scholarly journals A Review-Behavior of Reinforced Concrete Exterior Beam-Column Connections under Cyclic Loading

2021 ◽  
Vol 318 ◽  
pp. 03008
Author(s):  
Hadeel A. H. Sabah ◽  
Ibrahim S. I. Harba
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Active Regions ◽  
Seismic Loading ◽  
Rc Buildings ◽  
Rc Structures ◽  
Low Cyclic Loading

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.

scholarly journals Concept of Computer Vision Based Algorithm for Detecting Thermal Anomalies in Reinforced Concrete Structures

Proceedings ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 18
Author(s):  
Michele De Filippo ◽  
Sasan Asadiabadi ◽  
Nigel Ko ◽  
Harris Sun
Keyword(s):  
Computer Vision ◽  
Reinforced Concrete ◽  
Qualitative Assessment ◽  
Current Status ◽  
Rc Buildings ◽  
Rc Structures ◽  
Thermal Anomalies ◽  
Beam Elements ◽  
Image Capturing ◽  
Thermal Infrared Anomalies

In Hong Kong, there is great abundancy of aged buildings and infrastructures for which a re-assessment of the current status is needed. Water exfiltrations/infiltrations, deteriorating insulations, thermal bridges and regions of failure are among the most recurrent symptoms to be found in existing Reinforced Concrete (RC) structures. Diagnosis of such symptoms, in the form of thermal infrared anomalies, is usually performed through infrared (IR) image capturing, followed by qualitative assessment. This paper presents a novel automated computer-vision-based method for detecting thermal anomalies. Such Computer-Vision (CV) algorithm is tested on different thermal scenarios including beam elements, roofs and entire façades of RC buildings. Thermal anomalies related to cases of water leakages, moisture trapping and debonding are successfully detected. The authors intend to undertake further research for successfully implementing the method for detecting also other thermal dissimilarities.

scholarly journals Flexural performance of RC columns with FRCC jacketing

2019 ◽  
Vol 97 ◽  
pp. 03037 ◽  
Author(s):  
Marta Del Zoppo ◽  
Costantino Menna ◽  
Marco Di Ludovico ◽  
Alberto Balsamo
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Strain Distribution ◽  
Deformation Capacity ◽  
Rc Buildings ◽  
Flexural Capacity ◽  
Rc Columns ◽  
Flexural Performance ◽  
Repair Technique ◽  
Control Column

A new repair technique consisting on a light jacketing with Fibre Reinforced Cementitious Composites (FRCC) for existing reinforced concrete (RC) buildings has been recently proposed to reduce durability problems of RC members and enhance their capacity. In this work, the effects of FRCC jacketing on the flexural capacity of existing RC columns, with and without a pre-damage, has been evaluated of full-scale specimens under cyclic loading. Digital Imagine Correlation (DIC) was also adopted for understanding the strain distribution in the FRCC jacket. The results shown that the FRCC jacket without a proper anchorage slightly enhanced the flexural capacity of the column. The strengthened column experienced a low damage with respect to control column, but occurrence of premature failures did not allow the achievement of high levels of deformation capacity and ductility.

scholarly journals Pseudodynamic Testing of Buildings Retrofitted with External Steel Reinforced Concrete Frames to Increase Lateral Strength for Earthquake Damage Prevention

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Ju-Seong Jung ◽  
Kang-Seok Lee
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Load Capacity ◽  
Earthquake Damage ◽  
Seismic Retrofitting ◽  
Rc Frame ◽  
Control Specimen ◽  
Rc Buildings ◽  
Loading Test ◽  
Steel Reinforced Concrete

In this study, a new technique for seismic retrofitting via the attachment of an “external steel reinforced concrete frame” (ESRCF) system was developed to strengthen medium-to-low-rise reinforced concrete (RC) buildings. Two methods (bolting and welding) were developed to connect existing RC frames and external strengthening elements; these methods are technically and practically suited to various construction conditions. The retrofitting method developed in this study can be used to perform seismic strengthening construction, while residents continue to live within the building. The method is categorized as a “strength design approach” implemented via retrofitting, allowing the lateral ultimate load capacity of RC buildings, whose failure mode is shear, to be increased easily. Test specimens were designed based on an existing RC building in Korea lacking seismic data and then strengthened using the ESRCF system. Pseudodynamic and cyclic loading tests were conducted to verify the effects of seismic retrofitting. In total, four RC frame specimens were prepared: one nonstrengthened control specimen for the cyclic loading test, one nonstrengthened control specimen, one specimen strengthened with a welded ESRCF system, and one specimen strengthened with a bolted ESRCF system for the pseudodynamic test. The earthquake response behavior with use of the proposed method, in terms of the maximum response strength, response displacement, and degree of earthquake damage, is compared with a control RC frame. The test results indicated that both the bolting and welding methods used for connecting the existing RC frame to the ESRCF effectively increased the lateral ultimate strength, resulting in reduced response displacement of building structures under large-scale earthquake conditions.

Experimental Study on Site-Built Reinforcing Rib Composite Wall under Low Cyclic Loading

2012 ◽  
Vol 256-259 ◽  
pp. 867-872
Author(s):  
Wei Dong Sun ◽  
Ai Min Wang
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Failure Mechanism ◽  
Seismic Performance ◽  
Failure Process ◽  
Building Structure ◽  
Composite Wall ◽  
Low Cyclic Loading

Site-built reinforcing rib composite wall is a kind of composite wall composed of reinforced concrete rib columns, rib beams and filling masonry. This paper mainly introduces the failure process and failure mechanism of this kind of composite wall under low cyclic loading. The wall has a good seismic performance and can be suitable for rural building structure.

Equivalent Ductility Damage Model for Seismic Response of RC Structures: Test and Verification

2010 ◽  
Vol 163-167 ◽  
pp. 1714-1718
Author(s):  
Guang Ming Chang ◽  
Guo Hua Xing ◽  
Bo Quan Liu
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Damage Model ◽  
Damage Index ◽  
Shear Walls ◽  
Rc Structures ◽  
Index Model ◽  
Concrete Members ◽  
Ultimate Failure ◽  
Total Structure

. It is possible to quantify the damage to reinforced concrete members under cyclic loading through a nondimensional parameter known as a “damage index”. The damage index can be either a global damage index for the total structure, or a local damage index for the element level. In this paper, a new damage model termed “equivalent ductility damage model” has been suggested for evaluation of the damage index, which is consistent with accepted definitions of ductility. Substructure method was applied to verify the suggested new damage model. A total of 3 identical half-scale reinforced concrete columns were tested under variable amplitude cyclic loading up to the ultimate failure of the specimens. The imposed displacement histories were obtained from analytical simulations of the model column subjected to a series of earthquakes. Test observations indicate that the proposed model predicts 100 percent damage at the ultimate failure state of the element. The proposed damage index model can be extended to other structural elements, such as shear walls, beams, beam-column junctions, etc.

Experimental Study on Reinforced Concrete Framework that Reinforced by Steel Tube Concrete Wing Wall

2014 ◽  
Vol 1079-1080 ◽  
pp. 22-27
Author(s):  
Shao Wu Zhang ◽  
Geng Biao Zhang ◽  
Ying Chuan Chen
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Bearing Capacity ◽  
Steel Tube ◽  
Skeleton Curve ◽  
Ductility Factor ◽  
Loading Tests ◽  
Low Cyclic Loading ◽  
Cyclic Loading Tests

In order to verify the feasibility of a new overallseismic reinforcement method of the framework. Firstly，carried low cyclic loading tests on reinforcedconcrete framework, then reinforced the framework with a new method, and repeatthe low cyclic loading tests , finally, compared and analyzed the data from twotests. Compared with the original framework, the shape of the hysteresis curveis more full and the skeleton curve of the parallel period is longer andthe ductility factor increased by 35% and the bearing capacity increased by 40%.The results show that reinforcement framework has better energy dissipationcapacity, ductility and transgender capacity.

Calculation on Crack Resistance of Reinforced Concrete Exterior Joints with Special-Shaped Columns

2013 ◽  
Vol 438-439 ◽  
pp. 510-513
Author(s):  
Fu Lai Qu ◽  
Yu Zhu Bai ◽  
Pei Yuan Tian ◽  
Lu Yang Qi
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Mechanical Behavior ◽  
Crack Resistance ◽  
Elasticity Theory ◽  
Mechanical Analysis ◽  
Effective Height ◽  
Low Cyclic Loading

According to the mechanical analysis of reinforced concrete (RC) joint with special-shaped column, the formula of crack resistance considering the effect of flange length was derived on the basis of the elasticity theory, and the expressions for calculating the frame joint core effective height and width were presented. Furthermore, four RC joints with special-shaped columns were tested under low cyclic loading to investigate the mechanical behavior. At last, the calculated results predicated by the proposed formula are compared with that by experiments, and indicate that the expression has good applicability.

scholarly journals Research on Seismic Performance of Reinforced Concrete Frame with Unequal Span Under Low Cyclic Reversed Loading

2016 ◽  
Vol 10 (1) ◽  
pp. 373-383 ◽  
Author(s):  
Wang Lai ◽  
Xuan Wei ◽  
Feng Ning-ning ◽  
Cong Shuping ◽  
Liu Feng ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Seismic Performance ◽  
Frame Structure ◽  
Existing Buildings ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Reversed Loading ◽  
Low Cyclic Loading ◽  
Fiber Element

In order to investigate the seismic performance of reinforced concrete frame with unequal span, a specimen was tested under low-cyclic loading and the seismic performance of this frame was analyzed based on fiber element method using software OpenSees. Hysteretic curves, skeleton curves, ductility, stiffness degradation and energy dissipating capacity of the frame are compared and analyzed. The experimental and simulate results demonstrate that this frame has a poor seismic performance. Thus, it is suggested that the seismic strengthening criteria of unequal-span frame structure should be raised and the existing buildings of this structure should be retrofitted.

scholarly journals A Durability Prediction Method for Historical Square Rebar Reinforced Concrete Buildings

2021 ◽  
Vol 11 (24) ◽  
pp. 11737
Author(s):  
Hui Jin ◽  
Qing Chun ◽  
Chengwen Zhang ◽  
Yidan Han
Keyword(s):  
Reinforced Concrete ◽  
Calculation Method ◽  
Model Simulation ◽  
Prediction Method ◽  
Rc Buildings ◽  
Historical Building ◽  
Typical Application ◽  
Rc Structures ◽  
In Situ Investigation ◽  
Durability Prediction

Square rebars were developed and used for decades in the early development of reinforced concrete (RC) structures; however, the objectives of modern concrete structure durability analyses and standards are centered on round rebars in past decades, which are not suited for RC buildings utilizing square rebars. Considering the absence of proper evaluation techniques to evaluate the square rebar RC structures’ durability accurately, a novel durability prediction method has been proposed for this type of historical building. The method is based on major parts as in-situ investigation, finite element model simulation, component importance analysis, and structural durability prediction. The durability prediction calculation method was established on the experimental results of the realistic historical concrete tests and corrosion-induced cover cracking experiments for square rebar components. It was found that the carbonization-resistant ability of historical concretes was relatively weaker than that of current concretes and the calculation method for critical corrosion depth of square rebar was different from that of round rebar. Furthermore, two typical application cases are presented to introduce the procedure of the method in detail. Consequently, the research outcomes can be directly used on the durability prediction and protection works for historical RC buildings.

Research of Assembled Monolithic Compound Spiral Reinforced Concrete Column Encased by Steel Plate Hoop and Jointed by Bolts

2012 ◽  
Vol 724 ◽  
pp. 255-258
Author(s):  
Jin Li ◽  
Xiao Jie Li ◽  
Qing Ning Li ◽  
Wei Shan Jiang ◽  
Yi Hui Ying
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Steel Plate ◽  
High Strength ◽  
Concrete Columns ◽  
Concrete Column ◽  
Reinforced Concrete Column ◽  
Compressive Loads ◽  
Seismic Property ◽  
Low Cyclic Loading

The assembled monolithic compound spiral reinforced concrete column in this paper is consisted of two concrete columns reinforced by high-strength compound spiral hoop and jointed by encased steel and bolts. Experiments of four specimens under low cyclic loading and different axial compressive loads are carried out, and the result testifies that the anti-seismic property of this measure is not worse than the integral compound spiral hoop columns under the same load.

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