
Experimental Analysis on the Cyclic Response of Beam to Column Joints: State-of-the-Art at Salerno University
The Open Construction and Building Technology Journal, 2014
Aiming to provide a contribution to the codification of design rules for dissipative joints to be applied to MRFs, in last five years, a comprehensive experimental and analytical work dealing with the cyclic behaviour of beam-to-column joints has been developed by the research group of the University of Salerno. In particular, the activity has regarded the study of both classical and innovative typologies characterized by the same initial stiffness and resistance but by different hysteretic behaviours due to the different source of energy dissipation supply imposed in the design process. In this paper, the main results of such a study, performed at the laboratory of materials and structures of the University of Salerno, are reported in order to provide an overview on the main mechanisms involved in the energy dissipation of partial-strength connections. A particular attention is given to the design issues by presenting the procedures aimed at providing to the joints adequate charact...
Finite Element Analysis of Load Bearing Capacity of a Reinforced Concrete Frame Subjected to Cyclic Loading
Many methods have been developed in order to study the impact behavior of solids and structures. Two common methods are finite element and experimental method. The nonlinear finite element method is one the most effective methods of predicting the behavior of RC beams from zero-load to failure and its fracture, yield and ultimate strengths. The advantage of this method is its ability to make this prediction for all sections of the assessed RC beam and all stages of loading. This paper compares the experimental results obtained for a RC frame with the numerical results calculated by ABAQUS software, and plots both sets of results as hysteresis–displacement diagrams. This comparison shows that the numerical FEM implemented via ABAQUS software produce valid and reliable results for load bearing capacity of RC frames subjected to cyclic loads, and therefore has significant cost and time efficiency advantages over the alternative approach
BEHAVIOUR OF BEAM-COLUMN JOINT UNDER CYCLIC LOADING
Beam-column joints of a reinforced concrete structure need special attention due to their highly complex behavior under seismic loads, which is marked by a combination of large shear forces, diagonal tension and high bond stresses in the reinforcement bars, all brittle mode of failure. This paper presents an experimental behavior of beam-column joints under cyclic loading. Four numbers of exterior beam-column joint specimens were cast and tested under cyclic loading. The specimens were designed for seismic load according to IS 1893(Part-I):2002 and IS 13920:1993. The test specimens were evaluated in terms of load-displacement relation, and cracking pattern.
Cyclic Testing of a Composite Joint between a Reinforced Concrete Column and a Steel Beam
Applied Sciences, 2020
This paper presents an experimental study on the seismic performance of a novel composite joint between reinforced concrete columns and steel beams (RCSs) for frame structures. In the proposed RCS joint, an H steel profile totally embedded inside an RC column is directly welded to the steel beam. The H steel profile was covered by two supplementary plates to avoid the stirrups resisting the shear in the connection region. Two full-scale joints were built and tested under reversed-cyclic loading at the University of Transport and Communications of Vietnam. Seismic performance in terms of load-bearing capacity, story drift capacity, energy dissipation, and stiffness degradation were evaluated. The test specimen showed a good response to cyclic load reversals.
A Review-Behavior of Reinforced Concrete Exterior Beam-Column Connections under Cyclic Loading
E3S Web of Conferences
In many seismically active regions worldwide, massive reinforced concrete (RC) structures built before the 1970s existed. These older RC buildings, in countries having seismic history, were designed for gravity loads only. Anyway, the beam-column connections influence the structures where the functions of connection shortage by transport the forces like shear, moment, and torsion through the beam to the column. Also, it could behave in a ductile manner to help the structure resist the seismic, as simulate the seismic loading by high and low cyclic loading. Due to the failure of external joints more than the internal beam-column joints, this review focuses on the behavior of exterior beam-column joints under cyclic loading, consequently simulated the behavior under an earthquake and the reinforcement detailed.
Parameter identification of three hysteretic models for the simulation of the response of CFT columns to cyclic loading
Engineering Structures, 2014
A computational study is conducted to investigate the nonlinear response of square concrete-filled steel tubes (CFT) subjected to constant axial load and cyclically varying flexural loading. An accurate nonlinear finite element model is created with the ATENA software which includes all the important factors affecting the response of CFT members, such as, cyclic local buckling of steel tube, nonlinear behavior of confined concrete into tension and compression, cyclic softening and the interface action between steel tube and in-filled concrete. The validity of this finite element model is established by comparing its results with those of existing experiments. Using this finite element model, an extensive parametric study is conducted to determine expressions, providing the necessary parameters in three hysteretic models including strength and stiffness degradation. These hysteretic models are: (a) the Bouc-Wen model, (b) the Ramberg-Osgood model, and (c) the Al-Bermani model. The parametric study involves sixty-four CFT columns with different width to thickness ratios, steel tube strength and concrete strength under a recognized cyclic load protocol with variable intensity. Using these calibrated hysteretic models in the framework of the RUAUMOKO program, comparisons with experimental and numerical results are made for further model adjustments. As a result, one can directly use the aforementioned hysteretic models for the simulation of CFT columns alone or as members of composite MRFs frames to determine their response to cyclic loading.
Related papers
Computer based estimation of backbone curves for hysteretic Response of reinforced concrete columns under static cyclic lateral loads
Cyclic test of the columns is of practical relevance to the performance of compression members during an earthquake loading. The strength, ductility and energy absorption capabilities of reinforced concrete (RC) columns subjected to cyclic loading have been estimated by many researchers. These characteristics are not normally inherent in plain concrete but can be achieved by effectively confining columns through transverse reinforcement. An extensive experimental program, in which performance of four RC columns detailed according to provisions of ACI-318-08 was studied in contrast with that of four columns confined by a new proposed technique. This paper presents performance of columns reinforced by standard detailing and cast with 25 and 32 MPa concrete. The experimentally achieved load-displacement hysteresis and backbone curves of two columns are presented. The two approaches which work in conjunction with Response 2000 have been suggested to draw analytical back bone curves of RC columns. The experimental and analytical backbone curves are found in good agreement. This investigation gives a detail insight of the response of RC columns subjected to cyclic loads during their service life. The suggested analytical procedures will be available to the engineers involved in design to appraise the capacity of RC columns.
Hysteretic performance of a new blind bolted connection to concrete filled columns under cyclic loading: An experimental investigation
Engineering Structures, 2013
The structural performance and reliability of a new blind-bolting technique is investigated in this study. The new blind-bolt is termed Extended Hollobolt (EHB) and is a modification of the standard Hollobolt. The EHB enhances the tensile resistance and stiffness of the fastener by anchoring it in the concrete infill of a tubular column. This paper reports on an investigation into the cyclic behaviour of end-plate connections to concrete filled tubular (CFT) columns using the EHB. A series of six full-scale connections were tested under quasi-static cyclic loading. The key parameters investigated were amplitude of cyclic loading procedure, bolt grade, tube wall thickness, and concrete grade. The strength, stiffness, rotation capacity and energy dissipation capacity of the connections were evaluated at different load cycles. In general, the EHB provided stable hysteretic behaviour with appropriate level of strength and stiffness. The influence of tube wall thickness and concrete grade on the strength, stiffness and failure mode of the connections is investigated. It is shown that sufficient performance can be achieved by controlling the tube wall thickness and concrete strength. The results indicate that the connection can offer energy dissipation capacity and ductility appropriate for its potential use in seismic design.
Validation of Numerical Models for RC Columns Subjected to Cyclic Load
Proceedings of the 4th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2013), 2014
The paper presents results from numerical analyses of reinforced concrete (RC) elements subjected to cyclic load. Many nonlinear numerical models have been proposed in literature to capture the cyclic behaviour of reinforced concrete (RC) elements. Depending on the expected level of accuracy and computational efficiency, numerical models employ different assumptions. These assumptions ultimately affect the stiffness, strength, energy dissipation capacities and hysteretic behaviours such as strength/stiffness degradation and pinching. All of these sensitively affect the dynamic response of a structure subjected to seismic load. The objective of this work is to investigate the effects of adopted numerical models on predicted seismic performances of RC structures. Three numerical elements that are widely used in research and practice are employed; fiber element in OpenSees, frame element in VecTor5, and continuum element in VecTor2. In an element level, the behaviour responses of the different numerical models are closely compared. A few representative experimental results from PEER Column Test Database are used to investigate the accuracy of each numerical model depending on the shear demand/capacity ratio of the columns. The paper concludes with a suggestion for the applicability of different numerical models for the seismic performance assessment.
Full-scale cyclic testing of realistic reinforced-concrete beam-column joints
MethodsX, 2021
The seismic performance of reinforced concrete (RC) structures are highly influence by the cyclic performance of the beam-column joints. The experimental seismic assessment of RC beam-column joints has been made essentially by cyclic tests performed on setups that do not totally simulate the real seismic loading and constrains conditions. A complex monitoring scheme is used to record the applied loads, reactions, joint distortion, strains on the reinforcement, lateral and axial displacements on the entire specimen, rotations and surface strains by using digital image correlation (DIC). The use of DIC is particularly important to record the strains on CFRP used to wrap the columns and beams. Based on the data recorded during the tests, it is possible compute moments; rotations and curvatures of the columns and beams; joint shear; dissipated energy by beams, columns and joint; yield displacement; ductility; peak-to-peak stiffness degradation; post-peak softening; and inter-cycle strength degradation. The innovative experimental setup herein presented has the following advantages compared with others: • Lateral loading applied on the top of the superior column and not on the beams • Real scale specimens and the possibility of have transversal beams and slab • Dead loads on the beams and columns with two different axial loads
Cyclic testing of reinforced concrete beam-column joints with crossed inclined bars
2007
The use of crossed inclined bars in external beam-column connections under cyclic deformations is experimentally investigated. For this purpose, test results of four Reinforced Concrete (RC) joint subassemblages subjected to constantly increasing pseudo-seismic loading are presented. The shear reinforcement in the joint area for two specimens was two pairs of inclined bars that formed a pair of X-type reinforcement. The other two specimens were conventionally reinforced joints (control specimens). The effectiveness of this X-type, non-conventional reinforcement on the overall seismic performance of the tested joints is examined. The beam and the columns of all the specimens were designed according to the requirements of ACI 318-02 and the recommendations of ACI-ASCE 352-02 (Type 2 exterior connections). The design of the joint area for one control specimen was also carried out according the ACI Design Codes and the required amount of steel stirrups (5∅8) was added in the joint body. The other control specimen had no stirrup at the joint area. Comparisons between the test results of the examined specimens indicated that the cyclic behaviour of the joints with X-bars was ameliorated with respect to the response of the control specimen without stirrups. Further, load capacity and hysteretic energy dissipation values of the joint with 2X-bars ∅14 were slightly lower than the values of the control specimen which joint area had stirrups (5∅8) according to the specifications of ACI Design Codes.
Cyclic Tests on External RC Beam-Column Joints: Role of Seismic Design Level and Axial Load Value on the Ultimate Capacity
Journal of Earthquake Engineering, 2013
A wide experimental program on beam-column RC joints carried out in the framework of the DPC-Reluis Project (DPC: Department of Civil Protection, Reluis: Network of University Laboratories of Earthquake Engineering) is presented. All the experimental tests were performed at the Laboratory of Structures of the University of Basilicata, Potenza (Italy). The main objective of the experimental campaign is to study and compare the post-elastic behaviour of beam-column joints with different earthquake resistant design levels, indicating the role of some structural parameters such as the axial load value acting on the column, the beam dimensions, and the steel type, on the joint performances and failure mechanism. The analyses have mainly been devoted to improving the assessment procedures regarding existing buildings but also to verifying the prediction capability of the capacity models relevant to beam-column joints contained in literature and in the new seismic codes. Following a short description of the experimental methodologies used in other campaigns, the experimental program is presented, providing a detailed description of the specimens and of the testing set-up. This is followed by a report of the main results of the cyclic tests performed on the beam-column specimens which highlight the role played by axial load and seismic design level in determining the failure mechanism and the global response of the joints.
Cyclic Testing of Reinforced Concrete Columns with Unbonded Reinforcement
This paper describes the seismic behavior of RC columns having different bond conditions of longitudinal bars to concrete. Four RC columns were tested up to final failure under reversed cyclic load. Bond conditions were varied between perfect bond and no bond. It was observed that the ductility of an un-bonded specimen was improved significantly compared to the bonded specimen and the final failure was changed from shear to flexure.
Cyclic Flexural Behavior of Reinforced Concrete Beams
E3S Web of Conferences
The present study aims at investigating the cyclic flexural behavior of reinforced concrete beams with varying depths. Five reinforced concrete beams with beam depth ranging from 250 mm to 750 mm were tested under reversed cyclic loading and the influence of beam depth on the flexural strength and ductility of reinforced concrete beams was investigated. In addition, OpenSees was used to model the test specimens and the analytical results were compared with the experimental reuslts. It is shown that there is no apparent size effect on the normalized ultimate flexural strength of the tested beams, while for the displacement ductility factor, a significant size effect is observed. Load-deflection hysteric curves of test specimens obtained by the fiber-based element of OpenSees with Concrete03 and Hysteric models are in good agreement with those from experimental tests.
Experimental hysteresis loops validation using HYSTERES program for beam-column joints under lateral cyclic loading
2016
This paper provides the comparison and validation between experimental and modeling results of three fullscaled emulative cast-in-place beam-column joints with corbels. The beam-column joints consist of corner, interior and exterior sub-assemblages, which represent connection elements in a two-storey existing precast school building. The subassemblages were designed in accordance to BS8110 which do not consider earthquake loading and tested in the laboratory under reversible lateral cyclic loading with specified inter-story drift. Load versus displacement curve (hysteresis loops) were generated for all three specimen tested from the experimental data obtained. Ruaumoko HYSTERES Program was implemented to model the experimental results. By using Pampanin Reinforced Concrete Beam-Column Joint Hysteresis rule with reloading slip factor, load versus displacement curves for corner, interior and exterior beam-column joints were generated. The modeling results were compared with the load versus displacement curves obtained from experimental work. It was found that the hysteresis loops exhibited good agreement between experimental and modeling results. The effective stiffness, displacement ductility and equivalent viscous damping for the sub-assemblages were also discussed and compared.
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.