• Title/Summary/Keyword: Asphalt concrete pavement

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Evaluation of Surface Temperature Variation and Heat Exchange Rate of Concrete Road Pavement with Buried Circulating Water Piping (열매체 순환수 배관이 매설된 콘크리트 도로 포장체의 표면 온도 변화와 방열량 평가)

  • Byonghu Sohn;Yongki Kim
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.19 no.3
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    • pp.1-13
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    • 2023
  • Hydronic heated road pavement (HHP) systems have been well established and documented to provide road safety in winter season over the past two decades. However, most of the systems run on asphalt, only a few are tested with concrete, and there rarely is a comparison between those two common road materials in their performance. The aim of this study is to investigate the thermal performance of the concrete HHP systems, including surface temperature variations of experimental pavements in winter season. For preliminary study a small-scale experimental system was installed to evaluate the heat transfer characteristics of the concrete HHP in the test field. The system consists of 3 concrete slabs made of 1 m in width, 1 m in length, and 0.25 m in height. In these slabs, circulating water piping was embedded with different pipe depths of 0.08 m (Case A), 0.12 m (Case B), and 0.20 m (Case C) and same horizontal space of 0.16 m. Heating performance in winter season was tested with different inlet temperatures of 25℃, 30℃, 35℃ and 40℃ during the entire measurement period. Overall, the surface temperature of the concrete HHPs remained above 3℃ in all experimental conditions applied in this study. The results of the surface temperature measurement with respect to the pipe depth showed that Case B was the highest among the three cases. However, the closer the circulating water pipe was to the pavement surface, the greater the heat exchange rate. This results is considered that the heat is continuously accumulated inside the pavements and then the temperature inside the pavements increases, while the amount of heat dissipation decreases as the temperature difference between the inlet and outlet of circulating water decreases. In this preliminary test the applicability of the concrete HHP on road deicing was confirmed. Finally, the results can be used as a basis for studying the effects of various variables on road pavements through numerical analysis and for conducting large-scale empirical experiments.

Evelopment of a Practical Mechanistic-Empirical design Procedure for Flexible Pavements (역학적이론과 경험에 근거한 실용적 연성포장 설계법 개발)

  • Park, Dong-Yeob;Kim, Hyung-Bae;Buch, Neeraj;Suh, Young-Chan
    • International Journal of Highway Engineering
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    • v.4 no.3 s.13
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    • pp.1-13
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    • 2002
  • Design methods for new flexible pavements and overlays are in the transition from empirical to mechanistic approach, and many state highway agencies trend to move toward the adoption and use of mechanistic-empirical (M-E) design in new constructions and rehabilitations of flexible pavements. Hence, the Michigan Department of Transportation (MDOT) decided to develop a M-E flexible pavement design procedure, in which major pavement distresses such as fatigue cracking and rutting are employed as indicators of the serviceability of a flexible pavement. The main concept of the developed design procedure is that a designed pavement that is supposed to carry a certain number of traffic must satisfy designated thresholds of rut depths and fatigue lives during a service period. For the M-E design procedure, transfer functions were developed to predict rut-depths and fatigue lives. These functions related the pavement responses to pavement performance. For validation, three current new flexible pavement design cases were obtained from the MDOT. In these cases, asphalt concrete (AC) layer thicknesses determined by the suggested M-E procedure compare favorably with those determined by the current MDOT design practice that is based on AASHTO design guide. This finding implies that the suggested Michigan M-E flexible pavement design procedure can provide a good opportunity to improve the current design practice.

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Real-time Road Surface Recognition and Black Ice Prevention System for Asphalt Concrete Pavements using Image Analysis (실시간 영상이미지 분석을 통한 아스팔트 콘크리트 포장의 노면 상태 인식 및 블랙아이스 예방시스템)

  • Hoe-Pyeong Jeong;Homin Song;Young-Cheol Choi
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.1
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    • pp.82-89
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    • 2024
  • Black ice is very difficult to recognize and reduces the friction of the road surface, causing automobile accidents. Since black ice is difficult to detect, there is a need for a system that identifies black ice in real time and warns the driver. Various studies have been conducted to prevent black ice on road surfaces, but there is a lack of research on systems that identify black ice in real time and warn drivers. In this paper, an real-time image-based analysis system was developed to identify the condition of asphalt road surface, which is widely used in Korea. For this purpose, a dataset was built for each asphalt road surface image, and then the road surface condition was identified as dry, wet, black ice, and snow using deep learning. In addition, temperature and humidity data measured on the actual road surface were used to finalize the road surface condition. When the road surface was determined to be black ice, the salt spray equipment installed on the road was automatically activated. The surface condition recognition system for the asphalt concrete pavement and black ice automatic prevention system developed in this study are expected to ensure safe driving and reduce the incidence of traffic accidents.

The Extacting Crack in Asphalt Concrete Pavement by Digital Image Processing (수치영상처리에 의한 아스팔트 포장노면의 균열 검출)

  • Jang, Ji-Won
    • Journal of Korean Society for Geospatial Information Science
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    • v.10 no.4 s.22
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    • pp.77-84
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    • 2002
  • Recently, damage of pavement represented by crack is depened by the increase of traffic demand up to ten million and wight, and interest about the efficient management of pavement is being increased gradually according to the growth of maintenance expense of road surface. In this study, the possibility of application for acquisition of crack information was tested by appling DCRP and digital image processing technique and measuring crack on road surface precisely. Based on this, objective and efficient road surface measurement was planned and done. Measuring crack width, acquire result of comparative high accuracy. So, it is considered that it can be utilized as plan draft data for deterioration estimation and repair reinforcement work of pavement.

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A Study on the Measurement of Texture Depth of Pavement Using Portable Laser Profiler (Portable Laser Profiler를 이용한 도로 포장의 노면조직 깊이 측정 방법 연구)

  • Hong, Seong Jae;Hyun, Tak Jib;Kim, Hyung Bae;Kwon, Oh Sun;Lee, Seung Woo
    • International Journal of Highway Engineering
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    • v.14 no.6
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    • pp.45-55
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    • 2012
  • PURPOSES : Skid resistance and noise of roads highly depend on the characteristics of pavement texture. Therefore, estimation of texture characteristics may give useful information for the skid resistance and noise of road. Generally, Sand Patch Test is performed in order to estimate MTD(Mean Texture Depth). However, it is time-consuming and needs traffic control. This study aimed to investigate the effectiveness of measurement texture depth using the Portable Laser Profiler that give the MPD(Mean Profile Depth). METHODS : MTD and MPD were collected on the number of expressway sections including Central Inland Test Road sections in Korea. Statistical analysis are performed to establish the relationship between MTD data based on Sand Patch Test and MPD data obtained by the Portable Laser Profiler. RESULTS : Linear relationship MPD and MTD is observed for both of asphalt pavement and concrete pavement such as R-square of 0.51 to 0.58. CONCLUSIONS : Even though, the test method and definition of MPD and MTD are different. EMTD(Estimated Mean Texture Depth) can be obtained by using the correlationship between MPD with MTD.

Overlap Tensile Strength testing of Waterproofing Sheet used in Concrete Bridges (콘크리트 교면에 적용되는 시트방수재의 접합 인장강도 확인)

  • An, Ki-Won;Kang, Hyo-Jin;Seon, Yun Suk;Kim, Chun-Hag;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.335-336
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    • 2018
  • This study discusses the development of asphalt based waterproofing sheet applied on the blind side of the concrete substrate. The inorganic coating membrane is applied on top of the waterproofing sheet surface for protection, and adhesive bond to the concrete substrate surface is secured via hydration reaction the cement. The study reveals the experimental results of the overlap section tensile strength to observe the effects of the adhesion strength of this material.

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Investigation of Friction Characteristics between Concrete Slab and Subbase Layers (콘크리트 슬래브와 보조기층 사이의 마찰특성 조사)

  • lim, Jin Sun;Park, Moon Gil;Nam, Young Kug;Jeong, Jin Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.6D
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    • pp.719-726
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    • 2009
  • In this study, a series of push-off tests for lean concrete, aggregate, asphalt subbases mainly used in Korea were performed to investigate the friction characteristics between the slab and subbase layers. Use of separation membrane and wet condition of subbase were other parameters in the tests. Horizontal displacements of the slabs and friction coefficients were measured at 1st loading, stable condition (2nd and 3rd loadings), and wet condition (4th loading) by applying 40mm/hour horizontal loadings. Larger maximum friction coefficients were measured in order of the lean concrete, asphalt, aggregate, and subbases using the separation membrane at 1st loading, and in order of the asphalt, aggregate, lean concrete, and subbases using the separation membrane at stable and wet conditions. The friction coefficients of the aggregate and asphalt subbases which did not used the separation membrane decreased by the wet condition while the subbases using the separation membrane were not affected. Additional push-off tests for effects of slab thickness and temperature sensitivity of asphalt will be performed. And, effects of the friction characteristics between the slab and subbase layers on behavior and performance of concrete pavements will be investigated by structural analyses using the test results.

Analysis of Characteristics in Low-shrinkage Cement Treated Base (저수축 시멘트 안정처리 기층의 특성분석)

  • Lee, Seung-Woo;Jeon, Beom-Jun;Kim, Jong-Won
    • International Journal of Highway Engineering
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    • v.6 no.2 s.20
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    • pp.61-70
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    • 2004
  • Cement treated Soil has superior characteristics as pavement-base including strength, curability, hardness, freezing resistance. However drying shrinkage of Cement treated base has been indicated as disadvantage, since reflection crack of surface layer is induced from drying shrinkage of cement treated base. This study propriety about low-shrinkage cement treated base that can control shrinkage of cement and control reflection crack at asphalt overlay & concrete slab.

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Properties of Concrete Precast Pavers using Non-Cement Binders (무시멘트 결합재를 사용한 콘크리트 보도블록의 특성)

  • Lee, Won-Gyu;Jo, Eun-Seok;Lee, Sang-Soo;Song, Ha-Young
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.11a
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    • pp.35-36
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    • 2018
  • Korea has many problems due to the asphalt pavement or impermeable pavement. Many methods are being implemented to improve water circulation. Among them, permeable packaging materials are used. However, existing permeable packaging materials have a problem of causing efflorescence and clogging the pores. The pores of the permeable packing material are clogged and the permeability is lost. This leads to economic problems and product problems. The purpose of this study was to develop a block to prevent efflorescence.

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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.