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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korea institute for structural maintenance and inspection
Journal Basic Information
Journal DOI :
Korea Institute for Structural Maintenance Inspection
Editor in Chief :
Volume & Issues
Volume 16, Issue 6 - Nov 2012
Volume 16, Issue 5 - Sep 2012
Volume 16, Issue 4 - Jul 2012
Volume 16, Issue 3 - May 2012
Volume 16, Issue 2 - Mar 2012
Volume 16, Issue 1 - Jan 2012
Selecting the target year
A Degradation Characteristic of FRP Rebars Attacked by Combined Environmental Factors
Oh, Hong Seob ; Moon, Do Young ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 1~10
DOI : 10.11112/jksmi.2012.16.3.001
In spite of high resistant to corrosion and its strength, over the last two decades, concerns still remain about the durability of FRP materials under severe environmental and thermal exposures. In this paper, authors experimentally examine the combined degradation by thermal and chemical attacks in heterogeneous FRP rebar be made up with various fibers and resins. Five types of Carbon, Glass and Hybrid FRP rebars had manufactured by different process and surface patterns are adopted for the experiments such as weight change, interlaminar shear strength, SEM and FT-IR analysis. FRP specimens were immersed in alkaline or distilled solution up to 150 days and then thermal exposed on 60, 100, 150 and
for 30 minutes. From the test results, the degradation of FRP bars are influnced by the resin type and manufacturing process as well as the fiber, and ILSS of exposed FRP bar in solutions is slightly increased in initial stage and then decresed with the passing of immersed time. But, in this test, it is observed that the discrepancy of ILSS between degraded by alkaline solution and distilled water is negligible value.
Feasibility Study of Structural Behavior Monitoring Using GPS and Accelerometer
Han, Jung Hun ; Ryu, Sung Chan ; Cho, Doo Yong ; Park, Sun Kyu ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 11~22
DOI : 10.11112/jksmi.2012.16.3.011
In this study, problems of RTK (Real Time Kinematic)-GPS (Global Positioning System) and an accelerometer sensor when applied to structures were experimentally identified through a comparison between results of the displacement measurement using the RTK-GPS, the accelerometer, and LVDT (Linear variable differential transformer). Integrated displacement was calculated by the improved RTK-GPS and accelerometer on the frequency of observation and positioning accuracy. This integrated displacement was also compared with that of LVDT to check the validity of application and feasibility.
Effect of Coating System to Prevent the Deterioration of Concrete Subjected to Compressive Stress
Yoon, In-Seok ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 23~30
DOI : 10.11112/jksmi.2012.16.3.023
For cracked concrete, it is obvious that cracks should be preferential channel for the penetration of aggressive substances such as chloride ions according to the previous researches. In order to extend the lifetime of cracked concrete, critical issues in the performance of the concrete is the risk of chloride-induced corrosion. Even though crack width can be reduced due to the high reinforcement ratio, the question is to which extend these cracks may jeopardize the durability of cracked concrete. If the size of crack is small, surface treatment system can be considered as one of the best options to extend the service life of concrete structures exposed to marine environment simply in terms of cost effectiveness versus durability performance. Thus, it should be decided to undertake an experimental study on the effect of surface coating system, which can be able to seal the concrete and the cracks to aggressive substances-induced corrosion in particular. In this study, it is excuted to examine the effect of surfaced treated systems on chloride penetration and carbonation through compressive stress induced cracks. Experimental results have showed conclusively that critical stress linked with deterioration, should be existed in compressive stress ratio 50 ~ 70% for chloride penetration and 70 ~ 80% for carbonation, respectively. When the critical stress is exceeded in concrete, a comparatively large deterioration was measured where the critical stress in concrete, the increase in the mass transportation is marginal in spite of the large increase in micro-cracks. As for the effect of surface coating system on crack-sealing, it can be seen conclusively that cracks can be healed.
Study for Progress Rate of Standard Deviation of Irregularity Based on Track Properties for the Railway Track Maintenance Cycle Analysis
Jeong, Min Chul ; Kim, Jung Hoon ; Lee, Jee Ha ; Kang, Yun Suk ; Kong, Jung Sik ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 31~40
DOI : 10.11112/jksmi.2012.16.3.031
The irregularity of railway track affects not only the comfort of ride such as noise or vibration but also the safety of train operation. For this reason, it is an interesting research area to design a reliable and sustainable railway track system and to analyze the train movement mechanism based on systematic approaches considering reasons of track irregularity possible in a specific local environment. Irregularity data inspected by EM-120, an railway inspection system in Korea includes unavoidable incomplete and erratic information, so it is encountered lots of problem to analyse those data without appropriate pre-data-refining processes. In this research, for the efficient management and maintenance of railway system, progress rate of standard deviation of irregularity is quantified. During the computation, some important components of railways such as rail joint, ballast, roadbed, and fastener have been considered. Probabilistic distributions of irregularity growth with respect to time are computed to predict the remaining service life of railway track and to be adapted for the safety assessment.
A Study for Relation Between Fatigue and Structural Members on Othortropic Steel Deck
Park, Jong In ; Hong, Sung Nam ; Kim, Tae Wan ; Park, Sun Kyu ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 41~50
DOI : 10.11112/jksmi.2012.16.3.041
Improvement of steel material quality made fatigue problems more critical than failure of the material itself. In many cases, cracks on the welded parts of steel deck bridges are reported against the failure of steel materials. And the cracks are caused by alternate stress on the welded parts due to live loads on the bridge. The range of alternate stress on the welded part is related to property of the sections which compose othortropic steel deck. Othortropic steel deck is mainly composed of deck plate, ribs and floor beams, wearing surface, etc. In this paper, a methology to estimate the alternate stress for pthortropic steel deck using Pelikan-Esslinger method and signed Von-Mises equivalent stress is proposed first. Parametric study served references for fatigue stresses when designing or repairing othortropic steel deck bridges, by analyzing relationship between alternate stress range and properties of steel deck members.
Behavior Monitoring of Precast Concrete Panels in Lifting
Yang, Sung Chul ; Kim, Seong Min ; Han, Seung Hwan ; Yoon, Sang Chun ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 51~59
DOI : 10.11112/jksmi.2012.16.3.051
Through this research safety factors were analyzed for concrete precast panels in road pavement which happens in lifting, moving, and installing. Two half size of full-scale precast concrete panels were made while one full-scale precast concrete panel was made. A series of strain gages for concrete and steel were installed and measured in lifting and transporting. Measurement results indicate that in case of 60 degree of lifting, small scale panel in dynamic motion produces about 3.54 times of strain compared to the static condition. However strain measurement of full-scale concrete panel in lifting and transportation does not yield any big difference compared to the small scale panels in the static condition. From this experimental results safety of the full-scale concrete panel was attained for the lifting system adopted in this research.
The Development of Real-time Feedback Vibration Control System Using Wireless Sensor Networks
Heo, Gwang Hee ; Kim, Chung Gil ; Ahn, Ui Jong ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 60~66
DOI : 10.11112/jksmi.2012.16.3.060
This paper aims to constitute a feedback vibration control system using wireless sensor networks and experiment it on a model structure to verify its effectiveness. For the purpose, we set up a feedback vibration control system composed of a wireless input/output(I/O) sensor node based on bluetooth, a home-made shear type MR damper, a shaker which generates a constant size of sine wave, and a simple beam model structure. The vibration control experiment was performed by shaking the 1/4 point of beam with a shaker. At the moment of shaking, we controled the vibration with MR damper which was placed vertically on the center of beam. Simultaneously, by acquiring acceleration response at the 2/4 point of beam, we evaluated the effectiveness of control capability. The control command was set to send a voltage signal to MR damper when the acceleration response, acquired from the wireless I/O sensor node placed at the center of beam, was more than a certain amount. Although the realtime feedback vibration control system constituted in this paper is effective only within a limited command system, it has been proven that the system was able to effectively decrease the vibration of structure by generating a control command aimed for realtime purpose. The system also showed a possibility to be used as a structural response control system adapting a variety of semi-active control algorithm.
Mechanical Properties of Mortar Containing Bio-Char From Pyrolysis
Choi, Won Chang ; Yun, Hyun Do ; Lee, Jae Yeon ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 67~74
DOI : 10.11112/jksmi.2012.16.3.067
Bio-char, obtained from biomass as a by-product of the pyrolysis process, is used successfully as a soil amendment and carbon sequester in this limited study. Recent and active research from literatures has extended the application of bio-char in the industry to promote sustainability and help mitigate the negative environmental impacts caused by carbon emissions. This study aims to investigate the feasibility of high-carbon bio-char as a carbon sequester and/or admixture in mortar and concrete to improve the sustainability of concrete. This paper presents the experimental results of an initial attempt to develop a cement admixture using bio-char. In particular, the effects of the water retention capacity of bio-char in concrete are investigated. The chemical and mechanical properties (e.g., the chemical components, microstructure, concrete weight loss, compressive strength and mortar flow) are examined using sample mortar mixes with varying replacement rates of cement that contains hardwood bio-char. The experimental results also are compared with mortar mixes that contain fly ash as the cement substitute.
Effect of Additional Water on Durability and Pore Size Distribution in Cement Mortar
Kwon, Seung Jun ; Lee, Hack Soo ; Park, Sun Gyu ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 75~83
DOI : 10.11112/jksmi.2012.16.3.075
Porosity in concrete has close relationship with durability characteristics. Additionally mixed water can help easy mixing and workability but causes increased porosity, which yields degradation of durability performance. In this paper, cement mortar samples with 0.45 of w/c (water to cement ratio) are prepared and durability performances are evaluated with additional water from 0.45 to 0.60 of w/c. Various durability tests including strength, chloride diffusion, air permeability, saturation, and moisture diffusion are performed. Then they are analyzed with changing porosity. Changing ratios and the patterns of durability performance are quantitatively evaluated considering pore size distribution, total porosity, and additional water content.
Effects of Cable Rupture on Dynamic Responses of a Concrete Cable-stayed Bridge
Kim, Yu Hee ; Go, Hyeong Gyu ; Kim, Jae Cheon ; Shin, Soobong ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 84~91
DOI : 10.11112/jksmi.2012.16.3.084
This paper aims to investigate the effects of cable rupture on the dynamic responses of concrete cable-stayed bridges in comparison with those of steel composite ones. It examines an adequate analysis method for simulating cable rupture using a time history function and evaluates the design guidelines for dynamic amplification factor (DAF). The computed DAFs from a concrete cable-stayed bridge are compared with those from a steel composite one based on the design guideline. As a conclusion, the current design guidelines for DAF may be reliable in overall but show some unstable cases despite satisfying the design guidelines, especially for concrete cable-stayed bridges.
Structural and Functional Measurements of a Space Truss Frame for Maintenance Works in Tunnels
Lee, Dong Kyu ; Kim, Do Hwan ; Kim, Jin Ho ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 92~98
DOI : 10.11112/jksmi.2012.16.3.092
This study shows details of a specific space truss frame structure devised to carry out maintenance and repair temporary works in tunnels. The purpose of this study is to verify structural safety and function of the innovative truss structure through an analysis tool, i.e.. ABAQUS, which is a suite of software application for finite element analysis and computer aided engineering. And then optimized size, i.e., thickness and diameter of truss members is evaluated in practice. In this study, construction methods in the temporary works are additionally represented by using the new space truss frame structure.
A Fundamental Study for the Behavior of Lightweight Aggregate Concrete Slab Reinforced with GFRP Bar
Jeon, Sang Hun ; Shon, Byung Lak ; Kim, Chung Ho ; Jang, Heui Suk ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 99~108
DOI : 10.11112/jksmi.2012.16.3.099
In this paper, to intend anticorrosive effect and weight reduction of conventional reinforced concrete slab, lightweight concrete slab reinforced with glass fiber reinforced polymer(GFRP) bar was considered and some basic behaviour of the slab were investigated. Measurement of splitting tensile strength and fracture energy of the concrete, a number of flexural experiment of the slab, numerical analysis using nonlinear finite element analysis, and comparison of the experimental results to the numerical analysis, were conducted. As a result, even the weight of the lightweight concrete slab could be reduced by about 28% than the normal concrete slab, failure load of the lightweight concrete slab was 36% smaller than the normal concrete slab. Such a thing can be attributed to the lower axial stiffness and lower bond strength of GFRP bar. In the numerical analysis, to consider decreasing property of bond strength of the lightweight concrete, interface element was used between the concrete and the GFRP bar elements and this method was shown to be a better way for the numerical analysis to approach the experimental results.
Mechanical Properties of the Alkali-Activated Slag Mortar with Gypsum
Kim, Tae Wan ; Hahm, Hyung Gil ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 109~116
DOI : 10.11112/jksmi.2012.16.3.109
This study investigated the effects of blast furnace slag mortars activated with sodium hydroxide(NaOH) and gypsum in relation to flow, setting time and compressive strength. The parameters in this studied was the gypsum ratio 0 to 50%, 3M and 6M of activator concentration and
of curing temperatures. The results of flow was increase, setting time was increase as the amount of gypsum increases. But the results of compressive strength was dependent on the gypsum ratio, indicating that the compressive strength increased with the increase of the amount of gypsum until a certain limit, beyond which the strength decreased quickly.
Numerical Study for Seismic Strengthening of RC columns Using Fiber Reinforced Plastic Composite
Chang, Chun Ho ; Kwon, Min Ho ; Kim, Jin Sup ; Joo, Chi Hong ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 117~127
DOI : 10.11112/jksmi.2012.16.3.117
As increasing number of large-size earthquake around Korean peninsula, many interests have been focused to the earthquake strengthening of existing structures. Fiber reinforced plastic composite material is one of strengthening material widely used to increase seismic performance of structures. It should have high stiffness as well as large ductility to provide best strengthening result. Thus selection of stiffener and fiber in composite is of important. In this study, the optimal combination of fiber and stiffener is selected with variety of tensile tests. In order to investigate performance of chosen composite material, several finite element analyses are performed with proposed FRP composite material for existing RC columns. It is discussed that the seismic performance of strengthened columns through the load-displacement relationship. It is shown that the proposed composite material can increase the strength as well as ductility of exiting RC columns.
Structural Performance of Hybrid Coupled Shear Wall System Considering Connection Details
Park, Wan Shin ; Yun, Hyun Do ; Kim, Sun Woong ; Jang, Young Il ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 3, 2012, Pages 128~137
DOI : 10.11112/jksmi.2012.16.3.128
In high multistory buildings, hybrid coupled shear walls can provide an efficient structural system to resist horizontal force due to wind and seismic loads. Hybrid coupled shear walls are usually built over the whole height of the building and are laid out either as a series of walls coupled by steel beams with openings to accommodate doors, elevator walls, windows and corridors. In this paper, the behavior characteristics of hybrid coupled shear wall system considering connection details is examined through results of an experimental research program where 5 two-thirds scale specimens were tested under cyclic loading. Such connections details are typically employed in hybrid coupling wall system consisting of steel coupling beams and reinforced concrete shear wall. The test variables of this study are embedment length of steel coupling beam and wall thickness of concrete shear wall. The results and discussion presented in this paper provide fundamental data for seismic behavior of hybrid coupled shear wall systems.