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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
Experimental Study on Behavior of Confined Concrete According to Configuration of High-Strength Transverse Reinforcement
Kim, Young Seek ; Kim, Dong Hwan ; Kim, Sang Woo ; Kim, Kil Hee ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 1~8
DOI : 10.11112/jksmi.2012.16.6.001
This study estimates the performance of confined concrete according to the configuration of transverse steel bars. The main test variables were the yield strength of spiral reinforcement and configuration of transverse reinforcement. A total of 27 specimens with rectangular cross section were cast and tested under monotonic concentric compression. R-type specimens with rectangular spirals, C-type specimens with circular spirals and O-type specimens with combined shape of rectangular and octagon were designed in this study. From experimental results, it is concluded that the proposed configuration of transverse reinforcement can provided improved ductility to the confined concrete compared to rectangular spiral reinforcement.
Engineering Properties of Sewage Polymer Concrete Culvert
Kwon, Seung Jun ; Min, Byung Yoon ; Park, Sang Soon ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 9~17
DOI : 10.11112/jksmi.2012.16.6.009
Concrete sewage culvert shows degradation with time since it is always exposed to various harmful ions, and deterioration of concrete culvert propagates to structural safety problems. After reclamation, maintenance for concrete sewage culvert is very difficult so that high durable and structural performance are essential for the sewage concrete culvert. Recently polymer concrete has been used to improve mechanical properties and durability performance. In this paper, engineering properties are evaluated for sewage culvert made with polymer concrete, and leakage and adhesive strength between joints are evaluated with small-scale models. The polymer sewage culvert shows high compressive strength over 100MPa with low water permeability and chloride penetration. Furthermore, high resistances to chemical and biological attack are evaluated. Through tests for leakage and adhesive, unification of joints is verified with evaluation of no leakage and high adhesive strength. Precast polymer sewage culvert in this paper can be actively used for severe conditions like sewage lines.
Experimental Study on Ductility of RC Columns According to Configuration of Transverse Reinforcement
Kim, Min Jun ; Kim, Do Jin ; Kim, Sang Woo ; Lee, Jung Yoon ; Kim, Kil Hee ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 18~25
DOI : 10.11112/jksmi.2012.16.6.018
This paper estimates the ductility of reinforced concrete columns according to configurations of transverse reinforcement. A total of 8 reinforced concrete columns were cast and tested in flexure. The test variables in this study were the configurations, yield strength, and amount of transverse reinforcement. The specimens had a cross-section of
and had a shear span-to-depth ratio of 4.1 to induce flexural failure. In the test, cyclic lateral load was applied to the specimens with a constant axial load. The experimental result indicated that the specimens with proposed configurations of transverse reinforcement showed higher ductility and energy dissipation capacity than the specimens with rectangular tie.
Influence of Blended Activators on the Physical Properties of Alkali-activated Slag Mortar
Kim, Tae Wan ; Park, Hyun Jae ; Seo, Ki Young ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 26~33
DOI : 10.11112/jksmi.2012.16.6.026
This paper reported on the effect of blended activator on the physical properties of alkali-activated slag mortar. Five different activators(caustic alkalis) were used: sodium hydroxide(NaOH, A Case), calsium hydroxide(
, B Case), magnesium hydroxide(
, C Case), aluminum hydroxide(
, D Case), and potassium hydroxide(KOH, E Case). We blended five caustic alkalis with sodium carbonate(
). The dosage of five caustic alkalis was 3M and sodium carbonate was 1M, 2M and 3M. The result of flow and setting time was decrease as the dosage of sodium carbonate increase. But the compressive strength was increase as the dosage of sodium carbonate increase. It was shown that there is a good effect of blended caustic alkalis with sodium carbonate in alkali-activated slag mortar.
Development of New Data Analysis Method to Evaluate Reliability of the Sensor or Measured Data
Park, Hyung Choon ; Hwang, Hea Jin ; Lee, Jong Wook ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 34~44
DOI : 10.11112/jksmi.2012.16.6.034
Many kind of sensors in the dam produce a lot of data associated with the maintenance and safety of the dam. So it is important to measure the reliability of the sensor (or measured data). In this paper, the new method using modified coherence function is proposed to measure the reliability of the sensor remotely. To verify feasibility of proposed method in the field, proposed method was applied to data of piezometer and earth pressure cell. Through field applications, the potential of the proposed method was verified.
On the Improvement for Design Methods of Luminaire Supports Based on the Structural Safety
Jung, Soo Hyung ; Shim, Jae Soo ; Choi, Hyun Gyu ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 45~55
DOI : 10.11112/jksmi.2012.16.6.045
The road luminaires have been treated as subsidiary electric apparatuses in the road although they are indispensable facilities which people use the road safely. Because of this misunderstanding, there are not many researches on luminaire supports against the wind loads. Therefore, a typhoon has overturned or damaged many luminaire supports without having sufficient structural safeties. The purpose of this study is to review the current design criteria and to suggest the improvement of design methods based on the structural safety and compatible with the site conditions of luminaire supports. The stress concentration around the inspection hole, which causes the collapse of luminaire supports, is analyzed and stress reduction method is suggested with the improved design methods.
Mechanical Properties of Ultra High Strength Concrete Using Ternary Blended Cement
Kim, Jin Bong ; Shin, Ki Su ; Park, Ki Bong ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 56~62
DOI : 10.11112/jksmi.2012.16.6.056
The results presented in this paper form part of an investigation into the optimization of a ternary blended cementitious system based on ordinary Portland cement (OPC)/blast furnace slag(BFS)/fly ash(FA) for the development of ultra high strength concrete. Concrete covering a wide range of BFS/FA blending proportions were investigated. Compressive strength at the ages of 3, 7 and 28 days for concrete specimens containing 0%, 10%, 20% and 30%FA along with 0%, 30%, 40% and 50%BFS as partial cement replacement at a water-binder ratio of 0.18 were investigated. Tests on porosity and pore size distribution were conducted using mercury intrusion porosimetry. The results show that the combination of FA10 and BFS30 can improve both short- and long-term properties of concrete as results of reducing of pores larger than 50nm.
Effects of Aggregate Grading on the Performance of High-Flowing Concrete with General Strength
Kim, Sang Chel ; Kim, Yun Tae ; Shin, Dong Cheol ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 63~72
DOI : 10.11112/jksmi.2012.16.6.063
The high-flowing concrete requires additionally or excessively more expensive admixture than conventional concrete. So, the concrete has not to be widely used in practical field due to the increase of production price, need of additional facilities, and excessive development of concrete strength in associate with addition of too much cementitious material even though it has more significant advantages than conventional concrete. Thus, this study aims at developing high-flowing concrete with general strength unlike high strength which has been carried out in conventional study. To observe the role of aggregate in the concrete quantitatively and to increase the performance of high-flowing concrete effectively, parametric studies were carried out such as W/C, s/a, fineness modulus of aggregate, contribution degree of particle sizes, and the effect of 13mm aggregate and fine stone powder as a partial replacement of aggregates. And the effect of these factors on performance of the concrete was evaluated by measuring slump-flow and gap of penetration height in U-typed instrument. As a result, it was found that flowability of high-flowing concrete depends upon grading of fine aggregate more significantly than that of coarse aggregate and is enhanced greatly as fineness modulus of fine aggregate decreases and the value of s/a increases. In addition, the application of 13mm aggregate and fine stone powder are expected as a partial replacement of aggregate in order to increase the performance of high-flowing concrete more effectively.
Characteristics of Pore Structure and Chloride Penetration Resistance of Concrete Exposed to Freezing-Thawing
Choi, Yoon Suk ; Won, Min Sik ; Yi, Seong Tae ; Yang, Eun Ik ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 73~81
DOI : 10.11112/jksmi.2012.16.6.073
Concrete structures are commonly exposed to freezing-thawing condition. This freezing-thawing action changes the pore structure of concrete, and it can reduce the durability of concrete. In this study, the change of the internal pore structure and durability of concrete due to freezing-thawing action are investigated. According to results, the excellent durability records were reported by the existing evaluation methods for all mixes. However, the pores, 50~100nm size in diameter, are increased in concrete specimens exposed to freezing-thawing action, and the chloride penetration resistance was significantly reduced. The linear relationship between pore structure and chloride penetration resistance was shown in water cured concrete. Meanwhile, the linear relationship was decreased when concrete is exposed to freezing-thawing condition. It is desirable to review the criterion of durability evaluation for concrete specimens exposed to freezing-fthawing and chloride attack condition, simultaneously.
Evaluation of Concrete Bridge Deck Deterioration Using Ground Penetrating Radar Based on an Extended Common Mid-Point Method
Baek, Jong Eun ; Lee, Hyun Jong ; Oh, Kwang Chin ; Eom, Byung Sik ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 82~92
DOI : 10.11112/jksmi.2012.16.6.082
This study proposed a new non-destructive evaluation method for concrete bridge deck deterioration using ground penetrating radar (GPR). To calculate dielectric constant of the concrete bridge deck, an extended common mid-point (XCMP) method was developed for a two-layered structure using an air-coupled GPR antenna setup. The deterioration conditions of the concrete bridge deck such as deterioration depth was evaluated based on the dielectric constant and surface-to-average dielectric constant ratio of the concrete bridge deck. A GPR field test was conducted on an old concrete bridge with asphalt concrete surfacing to validate the new evaluation method. The test results showed that the newly proposed method estimated pavement thickness and deterioration depth of the concrete deck in a reasonable level.
A Study on Condition Assessment of the General National Road Bridge Deck
Oh, Kwang Chin ; Lee, Jun Gu ; Shin, Ju Yeoul ; Chang, Buhm Soo ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 93~101
DOI : 10.11112/jksmi.2012.16.6.093
Bridge deck has a role in a comfortable and safe passage of vehicles. At the same time, it preserves upper structure against the abrasion and shearing due to impact of traffic loads in bridges or has a role to protect the plate from off adverse effect of climatic process as rain, chemicals. Currently, the total number of inspected bridges is 6,248 in the general national road and to maintain effectively, Introduction of GPR system mounted in the vehicle has been considered. In this research, the comparison and analysis of bridge deck condition on general national road has been performed with major variations of superstructure type, span lengths, located region and ages by using `the current status of road bridge and tunnel` that is provided by MLTM(Ministry of Land, Transport and Maritime Affairs). As a result, Condition assessment grade, superstructure type, age and length were derived as a major factor to determine priority for the condition assessment.
Assessment of Flexural Strengthening Behavior Using the Stirrup-Cutting Near Surface Mounted(CNSM) CFRP strip
Moon, Do Young ; Oh, Hong Seob ; Zi, Goang Seup ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 102~112
DOI : 10.11112/jksmi.2012.16.6.102
Recently, the near surface mounted (NSM) FRP strengthening technique has been actively applied to deteriorated concrete structures for rehabilitation purposes. However, the use of this conventional NSM technique could be restricted due to the insufficient height or strength of the concrete cover. In this study, the stirrup-Cutting Near Surface Mounted(CNSM) technique was considered as an alternative, whereby NSM strips are placed at a deeper level, namely at the level of the main steel reinforcement. A flexural test of a concrete beam strengthened with CNSM technique was performed and the results were then compared to those for a concrete beam strengthened by the conventional NSM technique. The embedment length of the CFRP strips was varied in order to increase the effect of the anchoring depth of the NSM and CNSM CFRP strips in the beam specimens. From the results of the test, the beam with the CNSM CFRP strip showed typical structural behavior similar to that of the beam with the NSM CFRP strip. Moreover, there was no apparent structural degradation resulting from the stirrup partial-cutting. Consequently, the CNSM strengthening technique can be suitably utilized for extensively damaged concrete structures where it is difficult to apply the conventional NSM technique.
Long-Termed Behavior and Durability of Foam-Mixed Concrete Containing Porous Aggregates
Kim, Sang Chel ; Yi, Seong Tae ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 113~123
DOI : 10.11112/jksmi.2012.16.6.113
The technology developed for the decrease of applying loads and self-weight of a structure is to improve conventional Foam Cement Banking Method (FCB) by applying mixed slurry of bottom ash, cement and foams. Since the foam-mixed concrete, which is a major material of the Bottom ash-mixed Light weight concrete Banking method (BLB) developed, contains mineral admixture such as cement, the behavior shows time-dependent deformation and deterioration of durability due to environmental exposure. Thus, this study is subject to figure out the characteristics of long-termed behavior and durability of the developed method by carrying out experiments for schemed parameters, which are considered to be factors affecting mainly on concrete`s characteristics from mechanical analysis. As results of tests, it was found that the developed concrete offers higher resistance than conventional foamed concrete in terms of long-termed behaviors associated with drying shrinkage and creep, and durability problems of freeze-thaw and carbonation processes, especially with addition of bottom ash.
Modeling on Compressive Strength in High Performance Concrete Using Porosity
Lee, Hack Soo ; Kwon, Seung Jun ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 124~133
DOI : 10.11112/jksmi.2012.16.6.124
Compressive strength in concrete increases with time. Regression analysis with time is conventionally performed for strength evaluation and prediction. In this study, hydrate amount is assumed as a function of hydration rate and porosity, and modeling on compressive strength is carried out considering decreasing porosity with time, which does not need the regression analysis with time. For twenty one mix proportions of HPC (High Performance Concrete), DUCOM (FE program) which can simulate the behavior in early aged concrete is utilized, and porosity from each mix proportions is obtained with time. For HPC with OPC (Ordinary Portland Cement) concrete, modeling on compressive strength is performed considering hydration rate, unit content of cement, and porosity with time. For HPC with mineral admixtures, a long-term parameter which can handle long-term strength development is additionally considered. From the comparison with the previous test results, the applicability of the proposed model is verified.
Long-term Tilt Prediction Model for the L-type Retaining Wall Adjacent to Urban Apartments
Koo, Ki Young ; Seong, Joo Hyun ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 134~142
DOI : 10.11112/jksmi.2012.16.6.134
This paper presents a study of system identification on the tilt response of the L-type retaining wall located at Tanhyun 11th ACE Apartment, Ilsan in order to understand mechanism how the structure behaves in operational conditions and to provide a reference tilt values for assessing structural abnormality. The retaining wall was extraordinarily tall (14m) in urban area so the long-term monitoring system had been installed with 3 tilts-meters and 9 temperature sensors operational from Oct 2004 upto Nov 2007. By using 5-months continuous data in which all the 12 channels were up and running, the two prediction models, 1) the linear model, and 2) the state-space equation (SSE) model, have been identified by finding the best fitness model among all possible 511 combinations of input temperatures out of the 9 temperatures. The linear model which was simple in the model structure achieved the validation fittness of 68% due to the fact that the static model wasn`t able to represent thermal dynamics. The SSE model achieved the validation fitness of 90% which was quite accurate considering various unexpected noises happening in field measurements.
A Study on the Test Construction Evaluation and Noise and Vibration Characteristics of Wireless Low-Floored Trams Trackway
Jeong, Young Do ; An, Dong Geun ; Jun, Jin Taek ; Jeong, Woo Tae ; Lee, Su Hyung ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 143~154
DOI : 10.11112/jksmi.2012.16.6.143
The wireless low-floored tram is an innovative transportation system which is environment-friendly and highly energy-efficient. In addition, the system has various advantages such as low construction cost, improvement of urban landscape, revitalization of surrounding commercial area, elevated convenience for passengers, etc. Therefore, more than ten local governments have proposed tram construction projects in Korea. Accordingly, many research and development projects are ongoing funded by government including the developments of tram vehicle, tram trackway, signal system, etc. The embedded rail system are commonly used in order to provide leveled roadway surface in urban area. It is effective to reduce the noise and vibration, caused at the interface between the wheel and track, to minimize the construction period, and to lower the maintenance cost. This paper investigated the design and construction processes for tram trackway and figured out the constructability for the test track with embedded rail system for the first time in Korea. The performance to reduce the noise and vibration were quantitatively measured in the test track with embedded rail system. In addition, the results were compared to the ones for track with conventional rail system.
Development and Application of Anti-Corrosive Steel Using Electro-Deposition of Sea Water (2)- Evaluation of Application Rebar with Electro-Deposition Using Sea Water
Kwon, Seung Jun ; Lee, Sang Min ; Park, Sang Soon ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 155~162
DOI : 10.11112/jksmi.2012.16.6.155
When RC (Reinforced Concrete) structures are exposed to sea water, steel corrosion can occur and this leads a degradation of structural performance. Referring the electro-deposition system with sea water from the 1st step research, durability and structural performance are evaluated in coated steel and RC members containing it in the 2nd research. In the durability performance test, Half Cell Potential test is performed and the coated steel is evaluated to have the high resistance to corrosion, which shows only 35% of corrosion velocity in normal (bare) steel. In the structural performance test, tensile strength, adhesive strength, and flexural/shear in RC member are performed. For the electro-deposit coated steel, increasing ratios of 3.2% and 8.8% are evaluated in the test of tensile strength and adhesive strength, respectively. For the structural test in RC member, there is no big difference between RC members with coated and non-coated steel in ultimate load and failure pattern It is evaluated that the chemical compound with
from electro-deposition causes slightly increased structural performance. The electro-deposit coated steel can be more widely applied after performance verification from several tests like fatigue, resistance to impact, and long term-submerging test.
Fundamental Properties of Magnesia-Prosphate Composite Considering Mix Conditions and Curing Temperature
Cho, Hyun Woo ; Kang, Su Tae ; Shin, Hyun Seop ; Lee, Jang Hwa ;
Journal of the Korea institute for structural maintenance and inspection, volume 16, issue 6, 2012, Pages 163~170
DOI : 10.11112/jksmi.2012.16.6.163
With the advantage of a rapid exothermic reaction property, jet set concrete may be used as a cold weather concrete because it can reach the required strength before being damaged by cold weathers. And it can be hardened more quickly if the field temperature is properly compensated by heating. Because ordinary concrete cannot be hardened well under sub-zero temperatures, anti-freeze agents are typically added to prevent the frost damage and to ensure the proper hardening of concrete. While the addition of a large amount of anti-freeze agent is effective to prevent concrete from freezing and accelerates cement hydration resulting in shortening the setting time and enhancing the initial strength, it induces problems in long-term strength growth. Also, it is not economically feasible because most anti-freeze agents are mainly composed of chlorides. Recent studies reported that magnesia-phosphate composites can be hardened very quickly and hydrated even in low temperatures, which can be used as an alternative of cold weather concrete for cold weathers and very cold places. As a preliminary study, to obtain the material properties, mortar specimens with different mixture proportions of magnesia-phosphate composites were manufactured and series of experiments were conducted varying the curing temperature. From the experimental results, an appropriate mixture design for cold weathers and very cold places is suggested.