• Title/Summary/Keyword: road materials

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Process and Results of Seoul Metropolitan Government's Environmental Health Policy Road Map (서울시 환경보건정책 로드맵 수립)

  • Lim, Ji-Ae;Kwon, Ho-Jang;Kim, Shinbum;Chou, Youngeun;Gu, Seulgi;Jeong, Hoi-Seong;Kim, Myung Han;Choi, Kyungho
    • Journal of Environmental Health Sciences
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    • v.40 no.5
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    • pp.425-434
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    • 2014
  • Objectives: The purpose of this study is to introduce the establishment process and results of the Seoul Metropolitan Government's road map on environmental health policy. Methods: The process consisted of expert group meetings, civic participation, research, and questionnaire survey for priority environmental health policy agenda items in Seoul. Results: The announced vision for the environmental health policy was "a healthy environment, safety in Seoul". This policy was established in order to define environment health policy initiatives for a period of five years with an aim to protect Seoul citizens' health from hazardous environmental factors. The resulting Seoul environmental health policy consisted of four areas and 16 key agenda items. The four areas were "Protection for children against hazardous materials", "Enhancement of health and safety of all", "Carcinogen-free and endocrine-disrupting chemical-free Seoul (reducing environmental exposure to hazardous materials), and "Establish the foundation of environmental health policy". Sixteen key agenda items include the enhancement of management of spaces for children, certification of environmental health status at schools, establishment of a unit responsible for the environmental health of children, strengthening environmental health management for susceptible populations (children, the aged, and the socioeconomically vulnerable), management of hazardous materials, physical hazardous factors (noise, radiation, etc.), indoor air quality, and the enhancement of monitoring, research, and regulation of environment health. Conclusion: The Seoul Metropolitan Government established an environmental health policy road map for a five-year period (2013-2017). To implement this environmental health policy, budget allocation, and detailed execution plans are required.

Using Gabion Systems with Vegetation Base Materials on Stability Analysis for the Forest Road Cut-slope Rehabilitation Techniques (임도비탈면의 복원을 위한 식생기반재 돌망태의 안정성 분석)

  • Park, Jae-Hyeon;Jeong, Yong-Ho;Choi, Hyung-Tae
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.2
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    • pp.106-113
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    • 2009
  • In this study, stability of the new gabion system with vegetation base materials was analysed. New gabion system with vegetation base materials is a new approach which has been developed to achieve lope stabilization and revegetation of forest road cut-slope by making the best use of advantages of gabion systems with vegetation base materials. Results from stability analysis are as follows. For the soil density, the angle of internal friction and unit weight of the rock fill was assumed to be $1.90g/cm^3$, $30^{\circ}$ and $2.30t/m^3$, respectively, the slope stability analysis showed that the new gabion system couldn't require any poles to fix it up, and could keep stable during both rainy and dry seasons. As the results of checks against overturning and sliding, the retaining wall with. the new gabion system could produce suitable factors of safety for overturning and sliding. Vegetation established on the surface of the new gabion systems indirectly can help to increase slope stability by prevention of surface erosion. Consequently, the new gabion system with vegetation base materials could achieve the desired effect on slope stabilization as much as existing gab ion system could do, and could promote rapid establishment of vegetation on cut-slopes.

A Study on the quality of High Early Strength Concrete as Whitetopping Materials (Whitetopping 포장재의 시험포설 및 시공품질에 대한 평가연구)

  • 임채용;엄태선;유재상;이종열;엄주용;조윤호
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.507-512
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    • 2002
  • In road pavements, it is known that cement concrete pavement has superior durability. But in repairing pavement, cement concrete pavement is not usually applied because of the length of time while the road is interrupted when using Ordinary and Rapid-hardening Portland Cement. And Super High Early Strength Cement and Ultra Super High Early Strength Cement are not favorable for ready mixed concrete because of rapid setting time, high slump loss and other restrictions. We developed special cement developing 1 day strength of over 30.0N/$mm^2$ to open the road within 1 day and workable time is maintained over 1 hour so that it can be used as ready mixed concrete. We performed experimental overlay construction with concrete and evaluated the properties of the fresh and hardened concrete. The flexural strength was over 5.0N/$mm^2$ and the compressive strength was over 30N/$mm^2$ at 1 day. So it is thought that the road can be open to traffic within 1 day after placement.

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Development of a Predictive Model for Cement Stabilised Roadbase

  • Chai Gray W.;Oh Erwin Y.;Smith Warren
    • International Journal of Highway Engineering
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    • v.8 no.2 s.28
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    • pp.31-35
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    • 2006
  • Cement stabilisation is a common method for stabilising recycled road base material and provides a longer pavement life. With cement effect, the increment of stiffness in the stabilised layer would provide better load transfer to the pavement foundation. The recycling method provides an environmentally option as the existing road base materials will not be removed. This paper presents a case study of a trial section along the North-South Expressway in West Malaysia, where the Falling Weight Deflectometer (FWD) was implemented to evaluate the compressive strength and in-situ stiffness of the cement stabilised road base material. The improvement in stiffness of the cement stabilised base layer was monitored, and samples were tested during the trial. FWD was found to be useful for the structural assessment of the cement-stabilised base layer prior to placement of asphalt layers. Results from the FWD were applied to verify the assumed design parameters for the pavement. Using the FWD, an empirical correlation between the deflection and the stiffness modulus of the pavement foundation is proposed.

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Field Applicability Of Emergency Road Repair Material Using the CAC (CAC를 이용한 긴급도로 보수재의 현장 적용성)

  • Hyun, Ji-Soo;Kim, Jin-Man;Choi, Hong-Beom;Lee, Ha-Na;Koo, Ja-Sul
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.154-155
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    • 2015
  • This study was to review the basic characteristics in order to evaluate field application of the emergency road repair materials for development of CAC(Calcium Aluminate Composite) usage. The experiment was conducted with two phases of field and laboratory conditions and the laboratory experiment consisted indoor and outdoor tests for compressive and flexural strength. In the result of an experiment, for the compressive strength test, the specimens that cured in the laboratory conditions were not satisfied the requirement of standards, while the specimens that cured in the field conditions were well satisfied with those. For flexural strength test, the result value was satisfied with the requirement on the standards only in outdoor curing condition of laboratory experiment. Based on these results, it is expected that the CAC can be used as an emergency road repair material for field conditions.

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The Thermal conductivity analysis and performance evaluation on the pavement applying geothermal snow melting system (지열 융설시스템을 적용한 포장체의 열전도분석 및 구조안전성 검토)

  • Lee, Seung-Ha;Park, Jeong-Sik;Lee, Seok-Jin;Kim, Bong-Chan
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.6 no.1
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    • pp.17-22
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    • 2010
  • A sliding accident on the road have a high percentage by road freezing, especially, it is often appeared at bridges and tunnel of freezing areas. Thus, the stability of road operations is enhanced by preventing a partial freezing phenomenon. According to the geothermal snow melting system analysis, a pattern of thermal conductivity is found out about pavement materials of concrete and asphalt when it is buried. For the feasibility study on geothermal snow melting system, analysis of the ground melting point when operating system, life evaluation of pavements and safety evaluation of pipes are performed.

Analysis of Geothermal Melting System Conductivity for Improving Road Safety (도로주행 안정성 향상을 위한 지열 융설시스템 열전도 분석)

  • Lee, Seok-Jin;Kim, Bong-Chan;Lee, Seung-Ha;Seo, Un-Jong;Kim, Jin-Han;Lee, Joo-Ho
    • Journal of Korean Society of societal Security
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    • v.3 no.1
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    • pp.43-50
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    • 2010
  • Sliding accidents on the road have a high percentage by road freezing, especially, they often have appeared at bridges and Tunnel of freezing areas. Thus, the stability of road operations is enhanced by preventing partial freezing phenomenon. According to the geothermal snow melting system analysis, a pattern of thermal conductivity is found out; pavement materials of concrete and asphalt where the system is buried. The heat transfer simulation is essential when the geothermal snow melting system is applied according to heating exchanger pipe placed in the lower pavements. The model tests are conducted on low temperature in freezer using the manufactured test model which is equal to pavement materials. Many variables are discovered from numerical analyses under the same conditions with model test.

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Preliminary Investigation into the Use of Methyl Methacrylate(MMA)-Based Materials for Road Repair (메틸 메타크릴레이트 기반 도로 보수재 개발을 위한 기초 연구)

  • Ji, Sung-Jun;Pyeon, Su-Jeong;Choi, Byung-Cheol;Kim, Jae-Hwan;Kim, Do-Su;Nam, Jeong-Soo
    • Journal of the Korea Institute of Building Construction
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    • v.24 no.1
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    • pp.35-42
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    • 2024
  • This research explores the potential of methyl methacrylate(MMA) as a material for road repair applications. It specifically examines two MMA formulations, referred to as type A and type B, in relation to their performance on concrete substrates. The evaluation criteria included drying time, tensile bond strength, and resistance to alkali. The condition of the substrate surface was varied across three curing environments: constant temperature and humidity(R), immersion in water(W), and immersion in water with chloride ions(N). The findings indicate that type B MMA exhibits a quicker drying time and superior resistance to alkali compared to type A. While type A demonstrated greater tensile bond strength, it failed to maintain adhesion with the concrete base. Based on the parameters tested in this study, type B MMA emerges as the more favorable option for road repair contexts. Nonetheless, the study underscores the necessity for additional testing on asphalt substrates to fully assess the material's durability and applicability for long-term road maintenance.

Emergency and Permanent Repair Technology for Damaged Road Bases and Slopes using Gravel-Netting Concrete (도로 및 비탈면 유실 항구적 긴급복구를 위한 골재망 콘크리트 활용기술 개발)

  • Kim, Yongjae;Jung, Haekook;Kim, Seungwon;Park, Cheolwoo
    • International Journal of Highway Engineering
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    • v.20 no.2
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    • pp.9-17
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    • 2018
  • PURPOSES : The frequency and severity of natural disasters such as torrential rain or typhoons have become increasingly significant worldwide. Events such as summer typhoons and localized torrential downpour can cause severe damages to a residential area and road networks, resulting in serious harm to the daily lives of people, especially in rural areas by isolating residents from road networks. An immediate and emergency repair technology for the collapsed road networks is urgently needed. This study introduces a new technology to repair road bases or slopes. METHODS : The development of new technology for emergency and permanent repair consists of first, packing of cement paste-coated gravel, second, combining appropriate equipment, and third, conducting a field applicability test. In this research, the compressive strength of cement pastecoated gravel, gravel-netting concrete properties, and packing efficiency were determined, and a full scale field mock-up test was carried out. RESULTS : The compressive strength of the cement paste-coated gravel concrete satisfied the required limit for road base of 5 MPa after 7 days. With appropriate netting materials and packing size, gravel-netting concrete was successful up to a slope of 1:1.5. The full scale field mock-up test showed efficiency in the field and penetration resistance performance. CONCLUSIONS : The new technology of emergency and permanent repair for damaged road bases and slopes, introduced in this study, showed satisfactory performance. The technology is expected to be applied in the field when construction procedures and quality specifications are made.

Interaction of a road-pavement system with pollution sources and environments (도로-포장시스템의 오염원 및 주변환경적 요인과의 상호작용)

  • Kim, Tae-Hyung;Nam, Jung-Man;Jeong, Jin-Seob
    • International Journal of Highway Engineering
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    • v.6 no.3 s.21
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    • pp.47-54
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    • 2004
  • The performance of road-pavement system is closely related to the constituent materials and their susceptibility to mechanical as well as physicochemical stresses. However, the influence of physical and chemical effects on the road-pavement system due to pollution intrusion has not been investigated fully. To study this topic, thu.;, the interaction of a road-pavement system with pollution sources and environments are identified and discussed preliminarily in this paper. Pollution intrusion to road-pavement system occurs by three basic mechanisms; 1) direct intrusion into pavement surface, 2) intrusion from the Right of way, and 3) physical-chemical-biological alterations. Pollution intrusion potential is closely related to material type, particle size, and climatological and topographical features. Stability and performance of road-pavement system is also directly affected by pollution intrusion. Based on these features, thus, engineers working in related to the road design, construction, and maintenance should be seriously considered this topic.

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