• 대한토목학회논문집
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• 제35권1호
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• pp.93-99
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• 2015

본 연구는 RC 휨부재에서 동일한 안전율을 갖으면서 경제성을 확보할 수 있는 휨 철근비를 결정하는 방법에 관한 실용적 연구이다. 재료비 및 인건비를 고려하여 공사비 함수를 구성하였고, 최저공사비를 유도하는 경제적 휨 철근비를 결정하는 식을 제안하였다. 제안식을 통해 단철근보의 최적 철근비는 0.65~1.0%를 추천하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.149-152
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• 2006

Serviceability of reinforced concrete building is affected dominantly by long term deflection of slab. And in case of reinforced concrete building with flat plate slab, severe long term deflection was expected because it has no beams which have large flexural stiffness. Therefore it is important to calculate exactly long term deflection of RC flat plate structure to assure its serviceability. However, current codes couldn't calculate exactly long term deflection of RC flat plate structure because they don't consider effects of boundary condition and construction load. By the way, recently the method to calculate long term deflection of RC flat plate structure was proposed by considering these effects. In the present study, long term deflection of RC flat plate structure was analyzed by comparing this method with recent experimental results. In conclusion, long term deflection of RC flat plate structure was affected considerably by effects of boundary condition, construction load and tensile strength of concrete. And recently proposed method considers these effects reasonably but it should be modified to reflect creep effect of RC flat plate slab reasonably.

• 한국농공학회논문집
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• 제47권1호
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• pp.71-77
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• 2005

Recycling of reclaimed concrete (RC) is very important in the management of construction and demolition wastes. Most of RC is utilized for land-filling after crushing in this country. In this study, a series of elution experiments were conducted to investigate the type and amount of pollutants released from the crushed RC. Most water quality parameters including heavy metals and some organic compounds were below standards for drinking water. Some of heavy metals such as As, Cd, Pb, Hg were detected in 0.5 N H2S04 solution after 24-hour immersing RC, which was conducted for evaluating a long term release effect. The concentration of the heavy metals were higher than the drinking water standards. The results also showed significant adsorption of heavy metals by crushed Re. Potential risks, based on the result of this study were not high in using crushed RC for land-filling. Appropriate management of RC would reduce the risk, for example the separation of hazardous materials from construction wastes. Long term evaluations for the sites of land filled with RC would be required to assess the environmental impacts.

• 한국건설관리학회논문집
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• 제16권5호
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• pp.12-20
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• 2015

최근 건설프로젝트는 기존의 노동집약적 현장생산 방식이 아닌, 공장 생산 기반의 현장 조립 방식인 모듈러 건축물에 주목하고 있다. 모듈러 건축 공법은 기존 방식에 비해 공기 단축효과가 높고, 해체 및 재사용이 용이해 임시 주거시설을 중심으로 적용되고 있다. 그러나 모듈러 공법 실현을 위한 초기 투자비용에 대한 부담으로 인해 국내의 모듈러 건축시장은 아직 활성화되지 못하고 있다. 이에 본 연구에서는 모듈러 건축물이 가지고 있는 경제적 부담에 대한 대안으로서 시장의 수요에 따라 이동 가능한 모듈러 건축 방식에 대하여, 기존의 건축 방식과의 생애주기비용 비교를 통해 경제적 효과를 분석하고자 한다. 본 연구에서 분석의 대상으로 삼은 RC 공법과 모듈러 공법의 이동형 모델의 경제성 평가 결과, 단기적인 측면에서는 RC공법이 빠른 수익률을 달성하였지만 건물의 전 생애주기 측면에서는 이동 가능한 모듈러 건축 방식의 경제성이 보다 큰 것으로 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.168-169
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• 2015

SMART Frame is a composite precast concrete structure system to deliver the advantages of both steel frame and reinforced concrete. Many studies have established to date that SMART Frame is more advantageous than conventional frame-type structure in terms of structural stability, constructability, economic viability as well as reduction of construction schedule. However, such studies have focused primarily on wall-type or flat slab-type apartment housing structures, failing to include Rahmen structures in their scope. Accordingly, this study aims to analyze the benefits of potential application of SMART Frame to RC Rahmen structures. As the structural stability and constructability of SMART Frame is already proven, this study reviews its benefits from the perspective of cost reduction. Conclusion of this study will be used subsequently in predicting the benefits of SMART Frame when it is adapted to RC Rahmen structures.

• 한국구조물진단유지관리공학회 논문집
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• 제6권1호
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• pp.95-102
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• 2002

The flexural behavior of the reinforced concrete (RC) structure upgraded by external reinforcements was examined in this study. It is well known that the incorporation of carbon fiber sheet (CFS) with concrete is one of the most effective ways to strengthen the RC structure. Complete bonding is required between CFS and concrete in order to make the RC structure provide its full function until the time the Re structures serve. Many studies have reported that construction deficiencies have caused the debonding of the CFS from concrete before the RC structure with CFS reaches its ultimate capacity. This research took a systematic look at the failure mechanism, macroscopic load-deformation characteristics, the maximum load applied, and maximum bending moment when construction deficiencies exist. The results of the experiment conducted were compared with theoretically derived values. In the future, the results of this investigation will help minimize the factors of construction deficiencies, which may occur when CFS is used to reinforce a RC structure. The experiment was manipulated with steel reinforcement ratio and piles of CFS on a total of 14 beams ($20cm{\times}30cm{\times}240cm$). The results showed that internal moment capacity increased even when construction deficiencies existed. However, RC structures with CFS in the field still contain a considerable level of potential risks.

• Structural Engineering and Mechanics
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• 제28권1호
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• pp.69-88
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• 2008

A number of construction practices, implemented during the design process of a reinforced concrete (RC) structural system, may have significant consequences on the behaviour of the structural system in the case of earthquake loading. Although a number of provisions are imposed by the contemporary Greek national design codes for the seismic design of RC structures, in order to reduce the consequences, the influence of the construction practices on the seismic behaviour of the structural system remains significant. The objective of this work is to perform a comparative study in order to examine the influence of three, often encountered, construction practices namely weak ground storey, short and floating columns and two combinations on the seismic performance of the structural system with respect to the structural capacity and the maximum interstorey drifts in three earthquake hazard levels.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 봄 학술발표회 논문집
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• pp.13-18
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• 1994

Most widened bridges have been constructed by the joining-construction method that makes new and existing bridge structurally single structure. However, joing-construction method has several problems in design and construction viewpoint. Therefore, this study is conducted in order to investigate structural behavior of widened RC slab and traffic-induced vibration of existing bridge during placing and curing of new concrete by the prototype flexural fatigue test. From the results of this study, it is shown that stress-concentration and slip occur between concrete and reinforcing rod at joint section but the reduction of load carrying capacity and of fatigue strength is negligible according to the traffic-induced vibration as well as the difference of construction method. A reasonable construction method for the bridge widening which takes into account the effects of the traffic-induced vibration and S-N curve for the widened bridge are also proposed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.177-178
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• 2016

The main structure of the building has been used reinforced concrete construction method in Korea. In recent years, it is necessary to demolition of buildings into urban redevelopment. But yet the demolition method is not being developed perfect. It is necessary to develop future deconstruction for safety and environment method. In this study, we surveyed the demolition method has been used in domestic construction. How the combination of these demolition method should be needed. Demolition method combinations were classified as low-rise, high-rise, middle. It suggested method to combine the demolition process of reinforced concrete structure with seven.

• Structural Engineering and Mechanics
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• 제53권4호
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• pp.791-818
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• 2015

RC buildings constitute the prevailing type of construction in earthquake-prone region like Kathmandu Valley. Most of these building constructions were based on conventional methods. In this context, the present paper studied the seismic behaviour of existing RC buildings in Kathmandu Valley. For this, four representative building structures with different design and construction, namely a building: (a) representing the non-engineered construction (RC1 and RC2) and (b) engineered construction (RC3 and RC4) has been selected for analysis. The dynamic properties of the case study building models are analyzed and the corresponding interaction with seismic action is studied by means of non-linear analyses. The structural response measures such as capacity curve, inter-storey drift and the effect of geometric non-linearities are evaluated for the two orthogonal directions. The effect of plan and vertical irregularity on the performance of the structures was studied by comparing the results of two engineered buildings. This was achieved through non-linear dynamic analysis with a synthetic earthquake subjected to X, Y and $45^{\circ}$ loading directions. The nature of the capacity curve represents the strong impact of the P-delta effect, leading to a reduction of the global lateral stiffness and reducing the strength of the structure. The non-engineered structures experience inter-storey drift demands higher than the engineered building models. Moreover, these buildings have very low lateral resistant, lesser the stiffness and limited ductility. Finally, a seismic safety assessment is performed based on the proposed drift limits. Result indicates that most of the existing buildings in Nepal exhibit inadequate seismic performance.