• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.191-201
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• 2006

The flood control ability improvement project on existing dams is the project for prevention of disasters from excessive flood due to climate changes and thus protects lives and property damages by increasing safety of dams. The collapse of dam brings unimaginable disasters, so the project needs to be swiftly conducted by Government's funding. This paper introduces tile examples of the flood control ability improvement projects of multi-purpose and water supply dams, which is conducted in the way of structural measures among 26 dams operated by Kwater.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.500-507
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• 1997

Recently, the construction of infrastructures has been booming and accelerating to keep up with rapid economic growth. Construction activities and operation of transportation facilities cause unfavorable effects such as civil petitions associated with vibration-induced damages or nuisances. The objective of this study is to develop vibration-controlled concrete using various vibration-controlling materials , and also to investigate dynamic properties of concrete beam depending on damage level. Vibration-controlled mixtures are latex, rubber powder and plastic resin, which have been determines to by and large reduce vibration. KS F2437 has been used to figure out 1st natural frequency and dynamic flexural rigidity. Dynamic damping rations have been, computed by adopting the polynomial curvefitting method on the frequency spectrum curve, of which results have been compared and analyzed hereon

• KIEAE Journal
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• v.9 no.5
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• pp.13-20
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• 2009

This study suggested practical application of decision aid tool on re-evaluation of current buildings with a focus on a energy and economics evaluation methodology. In Europe, over forty percent of all construction activities are for retrofit. For efficient construction, various tools for re-evaluating existing buildings have been developed and are in use. Legislations of relevant laws and studies are actively initiated. In particular, EPIQR (Energy Performance Indoor environment Quality Retrofit), which was developed through the EU's Third and Fourth Framework Programs laid a foundation on a new concept-based decision aid tool for re-evaluation of existing buildings. As for actual applications, based on this, EPIQR+ was developed to be in line with a building maintenance guideline (SIA 469) and is actively applied to public buildings. This tool quantifies the degree of damages of existing buildings and suggests alternatives to users in energy (SIA 380/1) and economical perspectives. This study examined these preceding tools and suggested some trenchant approaching for more comprehensive and efficient use of re-evaluation tools in building maintenance.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.257-258
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• 2015

The amount of damages caused by natural hazards is consistently growing due to the unusual weather and extreme events. At the same time, property damage by natural hazards is rapidly increasing as well. Hence, we need systematic anti-disaster activities and consulting that can react to such a situation. To address these needs, we investigated and analyzed insured claim payouts from natural hazards by administrative area, and calculate the risk index utilizing GIS. According to the index, this map is identifying the areas of greatest natural hazard risk. The ranking of natural disaster vulnerability based on the risk index, and risk grades were divided into five based on the ranking. This map integrates the natural hazard losses to assist in comprehensive and effective loss prevention activities using analysis of regional loss claims from natural hazards. Moreover, this map can be as utilized as loss mitigation and prevention activities to verify the distribution of exposure and hazards.

• Advances in concrete construction
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• v.5 no.4
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• pp.303-311
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• 2017

The concrete industry of developing countries like India consumes majority of natural resources. The increase in population has necessitated the construction of more and more structures. Further many structures have completed their life span or have undergone damages thus warranting the demolition of these structures. India produces approximately 23.75 million tons of recycled concrete aggregate (RCA) annually. The natural resources are depleting at a higher rate with the increasing demand of concrete industry. This difficulty can be reduced with the use of RCA in land fill and concrete manufacturing. Use of RCA can provide cost savings and better energy utilization. This paper presents mechanical behavior of concrete comprising successively recycled concrete aggregate. Mechanical properties of recycled concrete get affected with number of recycling. In mix design successive recycled concrete aggregate (SRCA) was used in place of natural aggregates (NA) with 100% replacement. The test results of the compressive, flexural strength and pulse velocity were obtained for 14 and 28 days of curing age which showed significant improvement in results.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.336-340
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• 2006

The cases of using new methods of big blocks are largely increasing on Recent large-scale bridge structures. So the accurate data of responses of bridges following environmental causes are required to be quickly recorded in order to predict. For this reason described above, the research on measuring system should be conducted for more knowledge of the details on application and stability of new methods. In this study, the new health monitoring system that can monitor the real behavior and damages of the bridge during all processes of construction is presented by analyzing cases of domestic and overseas bridge health monitoring system, and applied methods of following bridges.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.207-208
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• 2017

The current study assumed a condition in which concrete curing was not completed correctly in the winter, in order to analyze the effect of changes in early low-temperatures in early-frost damage depth. As a result, lower external temperature early on after depositing the concrete greatly reduced the temperature in the upper parts of the concrete, and it delayed the time during which the concrete temperature restored. In addition, for early-frost damages, lower early temperature increased the expansion of frozen water, which in turn relaxes the concrete structures and increases the absorption rate, ultimately extending the depth of early-frost damage.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.155-156
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• 2017

Borosilicate glass was incorporated to improve the neutron shielding capability of concrete. Boron is a typical neutron shielding material, and it is contained in borosilicate glass. However, borosilicate glass causes alkali-silica reaction, which damages the concrete. Therefore, studied to reduce the expansion due to alkali-silica reaction and to improve the neuton shielding capability. The measurement of the expansion due to the alkali-silica reaction was based on ASTM C 1260. Experimental results show that the expansion due to alkali-silica reaction is reduced when borosilicate glass powder incorporated. In addition, the neutron shielding capability was significantly improved when the fine aggregate replaced with borosilicate glass.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2229-2231
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• 2005

Recently, damages of electronic equipments due to lightning surges coming from AC power lines are increasing. In this work, to propose the effective installation methods of surge protective devices(SPDs), the protective performances of SPDs in actual-sized test circuits were experimentally investigated. In order to obtain the lowest limiting voltage and best protection, long leads of SPDs in installation practices are significantly undesirable. An effective installation method of SPDs for AC mains was proposed. The way of installing SPDs at every branch circuits is more effective than that of installing a SPD near the point of entry.

• Advances in concrete construction
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• v.8 no.3
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• pp.165-172
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• 2019

Progressive collapse is one of the factors which if not predicted at the time of structure plan; its occurrence will lead to catastrophic damages. Through having a glance over important structures chronicles in the world, we will notice that the reason of their collapse is a minor damage in structure caused by an accident like a terrorist attack, smashing a vehicle, fire, gas explosion, construction flaws and its expanding. Progressive collapse includes expanding rudimentary rupture from one part to another which leads to total collapse of a structure or a major part it. This study examines the progressive collapse of a 5-story concrete building with three column eliminating scenarios, including the removal of the corner, side and middle columns with the ABAQUS software. Then the beams and the bottom of the concrete slab were reinforced by (reinforcement of carbon fiber reinforced polymer) FRP and then the structure was re-analyzed. The results of the analysis show that the reinforcement of carbon fiber reinforced polymer sheets is one of the effective ways to rehabilitate and reduce the progressive collapse in concrete structures.