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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 15, Issue 6 - Nov 2011
Volume 15, Issue 5 - Sep 2011
Volume 15, Issue 4 - Jul 2011
Volume 15, Issue 3 - May 2011
Volume 15, Issue 2 - Mar 2011
Volume 15, Issue 1 - Jan 2011
Selecting the target year
The Evaluation of Structural Behavior of Hollowed PPC Girder Using Lightweight Aggregate Concrete
Lho, Byeong Cheol ; Lee, Kyung Su ; Kim, Ik Sang ; Cha, Kwang Il ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 75~81
DOI : 10.11112/jksmi.2011.15.5.075
Recently prestressed concrete bridges are generally used instead of reinforced concrete. PSC is more durable than RC because it can reduce crack problems, reinforcement corrosion, leakage and carbonation etc. And also PSC is more effective because there is no crack in tension area, and the entire concrete section is considered in section analysis. And it can reduce section size because vertical component by prestressing force can reduce the shear force. However, using high strength concrete can increase the self weight of bridge because of it's higher density. So the hollowed PPC girder with light weight aggregate can be a alternative. In this study the hollowed PPC girder with light weight aggregate is designed and the performance of hollowed PPC girder is evaluated by experimental tests as well as numerical analysis. As a result, The hollowed PPC girder of light aggregate behaved fully elastically under service load of 110kN, and the plastic behavior was showed after elastic behavior through experimental test, and it can be also estimated by numerical analysis.
A Study on Shear Capacity and Behavior of Large Sized Concrete Anchorage System
Kim, Kang Sik ; Shin, Sung Woo ; Lee, Kwang Soo ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 82~91
DOI : 10.11112/jksmi.2011.15.5.082
In this study, 24 prototype specimens were tested to find out the shear behavior and strength of large anchorage system exceeding 50mm(2") in anchor bolt diameter(
) and 635mm(25") in effective embedment depth(
) not addressed by ACI349-06 Appendix B. Test variables are anchor bolt diameter(
= 63.5, 76.2, 88.9mm), effective embedment depth(
=635, 762mm), and edge distance(
=381, 508, 762mm). Concrete compressive strength is constant(
=38MPa). Test results (
) were overestimated by
(shear strength by ACI 349-06) and
(shear strength by CCD method). In large anchorage system exceeding 50mm(2") of anchor bolt diameter(
) and 635mm(25") of anchor bolt effective embedment depth(
), the bolt diameter variation and effective embedment depth(
) has no influence on the shear strenth, But, according to the analysis results of the feature ratio on edge distance(
) and anchor bolt diameter, the feature ratio become smaller, which means anchor bolt diameter is bigger, predicted ratio of test results and predicted equation is larger. It was found that anchor bolt diameter is immediate cause of deterioration in the shear capacity of large anchorage system. To improve and extend the validity of current design recommendations further theoretical and numerical work is needed.
Calculation of Deflection Using the Acceleration Data for Concrete Bridges
Yun, Young Koun ; Ryu, Hee Joong ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 92~100
DOI : 10.11112/jksmi.2011.15.5.092
This paper describes a numerical modeling for deflection calculation using the natural frequency response that is measured acceleration response for concrete bridges. In the formulation of the dynamic deflection, the change amounts and the transformed responses about six kinds of free vibration responses are defined totally. The predicted response can be obtained from the measured acceleration data without requiring the knowledge of the initial velocity and displacement information. The relationship between the predicted response and the actual deflection is derived using the mathematical modeling that is induced by the process of a acceleration test data. In this study, in order to apply the proposed response predicted model to the integration scheme of the natural frequency domain, the Fourier Fast Transform of the deflection response is separated into the frequency component of the measured data. The feasibility for field application of the proposed calculation method is tested by the mode superposition method using the PSC-I bridges superstructures under several cases of moving load and results are compared with the actually measured deflections using transducers. It has been observed that the proposed method can asses the deflection responses successfully when the measured acceleration signals include the vehicle loading state and the free vibration behavior.
Evaluation of Nominal Flexural Strength in RC Beams Strengthend with CFRP Plate and Failed by Intermediate Crack Debonding
Hong, Sung Nam ; Park, Jong In ; Kim, Tae Wan ; Park, Sun Kyu ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 101~112
DOI : 10.11112/jksmi.2011.15.5.101
This paper shows a study carried out on the estimation of nominal flexural strength for CFRP-plated RC beams failed by intermediate crack debonding. A strength reduction factor is proposed to consider the effect of the intermediate crack debonding for the determination of nominal flexural strength. The proposed factor is derived from experimental data and utilizes the ratio of effective stress(or strain) in the CFRP plate to its ultimate strength(or strain) which is called effective strain model. An analytical equation for the estimation of the nominal flexural strength is formulated as a function of strength reduction factor. The validity, accuracy and efficiency of the proposed factor are established by comparing the analytical results with the experimental data, and the major design codes, as well as a number of factors given by researchers. The analytical results presented in this paper indicate that the proposed factor can effectively estimate the flexural nominal strength of CFRP-plated reinforced concrete beams failed by intermediate crack debonding.
LCC Analysis of Steel Plate Bridge Deck Pavement Through Internalization of Improved Functions
Baek, Jae Wook ; Park, Tae Hyo ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 113~123
DOI : 10.11112/jksmi.2011.15.5.113
LCC analysis is a method that coordinates with function evaluation for value improvement, rather than a separate one for cost evaluation. Although its accuracy is rising, materials and structural types developed or applied relatively recently have yet to obtain a sufficient maintenance profile DB, inducing reliability to reduce from difficulties in estimating maintenance records. Based on the above mentioned background, this paper presents the LCC methodology of coordinating functional intensification matters with cost for analysis on alternatives with difficulties in setting maintenance profile. Recently, steel plate bridge deck pavements are faced with problems such as plastic deformation due to the increase in heavy vehicles and traffic, promoting the development of a new compound pavement. This paper execute LCC analysis by mentioning case studies of SMA, Guss and PSMA pavements to include performance scale compared between alternatives as relative evaluation coefficients into the maintenance profile.
Variation of Seismic Behavior of Continuous Skew Plate Girder Bridges According to the Arrangement of Bearings
Moon, Seong Kwon ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 124~135
DOI : 10.11112/jksmi.2011.15.5.124
The capacity of bearings installed at abutments and piers for continuous bridges is usually determined by the magnitude of the maximum vertical reaction at each support and the capacity of bearings placed at piers is higher than that at abutments. In this study, the possibility of the improved seismic performance of base-isolated continuous skew bridges was investigated by analysing the variation of the seismic behavior of them according to three arrangements of bearings. Based on the conventional arrangement of bearings(Case A), three arrangements of bearings such as Case A, Case B and Case C were selected considering the variation of the horizontal stiffness of the lead rubber bearing(LRB) installed at the pier. The seismic behavior of the total 36 skew bridges was investigated by conducting the response spectrum analysis using the hybrid response spectrum considered the effect of LRB's damping. Results of analyses show that a more desirable seismic behavior of base-isolated continuous skew bridges can be obtained by reducing the magnitude of the horizontal stiffness of LRB placed at the pier to similar to or less than that of LRB installed at abutments. The variation of LRB's stiffness at the pier brings about period elongation and the change of mode shapes of base-isolated skew bridges and results in the reduction of the total base shear, the maximum base shear at the pier and the girder stresses. Although positive effects on the seismic behavior of base-isolated skew bridges caused by the change of arrangement of bearings decreased slighty with an increase in the flexibility of the substructure, the proposed arrangements of bearings bring about the improved seismic performance of base-isolated continuous skew plate girder bridges with less than 10m height of piers.
An Experimental Study About a Net-Type External Prestress Strengthening Method for Slab Bridges
Han, Man Yop ; Kang, Tae Heon ; Choi, Sok Hwan ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 136~149
DOI : 10.11112/jksmi.2011.15.5.136
Large portion of the domestic bridges are slab bridges reflecting the geographical characteristic of the country, where exists lots of inclines and small winding brooks. Many of the slab bridges are damaged and superannuated as they become obsolete. Deterioration is accelerated when the traffic density becomes large and heavy vehicles pass frequently. A strengthening method for deteriorated slab bridges was studied in this work. The examined net-type strengthening method uses both longitudinal and transverse prestressing for strengthening. In this way, the deflection at the center of the slab can be better controlled, and consequently, the slab is more efficiently strengthened. Three slab specimens were fabricated for the experimental test and subjected to three different loading conditions, and the load bearing capacities and deflections of slabs were examined. Flexural stiffness of slabs increased by 30.7~107.3%, and deflection of slabs decreased by 27.6~52.2% after net-type strengthening. The net-type prestressing is efficient to the strengthening for the center of a slab, and its efficiency is also valid under eccentric loadings. Since extra prestress forces can be added in the future, if necessary, the net-type strengthening system is advantagous for the maintenance and repair of slab bridges.
The Stability Assessment of ASSM Tunnels in Service
Kwon, Young Jeong ; Park, Min Chul ; Shin, Hyo Hee ; Lee, Song ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 150~159
DOI : 10.11112/jksmi.2011.15.5.150
The need of securing the stability and extending service lives by efficient maintenance of deteriorated tunnels for several decades has been increased. The stability and the usability of conventional tunnels can be decreased by change of physical properties of the surrounding ground, geometrical properties of the tunnel, an underground water level, environmental conditions, oxidation of lining and the breakdown of constituent materials. In respect of a long-term view, it is need to check all sorts of degradation, the degree of damage and durability to improve the serviceability and to come up with measures to maintain effectively. This paper is about study to analyze the stability of conventional tunnels(American Steel Support Method. ASSM). Three tunnels are chosen in those built in the 1930s and 1960s and the locations of tunnels are selected variously(ChungCheong, GyungBuk, GangWon, Jeolla, etc.) to secure reliability of this study. The state of repair and reinforcement of linings, cracks, and thickness and strength of lining of conventional tunnels in service are researched, compared and analyzed. The crack gauge, the GPR, the schmitt hammer was used for the crack investigation, cavitation, the strength respectively. By using these, the comparative analysis for conventional tunnels was conducted. As a result, there are more cracks in tunnels built in the 1930s than those of tunnels built in the 1960s, and lining strength of the 1930s is higher than those of the 1960s. The thickness of lining in tunnels built in the 1960s is higher than those in tunnels built in the 1930s. In proportion to thickness, cavitation occurred more frequently in tunnels built in the 1960s compared to those in tunnels built in the 1930s.
Problems of Insufficient Detailed Inspection and Precision Safety Diagnosis and the Improving Direction for the Evaluation System
Ha, Myung Ho ; Park, Jong Sup ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 160~168
DOI : 10.11112/jksmi.2011.15.5.160
As importance of the field of maintenance and management come to the fore because of collapses of the Seongsu bridge and the Sampoong department store, "Special Act for the Safety Control of Public Structures" was established in 1995 and the major maintenance and management system began taking effect "Detailed inspection and Precision safety diagnosis". However, a technical standard of "Detailed inspection and Precision safety diagnosis" was low because its history was not long, and also the results of research were not enough so anxiety for "Insufficient Detailed inspection and Precision safety diagnosis" was continuously left. While its evaluation system introduced in 2002, the ratio of "Insufficient Detailed inspection and Precision safety diagnosis" has been getting lower. However, according to the evaluation result after carrying out "Detailed inspection and Precision safety diagnosis" recently, it seems difficult to become lower for the ratio of "Insufficient Detailed inspection and Precision safety diagnosis" in future. Therefore, it is considered of questionary survey of the concerned organization and the mechanism side in connection with "Insufficient Detailed inspection and Precision safety diagnosis". So it is arranged the fundamental problems caused by an "Insufficient Detailed inspection and Precision safety diagnosis" that is to show the improving direction of the existing evaluation system in a based on this.
Behaviors of Concrete Segmented Composites Using Polymer Mortar Under Static and Impact Loadings
Min, Kyung Hwan ; Lee, Jin Young ; Kim, Mi Hye ; Yoon, Young Soo ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 169~177
DOI : 10.11112/jksmi.2011.15.5.169
In this study, an impact resistance of concrete segmented composites adopted shell's structures which have the excellent impact resistance was assessed. In order to enhance the performances of concrete segmented composite, the bond strength of mortar between the concrete blocks should be improved. Hence, in this study polymer mortars were applied to increase the bond strength of mortar. From the results of bond tests, the 15% latex mortar was selected and static and low-velocity impact tests were carried out for the specimens applied the plain and latex mortar. The concrete segmented composites, of which the bond strength of mortar was enhanced, showed improved low-velocity impact resistances. A Nonlinear finite element analysis using the discrete crack model showed similar energy dissipating capacities to the impact test's results. Consequently, by improving the analysis models for segmented composites, the impact resistances for manifold variables can be predicted and assessed.
Characteristics of Shear Behavior of Reinforced Concrete Beams Strengthened with Near Surface Mounted CFRP Strips
Han, Sang Hoon ; Hong, Ki Nam ; Shin, Byoung Gil ; Lim, Jin Mook ; Kwak, So Shin ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 178~189
DOI : 10.11112/jksmi.2011.15.5.178
Tests and analyses were performed in this study to assess the shear strength of Reinforced Concrete(RC) members strengthened by the Near Surface Mounted(NSM) technique in shear, which is drawing attention as an alternative to the Carbon Fiber Reinforced Polymer(CFRP) bonding strengthening technique. Four-point bending tests were performed on 7 RC specimens without any shear reinforcement. The test variables such as the inclination of CFRP strip (45 degrees and 90 degrees), and the spacing of CFRP strip (250mm, 200mm, 150mm, 100mm) were considered. Through the testing scenarios, the effect of each test variable on the failure mode and the shear strength of the RC members strengthened by the NSM technique in shear were assessed. The test results show that the specimens with CFRP strips at 45 degrees go to failure as a result of the strip fracture, but the specimens with CFRP strips at 90 degrees go to failure as a result of the slip of strips. Strips at 45 degrees was the more effective than strips at 90 degrees, not only in terms of increasing beam shear resistance but also in assuring larger deformation capacity at beam failure. In addition, the RBSN analysis appropriately predicted the crack formation and the load-displacement response of the RC members strengthened by the NSM technique in shear.
Evaluation of Dynamic Stability for Structural Bar Reinforced Precast and Prestressed Retaining Wall for Moving Train Load
Lee, Il Wha ; Um, Ju Hwan ; Lee, Kang Myung ; Keum, Chang Jun ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 190~198
DOI : 10.11112/jksmi.2011.15.5.190
The precast production has many advantages by fast construction period, labor-saving and high quality. In recent years, the application of the precast product has been increased in the earth retaining wall field. This paper presents the results of the numerical analysis that was carried out to evaluate the dynamic stability of precast and prestressed earth retaining wall under moving train load. The two-dimensional FEM analysis was used to the numerical analyses. The train load to act on trackbed is combined by the real measured roughness phase angle and quasi-static load. The dynamic stability is analysed by the displacement, acceleration and stress under moving train load at each specified location. The results of the analysis show that the precast and prestressed retaining wall has very stable capability for the railway.
Hysteretic Behaviors of Metallic Dampers with the Various Slit Shape
Lee, Hyun Ho ; Kim, Seh Il ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 199~208
DOI : 10.11112/jksmi.2011.15.5.199
The purpose of this study is to evaluate of the strength and deformation capacity of metallic dampers with the variable slit shape. For this purpose, 12 metallic damper specimens were prepared and shear testing was performed. According to the test results, the S shaped metallic damper with the strut height of 200mm and angle of
shows better hysteretic performance than any other specimens. By making a comparison between the yield strength in test and the proposed strength formula, test results shows larger yield strength than calculation method.
An Experimental Study for the Strength Variations of High-strength Lightweight Concrete According to Grain-size of Artificial Lightweight Aggregate
Kim, Sung Chil ; Park, Ki Chan ; Choi, Hyoung Wook ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 209~217
DOI : 10.11112/jksmi.2011.15.5.209
In recent days, while taller and more massive structures such as huge bridges and super skyscrapers have been welcomed, the structural stabilization in design and construction have been gradually limited due to the major weakness of current concrete which is relatively heavier when compared with its strength. To improve the weakness of the current concrete, The lightweight concrete with light weight and high strength should be used; however, not many researchers in Korea have studied on the lightweight concrete. Generally, artificial lightweight aggregate produced through high-temperature-plasticization has a possibility of its body-expansion with many bubbles. Therefore, depending on the size of aggregate, the effects of bubbles on the specific weight and strength of the lightweight concrete should be studied. In this study, considering grain-size, the mix design of the artificial lightweight aggregate produced through the high-temperature-plasticization and the body-expansion of waste and clay from the fire power plant in Korea was conducted. The experiment to analyze the variation in specific weight and strength of the lightweight concrete was followed. From these experiments, the optimized grain-size ratio of the artificial lightweight aggregate for the enhancement of high-strength from the lightweight concrete was revealed.
Field Application of Low Heat Concrete Using Strontium Hydroxide Based Latent Heat Material
Khil, Bae Su ; Yun, Hyun Do ; Jeong, Ok Ran ;
Journal of the Korea institute for structural maintenance and inspection, volume 15, issue 5, 2011, Pages 218~226
DOI : 10.11112/jksmi.2011.15.5.218
Low heat concrete using strontium hydroxide based latent heat material was manufactured in ready-mixed concrete batcher plant and its fundamental properties were tested. As a result of B/P test, its applicability to the construction site was verified. After B/P test, low heat concrete using strontium hydroxide based latent heat material was applied to the real construction site of bridge footing. Through the analysis and the actual measurement of the hydration heat of the concrete footing, the reduction effect of hydration heat and thermal crack was confirmed.