• International Journal of Concrete Structures and Materials
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• v.10 no.2
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• pp.125-142
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• 2016

An overall review of the structural behaviors of ultra-high-performance fiber-reinforced concrete (UHPFRC) elements subjected to various loading conditions needs to be conducted to prevent duplicate research and to promote its practical applications. Thus, in this study, the behavior of various UHPFRC structures under different loading conditions, such as flexure, shear, torsion, and high-rate loads (impacts and blasts), were synthetically reviewed. In addition, the bond performance between UHPFRC and reinforcements, which is fundamental information for the structural performance of reinforced concrete structures, was investigated. The most widely used international recommendations for structural design with UHPFRC throughout the world (AFGC-SETRA and JSCE) were specifically introduced in terms of material models and flexural and shear design. Lastly, examples of practical applications of UHPFRC for both architectural and civil structures were examined.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.574-577
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• 2006

Recently, the deterioration due to salt damage and carbonation as the main factors of deteriaoration of the domestic reinforced concrete structures has been increased. Also the national and social concern about the durability recovery of the deteriorated reinforced concrete structures is geratly being raised. Therefore, it is the final purposes of this study to develop the performance evaluation technique for durability of reinforced concrete structures deteriorated due to salt damage and carbonation with the proposal of the service life prediction method for the investigation and diagnosis of reinforced concrete structures, and accelerated test in Lab.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.352-361
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• 1998

The post-processing modules are parts of an integrated system for reinforced concrete structures. This modules are composed of two modules: member design module and calculation report module. The purpose of this paper is to develope modules that increase efficiency and usefulness of an integrated system used reinforced concrete structures design. The development of post-processing modules is necessary for user to design reinforced concrete structures conveniently and quickly. This modules are connected with central database for the benefit of storing amount of input/output data and being used system with little effort. Post-processing modules used Object-Oriented concepts and techniques include identity, classification, polymorphism, and inheritance. Member design module automatically converts no good members into satisfied members by changing section size or reinforcement bar arrangement. This module can be operated both independent member design modules with user input and a part of integrated system with database input. If user operates member design module, calculation report module is created automatically.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.258-259
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• 2019

Corrosion of rebar in RC structures, which results in premature deterioration of reinforced concrete structures, is a very serious problem. Most corrosion monitoring and sensing technologies require some type of wired or wireless connection between the sensor and monitoring electronics. This causes significant problems in their installation and long-term use. In this paper we describe a corrosion monitoring technology of rebar in reinforced concrete structures. Especially, it is emphasize that the development of sensors and monitoring system not only occurrence of rebar corrosion but also penetration of deterioration factor such like chloride ion and carbon dioxite etc..

• Earthquakes and Structures
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• v.15 no.3
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• pp.307-317
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• 2018

The current study explores the soil-structure interaction (SSI) effect on the potential seismic damage of mid-rise non-seismically designed reinforced concrete frames retrofitted by Fibre Reinforced Polymer (FRP). An 8-storey reinforced concrete frame poorly-confined due to transverse reinforcement deficiency is selected and then retrofitted by FRP wraps to provide external confinement. The poorly-confined and FRP retrofitted frames with/without SSI are modelled using hysteretic nonlinear elements. Inelastic time history and damage analyses are performed for these frames subjected to different seismic intensities. The results show that the FRP confinement significantly reduces one or two damage levels for the poorly-confined frame. More importantly, the SSI effect is found to increase the potential seismic damage of the retrofitted frame, reducing the effectiveness of FRP retrofitting. This finding, which is contrary to the conventionally beneficial concept of SSI governing for decades in structural and earthquake engineering, is worth taking into account in designing and evaluating retrofitted structures.

• Journal of Korean Association for Spatial Structures
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• v.7 no.3 s.25
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• pp.141-151
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• 2007

The appearance of many Glass Fiber Reinforced Plastic (GFRP) constructions look like ordinary steel construction, because GFRP has been imitated by the same way with the traditional steel's cross section as well as connection system. In terms of detachable connection, there was not enough appropriate option of GFRP connection, such as a traditional bolt connection for steel and wood structures. Most of all, from material characteristic of GFRP related to the deficient ductility, the shearstress principle of GFRP s not proper for the material property, which causes ineffective and not economic application of material. With this research problem, the innovative and detachable onnection system, which is more considered with appropriate material characteristic for FRP, is developed. Not only short time but also long time research with various connection variations is carried out.

• Computers and Concrete
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• v.20 no.5
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• pp.511-519
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• 2017

The reliability of reinforced concrete structures is frequently compromised by the deterioration caused by reinforcement corrosion. Evaluating the effect caused by reinforcement corrosion on structural behaviour of corrosion damaged concrete structures is essential for effective and reliable infrastructure management. In lifecycle management of corrosion affected reinforced concrete structures, it is difficult to correctly assess the lifecycle performance due to the uncertainties associated with structural resistance deterioration. This paper presents a stochastic deterioration modelling approach to evaluate the performance deterioration of corroded concrete structures during their service life. The flexural strength deterioration is analytically predicted on the basis of bond strength evolution caused by reinforcement corrosion, which is examined by the experimental and field data available. An assessment criterion is defined to evaluate the flexural strength deterioration for the time-dependent reliability analysis. The results from the worked examples show that the proposed approach is capable of evaluating the structural reliability of corrosion damaged concrete structures.

• Earthquakes and Structures
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• v.16 no.2
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• pp.141-148
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• 2019

In this study, a well-established model and a new simplified version of it, that help avoid collapses in reinforced concrete structures during strong earthquakes, are presented and discussed. Using this model, the initial formation of plastic hinges and the final concentration of the damages only in beams are accurately assured. The model also assures that the columns and the beam-column joints can remain intact. This model can be applied for the design of modern R/C structures, as well as for the design of strengthening schemes of old R/C structures by the use of reinforced concrete jackets. The model can also predict the form of earthquake damages in old structures but also earthquake damages in the modern structures.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.587-592
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• 2002

Fiber reinforced concrete has been used for tunnel lining and rehabilitation of old structures. Recently, structural synthetic fiber was developed to overcome the corrosive properties of steel fibers. Fibers play a role to increase the tensile and cracking resistance of concrete structures. The Post cracking behavior must be clarified to predict cracking resistance of fiber reinforced concrete. The purpose of the present study is to develop a realistic analysis method for post cracking behavior of synthetic fiber reinforced concrete members.

• Ocean Systems Engineering
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• v.2 no.2
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• pp.159-171
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• 2012

Reinforced concrete structures in cold coastal regions are subjected to coupled effects of service load, freeze-thaw cycles and seawater corrosion. This would significantly degrade the performance and therefore shorten the service life of these structures. In the current paper, the mechanical properties of concrete material and the structural behaviour of eccentrically loaded reinforced concrete columns under multiple actions of seawater corrosion, freeze-thaw cycles and persistent load have been studied experimentally. Results show that when exposed to alternating actions of seawater corrosion and freeze-thaw cycles, the compressive strength of concrete decreases with the increased number of freeze-thaw cycles. For reinforced concrete column, if it is only subjected to seawater corrosion and freeze-thaw cycles, the load resistance capacity is found to be reduced by 11.5%. If a more practical service condition of reinforced concrete structures in cold coastal regions is simulated, i.e., the environmental factors are coupled with persistent loading, a rapid drop of 15% - 26.9% in the ultimate capacity of the eccentrically loaded reinforced concrete column is identified. Moreover, it is observed that the increase of eccentric load serves to accelerate the deterioration of column structural behavior.