scholarly journals Effect of stiffeners in lateral stiffness of masonry infill reinforced concrete (RC) frames

2015 ◽  
Vol 3 ◽  
pp. 7-20 ◽  
Author(s):  
Chandra Kiran Kawan
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Element Model ◽  
Reduction Factor ◽  
Lateral Stiffness ◽  
Reinforced Concrete Frame ◽  
Masonry Infill ◽  
Wooden Frame ◽  
Infilled Frame ◽  
Gap Element

Infilled frames are reinforced concrete frames with masonry infill. The provision of masonry walls as infill increases the lateral stiffness of frame. Unreinforced masonry infill effects the strength and stiffness of frame but being ignored for a long time. The main objective of this paper is to study the individual and combined effect of infill masonry wall, stiffeners and wooden frame in the lateral stiffness of infill reinforced concrete frame with central opening, with and without gap element consideration. From the analysis using SAP software, it is observed that with increase in openings, stiffness decreases but introducing stiffeners and wooden frame increases the lateral stiffness. Embedding the gap element as the boundary condition reduces the stiffness of the infilled frame. Numerical investigations are carried out by finite element modeling for analyzing the behavior of infilled frame. The single equivalent diagonal strut width was determined by obtaining the same lateral stiffness from finite element model, and also strut reduction factor for different conditions with central openings are proposed.

SEISMIC BEHAVIOR OF UNREINFORCED CONCRETE MASONRY INFILL WALLS

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ziad Azzi ◽  
Caesar Abi Shdid
Keyword(s):  
Reinforced Concrete ◽  
Ground Motion ◽  
Element Model ◽  
Reinforced Concrete Frame ◽  
Infill Wall ◽  
Infill Walls ◽  
Existing Building ◽  
Masonry Infill ◽  
Masonry Infill Walls ◽  
Out Of Plane

The majority of new and existing building inventories in the Middle East consist of reinforced concrete skeletal structures with outer shells composed of unreinforced masonry infill walls. In the absence of any mandatory seismic design requirements, these buildings will sustain catastrophic damage when exposed to high seismic activity. Investigating the behavior of such infill walls when exposed to ground motion is therefore an important topic. Experimental tests using shake table out-of-plane ground motion of the 1940 El Centro earthquake displacement are conducted on 3:10 scaled specimens of a single story reinforced concrete frame with a masonry infill wall in between. The test specimens are constructed with the same materials and construction practices commonly used in the region. Displacements and strains are compared with a finite element model of the frame. Moreover, the observed overall behavior of the infill is compared to that of the computer model. The recorded strains in the mortar joints exceeded cracking limits, whereas the overall stability of the wall in out-of-plane bending was not compromised. Recommendations on the use of these structural elements are formulated.

scholarly journals Numerical analysis of reinforced concrete frame buildings with decoupled infill walls

2020 ◽  
Vol 63 (4) ◽  
pp. 13-48
Author(s):  
Marko Marinković ◽  
Santiago Calvinisti ◽  
Christoph Butenweg
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Characteristics ◽  
Numerical Models ◽  
Rc Frame ◽  
Reinforced Concrete Frame ◽  
Infill Wall ◽  
Infill Walls ◽  
Masonry Infill ◽  
Infilled Frame ◽  
Frame Buildings

Reinforced concrete (RC) buildings with masonry infill walls are widely used in many countries all over the world. Although infills are considered as non-structural elements, they significantly change dynamic characteristics of RC frame structures during earthquake excitation. Recently, significant effort was spent on studying decoupled infills, which are isolated from the surrounding frame usually by adding a gap between frame and infill. In this case, the frame deformation does not activate infill wall, thus infills are not influencing the behaviour of the frame. This paper presents the results of the investigation of the behaviour of RC frame buildings with the INODIS system that decouples masonry infills from the surrounding frame. Effect of masonry infill decoupling was investigated first on the one-bay one-storey frame. This was used as a base for parametric study on the frames with more bays and storeys, as well as on the building level. Change of stiffness and dynamic characteristics was analysed as well as response under earthquake loading. Comparison with the bare frame and traditionally infilled frame was performed. The results show that behaviour of the decoupled infilled frames is similar to the bare frame, whereas behaviour of frames with traditional infills is significantly different and demands complex numerical models. This means that if adequate decoupling is applied, design of infilled frame buildings can be significantly simplified.

Finite Element Analysis of Reinforced Concrete Frame Exterior Joints with T-Section Columns

2013 ◽  
Vol 438-439 ◽  
pp. 505-509 ◽  
Author(s):  
Gui Rong Liu ◽  
Yu Xin Wang ◽  
Shun Bo Zhao
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Three Dimensional ◽  
Load Ratio ◽  
Element Model ◽  
Reinforced Concrete Frame ◽  
Element Analysis ◽  
Concrete Frame ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Nonlinear three-dimensional finite element method was used to analyze the crack pattern and stress distribution of reinforced concrete frame exterior joints with T-section columns. On the basis of the smear-crack approach, the cracking of reinforced concrete joint was predicted. And the capability of finite element model was demonstrated by comparing the predictions with test results. Further analysis was carried out to study the effect of axial load ratio and limb length on stresses of the joints. It is seen that the stresses of joint were influenced by these two factors, which should be considered in the design of reinforced concrete joint with T-section column.

scholarly journals A Computational Study of the Shear Behavior of Reinforced Concrete Beams Affected from Alkali–Silica Reactivity Damage

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3346
Author(s):  
Bora Gencturk ◽  
Hadi Aryan ◽  
Mohammad Hanifehzadeh ◽  
Clotilde Chambreuil ◽  
Jianqiang Wei
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Parametric Study ◽  
Computational Study ◽  
Element Model ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Alkali Silica Reactivity ◽  
Concrete Mechanical Properties

In this study, an investigation of the shear behavior of full-scale reinforced concrete (RC) beams affected from alkali–silica reactivity damage is presented. A detailed finite element model (FEM) was developed and validated with data obtained from the experiments using several metrics, including a force–deformation curve, rebar strains, and crack maps and width. The validated FEM was used in a parametric study to investigate the potential impact of alkali–silica reactivity (ASR) degradation on the shear capacity of the beam. Degradations of concrete mechanical properties were correlated with ASR expansion using material test data and implemented in the FEM for different expansions. The finite element (FE) analysis provided a better understanding of the failure mechanism of ASR-affected RC beam and degradation in the capacity as a function of the ASR expansion. The parametric study using the FEM showed 6%, 19%, and 25% reduction in the shear capacity of the beam, respectively, affected from 0.2%, 0.4%, and 0.6% of ASR-induced expansion.

Resistance of Reinforced Concrete Frames with Masonry Infill Walls to In-Plane Vertical Loading

2016 ◽  
Vol 711 ◽  
pp. 982-988
Author(s):  
Alex Brodsky ◽  
David Z. Yankelevsky
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Progressive Collapse ◽  
Lateral Loading ◽  
Masonry Walls ◽  
Reinforced Concrete Frame ◽  
Masonry Infill ◽  
Concrete Frame ◽  
Vertical Loading ◽  
Infill Masonry

Numerous studies have been conducted on the in plane behavior of masonry infill walls to lateral loading simulating earthquake action on buildings. The present study is focused on a problem that has almost not been studied regarding the vertical (opposed to lateral) in-plane action on these walls. This may be of concern when a supporting column of a multi-storey reinforced concrete frame with infill masonry walls undergoes a severe damage due to an extreme loading such as a strong earthquake, car impact or military or terror action in proximity to the column. The loss of the supporting column may cause a fully or partly progressive collapse to a bare reinforced concrete frame, without infill masonry walls. The presence of the infill masonry walls may restrain the process and prevent the development of a progressive collapse. The aim of the present study is to test the in-plane composite action of Reinforced Concrete (RC) frames with infill masonry walls under vertical loading through laboratory experiments and evaluate the contributions of infill masonry walls, in an attempt to examine the infill masonry wall added resistance to the bare frame under these circumstances. Preliminary results of laboratory tests that have been conducted on reinforced concrete infilled frames without a support at their end, under monotonic vertical loading along that column axis will be presented. The observed damages and failure modes under vertical loading are clearly different from the already known failure modes observed in the case of lateral loading.

Uniform loading on the reinforced concrete beam produced by the specific cylinder-shaped rubber bags fully filled with air or water

2020 ◽  
Vol 23 (9) ◽  
pp. 1934-1947
Author(s):  
Dapeng Chen ◽  
Li Chen ◽  
Qin Fang ◽  
Yuzhou Zheng ◽  
Teng Pan
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Element Model ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Element Model ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Uniform Loading ◽  
Air Bag

The bending behavior of reinforced concrete beams under uniform pressure is critical for the research of the blast-resistance performance of structural components under explosive loads. In this study, a bending test of five reinforced concrete beams with the dimensions of 200 mm (width) × 200 mm (depth) × 2500 mm (length) under uniform load produced by a specific cylinder-shaped rubber bag filled with air or water was conducted to investigate their flexural performances. An air bag load was applied to three of the reinforced concrete beams, a water bag load was applied to one reinforced concrete beam, and the remainder beam was subjected to the 4-point bending load. The experimental results highlighted that the air bag and water bag loading methods can be used to effectively apply uniform loads to reinforced concrete beams. Moreover, the stiffness of the air bag was improved by 123% in accordance with the initial pressure increases from 0.15 to 0.45 MPa. In addition, a finite element model of the test loading system was established using ABAQUS/Standard software. Moreover, the critical factors of the air bag loading method were analyzed using the numerical model. The calculated results were found to be in good agreement with the test data. The established finite element model can therefore be used to accurately simulate the action performances of the uniform loading technique using rubber bags filled with air or water.

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