• Steel and Composite Structures
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• v.51 no.3
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• pp.289-304
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• 2024

The seismic performance of traditional steel frame-shear wall structures was significantly improved by the application of self-centering steel-reinforced concrete (SRC) wall-panel structures in the steel frames. This novel resilience functionality can rapidly restore the structure after an earthquake. The presented steel frame with steel-reinforced concrete self-centering wall-panel structures (SF-SCW) was validated, indicating its excellent seismic performance. The seismic design method based on bear capacity cannot correctly predict the elastic-plastic performance of the structure, especially certain weak floors that might be caused by a major fracture. A four-level seismic performance index, including intact function, continued utilization, life safety, and near-collapse, was established to achieve the ideal failure mode. The seismic design method, based on structural displacement, was proposed by considering performance objectives of the different seismic action levels. The pushover analysis of a six-floor SF-SCW structure was carried out under the proposed design method and the results showed that this six-floor structure could achieve the predicted failure mode.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.3
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• pp.215-223
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• 2013

An experimental research on the possibility of using fiber reinforced concrete precast tunnel segments instead of traditional reinforced concrete(RC) segment has been performed in europe. This solution allows removing the traditional reinforcement with several advantages in terms of quality and cost reduction. Full-scale bending tests were carried out in order to compare the behaviour of the segments under flexural actions on both rebar reinforced concrete and rebar-fiber reinforced elements. The test results showed that the fiber reinforced concrete can substitute the traditional reinforcement; in particular the segment performance is improved by the fiber presence, mainly in terms of crack.

• Journal of the Korean Geosynthetics Society
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• v.10 no.3
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• pp.1-8
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• 2011

This paper presents the performance evaluation of asphalt pavement reinforced with fiber sheet type of geosynthetics and observations conducted to evaluate the practical efficiencies and performance of overlay asphalt pavement reinforced with geosynthetics. In this study, performance evaluation were performed for the six section of construction site. The performance indcators of asphalt pavement reinforced with geosynthetics has been collected Automatic Road Analyzer (ARAN), Falling Weight Deflectometer (FWD) and have been analyzed for rutting, cracking ratio, falling weight and international roughness index. As a result of performance evaluations, geosynthetics reinforced asphalt pavement is sigficant effect on increasing a cracking resistance than the non-reinfroced asphalt pavement, also rutting and crak is slowly increase as incerasingly performance period.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.470-476
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• 2016

Many studies have been performed on hybrid fiber reinforced concrete for years, which is to improve some of the weak material properties of concrete. Studies on characteristics of hybrid fiber reinforced concrete using amorphous steel fiber and polyamide fiber, however, yet remain to be done. The purpose of this experimental research is to evaluate the workability and mechanical properties of hybrid fiber reinforced concrete using amorphous steel fiber and polyamide fiber. For this purpose, the hybrid fiber reinforced concrete containing amorphous steel fiber(ASF) and polyamide fiber(PAF) were made according to their total volume fraction of 0.5 % for water-binder ratio of 33 %, and then the mechanical properties such as the compressive strength, direct tensile strength, flexural strength, and flexural toughness of those were estimated. It was observed from the test results that the compressive strength was slightly decreased with increasing ASF and decreasing PAF and the effect of fiber combination on the flexural strength was not much but the flexural toughness was relatively largely increased with decreasing ASF and increasing PAF.

• Structural Engineering and Mechanics
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• v.90 no.4
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• pp.371-390
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• 2024

Investigating the impact of openings on the structural behavior of ferrocement I-beams with two distinct types of reinforcing metallic and non-metallic meshes is the primary goal of the current study. Up until failure, eight 250x200x2200 mm reinforced concrete I-beams were tested under flexural loadings. Depending on the kind of meshes used for reinforcement, the beams are split into two series. A control I-beam with no openings and three beams with one, two, and three openings, respectively, are found in each series. The two series are reinforced with three layers of welded steel meshes and two layers of tensar meshes, respectively, in order to maintain a constant reinforcement ratio. Structural parameters of investigated beams, including first crack, ultimate load, deflection, ductility index, energy absorption, strain characteristics, crack pattern, and failure mode were reported. The number of mesh layers, the volume fraction of reinforcement, and the kind of reinforcing materials are the primary factors that vary. This article presents the outcomes of a study that examined the experimental and numerical performance of ferrocement reinforced concrete I-beams with and without openings reinforced with welded steel mesh and tensar mesh separately. Utilizing ANSYS-16.0 software, nonlinear finite element analysis (NLFEA) was applied to illustrate how composite RC I-beams with openings behaved. In addition, a parametric study is conducted to explore the variables that can most significantly impact the mechanical behavior of the proposed model, such as the number of openings. The FE simulations produced an acceptable degree of experimental value estimation, as demonstrated by the obtained experimental and numerical results. It is also noteworthy to demonstrate that the strength gained by specimens without openings reinforced with tensar meshes was, on average, 22% less than that of specimens reinforced with welded steel meshes. For specimens with openings, this value is become on average 10%.

• Advances in concrete construction
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• v.9 no.3
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• pp.313-326
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• 2020

Glass fiber-reinforced polymer (GFRP) bars have been introduced as an effective alternative for the conventional steel reinforcement in concrete structures to mitigate the costly consequences of steel corrosion. However, despite the superior performance of these composite materials in terms of corrosion, the effect of replacing steel reinforcement with GFRP on the seismic performance of concrete structures is not fully covered yet. To address some of the key parameters in the seismic behavior of GFRP-reinforced concrete (RC) structures, two full-scale beam-column joints reinforced with GFRP bars and stirrups were constructed and tested under two phases of loading, each simulating a severe ground motion. The objective was to investigate the effect of damage due to earthquakes on the service and ultimate behavior of GFRP-RC moment-resisting frames. The main parameters under investigation were geometrical configuration (interior or exterior beam-column joint) and joint shear stress. The performance of the specimens was measured in terms of lateral load-drift response, energy dissipation, mode of failure and stress distribution. Moreover, the effect of concrete damage due to earthquake loading on the performance of beam-column joints under service loading was investigated and a modified damage index was proposed to quantify the magnitude of damage in GFRP-RC beam-column joints under dynamic loading. Test results indicated that the geometrical configuration significantly affects the level of concrete damage and energy dissipation. Moreover, the level of residual damage in GFRP-RC beam-column joints after undergoing lateral displacements was related to reinforcement ratio of the main beams.

• Earthquakes and Structures
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• v.14 no.1
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• pp.73-84
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• 2018

Low cyclic loading tests are conducted on the steel reinforced recycled concrete (SRRC) column-steel (S) beam composite frame joints. This research aims to evaluate the earthquake damage performance of composite frame joints by performing cyclic loading tests on eight specimens. The experimental failure process and failure modes, load-displacement hysteresis curves, characteristic loads and displacements, and ductility of the composite frame joints are presented and analyzed, which shows that the composite frame joints demonstrate good seismic performance. On the basis of this finding, seismic damage performance is examined by using the maximum displacement, energy absorbed in the hysteresis loops and Park-Ang model. However, the result of this analysis is inconsistent with the test failure process. Therefore, this paper proposes a modified Park-Ang seismic damage model that is based on maximum deformation and cumulative energy dissipation, and corrected by combination coefficient ${\alpha}$. Meanwhile, the effects of recycled coarse aggregate (RCA) replacement percentage and axial compression ratio on the seismic damage performance are analyzed comprehensively. Moreover, lateral displacement angle is used as the quantification index of the seismic performance level of joints. Considering the experimental study, the seismic performance level of composite frame joints is divided into five classes of normal use, temporary use, repair after use, life safety and collapse prevention. On this basis, the corresponding relationships among seismic damage degrees, seismic performance level and quantitative index are also established in this paper. The conclusions can provide a reference for the seismic performance design of composite frame joints.

• International Journal of Highway Engineering
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• v.12 no.1
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• pp.47-54
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• 2010

This study had a focus on investigating technical validity of Two-Lift Concrete Pavements which had never been constructed in Korea in order to olve the problem of existing concrete pavements. This study found out the application of Steel Fiber Reinforced Concrete (SFRC) which was one of ew techniques. Also, optimal steel fiber contents and pavement thickness were determined. This study also measured compressive strengths, lexural strengths, toughness indexes, tensile strengths and fatigue strengths to estimate the performance of SFRC of according to results of aboratory experiments, slumps and air contents of concrete specimens the standards satisfied and compressive strengths to open traffic. At bending ests, Toughness Index of SFRC increased but flexural strength didn’'t increase as compared with non-steel fiber concretes. And, energy absorption of SFRC was very good and SFRC showed improvement in freezing and thawing resistances. To complete this research, we will evaluate the pplication methods and performance of SFRC at field section.

• Advances in concrete construction
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• v.9 no.5
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• pp.511-527
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• 2020

The main aim of the current research is to investigate the flexural behavior of the reinforced concrete (RC) slabs strengthened with strain hardening cementitious composites (SHCC) experimentally and numerically. Seven RC slabs were prepared and tested under four-points loading test. One un-strengthened slab considered as control specimen while six RC slabs were strengthened with reinforced SHCC layers. The SHCC layers had different reinforcement ratios and different thicknesses. The results showed that the proposed strengthening techniques significantly increased the ultimate failure load and the ductility index up to 25% and 22%, respectively, compared to the control RC slab. Moreover, a three dimensional (3D) finite element model was proposed to analyze the strengthened RC slabs. It was found that the results of the proposed numerical model well agreed with the experimental responses. The validated numerical model used to study many parameters of the SHCC layer such as the reinforcement ratios and the different thicknesses. In addition, steel connectors were suggested to adjoin the concrete/SHCC interface to enhance the flexural performance of the strengthened RC slabs. It was noticed that using the SHCC layer with thickness over 40 mm changed the failure mode from the concrete cover separation to the SHCC layer debonding. Also, the steel connectors prevented the debonding failure pattern and enhanced both the ultimate failure load and the ductility index. Furthermore, a theoretical equation was proposed to predict the ultimate load of the tested RC slabs. The theoretical and experimental ultimate loads are seen to be in fairly good agreement.

• Journal of the Korean Society of Industry Convergence
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• v.10 no.3
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• pp.149-155
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• 2007

Damage assessment and Damage index for RC members failed in flexure was investigated by using the nonlinear finite element analysis, included with nonlocal constitutive law, which is analyzed for the localization of the failure on the post-peak region. In the nonlcal constitutive law, The local strains obtained at gauss points were averaged over a particular length, i.e. characteristic length and it was used to evaluate the damage of RC column member. As the analysis results, The value of nonlocal strain shows less mesh sensibility. In the damage assessment, It was confirmed that evaluations of damage of RC member were able to use nonlocal compressive strain on a cover concrete and a core concrete of the member. Moreover it was confirmed that damage process for the statically indeterminate structure was able to evaluate the damage context of the component members of the structure.