• Title/Summary/Keyword: Porous Asphalt

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Theoretical Study on Snow Melting Process on Porous Pavement System by using Heat and Mass Transfer (열전달 및 물질전달을 이용한 공극 발열도로에서의 융설 해석에 대한 이론적 연구)

  • Yun, Taeyoung
    • International Journal of Highway Engineering
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    • v.17 no.5
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    • pp.1-10
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    • 2015
  • PURPOSES : A finite difference model considering snow melting process on porous asphalt pavement was derived on the basis of heat transfer and mass transfer theories. The derived model can be applied to predict the region where black-ice develops, as well as to predict temperature profile of pavement systems where a de-icing system is installed. In addition, the model can be used to determined the minimum energy required to melt the ice formed on the pavement. METHODS : The snow on the porous asphalt pavement, whose porosity must be considered in thermal analysis, is divided into several layers such as dry snow layer, saturated snow layer, water+pavement surface, pavement surface, and sublayer. The mass balance and heat balance equations are derived to describe conductive, convective, radiative, and latent transfer of heat and mass in each layer. The finite differential method is used to implement the derived equations, boundary conditions, and the testing method to determine the thermal properties are suggested for each layer. RESULTS: The finite differential equations that describe the icing and deicing on pavements are derived, and we have presented them in our work. The framework to develop a temperature-forecasting model is successfully created. CONCLUSIONS : We conclude by successfully creating framework for the finite difference model based on the heat and mass transfer theories. To complete implementation, laboratory tests required to be performed.

Characterization of Porous Asphalt Concrete Coated with MMA Resin (아크릴 수지로 코팅한 배수성 아스팔트 콘크리트의 특성 평가)

  • Choi, Tae-Jun;Lee, Hyun-Jong;Kim, Tae-Woo;Song, Jae-Hyok
    • International Journal of Highway Engineering
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    • v.11 no.2
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    • pp.111-120
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    • 2009
  • This paper presents a fundamental findings of the functional and structural performance of the porous asphalt concrete coated with MMA resin. To evaluate the structural performance, cantabro, wheel tracking, moisture sensitivity and indirect tensile fatigue tests are performed. The tests results show that the cantabro loss is reduced three times and fatigue resistance is significantly increased after the specimens are coated with MMA resin. However there are little changes in the rutting and moisture damage resistances before and after the coating. Air voids, permeability and BPT(British Pendulum Test) tests are conducted to study the functional performance. It is observed form the tests that the air voids and permeability are slightly decreased after the coating. However, the changes in the air voids and permeability are negligible. The skid resistance of the coated specimens is lower than reference specimens. However, the skid resistance is maintained beyond the level of the reference specimens when silica sands are chipped on top of the coated surface.

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A Case Study on Noise Reduction Effect of Two-layer Porous Asphalt Pavement in an Urban Area (도심지 내 복층 저소음포장 설치에 따른 소음저감 사례연구)

  • Jung, Jong-Seo;Sohn, Jeong-Rak;Lee, Soo-Hyoung;Yang, Hong-Seok
    • International Journal of Highway Engineering
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    • v.18 no.5
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    • pp.49-56
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    • 2016
  • PURPOSES : In this study, noise reduction effect of a two-layer porous asphalt pavement was investigated through site measurement and computer simulation. METHODS : To examine noise reduction effect, a 3 km long quiet pavement was installed by removing previous normal pavement, which had a rather low porosity. The studied site was a high-rise apartment building surrounded by the quiet pavement and Seoul ring road with heavy traffic volume, indicating relatively high background noise. RESULTS : The measurement result before and after installing the quiet pavement showed a noise reduction effect of 4.3 dB(A) at a distance of 7.5 m from the road. After validating the accuracy of simulation using SoundPLAN, the reduction in SPL(sound pressure level) at the facades by the quiet pavement was predicted by considering five different road conditions generating traffic noise from each road or in the combination of the quiet pavement and Seoul ring road. In the case of no noise from Seoul ring road, noise reduction at the facades was 4.2 dB(A) on average for 702 housing units. With background noise from Seoul ring road, however, the average SPL decreased to 2.0 dB(A). Regarding subjective response of noise, the number of housing units with a noise reduction of over 3 dB(A) was 229 out of 706 units (approximately 32%). For 77 housing units, the noise reduction was between 1~3 dB(A), while it was less than 1 dB(A) for 400 housing units. CONCLUSIONS : The overall result indicates that the quiet pavement is useful to reduce noise evenly at low and high floors compared to noise barriers, especially in the urban situation where background noise is low.

A review on pavement porous concrete using recycled waste materials

  • Toghroli, Ali;Shariati, Mahdi;Sajedi, Fathollah;Ibrahim, Zainah;Koting, Suhana;Mohamad, Edy Tonnizam;Khorami, Majid
    • Smart Structures and Systems
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    • v.22 no.4
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    • pp.433-440
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    • 2018
  • Pavements porous concrete is a noble structure design in the urban management development generally enabling water to be permeated within its structure. It has also capable in the same time to cater dynamic loading. During the technology development, the quality and quantity of waste materials have led to a waste disposal crisis. Using recycled materials (secondary) instead of virgin ones (primary) have reduced landfill pressure and extraction demanding. This study has reviewed the waste materials (Recycled crushed glass (RCG), Steel slag, Steel fiber, Tires, Plastics, Recycled asphalt) used in the pavement porous concretes and report their respective mechanical, durability and permeability functions. Waste material usage in the partial cement replacement will cause the concrete production cost to be reduced; also, the concretes' mechanical features have slightly affected to eliminate the disposal waste materials defects and to use cement in Portland cement (PC) production. While the cement has been replaced by different industrial wastes, the compressive strength, flexural strength, split tensile strength and different PC permeability mixes have depended on the waste materials' type applied in PC production.

Evaluation of Surface Temperature Characteristics of Water Retaining Pavement using Sepiolite and Charcoal (해포석과 숯을 이용한 보수성포장의 노면온도 특성 평가)

  • Lee, Soo-Hyung;Lee, Hak-Ju;Kim, Je-Won;Yoo, In-Kyoon
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.357-360
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    • 2007
  • Water retaining pavement is a pavement to lower the surface temperature by using evaporation of the water that the pavement contains when the pavement is heated by the sun in the daytime. The objective of this study is to develop water retaining materials. In this study we evaluated the practical application of a sepiolite and a charcoal as a water retaining material. We produced dense grade asphalt pavement, porous asphalt pavement, semi-rigid Pavement, semi-rigid pavement included a charcoal and semi-rigid pavement included a sepiolite, and then tested surface temperature characteristics. The test result says that water retaining pavements using a sepiolite and a charcoal lower surface temperature more than $10^{\circ}C$ compared to dense grade asphalt pavement. We confirm the practical application of a sepiolite and a charcoal as a water retaining material according to the test results.

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Heat Transfer Characteristics of the Asphalt pavement by Solar Energy accumulation (열에너지 누적에 따른 아스팔트 포장의 열전달 특성 변화)

  • Lee, Kwan-Ho;Kim, Seong-Kyum;Oh, Seung-Sig
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.6
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    • pp.490-497
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    • 2020
  • Asphalt pavement accounts for more than 90% of the total pavement in Korea. Pavement is most widely constructed among construction structures. The heat transfer characteristics (Thermophysical Properties) of the asphalt pavement cause the heat island effect in downtown areas. An increasing asphalt surface temperature is one of the major causes of damage to asphalt pavement. This study examined the heat transfer characteristic factors according to solar energy accumulation in an asphalt mixture. The specimens (WC-2 & PA-13, Recycled aggregate used WC-2) used in the experiment were compacted with a Gyratory Compactor. The thermo-physical properties (thermal conductivity, specific heat capacity, thermal diffusivity, and thermal emissivity) and solar energy accumulation were evaluated. The thermal accumulation and HFM tests revealed a 1.2- to 2.0-fold difference. This indicates that the thermal conductivity of the asphalt mixture pavement changes with the accumulation of solar energy. An analysis of the correlation of thermal conductivity according to the surface temperature of the asphalt mixture showed that WC-2 was logarithmic, and PA-13 was linear. Experiments on the heat transfer characteristics of asphalt pavement that can be used for thermal failure modeling of asphalt were conducted.