• Title/Summary/Keyword: conventional concrete

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Experimental Study on Bank Protection System using Fabric Foam (친환경 섬유대공 하천호안공법의 현장계측 연구)

  • Kim, Jin-Man;Cho, Sam-Deok;Choi, Bong-Hyuck;Kwak, Ki-Seok;Woo, Hyo-Seop;Ahn, Hong-Kyu
    • Journal of the Korean Geosynthetics Society
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    • v.3 no.2
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    • pp.3-11
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    • 2004
  • Fabric Foam systems provide a variety of flexible bank protection for open channels and hydrulic structures. The structural performance and durability of conventional bank protection materials such as concrete, gravel, riprap and vegetation can be significantly improved by confining the materials within the cells of Fabric Foam system. This paper presents the results of field and laboratory tests carried out to evaluate the performance of new Fabric Foam System as a Bank Protection. The results of the tests confirmed effect of Fabric Foam System in Bank Protection.

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A Study on Normal Range of Surface Deflection for Epoxy Asphalt Pavement using Light Weight Deflectormeter (LWD를 활용한 에폭시 아스팔트 포장의 정상 표면처짐 범위 연구)

  • Park, Ki Sun;Kim, Kyung Nam;Kim, Nak Seok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.1
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    • pp.229-236
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    • 2015
  • In this study, the resilient modulus test and Light Weight Deflectormeter (LWD) test were conducted to simulate the moving vehicle load for the evaluation of the internal failure of epoxy asphalt pavement. The Measured displacement in the resilient modulus test of epoxy asphalt concrete showed very little residual deformation under repeated loads unlike the conventional asphalt. Therefore, the test results were evaluated as a normal state due to its similarity with elastic deformation. The deflection results from the resilient modulus tests were converted to the surface deflection modulus and the normal range of surface deflection modulus was estimated applying LWD measurement of 1 SIGMA level. Internal failure of pavements were estimated using the suspicious failure range at $60^{\circ}C$ and hysteresis. Internal moisture penetration and a decrease in bonding were observed in partial areas at $140{\mu}m$ of surface deflection. However, the areas showed inflection points in the hysteresis. Field investigation by suggested criterion indicated a high degree of accuracy.

A Study on Field Application of Preventive Maintenance Method for Flexible Pavements (연성포장의 예방적 유지보수공법에 대한 현장 적용성 연구)

  • Kim, Nakseok;Jin, Jung-Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.4D
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    • pp.565-569
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    • 2011
  • This paper presents minimum area repair method that is one of the preventive maintenance techniques in asphalt concrete pavements. In this method, a 70cm-width as an effective repair zone was suggested considering the conventional longitudinal damages (rutting and fatigue cracking) in early stages. In addition, the repair zone can be readjusted according to the pavement damage levels. A field test bed was constructed to verify the adaptness for the repair method. Test results revealed that the minimum area repair method can be adopted as a preventive maintenance technique in flexible pavements to recover an appropriate serviceability level. The preventive maintenance method may be one of the major maintenance methods of flexible pavements with an appropriate application. It is also noted that the method may be a long term maintenance cost effective and pavement life ensuring one.

Environment Design of an Estuary Dike on the Youngsan-River (영산강 하구둑 환경설계)

  • 배현미
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.1
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    • pp.44-51
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    • 2002
  • The objective of this project is to improve the environment of the estuary dike on the Youngsan-River through Re-landscaping. An estuary dike of the Youngsan-River, the largest in the Orient, was constructed in 1981 and connects Mokpo City and Youngam-Gun province. Twenty years ago, when this dike was completed, this place was one of the famous tourist attractions of Korea. It symbolized the development and growth of Korea. But this dike at present is only a dreary sight as a huge concrete construction element. Therefore, a wall painting on the estuary dike was planned to improve this image. The site, an estuary dike of the Youngsan-River, is located in Mokpo City and its length is about 1,360m. The planning focus of this re-landscaping, which is a proposed improvement design through the analysis of characteristics and problems in conventional facilities, is as follows: (1) Introduction of a wall painting that is a symbol of the sea and river (by the creation of an illusion), (2) Production of the wall painting which is under consideration to create a friendly atmosphere of the circumference view and (3) Preparation of a design to establish an approach to the waterfront. By following these steps, an estuary dike can function as a tourist attractions and can be transformed in to cultural space for civilian. This project is good example of environment design that is completed with the regional residents participation through community input in the planning and initiation of a wall painting. The concept of environment design which involves the residents participation and re-landscaping in Korea has not been established up to now on. However, as this projects has proven, consideration for regional residents is a very important factor for the administrative office and planing specialist to address. In the future, it will have a direct influence on the development of design planning. If the establishment of space that can be accepted by residents with love, affection and self-confidence is possible, environment design in which residents participate actively, can be realized.

Case Study on Global Slope Failure Case of Segmental Retaining Wall (블록식보강토옹벽의 전면 사면붕괴 사례연구)

  • Han, Jung-Geun;Cho, Sam-Deok;Jeong, Sang-Seom;Lee, Kwang-Wo;Hong, Ki-Kwon
    • Journal of the Korean Geosynthetics Society
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    • v.4 no.2
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    • pp.47-56
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    • 2005
  • Recently, geosynthetic reinforced earth walls are gradually replacing conventional concrete retaining walls for reasons of economy, expediency of construction, and aesthetics. A number of reinforced soil walls having more than 10m heights have been constructed to make more effective development in the country. However, mistakes in design and construction of reinforced earth walls have resulted in many troubles such as failure of reinforced earth walls, horizontal deformationor breakdown of facings, and so forth during or after construction. In this paper, a case study on global sliding failure of a geogrid-reinforced tiered wall is carried out to investigate the causes of the failure and suggest the proper countermeasures. From the subsurface investigation and field instrumentation, It is found that the cause of the global sliding failure was occurred by decreasing of bearing capacity of foundation ground induced by infiltration of rainwater.

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Stability Analysis According to the Shape of Assembled Earth Retaining Wall by the Field Model Tests and 3D-Numerical Analysis (현장모형실험과 3D 수치해석을 통한 AER 조립식 지주옹벽의 형태에 따른 안정성 분석)

  • Seo, Minsu;Im, Jong-Chul;Son, Su Won;Kim, Hong-Sun;Choi, Jung-Hyun;Kim, Changyoung
    • Journal of the Korean Geotechnical Society
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    • v.33 no.1
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    • pp.17-30
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    • 2017
  • There are many limitations for ensuring structural stability of retaining wall. Especially, L-shaped retaining wall and gravity retaining wall need large space, and massive concrete, respectively. Assembled Earth Retailing (AER) wall was developed to overcome the shortcomings. In this paper, stability of AER wall is verified by field model tests and the 3D-numerical analysis. The results show that horizontal displacement of AER wall was reduced by maximum 67.84% for conventional retaining walls, and earth pressure acting on the retaining wall was reduced by maximum 73.19%.

Punching Shear Strength of CFT Column to RC Flat Plate Connections Reinforced with Shearhead (전단머리 보강 CFT기둥-RC 무량판 접합부의 펀칭전단강도)

  • Kim, Jin-Won;Lee, Cheol-Ho
    • Journal of Korean Society of Steel Construction
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    • v.24 no.4
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    • pp.423-433
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    • 2012
  • This paper summarizes full-scale gravity-load test results on CFT column-to-RC flat plate connections reinforced with shearhead. CFT construction has many structural and constructional advantages over conventional steel and RC column construction and is gaining wide acceptance. Meanwhile the use of RC flat plate system in the basement and residential floors of tall buildings is often mandatory to reduce story height and enable rapid construction in domestic practice. Combining CFT column and flat plate floor is expected to result in further rapid construction. However, the issues related to connecting CFT column to RC flat plate have not been fully addressed yet. Several promising connecting schemes by using steel shearhead were proposed and tested in this study. Test results showed that the proposed connection can exhibit the punching shear strength higher than RC flat plate counterparts. An empirical formula that can reasonably predicts the punching shear strength of the proposed connection was also proposed.

Time-Dependent Deformation Characteristics of Geosynthetic-Reinforced Soil Using Plane Strain Compression Tests (평면변형압축시험을 이용한 보강토의 시간 의존적 변형 특성 연구)

  • Yoo Chung-Sik;Kim Sun-Bin;Lee Bong-Won
    • Journal of the Korean Geotechnical Society
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    • v.21 no.10
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    • pp.85-97
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    • 2005
  • Despite a number of advantages of reinforced earth walls over conventional concrete retaining walls, there exist concerns over long-term residual deformation when subjected to repeated and/or cyclic loads, especially when used as part of permanent structures. In view of these concerns, in this paper time-dependent deformation characteristics of geosynthetic reinforced soil under sustained and/or repeated loads were investigated using a series of plane strain compression tests on geogrid reinforced weathered granite soil specimens. The results indicate that sustained or repeated loads can yield appreciable magnitudes of residual deformations, and that the residual deformations are influenced not only by the loading characteristics but by the mechanical properties of geogrid. It is also found that the preloading technique can be effectively used in controlling residual deformations of reinforced soils subjected to sustained and/or repeated loads.

Noise reduction of Asphalt Concrete Pavement : Techniques and their performance evaluation (아스팔트 저소음 포장의 개발 및 공용성 평가)

  • Ock, Chang-Kwon;Kim, Jin-Hwan;Lee, Jong-Sup
    • International Journal of Highway Engineering
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    • v.12 no.1
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    • pp.29-37
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    • 2010
  • Porous pavements can provide road users with beneficial characteristics such as skid resistance and surface water drainage under rainy condition, and they cause less tire-road noise than conventional hot mix asphalt(HMA) pavements. However, voids of porous pavements are easily clogged by road debris at early stages, which leads to frequent maintenance works. Therefore, this study focused on the way of minimizing void clogging in porous pavements. During mixture design, the quantity of coarse aggregate has been increased to form many straight void conduits (SVCs) in porous HMAs. These SVCs were found to be effective resisting the void clogging problems. Four different porous HMAs(19mm, 13mm, 10mm, and 8mm) were developed and placed on highway roads. Their performances were validated with field tests during the past four years.

A Study on the Computer Graphics Education in Network Environments (박람회장 공간의 특수전시 연출 및 기획에 관한 연구 - 대전 엑스포 '93 정부관을 중심으로 -)

  • 한은수
    • Archives of design research
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    • v.11 no.3
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    • pp.58-67
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    • 1998
  • Exposition primarily reguires the basic understanding of the mutual effect between the conventional culture and the future-oriented change of society.A number of fundamental and general research articles exist which are related to the exhibition planning and design. Unfortunately, the concrete research works dealing with the large-scale international expositions are hardly found in the literature. In this connection, this research was particularly focused on the special exposition display and planning. The International Exposition, the World Design Exposition and the International Garden and Greenery Exposition were chosen in order to examine the conceptual characteristics as the proper examples creating the fantastic space and developing the new exposition display technigue. The Government Pavilion in the Taejon Expo , 93 was chosen as an example for the exposition planning. An overall research concerning the basic direction and structure of the exposition design, the exposition display and the special system technigue was carried out in order to represent the basic spirit and theme with the most efficient way.

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