Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
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 13, Issue 6 - Nov 2009
Volume 13, Issue 5 - Sep 2009
Volume 13, Issue 4 - Jul 2009
Volume 13, Issue 3 - May 2009
Volume 13, Issue 2 - Mar 2009
Volume 13, Issue 1 - Jan 2009
Selecting the target year
Shrinkage Characteristics of 50MPa High-strength Concrete with Compositions of Cementitious Materials
Jung, Hyung-Chul ; Min, Kyung-Hwan ; Yang, Jun-Mo ; Yoon, Young-Soo ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 93~100
This study forms part of a research project that was carried out on the development and application of high-strength concrete for large underground spaces. In order to develop 50MPa high-strength concrete, eight optimal mixtures with different portions of fly ash and ground granulated blast furnace slag were selected. For assessments of shrinkage characteristics, free shrinkage tests with prismatic specimens and shrinkage crack tests were performed. The compressive strength was more than 30MPa at 7days, and stable design strength was acquired at 28days. High-strength concrete containing blast furnace slag shows large autogenous shrinkage, while large shrinkage deformations and cracks will occur when mixtures are replaced with large volumes of cementitious materials. Hence, for these high-strength concrete mixtures, the curing conditions of initial ages that affect the reaction of hydration and drying effects need to be checked.
Estimation of Dynamic Displacements of a Bridge using FBG Sensors
Shin, Soobong ; Yun, Byeong-Goo ; Kim, Jae-Cheon ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 101~109
An algorithm is proposed for estimating dynamic displacements of a bridge by using FBG sensors and by superposing some measurable low modes. Modal displacements are obtained from the beam theory and the generalized coordinates are deduced from the strains measured by FBG sensors. By considering flexural and torsional modes occurred in bridges only as flexural modes of a simply supported beam by separating a bridge into multiple girders or parts, the proposed algorithm can be applied to various types of bridges. Guidelines are provided theoretically for determining the number of modes and the number of strain gages to be used. The proposed algorithm has been examined through simulation studies on various types of bridges, laboratory experiments on a model bridge, and field tests on a simple span PC Box girder bridge. Through the simulation study, the effects of the error in the vibration modes and measurement noise on estimating the dynamic displacements are analyzed.
Performance Evaluation of Organic and Inorganic Fiber Reinforced Concrete in Tunnel Lining Structure
Lee, Jong-Eun ; Kim, Tae-Won ; Kim, Su-Man ; Jeon, Joong-Kyu ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 110~118
The tunnel structure is widely used for transportation in the mountain area. To reduce the duration of construction and thus the expense, a tunnel excavation is often performed simultaneously with a tunnel lining in in-situ. However, cracking of the tunnel lining may occur arising from the vibrating impact in the excavation process. The present study concerns the role of steel fiber and nylon fibers in tunnel lining concrete to reduce the vibrating impact. As a result it was found that both the nylon fiber and steel fiber improved the durability and physical properties of concrete.
Fire Resistant Properties of the RC Columns Applying Various Splling Prevention Methods
Han, Cheon-Goo ; Pei, Chang-Chun ; Lee, Jong-Suk ; Lee, Chan-Young ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 119~126
This study investigated the fire resistance of RC columns applying Fiber addition method, Fire board attaching method, and Fire proof sparying method. The results were summarized as following. The test showed that increase of fiber content, as expected, decreased the fluidity of fresh concrete, but for the types of fiber, the specimens containing nylon(NY) was favorable. The incline of fiber content also affected on the air content of concrete, which the specimens adding polypropylene(PP) fiber was the lowest, followed by a less decrease in polyvinyl alchhol(PVA) and then NY respectively. For the compressive strength at 28days, it was over 50MPa and showed slight increasing tendency by rising fiber contents. After the fire test completed, control concrete exhibited the severe demage, while the specimens containing more than 0.05vol.% of PP and NY was able to protect from spalling. In the case of splay, the partly spalling occurred at the all finishing material, however the RC columns were protected from spalling. For the methods attached with boards, all RC columns were protected except the dry attaching method. The reduced weight ratio was favorable because it was below 8 % except for plain concrete.
Spalling Prevention of High Strength concrete Corresponding to the Various Heating Curves
Han, Cheon-Goo ; Pei, Chang-Chun ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 127~134
This study investigated their properties of spalling resistance and residual compressive strength after fire test corresponding to various ISO, RABT heating curves, and contents of hybrid organic fiber of high strength concrete. The results were summarized as following. As fundamental characters of concrete with hybrid organic fiber, the flowability was directly declined as the increase of fiber contents, and air contents were decreased or increased a little bit, but there was not big difference. The compressive strength was gradually declined sluggishly at 28 days. As properties of fire resistance, in case of RABT heating curves, compare with ISO heating curves a spalling aspect showed till range that has much contents of hybrid organic fiber, but they are mostly peeling spalling, which means spalling aspect didn't happen to inside. In conclusion, in case of W/B 25% high strength concrete, the spalling was prevented over 0.04% of contents of fiber at ISO heating curve and over 0.10% of contents of fiber at the RABT heating curve. In case of spalling was prevented, mass reduction rate according to the change of heating temperature curves showed around 7% at ISO heating curves and around 9% at RABT heating curves. The residual compressive strength rate corresponding to the change of heating temperature curves showed 50%~60% at ISO heating temperature curves and 30%~35% at RABT heating temperature curves in case of spalling was prevented.
An Analysis of the Long-term Behavior of the Cable System in the Suspension Bridge
Ryu, Duck-Yong ; Kim, See-Dong ; Jung, Hie-Young ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 135~144
The cable system of suspension bridges is a very important non-elastic element which caries an external load by a tension force of the cable, such that creates the integrity of a structure. It is not easy to find if cable system have been changed by the maintenance activities such as repairs or reinforcement. Sometimes the maintenance can cause structural deformations and changes of the tension force in cables. In most cases, the cable stayed bridges are managed by health monitering system, however, the main cable of suspension bridges need to develop more accurate and efficient monitoring system. The Namhee Bridge was constructed 35 years ago and it has been continually repaired and reinforced after then. This study describes the behavior of the cable system by analysing many of inspective reports and by using the results of hanger rope test and for the shape of main cables surveys.
Analysis of Effective Flexural Rigidity of Corrugated Steel-Concrete Composite Deck with I-beam Welded
Son, Chang-Du ; Hong, Sung-Nam ; Park, Jun-Myung ; Park, Sun-Kyu ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 145~154
Steel-Concrete Composite Deck with I-beam welded is lighter and easier to construct than conventional in situ reinforced concrete slabs due to the I-beam embedded in the corrugated slab. For the calculation of effective flexural rigidity of conventional reinforced concrete structures, methods suggested in Design Standard for Roads and Bridges and ACI have been used. In this paper, the calculation methods were applied to steel-concrete composite deck with I-beam welded and then results of the steel-concrete composite deck were compared with those of reinforced concrete slabs. In addition, applicability of the methods to steel-concrete composite deck with I-beam welded was estimated. In order to compare the effective flexural rigidity, flexural experiments were conducted. Fifteen slabs were built and the variables considered in the experiments were studs, length of the slab, shape of the section and connecting methods.
An Experimental Study on Flexural Tensile Strength and Bond Strength Between Concrete-to-Concrete
Yang, In-Hwan ; Yoo, Sung-Won ; Seo, Jung-In ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 155~163
The purpose of this paper is to investigate the bond strength between old and new concrete as well as flexural tensile strength of concrete. To achieve this purpose, a comprehensive experimental program has been set up and strength tests using a series of specimens have been carried out. The present study represents that the flexural bond strength between old and new concrete is much smaller than that of flexural tensile strength. The ratio of bond strength to flexural tensile strength ranged through 15~27%. It is seen that concrete-to-concrete bond strength has been affected by curing condition. Also, test results of tensile strength show that recommendation by ACI 363 committee is estimated to be more realistic than another recommendations for predicting tensile strength of concrete.
Erection Sequence Analysis of Suspension Bridge Considering to Sliding of Main Cable
Yhim, Sung-Soon ; Kong, Min-Sik ; Kim, Byeong-Cheol ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 164~172
Anchors and saddles are used to have sufficient geometrical rigidity and make target configuration of main cable of suspension bridge. Neglecting the sliding effect at saddles, points at them have been idealized as fixed nodes in lots of former studies. In general, sliding effects are reported to show significant structural behaviors of main cable and cause to the different responses of bridges. During early erection steps of the suspension bridge, especially, the sliding effect occurs easily because there is large difference of cable tension between main and side span in removing set-back ropes or not applying set-back. This study presents the finite element analysis considering to cable sliding effect and shows the comparison of differences between sliding and non-sliding at election sequence. The analysis of sliding between main cables and saddles needs to obtain more realistic responses because the analysis result can represent unfavorably different responses of bridges. Moreover, the sliding analysis method and results in this study can be used to basic criteria in engineering design and construction steps.
Crack Example and Crack Control Method of Very-Early Strength Latex-Modified Concrete
Choi, Pan-Gil ; Yun, Kyong-Ku ; Lee, Bong-Hak ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 173~180
Very-early strength latex-modified concrete(below ; VES-LMC) was developed for possible early-opening-to-traffic after overlay of bridge deck concrete. The purpose of this study is to analyze the cause of map, transverse and longitudinal cracking in VES-LMC and to provide a control method for minimizing occurrence of cracking. The proposed prevention method against map and transverse cracking was verified by field data. VES cement was modified as the unit cement content was reduced from 390kg/
. The maximum size of coarse aggregate was increased from 13mm to 19mm. The wire mesh and steel fiber were adopted in concrete mixture. From the results, the proposed prevention method against map and transverse cracking was verified since structural cracking was not occurred until 3 years after overlay.
Flexural Capacity of Reinforced Concrete Beams Strengthened by Bow System
Lim, Jae-Hyung ; Moon, Jeong-Ho ; Lee, Jae-Yeon ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 181~187
This paper is to investigate about a new technique (Bow system) which is to develop the disadvantages of the external post-tensioned method. The purpose of this paper is to analyze about the prestress loss when the loads apply along the long term and to improve the capacity of the members strengthened by Bow system. The variables in the test program are the span/depth ratio, the amount of tendon area. And the test was carried out to confirm the long term behaviour. It is shown that can apply the current code in the design, and have no the structural problems about the prestress loss.
A Study on the Development of Flat-Ring Type Restrained Test Method and Performance Evaluation for Evaluating Shrinkage Cracking Properties of Concrete in Early Age
Kim, Gyu-Yong ; Choi, Hyeong-Gil ; Lee, Eui-Bae ; Nam, Jeong-Soo ; Han, Min-Ki ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 188~196
In Concrete, shrinkages occur like plastic shrinkage and drying shrinkage in the early age because of evaporation and transfer of moisture. Within the country, the crack test standardized by KS is used to test the drying shrinkage of the concrete by using the restricted drying shrinkage of Dumbbell type mold, but this test is for the cracking-point and the restricted shrinkage stress. Thus it is difficult to valuate the crack quantitative test. In this study, it is intended to develop the Flat-ring type restrained test method for the shrinkage deformation movement of the concrete and to provide the quantitative data for evaluating the cracks in concrete. And it suggest the proper specimen diameter and quantitative test method about shrinkage crack properties on Flat-ring type restrained test method. And Verified the suitability.
Evaluation of Crack Estimation Equation for the Reinforced Concrete Tension Member
Park, Chan-Wook ; Noh, Sam-Young ; Shin, Eun-Mi ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 197~208
The purpose of this research is the evaluation of the estimation equation of "CEP-FIP Model Code 1990(1991)", recently included in the domestic "Concrete Structure Design Code(2007)" in consideration of the concrete strength. As evaluation tools, crack element model applied a detailed bond-slip model as well as crack width obtained from experimental results by earlier researches. The crack element model is verified through the comparison with experimental results. The important variables in the estimation equation for the crack width in CEP-FIP Model Code 1990 are the tension stiffening effect and mean bond stress proposed in the paper to be improved in consideration of the concrete strength.
Effect of Reinforcement details on the Seismic Performance of Precast Strain-Hardening Cementitious Composite(SHCC) Infill Walls
Kim, Sun-Woo ; Yun, Hyun-Do ; Song, Seon-Hwa ; Yun, Yeo-Jin ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 209~216
Flexible frames on their own offer little resistance to lateral forces, resulting often in large deflections and rotations at the joints. On the other hand, walls subjected to lateral loads fail mainly in shear at relatively small displacements. Therefore, when the nonductile frames and wall act together, the combined action of the composite system differs significantly from that of the frame or wall alone. The objective of the study is to evaluate seismic response of infill walls with notched midsection. Reinforcement detail of wall was main variable in the experiment. Also SHCC was used in order to prevent damage concentration into notched midsection of walls. Test results, SHCC infill walls show the multiple crack patterns as expected. However, PIW-ND specimen exhibits less story drift, stiffness and energy dissipation capacity than those of PIW-NC specimen.
An Experimental Study on the Damping Capacity of Lead Rubber Bearing with High Lead-plug Area Ratio
Choi, Jung-Ho ; Kim, Woon-Hak ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 217~224
Many engineering researches are performed to ensuring structural safety from earthquake. In this study, the damping capacity of LRB(lead rubber bearing) with high lead-plug area ratio was examined by hysteresis loop from experiments. The displacement controlled tests were performed for 12 specimens designed in 2 types by lead-plug area ratio as main parameter. Each coupled specimens were tested by 3 times sinusoidal loads with different loading velocities. From the experimental results, LRB with high lead-plug area ratio has sufficient damping ratio for reducing horizontal seismic load to structures.
Static Behavior of Concrete-Filled and Tied Steel Tubular Arch(CFTA) Girder
Kim, Jong-In ; Kim, Doo-kie ; Lee, Jang-hyeong ; Kim, Jeong-Ho ;
Journal of the Korea institute for structural maintenance and inspection, volume 13, issue 3, 2009, Pages 225~231
This study introduces the CFTA girder(Concrete-Filled and Tied Steel Tubular Arch Girder) which is a combined structural system of traditional CFT, arch, and prestress structures. Static load tests and structural behavior analyses were carried out for a 25m long CFTA girder. In the analysis, each load of 58kN, 88kN, 148kN, 207kN,and 298kN was applied incrementally at the positions of 1.0 m distances in both directions from the center of the girder. On each test, strain and displacement were measured. Linear static FEM analyses using Strand7 code were also performed to check the structural stability and to investigate the effects of prestressing(
20%) and material property(Young's modulus) on the displacement and strain. The results of this study are summarized as follows: the initial strain & displacement under selfweight and prestressing were influenced with the variation of prestressing, but they were mainly effected only by Young's modulus when additional loads were applied.