• Title/Summary/Keyword: Paving materials

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An Evaluation of the Phenomenon of Heat-Island Effect by Multi-Criteria Methods (다항목 평가기법의 적응을 통한 열섬현상의 평가)

  • Lee Jung-Min;Do Hu-Jo;Ra Jung-Hwa;Kim Soo-Bong;Jung Eung-Ho
    • Journal of Environmental Science International
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    • v.14 no.11
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    • pp.1005-1014
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    • 2005
  • The purpose of this research was to present multi-criteria which were related to the heat island and find methods which decreased heat island affection on the ecological landscape planning. The results of this study were as follows. According to the analysis of surface temperatures, the first grade was the outside-city like a mountain and its temperature was less than $13.0^{\circ}C$. The fifth grade was the downtown, industrial area and its temperature was more than $26.9^{\circ}C$. Therefore, the result was seen the serious heat-island effect. The results of field survey, the closer to the first grade, the higher the value of green coverage. The closer to the fifth grade, the higher the value of impermeability surface, paving materials and colors. According to the correlation analysis, the temperature had high correlation with impermeability surface, paving materials and colors. According to the simple regression analysis, permeability surface, green coverage, topography, impermeability surface, paving materials f: colors, human impact related with surface temperatures. To plan for the decrease of Heat-Island Effect needed the extension of green space, decrease of impermeability surface. This research suggested data for urban green plan and decrease of heat island effect, but there was a limit to get the objective method for grade classification because of lacking in the basic data, the research of multi-criteria will be accomplished continuously.

Evaluation of Applicability of Heavy Oil Upgrading By-Product (Pitch) as A Pavement Paving Material (중질유 고도정제 부산물의 도로포장용 역청재료로서의 적용성 평가)

  • Yang, Sung Lin
    • International Journal of Highway Engineering
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    • v.16 no.5
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    • pp.9-18
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    • 2014
  • PURPOSES : The objective of this study is to evaluate the applicability of the pitch, which is produced during SDA petroleum upgrading process, as a pavement paving material. In order for the purpose, the physical and chemical properties of the pitch are analyzed, and then the various plasticizers are applied in the pitch. METHODS : Two types of pitch are selected from oil refinery companies, which are owned the SDA petroleum upgrading process. Also, two types of asphalt binders, PG 64-22 and PG 58-22, are employed to compare with the pitch because these two types of asphalt binders are currently used as paving materials. For the chemical property of the pitch, the composition of SARA (Saturate, Aromatic, Resin, Asphaltene), the elementary composition, and the functional group are analyzed. For the physical property of the pitch, the basic material property tests, such as penetration test, softening point test, flash point test, ductility test, and rotational viscometer test, are performed. Also, the DSR (Dynamic Shear Rheometer) test and the BBR (Bending Beam Rheometer) test are conducted using asphalt binder specimens obtained by both short term aging (Rolling Thin Film Oven, RTFO) and long term aging (Pressure Aging Vessel, PAV) processes. The rheological property of each pitch type is evaluated as a function of temperatures and loading cycles. PG 64-22 asphalt binder is used as a control material. RESULTS AND CONCLUSIONS : The Pitch may not be suitable for the pavement paving material without modifications, but the pitch can be used as alternatives of modified addictive or asphalt. If low molecular component, such as saturate and aromatic components, are added in the pitch based on the development of various plasticizers, it has a strong possibility for the pitch to be used as a alternative. However, in order to verify the performance property of the pitch, further research is needed.

Hydration Characteristics and Chemical Composition of Lead-glazed Paving Bricks Excavated from the Beopgwangsa Temple Site, Pohang (포항 법광사지 납유 전돌의 수화 양상과 화학조성)

  • Jeon Sangeun;Kim Gyuho
    • Conservation Science in Museum
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    • v.29
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    • pp.65-80
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    • 2023
  • This study investigated seven specimens of lead-glazed paving bricks in order to identify the materialistic characteristics of the lead glaze used for paving bricks during the late Unified Silla period in Korea. The samples were excavated from the Beopgwangsa Temple site, Pohang. As a result of observing the surface and cross-section of the glaze with a microscope, the study confirmed that the lead glaze demonstrates various traits of hydration, which were classified into four layers: Surface layer, hydration layer A, hydration layer B, and green layer. After measuring the composition of each layer with SEM-EDS analysis, the green layer was found to have been less affected by the external environment, which renders it highly reasonable to view the green layer as the original composition of the lead glaze. The green layer is a low-temperature glaze composed mainly of PbO and SiO2 at a ratio of 8:2, with approximately 2% CuO acting as the main colorant. Comparing the green layer composition with those from Gyeongsang-do, it was confirmed that the mixture ratio of lead glaze materials was similar to other sites such as the Sacheonwangsa Temple site, the Cheonryongsa Temple site, and the Buseoksa Temple site.

Experimental Study on Capacity Variation of Paving Materials with TiO2 in Wet Condition (광촉매 이산화티타늄(TiO2)을 혼합한 도로 포장재의 습윤 조건에서의 성능 변화에 관한 실험적 연구)

  • Seo, Dawa;Yun, Tae Sup
    • Journal of the Korean Geotechnical Society
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    • v.32 no.5
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    • pp.49-55
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    • 2016
  • This study aims to present the practical Nitrogen monoxide (NO) removal capacity of cement mortar with Titanium dioxide ($TiO_2$) which is one of the paving materials by considering the environment of pavement in urban areas. NO removal capacity test under designated conditions of humidity of inflow gas and the test with variation of the degree of saturation of specimen were conducted. In the test for humidity, dry specimen is subject to the test and NO removal ratio was observed. Humidity-NO removal ratio curve is a log normal distribution in shape, and the maximum NO removal ratio appears at specific humidity. NO removal capacity test relying on the degree of saturation was carried out with wet specimen to reflect the unsaturated pavement by rainfall and domestic sewage. Wet specimen presents less NO removal capacity than dry specimen and the recovering evolution of NO removal capacity follows evaporation. Moreover, $TiO_2$ under the specific depth of specimen hardly contributes to NO removal capacity.

A Study on the Safety and Comfort of Pedestrians according to the Type of Sidewalk Pavement (보도포장의 종류에 따른 보행자의 안전성 및 쾌적감에 대한 연구)

  • Choi, Jae Jin
    • Journal of the Korean Society of Safety
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    • v.30 no.1
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    • pp.66-71
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    • 2015
  • Safety, resilience and comfort of pedestrian were assessed by the British Pendulum Test and SB/GB factor test at 8 kinds of sidewalk pavement. Sidewalk paving materials were normal concrete, porous concrete, concrete block, soil concrete, asphalt, rubber chip/resin mixture, wood chip/resin mixture and floor tile. In addition, a survey was conducted to investigate the perception of pedestrians on the sidewalk paving material. As a result, while the skid resistance value was measured in the most 60BPN above, the floor tile showed a low value of about 30BPN. The ratios of SB factor to GB factor of the elastic pavements(rubber/resin mixture and wood chip/resin mixture) appeared to be relatively large when compared with those of the conventional sidewalks. The survey showed that respondents perceived as more safe and comfortable elastic pavements compared to conventional pavements. Approximately 50% of respondents answered that hardened soil pavement was the most environmentally friendly.

Development and Evaluation of the Bender Type Piezoelectric Energy Harvester According to Installation Methods and Vehicle Weight (매설방법과 차량하중에 따른 벤더형 압전에너지 하베스터의 설계 및 평가)

  • Kim, Chang-Il;Jeong, Young-Hun;Yun, Ji-Sun;Cho, Jeong-Ho;Paik, Jong-Hoo;Jang, Yong-Ho;Choi, Beom-Jin;Park, Shin-Seo;Cho, Young-Bong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.5
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    • pp.274-278
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    • 2016
  • A road energy harvester was designed and fabricated to convert mechanical energy from the vehicle load to electrical energy. The road energy harvester is composed of 20 piezoelectric materials. This study attempted to evaluate output depending on pavement materials when paving road piezoelectric energy harvester in the road. Harvester is the bender type and is the method of supporting the both ends of piezoelectric material and applying the load in the middle part. Harvester was paved in the type paved with asphalt, type paved with cement and in the exposed type not covering the top of harvester. The output characteristics were compared and evaluated depending on changes in vehicle load and vehicle speed changes. As vehicles, truck (11.9 ton), SUV(1.6 ton) and sedan (1.5 ton) were used and the output characteristics when driving at the interval of 10 km/h from 10 km/h to 100 km/h were evaluated.

A Study on Preference of Pavement Materials for Children's outing Playground in Apartment Complex - With Focus on Jeonju City - (아파트내 어린이 놀이터 포장재의 선호도에 관한 연구 - 전주시를 중심으로 -)

  • Jeong, Soo-Gyoung;Park, Yool-Jin
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.4
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    • pp.97-109
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    • 2012
  • In this study this writer carried out survey and analysis on paving materials of children's playground for 40 apartment buildings with each of such apartment containing 100 households or more and which were built within last 15 years in Jeonju. As a result of analysis of such questionnaires this author could draw following conclusion. In the second half of 1990s pavement materials which were used mainly were sand and during first half of 2000s they were mixture of sand and rubber block and around 2010 they were rubber block or rubber chip pavements. Such change seemed to be a result of consideration of convenience for management and safety rather than in deference to diversity of children's outing places. Survey on the current status of pavement materials revealed need for directives by the main entity for management and their firm resolve for its implementation. And there was need for their coping with problems such as pressure of treading or lack of it or poor condition of drainage in case of sand and phenomena of pitting or dipping down, discoloring and poor drainage in case of rubber chips and rubber blocks and loosening of gaps between rubber blocks etc. Result of analysing status of usage disclosed that 50.4% of the respondents to questionnaires stated that they had experience of accidents. With regard to cause of such accident it was found that 47.5% of accidents were attributable to play facilities and 19.5% were due to paving (floor) materials thus it was disclosed that not only play facilities but also pavement materials had impact on safety for the children. Result of analysing level of satisfaction with pavement materials showed that pavement by rubber chips and blocks had higher level of satisfaction which was reflection of fear on cleanness of sand. In terms of preference rubber chip and rubber block pavements were highest and the next one was sand. Reason for such preference was based on concern with safety.

Development and Evaluation of Rack Type Piezoelectric Harvester for Smart Street Lamps Control (가로등 제어용 다층패드형 압전 하베스터의 개발 및 평가)

  • Kim, Chang-Il;Jeong, Young-Hun;Park, Woon Ik;Cho, Jeong-Ho;Jang, Yong-Ho;Choi, Beom-Jin;Park, Shin-Seo;Paik, Jong-Hoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.11
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    • pp.696-701
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    • 2016
  • In this study, to increase output of road piezoelectric energy harvester, it was made into rack type in which many piezoelectric materials can be installed and load transfer device of the leverage type to transfer vehicle load was made. By paving it in the road, the output characteristics depending on vehicle load and speed were evaluated. Changing vehicle load, harvester output characteristics depending on speed changes were evaluated at the interval of 10 km/h from 10 km/h to 100 km/h. Also, by making a wireless switch and sending wireless signal with output of rack type harvester, whether to receive it was evaluated by distance. It was checked that all switches work up to front-to-back 100 m from harvester.

Strength Characteristics of the Soil Mixed with a Natural Stabilizer (친환경 토양안정재를 혼합한 지반의 강도특성)

  • Kwon, Youngcheul;Oh, Sewook
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.1
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    • pp.45-51
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    • 2012
  • This article aims to find method to mix a harmless hardening agent and soil generated during construction to make paving materials. The main purpose of this research is to get rid of the harmfulness(Chromium (VI), etc.) of cement which has been generally and frequently used as a hardening agent and strengthen it so that it can be used for the general foundation solidification and stabilization of civil engineering/construction structures such as dredging soil treatment, marine structure foundation treatment, surface soil stabilization, and river bank erosion prevention. NSS(Natural Stabilizer Soil) used for this study takes as its chief ingredient the mixture of lime and staple fibers extracted from natural fibers. It increases the shearing strength of soil that it improves the support and durability of the foundation and prevents flooding and frost as well. The pH measured to know its eco-friendliness was 6.67~7.15, and according to the migration testing, only Pb and CN were lower than the standards, so it can be said that NSS has almost no harmful components in it. According to the result of uniaxial strength testing, when the mixture ratio of weathered soil to NSS was 6%, about 1,850kpa strength was expressed. And according to the result of CBR. testing to figure out its appropriateness as a paving material, the CBR of the foundation was 4%~6%. But when the mixture ratio of NSS is over 6%, the water immersion CBR. is over 100%; thus, it is expected that it will show great utility as a paving material.