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

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.

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Cyclic loading test of reinforced concrete frames protected with brace-type friction dampers

Advances in Structural Engineering ◽

10.1177/13694332211042785 ◽

2021 ◽

pp. 136943322110427

Author(s):

Yusuke Maida ◽

Hiroyasu Sakata

Keyword(s):

Reinforced Concrete ◽

Cyclic Loading ◽

Early Stage ◽

Rc Beam ◽

Rc Frame ◽

Axial Deformation ◽

Loading Test ◽

Friction Dampers ◽

Axial Forces ◽

Connection Method

In this study, cyclic loading tests were conducted on reinforced concrete (RC) portal frames with brace-type friction dampers. The boundary conditions that could reproduce the axial forces exerted on the beams were adopted. To resist the axial force acting on the RC member, a damper connection method was employed by using steel inserted through the center of the RC member. The purpose of this study was to a) understand the behavior of the damper connection and the RC frame with brace-type friction dampers based on experimental tests and b) to confirm the effectiveness of the new connection method. According to the test results, the proposed connection method achieved effective damper connections in the RC frames. For the RC frame specimens with dampers, it was confirmed that the damper reached its sliding force and started to dissipate energy at an early stage with story drift ratios smaller than those at RC beam yielding. The welded part of the gusset plate and the steel inserted through the center of the RC beam were broken. When the welded part inside the beam broke and the axial deformation of the beam increased, the sliding displacement of the damper decreased. Therefore, a reliable jointing method of this part needs to be established.

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The flexural behavior model of bamboo reinforced concrete beams using a hose clamp

MATEC Web of Conferences ◽

10.1051/matecconf/201927601033 ◽

2019 ◽

Vol 276 ◽

pp. 01033

Author(s):

Muhtar ◽

Sri Murni Dewi ◽

Wisnumurti ◽

As’ad Munawir

Keyword(s):

Reinforced Concrete ◽

Concrete Beam ◽

Load Capacity ◽

Reinforced Concrete Beam ◽

Load Test ◽

Reinforced Concrete Beams ◽

Flexural Behavior ◽

Steel Reinforced Concrete ◽

And Behavior ◽

Hose Clamp

Bamboo can use at the simple concrete construction because of the tensile strength of its mechanical property. Meanwhile, a slippery surface of the bamboo caused cracks in the bamboo reinforced concrete beam (BRC) not to spread and yield slip failure between a bamboo bar and concrete. Load test at the BRC beam yield humble load capacity. This study aims to improve the capacity and behavior of BRC beam bending by giving waterproof coating, sand, and hose clamp installation. The beam test specimen with the size of 75x150x1100mm made as many as 26 pieces with the variety of reinforcement. The hose clamp used on the bamboo reinforcement varies with a distance of 0 cm, 15 cm, 20 cm, and 25 cm. The testing using a simple beam with two-point loading. The test results show that BRC beams have different bending behavior compared to the steel reinforced concrete beam (SRC).

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High-strength bar reinforced concrete walls: Cyclic loading test and strength prediction

Engineering Structures ◽

10.1016/j.engstruct.2019.109508 ◽

2019 ◽

Vol 198 ◽

pp. 109508 ◽

Cited By ~ 3

Author(s):

Xiangyong Ni ◽

Shuangyin Cao ◽

Shuai Liang ◽

Yizhu Li ◽

Yang Liu

Keyword(s):

Reinforced Concrete ◽

Cyclic Loading ◽

High Strength ◽

Strength Prediction ◽

Loading Test ◽

Concrete Walls ◽

Cyclic Loading Test ◽

Reinforced Concrete Walls

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Steel-reinforced concrete-filled steel tubular columns under axial and lateral cyclic loading

International Journal of Advanced Structural Engineering ◽

10.1007/s40091-018-0186-0 ◽

2018 ◽

Vol 10 (1) ◽

pp. 61-72 ◽

Cited By ~ 9

Author(s):

Ebrahim Farajpourbonab ◽

Sunil Y. Kute ◽

Vilas M. Inamdar

Keyword(s):

Reinforced Concrete ◽

Cyclic Loading ◽

Steel Reinforced Concrete ◽

Tubular Columns

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Flexural performance of RC columns with FRCC jacketing

E3S Web of Conferences ◽

10.1051/e3sconf/20199703037 ◽

2019 ◽

Vol 97 ◽

pp. 03037 ◽

Cited By ~ 1

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.

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Structural Health Monitoring and Interface Damage Detection for Infill Reinforced Concrete Walls in Seismic Retrofit of Reinforced Concrete Frames Using Piezoceramic-Based Transducers Under the Cyclic Loading

Applied Sciences ◽

10.3390/app9020312 ◽

2019 ◽

Vol 9 (2) ◽

pp. 312 ◽

Cited By ~ 8

Author(s):

Wen-I Liao ◽

Fu-Pei Hsiao ◽

Chien-Kuo Chiu ◽

Chin-En Ho

Keyword(s):

Reinforced Concrete ◽

Cyclic Loading ◽

Structural Health Monitoring ◽

Health Monitoring ◽

The Other ◽

Structural Members ◽

Interface Failure ◽

Loading Test ◽

Structural Health ◽

Interface Damage

In this work, the piezoceramic-based transducers are used to perform the structural health monitoring (SHM) and interface damage detecting of non-ductile reinforced concrete (RC) frames retrofitted by post-installed RC walls. In order to develop the post-embedded piezoceramic-based transducers that can be used to identify interface failure or cracks between two structural members in retrofit construction, this work adopts the cyclic loading to test two specimens with post-embedded piezoceramic-based transducers (PPT). Since the failure of an interface between the post-installed wall and beam occurs, one of the specimens has damage in the foundation and existing boundary column and the other has damage in the top ends of column and wall. During the cyclic loading test, one transducer was used as an actuator to generate the stress waves and the other transducers were used as the sensors to detect the waves. In damaged specimens, the existence and locations of cracks and the interface damage can be detected by analyzing the wave response. Moreover, the severity of damage to the specimens can also be estimated. The experimental results indicate the effectiveness of the piezoceramic-based approach in the SHM and locating damage in shear-critical RC structural members under the seismic loading.

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