• Title/Summary/Keyword: pavement materials

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A Design Principles and Characteristics of the Garden of Salt Merchant in Yangzhou, China's Ming and Qing Dynasties (중국 명·청 양주 염상원림의 설계원리 및 조영특성)

  • Shin, Hyun-Sil
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.37 no.3
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    • pp.83-92
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    • 2019
  • This study aims to examine at the garden characteristics of salt merchant in Yangzhou, China during the Ming and Qing Dynasties, I looked at the background of garden formation through the literature. In addition, analyzed the garden design method and components of salt merchants. The results were as follows; First, the Yangzhou area in the past has achieved cultural and economic development with the establishment of the ancient Grand Canal. Salt merchants accumulated wealth through trade, and created many gardens under the background of securing materials for create garden through trade, forming political forces through the cultivation of students, and inflow of foreign cultures. Second, salt merchants in Yangzhou asked garden experts to design and create the garden as a place for exchange and relaxation. Also, through the production of landscape changes using Gasan(假山) and a long corridor(長廊), clear classification of spaces using architectural elements, and the placement of buildings in scenic areas adjacent to the water, the gardens with practical and aesthetic functions were owned. Third, the gardens of Yangzhou Salt Merchants have a building-oriented commercial space on the front, and a garden-centered design characteristic on the back. The garden of the commercial zone was built in a simple form using pots, oddly shaped stone, bamboo and fence patterns in the remained space, focusing on the front of the building. The garden at the back formed a curved waterway connected to the canal is refracted across the garden. The garden also features piled stones(疊石), stone bridges and ship-shaped stone building(石舫). In addition, the design reflected the introduction of trees that take into account the climate and color contrast of Yangzhou province, pavement of various materials and patterns.

Engineering Character of Ultra Rapid Hardening Concrete-Polymer Composite using CAC and Gypsum Mixed CAC (CAC 및 석고혼입 CAC를 사용한 초속경 콘크리트-폴리머 복합체의 공학적 특성)

  • Koo, Ja Sul;Yoo, Seung Yeup;Kim, Jin Man
    • Journal of the Korea Institute of Building Construction
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    • v.16 no.2
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    • pp.97-105
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    • 2016
  • Recently, application case of the ultra rapid hardening concrete-polymer composite(URHCPC) are increasing to repair for the deterioration of pavement. But it is a major disadvantage that the main material is expensive and has environmental load. For these reasons, the development of the economic, eco-friendly materials is needed. Calcium Aluminate Composite (CAC), produced by rapid cooling of atomizing method with molten ladle furnace slag, is a material capable of improving the economic feasibility and reducing the environmental load of URHCPC. In this paper, the properties of CAC and gypsum mixed CAC (GC) as alternative materials of RSC according to the types of polymer dispersion were studied. The results were as follows; compressive strength, tensile strength, flexural strength, bonding strength and modulus of elasticity of the composites using CAC or GC showed higher values than those of plain proportion in 3 hour. In later age, they were at the same level as the general proportions. URHCPC using BPD as polymer dispersion had superior strength properties generally. But modulus of elasticity was the same level as the case of using a SBR latex. According to these results, CAC or GC can partially substituted for RSC to product the URHCPC. When URHCPC uses the BPD as the polymer dispersion, it can be improved performance.

The Mechanical Properties of SMA Concrete Mixture Using Steel Slag Aggregate (제철 슬래그 골재를 이용한 SMA 혼합물의 역학적 특성)

  • Kim, Hyeok-Jung;Na, Il-Ho
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.9 no.1
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    • pp.109-116
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    • 2021
  • In order to replace mineral aggregate used as road pavement materials with steel slag aggregate, this present study evaluated mechanical properties of SMA Concrete mixtures using steel slag aggregate as oxidized slag from electric furnace in iron works. The variables of this experiment are the aggregate type of mineral and steel slag and the sieve sized of 10mm and 13mm. The physical properties inclu ding the specific gravity and absorption rate etc. of the slag aggregate mixtu res satisfied the KS standard as asphalt mixtu re. As a resu lt of evalu ating the mechanical properties of the asphalt mixtures, the optimum asphalt content of the slag aggregate mixtures were lower than that of the mineral aggregate mixtures, but other quality standards were all satisfied. In the deformation strength evaluation, the slag aggregate mixtures were measu red slightly higher than that of the mineral aggregate mixtu res, and the dynamic stability test satisfied the 2,000pass/mm standard value in all specimens. And, the moduli of resilient of the slag aggregate mixtures showed an improved value compared with the mineral aggregate mixtures. Therefore, as the resilient rate of the slag aggregate mixtures improved, it is speculated that there will be an effect of improving public performance according to the repeated traffic load of the vehicle.

LIM Implementation Method for Planning Biotope Area Ratio in Apartment Complex - Focused on Terrain and Pavement Modeling - (공동주택단지의 생태면적률 계획을 위한 LIM 활용방법 - 지형 및 포장재 모델링을 중심으로 -)

  • Kim, Bok-Young;Son, Yong-Hoon;Lee, Soon-Ji
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.3
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    • pp.14-26
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    • 2018
  • The Biotope Area Ratio (BAR) is a quantitative pre-planning index for sustainable development and an integrated indicator for the balanced development of buildings and outdoor spaces. However, it has been pointed out that there are problems in operations management: errors in area calculation, insufficiency in the underground soil condition and depth, reduction in biotope area after construction, and functional failure as a pre-planning index. To address these problems, this study proposes implementing LIM. Since the weights of the BAR are mainly decided by the underground soil condition and depth with land cover types, the study focused on the terrain and pavements. The model should conform to BIM guidelines and standards provided by government agencies and professional organizations. Thus, the scope and Level Of Detail (LOD) of the model were defined, and the method to build a model with BIM software was developed. An apartment complex on sloping ground was selected as a case study, a 3D terrain modeled, paving libraries created with property information on the BAR, and a LIM model completed for the site. Then the BAR was calculated and construction documents were created with the BAR table and pavement details. As results of the study, it was found that the application of the criteria on the BAR and calculation became accurate, and the efficiency of design tasks was improved by LIM. It also enabled the performance of evidence-based design on the terrain and underground structures. To adopt LIM, it is necessary to create and distribute LIM library manuals or templates, and build library content that comply with KBIMS standards. The government policy must also have practitioners submit BIM models in the certification system. Since it is expected that the criteria on planting types in the BAR will be expanded, further research is needed to build and utilize the information model for planting materials.

Analysing the effect of impervious cover management techniques on the reduction of runoff and pollutant loads (불투수면 저감기법의 유출량 및 오염부하량 저감 효과 분석)

  • Park, Hyung Seok;Choi, Hwan Gyu;Chung, Se Woong
    • Journal of Environmental Impact Assessment
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    • v.24 no.1
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    • pp.16-34
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    • 2015
  • Impervious covers(IC) are artificial structures, such as driveways, sidewalks, building's roofs, and parking lots, through which water cannot infiltrate into the soil. IC is an environmental concern because the pavement materials seal the soil surface, decreasing rainwater infiltration and natural groundwater recharge, and consequently disturb the hydrological cycle in a watershed. Increase of IC in a watershed can cause more frequent flooding, higher flood peaks, groundwater drawdown, dry river, and decline of water quality and ecosystem health. There has been an increased public interest in the institutional adoption of LID(Low Impact Development) and GI(Green Infrastructure) techniques to address the adverse impact of IC. The objectives of this study were to construct the modeling site for a samll urban watershed with the Storm Water Management Model(SWMM), and to evaluate the effect of various LID techniques on the control of rainfall runoff processes and non-point pollutant load. The model was calibrated and validated using the field data collected during two flood events on July 17 and August 11, 2009, respectively, and applied to a complex area, where is consist of apartments, school, roads, park, etc. The LID techniques applied to the impervious area were decentralized rainwater management measures such as pervious cover and green roof. The results showed that the increase of perviousness land cover through LID applications decreases the runoff volume and pollutants loading during flood events. In particular, applications of pervious pavement for parking lots and sidewalk, green roof, and their combinations reduced the total volume of runoff by 15~61 % and non-point pollutant loads by TSS 22~72 %, BOD 23~71 %, COD 22~71 %, TN 15~79 %, TP 9~64 % in the study site.

Sensitivity of NOx Removal on Recycled TiO2 in Cement Mortar (재생 이산화티탄을 혼입한 모르타르의 NOx 저감률 민감도 분석)

  • Rhee, Inkyu;Kim, Jin-Hee;Kim, Jong-Ho;Roh, Young-Sook
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.4
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    • pp.388-395
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    • 2016
  • This paper explores the photocatalytic sensitivity of cement mortar incorporated with recycled $TiO_2$ from waste water sludge. Basically, $TiO_2$ cluster sank down slowly to the bottom of cement mortar specimen before setting and hardening process. This leads the mismatch of $TiO_2$ concentration on the top and the bottom faces of a specimen. This poorly dispersed $TiO_2$-cement mortar naturally exhibits poor NOx removal efficiency especially on the top of cementitious structure. In architectural engineering application such as building or housing structures, one can simply filp over from the bottom so that more $TiO_2$ concentrated surface can be placed outward into the air. However, in highway pavement case, this could not be applicable due to in-situ installation of concrete pavement. Hence, the dispersion of $TiO_2$ cluster inside the cementitous material is getting important issue onto road construction application. To elaborate this issue, according to our results, silica fume, high-ranged water reducer, viscosity agent, blast furnace slag were not enhanced much of dispersion characteristics of $TiO_2$ cluster. The combination of foaming agent and accelerator of hardening with viscosity agent and small grain size of fine aggregate may help the dispersion of $TiO_2$ inside cementitious materials. Even though the enhanced dispersion were applied to the specimen, NOx removal efficiency doest not change much for the top surface of the specimen. This concurrently affected by the presence of tiny air voids and the dispersion of $TiO_2$ in that these voids could easily adsorbed NOx gas with the aid of large surface area.

Statistical Evaluation of Moisture Resistance by Mixing Method of Recycled Asphalt Mixtures (혼합방법에 따른 순환아스팔트 혼합물의 수분저항성 통계검정 평가)

  • Kim, Sungun;Kim, Yeongsam;Jo, Youngjin;Kim, Kwangwoo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.9 no.2
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    • pp.167-176
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    • 2021
  • When producing recycled asphalt mix, it is important that the old binder of reclaimed asphalt pavement(RAP) should be well melted during blending in the mixer. The recycled asphalt mix is produced by instant mixing(IM) of all materials(RAP, virgin asphalt and new aggregates) all together in the mixer. However, in the same recycled mix, the binder around RAP aggregate was found to show higher oxidation level than the binder coated around the virgin aggregate because the old binder of RAP was not rejuvenated properly while instant mixing. The partially-rejuvenated RAP binder is assumed to be a high stiffness point in IM recycled mix. In this study, the stage mixing(SM) method was introduced; blending RAP and virgin asphalt for the first stage, and then mixing all together with hot new aggregates for the second stage. To compare the effect of the two mixing methods on moisture resistance of recycled mixes, a statistical t-test was performed between SM and IM using indirect tensile strength(ITS) and tensile strength ratio(TSR). Three conditioning methods were used; a 16-h freezing and then 24-h submerging, 48-h submerging, and 72-h submerging in 60℃ water. It was found that the TSR(=ITSwet/ITSdry) values of the mixes prepared by SM was clearly higher than the IM mixes, and coefficients of variation of SM mixes were lower than the IM mixes. It was also observed that the ITSWET of SM was significantly different from the IM at α=0.05 level by statistical t-test. The ITSWET of SM mix was reduced less than the IM mix in severer conditioned mixes. Therefore, it was concluded that the stage mixing method was an important blending technique for producing better-quality of recycled asphalt mixes, which would show higher moisture resistance than the recycled mixes produced by conventional instant mixing.

Characteristics of Plastic Concept of Minimalism in Comtemporary Landscape Design (현대조경설계에서 미니멀리즘의 조형개념 특성)

  • Ahn, Seung-Hong
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.5
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    • pp.64-77
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    • 2009
  • In landscape architecture, the pursuit of pluralism requires diverse expression based on cultural and philosophical differences. Landscape architects impart social purposes and spatial relationships to the contemporary generation by providing particular environments that reflect the culture of the day. Particularly, landscape architects reflect contemporary art in their design works and express the characteristics of the arts of the day in real spaces. Historically they have sought motives from all fields of art. The plastic concept in landscape design is based specifically on paintings that directly influence spatial composition. Minimalism in landscape architecture contributes to the formation of artistic characteristics that can be explained to improve artistry in landscapes as aesthetic objects, which were eliminated in the modernist era, and to realize contemporary art. By interpretively studying design works, therefore, this study reveals plastic concepts' influence on landscape design affected by minimalist art. The characteristics of plastic concepts in minimalist landscape design can be summarized as follows. First, the reduction of Minimalist Landscape is meant for viewers to immediately understand a work's identity and to easily perceive its intention by using design language implied by the pure geometric forms such as circles, triangles and squares. Second, the extension intends to seek internal order by connecting design elements mutually and externally to provide visual direction by adopting linear expression. Third, the flatness that defines meaningless space tends to overlay additional elements on a flattened site to induce the perception of a sequence of landscapes and to patternize pavement to improve its visual image. Finally, seriality has two characteristics: to make centrality in space and to compose by repeating formative elements and materials based on the pursuit of a site's totality, rather than an individual space's originality.

Development of Surface Pavement Materials for Environment-Friendly Farm Road (환경친화형 경작로를 위한 표층포장재료의 개발)

  • Sung, Chan-Yong;Kim, Young-Ik
    • Korean Journal of Agricultural Science
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    • v.31 no.2
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    • pp.105-114
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    • 2004
  • This study was performed to examine the physical and mechanical properties of eco-concrete using soil, natural coarse aggregate, soil compound and polypropylen fiber. The mass loss ratio was decreased with increasing the content of coarse aggregate and soil compound. The compressive strength, flexural strength, ultrasonic pulse velocity and dynamic modulus of elasticity were increased with increasing the content of coarse aggregate, soil compound and polypropylene fiber. The compressive and flexural strengths were showed in 8.07 MPa and 2.641 MPa at the curing age 28 days, respectively. The coefficient of permeability was decreased with increasing the content of coarse aggregate and soil compound, but it was increased with increasing the content of polypropylene fiber. The lowest coefficent of permeability was showed in $5.066{\times}10^{-9}cm/s$.

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Estimation of Bond Performance Improvement by Surface Treatment Equipments and Polymer Content by Boned Concrete Overlays (접착식 콘크리트 덧씌우기 경계면 처리 방식 및 폴리머 혼입률에 따른 부착성능 평가)

  • Jung, Won Kyong;Kim, Hyun Seok;Kwon, Oh Seon;Kim, Hyung Bae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.1
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    • pp.39-47
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    • 2016
  • Repair methods of aging concrete pavement are generally used composite structure pavements, such a composite structure is subjected to a large impact on the mechanical behavior and ensure long-term commonality integrated under vehicle loads, environmental loads of the public in accordance with the bond strength between old and new concrete. A common of bonded concrete overlays that are currently available is Interface arrangements using a variety of equipment to ensure the excellent bond strength between old and new concrete than standard concrete, mixed with a material such as a polymer in order to improve the adhesion with the material itself. However, these method of constructions are being applied, depending on the developer site presents no special specifications apply when a specific application criteria objectively, this is due to the situation of each individual method, which is based on the difficulty in quality control of the site manager. In this study by performing a field test for polymer content via the variables that contribute most significantly to ensure bond strength and the field element core of the interface processing method and materials to ensure bond strength between the old and the new concrete, it was to derive the construction site construction method that can improve the performance of the bond strength through a review of the construction around the correlations and the bond strength according to the effective performance analysis of the conventional surface treatment process and variation of polymer volume fraction.