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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 17, Issue 6 - Nov 2013
Volume 17, Issue 5 - Sep 2013
Volume 17, Issue 4 - Jul 2013
Volume 17, Issue 3 - May 2013
Volume 17, Issue 2 - Mar 2013
Volume 17, Issue 1 - Jan 2013
Selecting the target year
Analytical Evaluation of High Velocity Impact Resistance of Two-way RC Slab Reinforced with Steel Fiber and FRP Sheet
Lee, Jin Young ; Shin, Hyen Oh ; Min, Kyeng Hwan ; Yoon, Young Soo ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 1~9
DOI : 10.11112/jksmi.2013.17.3.001
This paper presents high-velocity impact analysis of two-way RC slabs, including steel fibers and strengthening with fiber reinforced polymer (FRP) sheets for evaluating impact resistance. The analysis uses the LS-DYNA program, which is advanced in impact analysis. The present analysis was performed similarly to the high-velocity impact tests conducted by VTT, the technical research center of Finland, to verify the analysis results. High-velocity impact loads were applied to
mm size two-way RC slab specimens, using a non-deformable steel projectile of 47.5kg mass and 134.9m/s velocity. In this research, extra impact analysis of material specimens was carried out to verify the material models used to the analysis. The elastic-plastic hydrodynamic model, concrete damage model and orthotropic elastic model were used to simulate the non-linear softening behavior of steel fiber reinforced concrete (SFRC), and material properties of normal concrete and FRP sheets, respectively. It is concluded that the suggested analysis technique has good reliability, and can be effectively applied in evaluating the effectiveness of reinforcing/retrofitting materials and techniques. Also, the Steel fiber and FRP sheet strengthening systems provided outstanding performance under high-velocity impact loads.
Experimental Study on Flexural Capacity of Precast Steel Mesh Reinforced Mortar Panel
Yi, Na Hyun ; Kim, Jang Ho Jay ; Lee, Sang Won ; Kim, Tae Gyun ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 10~19
DOI : 10.11112/jksmi.2013.17.3.010
Recently, researches related to precast modular construction have been actively conducted for nuclear power plant, LNG gas tank, and small-medium PCCV as well as bridges and buildings. In this study, the precast panel cast with steel mesh reinforced mortar (SRM) which is similar reinforced ferrocement was developed for efficient precast construction, construction time reduction, and easy transportation. Mortar mixture with high strength and flowability was obtained from various case studies using silica fume and GGBS. Also,
SRM and reinforced concrete (RC) panels were manufactured with reinforcing ratio of 2% and 4%. To verify structural performance of the SRM specimen, the basic material tests, free shrinkage test, and 3-point flexural test with a line loading were carried out. From the test results, it was determined that SRM specimens showed outstanding flexural capacity and ductility. However, the 4% reinforced SRM specimens must consider shear reinforcing to be used as a precast modular member.
The Influence of the Loading Sizes on Natural Frequency of the Advanced Composite Material Structures
Han, Bong Koo ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 20~27
DOI : 10.11112/jksmi.2013.17.3.020
Simple Iteration Method for calculating the natural frequency is presented in this paper. This method is simple but exact method of calculating natural frequencies corresponding to the modes of vibration of beams and tower structures with irregular cross sections and arbitrary boundary conditions. This method consists of determining the deflected mode shape of the member due to the inertia force under resonance condition. Finite difference method is used for this purpose. The influence of the
stiffness on the natural frequency is rigorously investigated. In this paper, the influence of the loading sizes, different cross section on the natural frequency of vibration of some structural elements is presented. This method extends to two dimensional problems including advanced composite material structures.
Seismic Performance Assessment of Unreinforced Masonry Wall Buildings Using Incremental Dynamic Analysis
Kwon, Ki Hyuk ; Kim, Man Hoe ; Kim, Hyung Joon ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 28~39
DOI : 10.11112/jksmi.2013.17.3.028
The most common housing type in Korea is low-rise buildings with unreinforced masonry walls (UMWs) that have been known as a vulnerable seismic-force-resisting system (SFRS) due to the lack of ductility capacities compared to high lateral stiffness of an UMW. However, there are still a little experimental investigation on the shear strength and stiffness of UMWs and on the seismic performance of buildings using UMWs as a SFRS. In Korea, the shear strength and stiffness of UMWs have been evaluated with the equations suggested in FEMA 356 which can not reflect the structural and material characteristics, and workmanship of domestic UMW construction. First of all, this study demonstrates the differences in shear strength and stiffness of UMWs obtained from between FEMA 356 and test results. The influence of these differences on the seismic performance of UMW buildings is then discussed with incremental dynamic analyses results of a prototype UMW building that were selected by the site survey of more than 200 UMW buildings and existing test results of UMWs. The seismic performance assessment of the prototype UMW building are analyzed based on collapse margin ratios and beta values repesenting uncertainty of seismic capacity. Analysis results show that the seismic performance of the UMW building estimated using the equations in FEMA 356 underestimates both a collapse margin ratio and a beta value compared to that estimated by test results. Whatever the estimation is carried out two cases, the seismic performance of the prototype building does not meet the criteria prescribed in a current Korean seismic code and about 90% collapse probability presents for more than 30-year-old UMW buildings under earthquakes with 2400 return years.
An Experiment of Flexural Behavior for the Damaged Low Reinforced Concrete Beams Rehabilitated with External Tendons
Yoo, Sung Won ; Suh, Jeong In ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 40~47
DOI : 10.11112/jksmi.2013.17.3.040
Most experiments carried out in the previous studies dealt with the highly reinforced concrete beams (RC beams) in case of rehabilitating with external tendon. However, the reinforcing effect of external tendons cannot be clearly analyzed in this kind of RC beams because the rehabilitating tendon quantity for it is too small. By this reason, this study chose the low RC beams rehabilitated with external tendons. Therefore, in this study, 7 test beams were manufactured and flexural behavior tests were performed to assess the reinforcing effect and to find more proper rehabilitating method by external tendon. The reinforcing effect increased according to the quantity of tendons, and was especially added by repairing cracks with epoxy resin. It was shown that the design equations of AASHTO 1994 and ACI-318 did not show a good agreement with test results. The result of this study will be able to be used effectively in finding the more proper rehabilitating method of the damaged RC beams.
Applicability of Hammer-Peening Treatment for Fatigue Life Improvement of Fatigue Damaged Weld Joints
Kim, In Tae ; Park, Min Ho ; Cheung, Jin Hwan ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 48~55
DOI : 10.11112/jksmi.2013.17.3.048
In this study, fatigue tests were performed on longitudinal out-of-plane gusset fillet welded joints and transverse non-load-carrying cruciform rib fillet welded joints, and then applicability of hammer-peening treatment on improvement of fatigue life for fatigue damaged weld joints were investigated. Fatigue tests were carried out on three types of gusset and rib welded specimens: as-welded specimens, post-weld hammer peened specimens and hammer peened specimens at 50% of as-welded specimen`s fatigue life. Before and after hammer peening treatment, the geometry of weld toes and surface stresses near weld toes were measured. As a result of hammer peening treatment, compressive residual stresses of 30-83MPa were introduced near weld toes of the gusset and rib welded joints, and 130% increase in fatigue life and fatigue limit of the welded joints could be realized by hammer peening treatment at 50% fatigue life of as-welded conditions.
Estimation of Wind Resistance Capacity of Nielsen Arch Bridge Based on Measured Data From Monitoring System
Lee, Deok Keun ; Yhim, Sung Soon ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 56~64
DOI : 10.11112/jksmi.2013.17.3.056
The wind resistant capacity of bridges with a span of less than 200m is typically evaluated by Wind Resistant Design Manual for Highway Bridges in Japan. Also, the first vertical frequency plays an important role in the evaluation of their aerodynamic performance. An unexpected vortex-induced vibration of Nielsen arch bridge with span of 183m designed by this manual has been measured by monitoring system during typhoon. The amplitude of vibrations was about 2 times than the allowable vibration displacement. This paper presents the feature of vortex-induced vibration of this Nielsen arch bridge based on measured wind velocity, wind direction, and responses at midspan of main girder. From the result of FFT, the
mode shape of the bridge is antisymmetric and the
is symmetric. Also, the dominant vibration of the bridge is the
vertical mode. According to these results, the
vertical vibration mode of this Nielsen arch bridge is prior to the first for the estimation of wind resistance capacity.
A Study on the Development and Performance Evaluation of Permeable GFRP Strengthening Panel for RC Structure
Jo, Byung Wan ; Kang, Seok Won ; Park, Cheol ; Kim, Jang Wook ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 65~73
DOI : 10.11112/jksmi.2013.17.3.065
Recently the exterior attaching reinforcement method is being often used by using FRP (Fiber Reinforced Polymer) as a method of strengthening concrete structure. this FRP exterior attaching reinforcement method has several advantages like high intensity, stiffness, good durability and easy installment comparing to its weight. but its structure is airtight covered by reinforcement material whose water permeability is low and water can`t be discharged, thus it may provoke a damage to the structure after a long while. the main purposes of this study are to develop GFRP reinforcement material which can discharge the surface water properly and to measure its special functions. for this, we have changed the normal reinforcement material to water permeable structure and measured its water permeance modulus by an indoor test which shows the process of water permeance with the parameter of contained GFRP quantity. also tried to verify the measured value of the water permeance modulus in theory by analyzing the numbers on water permeance process. the test result showed that the biggest quantity of water, 0.5129 g/h
was discharged when the fiber contained quantity reached at 75% and the tensile strength was also biggest by 476.6MPa at 75%, so it appeared that COSREM GP panel with 75% fiber contained quantity is the best in ventilation and structure.
The Physical Properties of Polymer Concrete for Ultra Thin Bridge Deck Pavement
Kim, Hyeon Jun ; Son, Yeong Hyo ; Han, Bum Jin ; Jung, Ji Eun ; Park, Sun Kyu ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 74~81
DOI : 10.11112/jksmi.2013.17.3.074
This research was performed to identify physical properties of polysulfide epoxy polymer concrete for ultra-thin bridge deck pavement, and improve domestic applicability. With the optimum mix ratio determined from mixing experiments of polymer concretes, compressive, flexural, and bond strength were tested to identify its strength properties along with the freezing-thawing resistance test to evaluate its durability in harsh environments. As a result, the tested polymer concretes showed excellent performance in strength and deflection characteristic and all tested strength satisfied the criteria of American Concrete Institute. Moreover, it had better performance under variable temperatures comparing to other existing pavement materials. By the results of freezing-thawing resistance test and strength measurement for specimens underwent the freezing-thawing process, it can be judged that there is no such problem to the concrete`s durability. In conclusion, the newly developed polymer concrete in this research has appropriate properties for use in ultra-thin pavement on bridge deck, and moreover it has superior applicability in comparison with former materials due to its improved temperature sensitivity.
Preliminary Tests of Mortars Containing Magnetite as Fine Aggregate
Yoon, Sang Chun ; Yang, Sung Chul ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 82~88
DOI : 10.11112/jksmi.2013.17.3.082
In this project a preliminary experimental research work was done to apply mortars containing magnetite as fine aggregates unto floor finishing materials in order to make indoor environment eco-friendly and to have noiseproof control between floors. Crushed magnetites were substituted as sands in the mix design with a range of 0, 20, 40, 60, 100%. First far-infrared radiation tests to determine emissivity and emission power were done in accordance with the KICM test standard and an outstanding result was obtained. Density and compressive strength test results also showed that as the substitution increases, test values increase in a linear trend. However dry shrinkage test results revealed that as the substitution increases, shrinkage strain also increases. To clearly seek a solution about this problem, more experimental works should be done on oncoming experimental program.
Development of High-Toughness Concrete Using the Mixed Materials for CO
Yi, Seong Tae ; Heo, Hyung Seok ; Noh, Jae Ho ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 89~96
DOI : 10.11112/jksmi.2013.17.3.089
Now-a-days, a manhole adopted since the late 1990s and produced using the polymer concrete has widely used due to the various benefits. While entering the High oil prices times, however, and with the price increase of the petrochemical materials, the cost of manufacture of polymer concrete was elevated and the resulting polymer concrete`s weakness is being put on. Accordingly, the development of economic cement concrete manholes, which can replace the outstanding bending strength of manhole made of high-price polymer concrete, has been required. In this study, based on the cement technology of fast hardening armorphous calcium aluminate (ACA), by minimizing the amount of cement using the industrial byproducts, to develop the eco-friendly high-toughness concrete manhole, which can reduce
reduction, was intended. As the results, the cement concrete manhole, which economic, eco-friend, and meeting the performance requirements, was developed.
Development of Visual Inspection System for Culvert in Levee Using Checklists and Smart Phone
Kim, Jin Man ; Cho, Jin Woo ; Choi, Bong Hyuck ; Cho, Won Beom ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 97~107
DOI : 10.11112/jksmi.2013.17.3.097
Culverts are structures constructed across river levees. Since river levees are to be constructed continuously, constructions of culvert are known to reduce the stability of river levees. In order to establish an effective inspection system of culverts, a visual inspection system using checklists and smart phone was recommended in this paper. It was determined that the recommended visual inspection checklist is applicable in establishing the investment priority based on the culvert`s repair plan establishment, repair and precision safety inspection.
Experimental Study on Evaluation of Material Properties in Cement Mortar with Pond Ash
Jung, Sang Hwa ; Kim, Joo Hyung ; Kwon, Seung Jun ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 108~117
DOI : 10.11112/jksmi.2013.17.3.108
Among the byproducts from thermal power plant using coal combustion, fly ash as mineral admixture is widely utilized in concrete manufacturing for its engineering merits. However residuals including bottom ash are usually reclaimed. This study presents an evaluation of engineering properties in cement mortar with pond ash (PA). For this work, two types of pond ash (anthracite and bituminous coal) are selected from two reclamation sites. Cement mortar specimens considering two w/c (0.385 and 0.485) ratios and three replacement ratio of sand (0%, 30%, and 60%) are prepared and their workability, mechanical, and durability performance are evaluated. Anthracite pond ash has high absorption and smooth surface so that it shows reasonable workability, strength development, and durability performance since it has dense pore structure due to smooth surface and sufficient mixing water inside. Reuse of PA is expected to be feasible since PA cement mortar has reasonable engineering performance compared with normal cement mortar.
Enhancing the Performance of Polypropylene Fiber Reinforced Cementitious Composite Produced with High Volume Fly Ash
Lee, Bang Yeon ; Bang, Jin Wook ; Kim, Yun Yong ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 118~125
DOI : 10.11112/jksmi.2013.17.3.118
The synthetic fibers including Polyvinyl alcohol and Polyethylene fibers have been successfully used in the manufacture of high ductile fiber reinforced cementitious composites. Polypropylene (PP) fiber has also been used in composites, not for the purpose of achieving a high level of tensile ductility but to improve the fire resistance performance of concrete exposed to high temperatures. This paper discusses the method for enhancing the performance of composites supplemented with PP fiber. Five types of mixture proportions were designed with high volume fly ash for testing the performance of composites. Type I cement and fly ash F were used as binding materials. The water-to-binder ratio was 0.23~0.25, and the amount of PP fiber used was 2 vol%. Polystyrene bead were also used to increase the tensile ductility of composites. A series of experiments including slump, density, compression and uniaxial tension tests were performed to evaluate the performance of cementitious composites supplemented with PP fiber. From the test results, it was exhibited that the performance of composites supplemented with PP fiber can be enhanced by adopting the mechanics and statistics theory.
The Analysis of Cracks in PSC Girder Using High Flowing Concrete
Lho, Byeong Cheol ; Ahn, Gwang Su ; Kwak, Kil Ho ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 126~135
DOI : 10.11112/jksmi.2013.17.3.126
Recently, mass concrete with high flowability are widely used to improve the quality and constructability in the longer span construction of prestressed concrete bridges, but it may induce nonstructural cracks due to the hydration heat and autogenous shrinkage etc. The stresses in concrete were evaluated by various experiments and numerical analysis. The tensile stress in mass concrete was increased in connection with the accumulation of hydration heat. Moreover, large amount of autogenous shrinkage from powder type admixture could add the tensile stress to mass concrete near anchorage zone. The tensile stresses in anchorage zone by heat and autogenous shrinkage exceeded the tensile strength of early stage of concrete, and small amounts of stress increasement were shown in other parts of PSC girder.
Fundamental Properties of Low Strength Concrete Mixture with Blast Furnace Slag and Sewage Sludge
Kwon, Chil Woo ; Lim, Nam Gi ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 136~144
DOI : 10.11112/jksmi.2013.17.3.136
In this study, in order to establish a plan that will enable safe use of renewable resources such as diverse industrial by-products and urban recycled materials, we conducted experiments that focused on flow, bleeding, compressive strength and environmental pollution evaluation to evaluate the material properties of low strength concrete using BFS and SS. In the case of low strength concrete using BFS and SS, blending of at least BFS 6000 within a 30% range regardless of the type of sand used was found to be the most effective approach for improving the workability by securing the minimum unit quantity of water, restraining the bleeding ratio and establishing compressive strength by taking account of the applicability at the work site. In particular, in view of the efficient use of SS, the optimal mixing condition was found to be the mixing of BFS 8000 with in the 30% range, not only for improving the workability restraining the bleeding ratio and establishing the compressive strength but also for application to the work site. Further, the results of tests on hazardous substance content and those of elution tests conducted on soil cement using SS indicated that all values satisfied the environmental standards without any harmful effects on the surrounding environment.
Survey Research on Thermal Situation of Office Buildings
Jung, Ui In ; Kim, Bong Joo ;
Journal of the Korea institute for structural maintenance and inspection, volume 17, issue 3, 2013, Pages 145~152
DOI : 10.11112/jksmi.2013.17.3.145
This study is to evaluate the thermal insulation of the curtain wall of the buildings constructed since the 1990s to the buildings currently under construction in 2011 and to provide the basic data for repairing and reinforcing and designing the thermal insulation. To this effect, the temperature difference by part was analyzed through measuring the inside and outside surface temperature of the curtain wall of the office building, and thereafter, the conditions of the thermal insulation and the thermal bridge part were examined. The result of the study is as follows; Not only in the winter season when the temperature difference between the indoor-outdoor is over
, but also in the summer season when there is a small temperature difference, the temperature difference between the inside and outside of the frame is
equally. Under such conditions as stated above, the thermal bridge occurred, which resulted from the heat flow of the steel frame part (mullion, transom), and therefore, the reinforcement of the thermal insulation is considered to be needed.