• Title/Summary/Keyword: Concrete curb

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Development of the Light Emitting System embedded Concrete Curb (발광체 인입형 콘크리트 경계블록 개발)

  • Bae, Hyun-Ung;Yun, Kyung-Min;Sung, Ik-Hyun;Lee, Chin-Ok;Lim, Nam-Hyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.8
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    • pp.3741-3746
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    • 2012
  • The safety accidents due to the insufficient visibility are frequently occurred at the coastal zone. Therefore, safety facilities that provide visibility are certainly required to prevent accidents. In order to solve this demand, the concept of the light emitting system embedded concrete (LESeCON) are established and then concrete curb is produced for application to the coastal zone. To investigate the mechanical and functional performance of concrete curb developed in this study, the bending strength test and the visibility test are conducted.

Evaluation of Impact Resistance for Concrete Median Barrier Depending on Vehicle Curb Weight, Concrete Cover Depth and Level of Deterioration (트럭 공차중량, 중앙분리대 피복두께 및 열화수준에 따른 중앙분리대 충돌해석모델의 민감도 분석)

  • Lee, Jaeha;Lee, Ilkeun;Jeong, Yoseok;Kim, Kyeongjin;Kim, WooSeok
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.4
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    • pp.297-306
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    • 2017
  • The concrete median barrier used currently in South Korea was developed the impact level of SB5-B(270kJ). However, the impact level of SB6(420kJ) should be considered in many placed with the increased accident of heavy vehicles. In order to increase the impact resistance of newly developed concrete median barrier, the computer simulation was conducted before real field test. For the accurate behavior of concrete, the parameter, such as impact vehicle, concrete cover depth and deterioration, was important. In this paper, a parametric study was conducted depending on vehicle curb weight, concrete cover depth and level of deterioration. The impact resistance of concrete median barrier was severely changed depending on vehicle curb weight and concrete cover depth. Furthermore, the impact resistance of concrete median barrier was also decreased due to deterioration of concrete, therefore the repair and rehabilitation should be conducted for damaged concrete depending on deterioration level. Therefore, vehicle curb weight, cover depth of concrete structures and deterioration level of concrete should be carefully considered for conducting analysis of concrete structure to vehicle collision.

Experimental Study on the Frost Resistance of Concete Product (콘크리트제품의 동결저항성에 관한 실험적 연구)

  • Sugawara, Takashi;Tsukinaga, Yhoichi;Lee, Sanghun
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.91-91
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    • 2011
  • The quality of the surface layer in concrete structures plays an important role in the durability of the concrete. The concrete factory products are made as they improve the appearance of the surface and compressive strength in need. A common criterion to judge the quality of concrete products frequently seen in our daily life appears to be "beauty" in terms of consistent shaping. However, as for most concrete curb in such areas where a large amount of anti-freezing agents(NaCl) and ice and snow melting agents(CaCl2) are spread over roads to ensure road safety during the winter season, since deterioration advances from the surface, scaling is seen on the surface concrete due to deterioration which combined freezing damage and salt damage. Especially, In cold northern districts, the spreading amount of deicing salts increases by regulation of studded tire use, and the scaling of the concrete products, the various parts of concrete structures for roads is increasing in recent years. In this study, L-shape concrete curb were targeted, the permeable form method with the commercial permeable sheet was applied to it and the improvements of the quality were examined. By the permeable form method, surface layers got strengthened, which prevented permeation of the deterioration factor from the outside, and the scaling resistance of the upper surface where the permeable sheet was applied improved exceedingly. It will be expected by applying the permeable form method to various concrete products that frost resistance improves and scaling damage decreases.

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Durability and mechanical performance in activated hwangtoh-based composite for NOx reduction

  • Kim, Hyeok-Jung;Park, Jang-Hyun;Yoon, Yong-Sik;Kwon, Seung-Jun
    • Advances in concrete construction
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    • v.11 no.4
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    • pp.307-314
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    • 2021
  • Activated hwangtoh (ACT) is a natural resource abundant in South Korea, approximately 15.0% of soil. It is an efficient mineral admixture that has activated pozzolanic properties through high-temperature heating and rapid cooling. The purpose of this study is to improve a curb mixture that can reduce NOx outside and investigate durability performance. To this end, mortar curb specimens were manufactured by replacing OPC with ACT. The ACT substitution ratios of 0.0, 10.0, and 25.0% were considered, and mechanical and durability tests on the curb specimens were conducted at 28 and 91 days of age. Steam curing was carried out for three days for the production of curbs, which was very effective to strength development at early ages. The reduction in strength at early ages could be compensated through this process, and no significant performance degradation was evaluated in the tests on chloride attack, carbonation, and freezing and thawing. The mortar curb with an ACT of 10.0~25.0% replacement ratio exhibited clear NOx reduction through photocatalytic (TiO2) treatment. This is due to the increase in physical absorption through surface absorption and the photocatalyst-containing TiO2 coating. In this study, the reasonable range of the ACT replacement ratio for NOx reduction was quantitatively evaluated through a comprehensive analysis of each test.

Recent Techniques for Design and Construction of CFRD (CFRD의 최근 설계ㆍ시공기술 동향)

  • Park Dong-Soon;Kim Hyoung-Soo;Lim Jeong-Yeul
    • The Journal of Engineering Geology
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    • v.15 no.1
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    • pp.77-86
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    • 2005
  • CFRD(Concrete Faced Rockfill Dam) is in widespread use because this type of dam has superior characteristics in structural, material aspects comparing with earth cored rockfill dam. On this paper, up-to-date re-searches and techniques are summed up to be available for future needs in design and construction of CFRD. For example, such items as embankment using weak rock, experience of sand-gravel fill CFRD, connecting slab applied between plinth and face slab, raising experience of old dm, inverse filtration problem, environmental friendly zone, thickness and reinforcing of face slab, alluvial foundation treatment, and curb element method, are summarized for understanding of related engineers.

A basic study on the production of an integrated lightweight concrete solar panel using recycled waste resources (폐자원을 재활용한 일체형 경량 콘크리트 태양광패널 제작에 관한 기초적 연구반복)

  • Lee, Kook-Jae
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.04a
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    • pp.168-169
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    • 2022
  • The continuous development of science and technology since the Industrial Revolution and the development of human civilization are based on the use of fossil fuels. However, the use of fossil fuels is increasing the greenhouse gas, the main cause of global warming, and global warming is an extreme climate anomaly that is rapidly increasing human and material damage. Therefore, efforts are being made worldwide to return greenhouse gases to pre-industrial levels. In Korea, 2050 carbon neutrality has been set as a major policy and efforts are being made to curb carbon emissions in the overall industry. Carbon emission suppression is based on the minimization of fossil fuel use, and research and development are underway on building a zero-emission house that minimizes the energy used in buildings in the construction field. Therefore, in this study, as part of the zero-emissions water system construction, waste resources generated at industrial sites were utilized and an integrated lightweight concrete solar panel grafted with a concrete lightweight panel and solar panel was manufactured and the possibility of its use was evaluated.

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Use of Recycled Brick Masonry Aggregate (RBMA) and Recycled Brick Masonry Aggregate Concrete (RBMAC) in Sustainable Construction

  • Tara L. Cavalline;David C. Weggel;Dallas E. Schwerin
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.390-390
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    • 2013
  • Use of recycled aggregates in portland cement concrete construction can offer benefits associated with both economy and sustainability. Testing performed to date indicates that RBMA can be used as a 100% replacement for conventional coarse aggregate in concrete that exhibits acceptable mechanical properties for use in structural and pavement elements, including satisfactory performance in some durability tests. RBMAC is currently not used in any type of construction in the United States. However, use of RBMAC could become a viable construction strategy as sustainable building practices become the norm. Rating systems such as LEED offer points for reuse of building materials (particularly on-site) and use of recycled materials. If renovations at an existing facility call for the demolition of existing brick masonry constructions, the rubble could be included as RBMA in new concrete pavement, sidewalks, or curb and gutter. Other potential uses for RBMAC could include those in the precast concrete industry, particularly in architectural precast concrete applications. In addition to providing acceptable strength and economy, the color of RBMA could be an attractive component of architectural precast concrete panels or other façade components. This paper explores the feasibility of use of RBMAC in several types of sustainable construction initiatives, based upon the findings of previous work with RBMAC produced from construction and demolition waste from a case study site. Guidance for obtaining and using RBMA is presented, along with a summary of material properties of RBMAC that will be useful to construction professionals.

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An innovative experimental method to upgrade performance of external weak RC joints using fused steel prop plus sheets

  • Kheyroddin, Ali;Khalili, Ali;Emami, Ebrahim;Sharbatdar, Mohammad K.
    • Steel and Composite Structures
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    • v.21 no.2
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    • pp.443-460
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    • 2016
  • In this paper, the efficiency and effectiveness of two strengthening methods for upgrading behavior of the two external weak reinforced concrete (RC) beam-column joints were experimentally investigated under cyclic loading. Since two deficient external RC joints with reduced beam height and low strength concrete were strengthened using one-way steel prop and curbs with and without steel revival sheets on the beam. The cyclic performance of these strengthened specimens were compared with two another control external RC beam-column joints, one the standard RC joint that had not two mentioned deficiencies and another had both. Therefore, four half-scale RC joints were tested under cyclic loading.The experimental results showed that these innovative strengthening methods (RC joint with revival sheet specially) surmounted the deficiencies of weak RC joints and upgraded their performance and bearing capacity, stiffness degradation, energy absorption, up to those of standard RC joint. Also, results exhibited that the prop at joint acted as a fuse element due to adding steel revival sheets on the RC beam and showed better behavior than that of the specimen without steel revival sheets. In other words by stiffening of beam, the prop collected all damages due to cyclic loading at itself and acted as the first line of defense and prevented from sever damages at RC joint.

Development of Eco-friendly Cement using Reverse Osmosis Brine Water and Metakaolin (역삼투압 농축수와 메타카올린을 사용한 친환경 시멘트의 개발)

  • Kim, Taewan;Han, Ki-Bong;Kim, Do-Hyung;Seo, Ki-Young
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.9 no.2
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    • pp.216-222
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    • 2021
  • This is an experiment to complement new ways of using concentrated water discharged from the seawater desalination plant. In this study, metakaolin, which has excellent chloride ion immobilization effect, was used as the main binder, and 10% and 20% of calcium oxide were substituted with the activator. In addition, tap-water(TW) and reverse osmosis brine water(RW) were used as mixed water. As a result of the experiment, the mixture using RW showed higher compressive strength than TW. It also showed low water absorption and high density. In the mixture using RW as mixed water, a hydration reaction substance called Friedel's salt could be observed. Considering the corrosion problem of steel, RW is considered to be applicable to products such as non-reinforced concrete, brick, and curb stone. Through this study, it is thought that it is meaningful to propose a new application method other than the ocean release of RW.

A Study on the Administration for the Han River Water Quality Control (漢江 水質保全 行政에 관한 硏究)

  • Kim, Kwang Hyop
    • Journal of Environmental Health Sciences
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    • v.10 no.2
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    • pp.9-40
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    • 1984
  • This thesis purports to overview the diverse administrative and organizational factors and plannings developed by the government organizations, municipal or otherwise, to tackle the Han River water pollution issues in the past years. This thesis also looks into the ever-worsening Han River water pollution problems, in particular, in terms of the various government plans ostensibly designed to reduce the pollution level but with little success. Also dealt with are the efficiencies with which the laws and decrees on water pollution the administrative organizations put to use in the prosecution of the diverse antiwater pollution projects involving the Han River basin. From the early 1960's up to the 1970's the government had concentrated on the growth-oriented economic policy with the result that little attention had been paid to the water pollution and other environmental issues that are bound to arise from the massive economic growth. Belatedly, the five-year Hah River Development Project was initiated in 1982 with emphasis on reducing the water pollution level at Hah River to the minimum. The following are the gists of the thesis and recommendations for the future antiwater pollution plans by the administrative organizations: 1. Documents to date indicate that the irrigation projects along the Han River area had been the main focus of attention during the Yi Dynasty and under the Japanese rule of the country. 2. Despite that the water pollution issue became the subject of many debates among the academic and research institutions in the 1960's and in the 1970's, the administrative organizations in charge of the Han River water quality control failed to come up with a concrete plan for the river's water quality control. 3. Nevertheless, the water pollution of the Han River area in fact began in the 1950's, with the unprecedented concentration into Seoul of population and the industrial facilities on a larger scale, in particular, enforced by the government's strong growthoriented policy in its Economic Development plans in the 1960's. 4. Starting in the 1960's, the Han River water pollution level dramatically increased, but the government was reluctant to promulgate or put into effect strong measures to curb the many factors contributing to the river water pollution, thus worsening the environmental issues along the Han River basin. 5. The environmental protection law and other laws and decrees relating to the antiwater and air pollution issues that were subsequently put into effect underwent so many changes that efficient anti-water pollution policies could not be effected for the Han River basin. The frequent organizational reshuffle within the administrative units concerned with environmental problems has resulted in the undue waste in personnel management and finance. 6. The administration on the environmental protection could not be efficiently carried out due to the organizational overlapping. Under the existing law, frequent organizational frictions and inefficiency are bound to occur among the central government offices themselves, as well as between the central government and the Seoul city administration, and among the city's administrative offices over the conservation of the Han River basin and over the river's anti-water pollution issue. 7. In the planning and prosecution of the Han River project, political influences from the president down to the lower-level politicious appear to have been involved. These political influences in the past had certainly had negative influence on the project, nevertheless, it appears that in the recent years, these political influences are not all that negative in view of the fact that they serve as a positive contributing factor in developing a better water quality control project along the Han River basin. The following are a few recommendations based on the data from the thesis: First, officials in charge of the Han River water quality control should pay attention to a careful screening of the opinions and recommendations from the academic circles and from the public should be made so that the government could better grasp the core issues in the environmental problems that require preventive and other necessary measures. Second, vigorous redistribution policies of population and industrial facilities away from the Seoul area should be pursued. Third, the government should refrain from revising or revamping too frequently the laws and decrees on the anti-water pollution, which is feared to cause undue inconveniences in the environmental administration. Fourth, a large-scale streamlining should be made to the existing administrative organization in an effort to do away with the inter- and intra-organizational friction. It is recommended that a secretariat for the Hah River basis conservation be established. Fifth, High-level administrative officials, with a thorough knowledge and vision on the Han River water quality control, should be prepared to better deal with the budgeting and personnel management for the Han River water pollution control not only at the control government, but also at the Seoul city municipal government levels. Environmental issues should be kept distinct from political issues. Environmental issues should not serve as a window-dressing for sheer political purposes. Sixth, the Hah River proiect should also include, along with the main Han River basin, those areas covering North Han River, South Han River, and the tributaries to the main river basin. The 'Han River Basin Water Quality Control Board' should be established immediately as a means of strengthening the current Han River basin water quality control policy. Seventh, in drawing up the Han River proiect, the administrative officials should be aware that Han River basin is a life line for those people in the region, providing them with not only a sheer physical space, but with a psychological living space for their everyday life.

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