• Computers and Concrete
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• v.12 no.5
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• pp.669-680
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• 2013

This paper unveils a new computer based stabilization methodology for automated modeling analysis and its experimental verification for corrosion in reinforced concrete structures under the effect of varying oxygen concentration. Various corrosion cells with different concrete compositions under four different environmental conditions (air dry, submerged, 95% R.H and alternate wetting-drying) have been investigated under controlled laboratory conditions. The results of these laboratory tests were utilized with an automated computer-aided simulation model. This model based on mass and energy stabilization through the porous media for the corrosion process was coupled with modified stabilization methodology. By this coupling, it was possible to predict, maintain and transfer the influence of oxygen concentration on the corrosion rate of the reinforcement in concrete under various defined conditions satisfactorily. The variation in oxygen concentration available for corrosion reaction has been taken into account simulating the actual field conditions such as by varying concrete cover depth, relative humidity, water-cement ratio etc. The modeling task has been incorporated by the use of a computer based durability model as a finite element computational approach for stabilizing the effect of oxygen on corrosion of reinforced concrete structures.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.50
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• pp.27-59
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• 2011

This article attempts to describe and analyze the rules on the service provider's duty to provide his service in conformity with the contract under the Draft Common Frame of Reference (here-in-after DCFR), which are applied to construction, storage, design and factual information contracts. It categorizes such rules in accordance with the requirements of conformity with the contract, the time when the service provided must be in conformity with the contract, and the exemptions of the service provider's duty. On the basis of such categorization, it examines the rules on the service provider's duty in each type of service contract under the DCFR. By doing so, it seeks to figure out how the members of EU compromised on the various issues of the service provider's duty under the DCFR which is regarded as the first uniformed legislation in the area of the service contract. This may provide some guidance to the legislators of domestic law for their amendment or interpretation of their laws. In addition to them, this article also seeks to point out problems in terms of their interpretations and gaps in their rules to cover various aspects of non-conformity and put forward some solutions for such problems and gaps.

• Wind and Structures
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• v.18 no.3
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• pp.235-252
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• 2014

An effective numerical technique to calculate the reactions of a multi-spanned transmission line conductor system, under arbitrary loads varying along the spans, is developed. Such variable loads are generated by High Intensity Wind (HIW) events in the form of tornadoes and downburst. First, a semi-closed form solution is derived to obtain the displacements and the reactions at the ends of each conductor span. The solution accounts for the nonlinearity of the system and the flexibility of the insulators. Second, a numerical scheme to solve the derived closed-form solution is proposed. Two conductor systems are analyzed under loads resulting from HIW events for validation of the proposed technique. Non-linear Finite Element Analyses (FEA) are also conducted for the same two systems. The responses resulting from the technique are shown to be in a very good agreement with those resulting from the FEA, which confirms the technique accuracy. Meanwhile, the semi-closed form technique shows superior efficiency in terms of the required computational time. The saving in computational time has a great advantage in predicting the response of the conductors under HIW events, since this requires a large number of analyses to cover different potential locations and sizes of those localized events.

• KCI Concrete Journal
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• v.13 no.1
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• pp.69-78
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• 2001

The inelastic behavior of a reinforced concrete columns is influenced by a number of factors : 1) level of axial load, 2) tie spacing, 3) volumetric ratio of lateral steel, 4) concrete strength, 5) distribution of longitudinal steel, 6) strength of lateral steel, 7) cover thickness, 8) configuration of lateral steel, 9) strain gradient, 10) strain rate, 11) the effectively confined concrete core area, and 12) amount of longitudinal steel. A new constitutive model of a confined concrete is suggested in order to investigate the nonlinear behavior of the reinforced concrete columns under concentric loading. The developed constitutive model for the confined concrete takes into account the effects of effectively confined area as well as the horizontal and longitudinal distributions of the confining pressures. None of the existing models incorporated these two main effects at the same time. A total of different six constitutive models for the behavior of the confined concrete under concentric compression were compared with the sixty-one test results reported by different researchers. The superiority of the developed model in its accuracy is demonstrated by evaluating the error function, which compares the weighted averages for the sum of squared relative differences in peak compressive strength and corresponding strain, stress at strain equal to 0.015, and total area under stress-strain curve up to strain equal to 0.015.

• Journal of Environmental Science International
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• v.31 no.6
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• pp.471-477
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• 2022

This field experiment aimed to identify the optimal planting density for establishing a management plan for ground-cover plants under roadside trees. Liriope platyphylla and Hosta longipes both widely used for planting under trees were selected as the plant materials and planted under Prunus serrulata var. spontanea at different planting densities. Based on the distance between each plant, 4 planting densities were used: 11%, 25%, 49%, and 83% with three replications. To estimate plant growth, plant height, number of leaves and tillers, fresh and dry weight, and visual quality were investigated. Liriope platyphylla exhibited relatively better growth at the highest planting density of 83%. For Hosta longipes, however, the lower growth was positively correlated with high planting density. Therefore, the optimal planting density for Liriope platyphylla is 83% and for Hosta longipes is 11%.

• Korean Institute of Interior Design Journal
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• no.28
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• pp.60-67
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• 2001

Built-up environments by humans are cultural byproducts which combine social ideology and architectural paradigm. The process of modernization in the Western countries has the characteristic of decisive paradgm based on materialism. Therefore, environmental design in modern world failed to focus on the essential features of humanity which are the subject of space and replaced it for objective and unilateral architectural environments, instead. Environment without supporting the human psychological and complicated behaviorism is as same as the hardware without the vitality. under these regards, this study will cover the design approach of pattern language as a design method of environment design. The purpose of design approach by pattern language lies in creating the space of flexibility, adaptability and strong vitality. It is summed up as humanization in space and it helps the user to verbalize individualized space language for their own. The range and method of in the study attribute to the pattern language of Christopher Alexander and a researcher' method on them. In premise that human behavior ought to the multilateral and indefinite under rapid change of circumstances in modern world, th study tried to find the design method stimulating creative behavior of human being.

• Structural Engineering and Mechanics
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• v.14 no.6
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• pp.649-660
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• 2002

Experimental results are presented from tests conducted on reinforced concrete beam-column joints with lap splices under reversed cyclic loading simulating earthquake action. Response curves are compared for twenty-four specimens designed according to Eurocode 2. The main parameters of the investigation are, the geometry of the reinforcing bar extension, the applied axial load (normalized), the available cover over lap splice region extended as length required from Eurocode 2, as well as the shape and the volumetric percentage of the stirrups confining the lap splice zone. The results are evaluated with regards to the load intensity, the energy absorption capacity and the characteristics of the load deflection curve.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.307-312
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• 2002

This paper deals with structural behavior of reinforced concrete beams under fire and fire damaged condition. The main purpose of this study is to investigate the structural behavior of the beams under high temperature condition and to evaluate the remaining strength of flexural members by exposure time to fire. For this purpose, twelve beam specimens are fabricated and experimented. Ten specimens are exposed to the fire for 1 and 2 hours and to the failure. After being cooled in room temperature, the specimens are loaded to the failure. The research result shows that the main variables of the test, concrete cover and exposure time to fire are much influenced on the structural behavior and the remaining strength.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.561-566
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• 2008

Recently, because of development of the high speed train technology, the vibration loads by train is significantly increased ever than before. This buried gas pipelines are exposed to both repeated impact loads, and, moreover, they have been influencing by vibration loads than pipeline which is not located under vehicle loads. The vibration characteristic of pipeline is examined by dynamic analysis, and variable is only train speed. Since an effect of magnitude of vibration loads is more critical than cover depth, as increasing the train speed, the vibration speed of buried pipelines is also increased. The slope of vibration velocity is changed by attenuation of wave, at train speed, 300 km/h. From the analysis results, the vibration velocity of pipelines is satisfied with the vibration velocity criteria which are established by Korea Gas Corporation. The results present operation condition of pipelines under rail loads has fully sound integrity based on KOGAS specification.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1391-1394
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• 2007

In order for Hypoid gear development. Gears are required to sustain heavy loads or on applications where the gear box is made or a material with a different coefficient of thermal expansion form that or the gears and shafts, it is desirable to make a deflection and contact check under load. The deflection test is performed in the actual gear mounting using completely processed gear. This test should cover the full operating range of gear loads from no load to peak load. Under peak load the contact pattern should extend to the tooth boundaries without showing a concentration of the contact pattern at any point on the tooth surface.