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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 14, Issue 6 - Nov 2010
Volume 14, Issue 5 - Sep 2010
Volume 14, Issue 4 - Jul 2010
Volume 14, Issue 3 - May 2010
Volume 14, Issue 2 - Mar 2010
Volume 14, Issue 1 - Jan 2010
Selecting the target year
Seismic Retrofit Effect for Column of Subway Tunnel Reinforced by FRP-Ductile Material Layered Composites
Kim, Doo-Kie ; Go, Sung-Hyuk ; Kim, Jin-Yeong ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 85~92
Recently the earthquake occurrences in Korea are likely to increase. Therefore, the facilities such as bridges and tunnels under the unexpected earthquakes need to be enhanced. Especially most of the subways previously built before 1988 have not been seismically designed, so their seismic safety requirements are required to be inspected and/or reinforced. In this study, the seismic reinforcement using FRP-ductile material layered composites was proposed to reinforce for the subway columns. Material properties of FRP-ductile material layered composites were calculated by laboratory tests considering the laminated conditions of the composites. Numerical simulations were performed using the experimental results of the specimens and the calculated properties of the composites. Seismic performance varied according to the types of composites: ductile material, number of layers, fiber orientations.
Seismic Isolation Effects According to Set up the Isolation Period in the Medium and Low-rise Framed Building
Chun, Young-Soo ; Hur, Moo-Won ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 93~99
Seismic isolation offers an attractive approach for reducing seismic loads in the building and its components. This paper deals with the seismic isolation effects due to variation in period ratio between superstructure and isolation layer of the building. Seismic isolation effects of the moment-resisting frames with the various period ratio were studied by nonlinear time history analysis, and the guidelines on the stiffness ratio of the superstructure and isolation layer of the building for the effective seismic isolation follow from the results of this study. It is recommended that the isolation period should be greater than 2.5 times of that of the superstructure for the effective seismic isolation.
Axial Strength of RC Columns Extracted from Existing Apartment Housings
You, Young-Chan ; Shin, Hyun-Seop ; Choi, Ki-Sun ; Lim, Byung-Ho ; Kim, Keung-Hwan ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 100~108
The axial strength of existing RC columns were experimentally investigated in this paper to understand the strength characteristics of existing structural members and to get a appropriate data in strengthening design of RC members in a remodelling construction. Ten RC columns were prepared by being cut and extracted directly from the demolition site of the apartment housings. Each column was tested under uniaxial loadings with different eccentricities in order to evaluate the axial strength of existing RC columns. From the test results, it was found that axial strength of all the specimens were at least 75% higher than those of the theoretical values required by current code. But member displacement ductility ratio were relatively low ranging from 2.12~5.86.
3-D Finite Element Model for Predicting Bending and Shear Failure of RC Beams
Cho, Chang-Geun ; Ha, Gee-Joo ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 109~116
Three-dimensional finite element model for analysis of reinforced concrete members was developed in order to investigate the prediction of bending and shear failure of reinforced concrete beams. A failure surface of concrete in strain space was newly proposed in order to predict accurately the ductile response of concrete under multi-axial confining stresses. Cracking of concrete in triaxial state was incorporated with considering the tensile strain-softening behavior of cracked concrete as well as the cracked shear behavior on cracked surface of concrete caused by aggregate interlocking and, dowel action. By correlation study on failure types of bending and shear of beams, current finite element model was well simulated not only the type of ductile bending failure of under-reinforced beams but also the type of brittle shear failure of no-stirruped reinforced concrete beam.
A Study on the Change of Strength of FRP Member Immersed in Chemical Solution
Kim, Ho-Sun ; Kim, Woo-Jong ; Jang, Hwa-Sup ; Kwak, Kae-Hwan ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 117~123
If FRP materials that have been known as high durability materials are exposed to harmful environmental factors, deterioration and characteristics of materials can be reduced due to chemical reaction such as hydrolysis. Therefore, to use FRP materials as building major materials, it is important to exactly grasp dynamic properties by use condition. Accordingly, this study stored FRP materials in a strong acid and alkali compound solution for a certain period to conduct simulation for acute or chronic, extreme changes by chemicals, and conducted a test for compressive, tensile, shear and bending strength to analyze changes in strength by kinds and storage days of chemicals. In conclusion, the study findings indicate excellent chemical resistance of FRP materials.
Analysis for Mechanical Behavior of GFRP Rock Bolt for Permanent Support of Tunnel
Sim, Jong-Sung ; Kang, Tae-Sung ; Lee, Yong-Taek ; Kim, Hyun-Joong ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 124~131
Rock Bolt generally utilizes deformed reinforcing bar welded from structural steel of which strength is higher than required for making advantageous use of the support function of ground. In the condition with highly corrosive underground water, however, problem frequently occurs on tunnel and slope stabilization in terms of repair, rehabilitation and maintenance issues due to the destruction of Rock Bolt by corrosion of steel. A structural performance evaluation for GFRP Rock Bolt was conducted for the purpose of resolving the foregoing problem and at the same time developing a permanently-usable support material. This study intended to evaluate the safety factor of GFRP Rock Bolt by implementing the slope stability interpretation via structural analysis on the basis of its structural characteristics derived from both tensile force function test and shear force function test. It is judged based on the results that GFRP Rock Bolt would secure sufficient ground stability as an alternative material for existing Steel Rock Bolt.
A Fundamental Study for Beneficial Use of Dredged Material as a Concrete Admixture
Oh, Hong-Seob ; Oh, Kwang-Jin ; Lee, Ju-Won ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 132~141
Recently dredged material generation has a tendency to increase since harbor construction are under progress. In this study, an experiment had been carried out which replacement of dredged material of Busan and Ulsan port as concrete mixing material. For this experiment, physical and chemical test of dredged material was carried out, and compressive strength test of mortal specimen with dredged material in scale, as aggregate replacement, was carried out. Compressive strength of Busan and Ulsan was both increased when the ratio of mixing materials was 10%. Compressive strength of Dredged material from Busan with about 70% of mineral silt showed increse when the ratio of aggregate replacement in 30%. In addition, in the result of the ICP test, both dredged materials satisfied the waste's marine discharge treatment and soil contamination concern and measures criterion on that using dredged material as a concrete material can influence on application of concrete positively.
Improvement and Evaluation of Structural Performance of Reinforced Concrete Beam using High Ductile Fiber-Reinforced Mortar with Ground Granulated Blast Furnace Slag
Ha, Gee-Joo ; Lee, Dong-Ryul ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 142~152
In this study, eleven reinforced concrete beams, without stirrup, using high ductile fiber-reinforced mortar with ground granulated blast furnace slag(SHF Series, SHFSC Series) and standard specimens without or with stirrup(SSS, BSS) were constructed and tested under monotonic loading. Experimental programs were carried out to improve and evaluate the shear performance of such test specimens, such as the load-displacement, the failure mode, the maximum strength, and shear strength. All the specimens were modeled in scale-down size. Test results showed that test specimens(SHF Series, SHFSC Series) was increased respectively the shear strength carrying capacity by 26%, 20% and the ductility capacity by 5.27, 5.75 times in comparison with the standard specimen without stirrup(SSS). And the specimens(SHF Series, SHFSC Series) showed enough ductile behavior and stable flexural failure.
Development of CFS Jacketing Retrofit Method for Rectangular High Strength Concrete Columns by Cross Sectional Shape Modification
Lee, Jong-Gil ; Kim, Jang-Ho Jay ; Park, Seok-Kyun ; Kim, Jin-Keun ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 153~161
Numerous past studies have shown that safety and serviceability of many concrete infrastructures and buildings built in 1970's have far less strength capacities than their original intended design capacities, thereby requiring repair and strengthening. Currently, aged concrete structures are being repaired using various methods developed in the past. Unfortunately, these methods do not consider the specific conditions that these members are under, but they merely attach repairing materials on the external surface for random strength improvements. Therefore, in order to improve repair and strengthening methods by considering composite behavior between repairing material and structural member, enhanced construction methodologies are needed. Also, the enhanced repairing and strengthening methods must be able to be implemented on structural members constructed using high performance concrete to meet the present construction demand of building mammoth structures. Therefore, in this study, a repairing and strengthening method for retrofitting high strength concrete (HSC) columns that can effectively improve column performance is developed. A square HSC column's cross-sectional shape is converted to an octagonal shape by attaching precast members on the surface of the column. Then, the octagonal column surface is surface wrapped using Carbon Fiber Sheets (CFS). The method allows maximum usage of confinement effect from externally jacketing CFS to improve strength and ductility of repaired HSC columns. The research results are discussed in detail.
Development of the Method for Inspecting the Clamping Force of Torque Shear Bolts Using the Electricity energy of Electric torque wrench
Lee, Hyeon-Ju ; Nah, Hwan-Seon ; Kim, Kang-Sik ; Kim, Kang-Seok ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 162~170
The torque-coefficient of torque-shear type high-strength bolts is affected by the environmental factors, such as 'wet', 'rust', 'exposure to air' and workability during tightening high strength bolts. It is difficult to assume the direct tension induced into the bolt due to variation of torque-coefficient for torque-shear type high-strength bolts. Therefore, it is essential to measure tension loads of bolts and to verify the clamping force under construction. In this study, the manufacture of trial product was planned to identify the induced force into the bolts. The algorithm for a trial product was composed of the relation between electricity energy taken from torque shear wrench and tension force from hydraulic tension meter. The regression analysis equation to measure the direct tension was derived by statistical analysis using Minitab program. It is considered that the trial product is reliable tool to evaluate the tension force comparable to a commercial torque wrench.
Real-time Health Monitoring of Pipeline Structures Using Piezoelectric Sensors
Kim, Ju-Won ; Lee, Chang-Gil ; Park, Seung-Hee ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 171~178
Pipeline structure is one of core underground infrastructure which transports primary sources. Since the almost pipeline structures are placed underground and connected each other complexly, it is difficult to monitor their structural health condition continuously. In order to overcome this limitation of recent monitoring technique, recently, a Ubiquitous Sensor Network (USN) system based on on-line and real-time monitoring system is being developed by the authors' research group. In this study, real-time pipeline health monitoring (PHM) methodology is presented based on electromechanical impedance methods using USN. Two types of damages including loosened bolts and notches are artificially inflicted on the pipeline structures, PZT and MFC sensors that have piezoelectric characteristics are employed to detect these damages. For objective evaluation of pipeline conditions, Damage metric such as Root Mean Square Deviation (RMSD) value was computed from the impedance signals to quantify the level of the damage. Optimal threshold levels for decision making are estimated by generalized extreme value(GEV) based statistical method. Throughout a series of experimental studies, it was reviewed the effectiveness and robustness of proposed PHM system.
Fundamental Study on Developing Embedded Mini-Sensor for Nondestructive Diagnosis Corrosion of Rebar
Joh, Sung-Hyung ; Lim, Young-Chul ; Ismail, Mohamed ; Lee, Han-Seung ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 179~187
Corrosion of rebar embedded reinforced concrete is the main cause of collapse and degradation of reinforced concrete structure. Degradation occurs in reinforced concrete structures from corrosion caused by the Chloride that the damage other than the severe degradation of the structure in terms of maintenance and construction when the huge expense required and deciding terms is hard. Therefore, early detection of rebar corrosion is important for efficient maintenance and repairing and planning. Meanwhile, how to evaluate the corrosion of the non-destructive measurements have been used a lot. In particular CM-II (corrosion meter) is used to measurement the natural potential, polarization resistance and the resistivity of the concrete, but has some disadvantages. Embedded mini-sensor has been developed in order to overcome these disadvantages. So Measurement corrosion for using the mini-sensor compares with the measured results CM-II (corrosion meter), the developed mini-sensor verify the validity.
Strength of RC Beam with Various Shear Reinforcement Ratios After Experiencing Different Duration of Fire Load
Seo, Soo-Yeon ; Jeoung, Chae-Myeoung ; Choi, Ki-Bong ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 188~197
This paper presents research result to study the change of structural capacity of reinforced concrete beams with various shear reinforcement ratios after damage by fire load. In addition, fundamental data are given in order to predict the strength variation of RC member due to fire damage by evaluating the previous calculation method codified in codes. Nine RC beam specimens were made and exposed to the fire controled by the standard fire curve. And the structural capacity was evaluated through a failure test under simple support condition. Previous code formula, ACI code and Eurocode were reviewed and used for the calculation of the strength of specimens damaged by fire. From the test, RC beam specimens exhibited very brittle failure when it exposed to fire controled by standard fire curve during more than one hour. And this failure pattern tended to be more serious when shear reinforcement ratio decreased or fire loading duration increased. From the evaluation of the calculation process in code, the change of strength due to fire can be properly predicted if the damage of materials is well defined.
A Fundamental Study on the Influence of Fresh Concrete Quality Properties due to the Cover of Concrete Mixer Truck
Chae, Young-Suk ; Lim, Byung-Hoon ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 198~204
The cover of truck agitator give in a part to prevent the lower flowing of fresh concrete when the concrete are transported from the ready mixed concrete plant to the construction field. As a result of the question data, it show up a dirty image to the general civil society. Due to the above image, it is predicted to affect the image of the construction company, so we did the site experiment of the flowing, the amounts of air, the temperature change of concrete with the concrete left in the site, to find out the usefulness. Also, for the comparing with this, we got the result by doing the inner experiment with the same condition. As the result of the experiment, the cover of truck agitator affect little to the reduction of slump. The change of the air amount, regardless of the existence of cover, was not effected much in proper level until 60minutes. In addition, The compression strength was proper to the goal design strength until 90minutes regardless of the cover of truck agitator exist or not exist.
An Estimation of Shear Capacity of Hexagonal Masonry Walls Under Cyclic Loading
Chang, Gug-Kwan ; Seo, Dae-Won ; Han, Tae-Kyoung ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 205~214
Masonry structures have been used throughout the world for the construction of residential buildings. However, from a structural point of view, the masonry material is characterized by a very low tensile strength. Moreover, the bearing and shear capacity of masonry walls have been found to be vulnerable to earthquakes. In this study, to improve the seismic performance of masonry walls, hexagonal blocks were developed and six masonry walls made with hexagonal block were tested to failure under reversed cyclic lateral loading. This paper focuses on an experimental investigation of different types of wall with hexagonal blocks, i.e. walls with different hexagonal blocks and with different reinforcing bar arrangements, subjected to applied cyclic loads. The cracking, damage patterns and hysteretic feature were evaluated. Results from the hexagonal masonry wall were shown more damage reduction and less brittle failure in comparison to the existing rectangular masonry walls.
Laboratory Tests and Numerical Simulations for Prediction of Stress-Stain Behavior Using Construction Materials for Embankment
Jeong, Sang-Guk ; Koo, Ja-Kap ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 215~219
The evaluation of the mechanical properties and behavior is very important for the design of embankment using granular materials. In this research, the lab. tests with Nak-dong river sand were conducted to find out mechanical properties related to stress-strain behavior. Also, numerical simulations which can express the behavior of granular material were conducted by distinct element method. Distinct element method can play a import role to predict stress-strain behavior for different confining stress and loading condition if micro-parameters can be estimated in specific condition.
Test research of Structural Safety for Steel Wire-Integrated Deck Plate System
Lee, Yong-Jae ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 220~228
A steel wire-integrated deck plate that welds integrated triangle truss steel wires on a galvanized steel sheet is developed to reduce construction costs of a slab or formwork such as shores and supports, and it is already widely applied in many construction fields. This study selected upper and lower steel wires, lattice steel wires, span, and cutting methods of ends as variables, and conducted an experimental test by manufacturing a total of 32 full scale test bodies. According to the result, changes in final destruction types of the test bodies and cutting methods of ends didn't affect structural performance of test bodies, and for a 3.2m-span test body, there was no big problems in using
of lattice steel wires.
A Research for the Determinant Factors of Safety Ratings in Road-Bridge
Hur, Youn-Kyoung ; Lee, Hong-Il ; Shin, Ju-Yeoul ; Park, Cheol-Han ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 229~237
This study analyzes the factors that affect the safety condition level of road-bridges, one of the important infrastructures. Utilizing Binary Logit model, this report empirically identifies the key factors that has influenced the recent assessed safety condition level of the first and the second major types of road-bridges, managed by public agencies, and the changes of the safety level for last six years. As a result of the analysis, the most important factor that influences the safety condition level is not the physical characteristics, but the management quality. As road-bridges are getting older and older, the management quality tends to bring about more differentials in assessing the safety condition level. The safety condition level, C or D, is likely to be improved the level, A or B, is likely to become degraded. To achieve the goal that keep the safety condition level, A and B, more than 90%, it should be considered to make the degrading rate from B to C lower. However, this study includes the limitation on data. It is essential to collect structure data that are spread out in many agencies to complement the limitation for further research.
An Evaluation of Progressive Collapse Resisting Capacity of RC Structure Using Static and Dynamic Analysis
Seo, Dae-Won ; Kim, Hae-Jin ; Shin, Sung-Woo ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 238~245
Progressive collapse is defined as a collapse caused by sectional destruction of a structural member which links to other surrounding structures. Currently the design guidelines for the prevention of progressive collapse is not available in Korea. So, structural engineers have a difficulty in evaluating progressive collapse. In this study, the static and dynamic analysis to evaluate the methods and procedures are conducted using commercial analysis program for RC moment resisting frames. According to the study, DCR value of RC moment resisting frame system based on code in Korea is over 2 and it shows that it can't provide alternate load paths due to the progressive collapse. And additional reinforcement should be considered for the progressive collapse resistance. As a result of vertical deflection and DCR value of linear static analysis and linear dynamic analysis, the results of dynamic analysis were underestimated more than the result of static analysis. Thus, the dynamic coefficient value of 2 provides conservative estimation.
Estimation of National Loss Expenses to Insufficient Safety Inspection and Precision Safety Diagnosis
Ha, Myung-Ho ; Park, Jong-Sup ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 246~253
National major facilities have been rigorously investigated using regular safety inspections and precision safety diagnosis since the Special Law for Facilities Safety Management was made in 1995. However, the process of safety inspection and precision safety diagnosis could be doubted due to intervention of facility owner for safety level evaluation, competition to obtain low price order, and low technical skills of inspection companies. Although the management processes for evaluating the inspection companies were used for several years, the process should continue to improve in the safety inspection field. This study analyzed the recent evaluation system and the ratios of insufficient inspection. Estimation of national loss expenses to the insufficient safety inspection was investigated to recognize the necessity for the improvement of facility inspection process and evaluation system.
An Experimental Evaluation on Vibration Serviceability of Existing Bridge by Non-contact Vibration Measurement Method
Shin, Hyun-Seop ; Park, Ki-Tae ; Lee, Kyu-Wan ; Jun, Jin-Taek ;
Journal of the Korea institute for structural maintenance and inspection, volume 14, issue 6, 2010, Pages 254~262
In order to evaluate vibration serviceability by means of non-contact vibration meter, serviceability of existing bridge were experimentally evaluated by using laser vibration meter. Test results were analyzed and compared with evaluation results acquired by using accelerometer and LVDT. To testify accuracy of laser vibration meter measured natural frequency were compared with that acquired by using accelerometer. According to test and comparison results it is showed that serviceability can be evaluated properly enough from the tolerance curve of Reiher-Meister for the estimated acceleration that can be calculated by the numerical differentiation of measured velocity. But because of cumulative numerical error occurred during integration of measured velocity in the time domain serviceability grade could be different from the result acquired by LVDT.