• Title/Summary/Keyword: Asphalt Concrete Pavement

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A Study on Freezing Characteristics of Pavements Using Data of Test Road (시험도로 자료를 이용한 포장의 동결특성 연구)

  • Jeong, Jin-Hoon;Bae, Sung-Ho;Kwon, Soon-Min
    • International Journal of Highway Engineering
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    • v.7 no.2 s.24
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    • pp.87-95
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    • 2005
  • To prevent the lowering of structural capability due to freezing and thawing in cold winter, numerous researches on frost heaving have been performed. As the result, the freezing index contour map of the Korea peninsula has been made for the design of the anti-freezing layer of pavements. However, the validity of the anti-freezing layer needs to be evaluated because systematic investigations on the variation of freezing depth with the thickness and material types of pavement layers and the configuration of the ground have been rarely performed. The freezing index of the Korea Highway Corporation test road site was calculated and the freezing depths of the concrete and asphalt pavements of the test road were investigated using the ambient and pavement temperature and water content. In addition, the investigated freezing depths were compared to the values estimated by existing freezing depth models. This is the preliminary study on the freezing-related data measured at the test road. The results with higher reliability will be produced by the long-term accumulation of the data and the analysis on it.

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A Study on the Determination of Density and Moisture Content of Asphalt Concrete Pavement and Subgrade Using Nuclear Density Meter (방사선측정치를 이용한 아스콘 포장 및 노상의 현장밀도와 함수비 측정에 관한 연구)

  • 진성기;도덕현
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.36 no.4
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    • pp.103-116
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    • 1994
  • The objective of this study was to determine the criteria for density and moisture content measurements made with a nuclear density meter on common materials in the construction field. The study also sought to test a full-type nuclear density meter in controlling the density of overlay layers( 2.5~5.0cm). In order to determine the accuracy and reliablility of nuclear guage measurements made on construction materials, laboratory and field tests were conducted. Wooden blocks( 65 x 45 ${\times}$ 50 cm) and a special steel compactor( 4.7kg) were constructed in order to carry out tests which were conducted on three different materials; coarse gramed soil, fine grained soil, and AC material. Throughout all laboratory and field tests, the nuclear density and moisture content were determined using Humboldt 5OOLP nuclear gauge. The tests on subgrade material entailed obtaining density measurements by means of both the sand replacement method and the nuclear density meter. The results of the sand replacement method were then compared to the readings recorded bu the meter. As in the subgrade material tests, density measurements made during AC pavement tests were also determined using the unclear meter in addition to a second means; through the core method. The meter readings and core densties were compared as was done in the tests on subgrade materials. The correlation between the results of the sand replacement test( also, the core method) and meter readings on subgrade material was then determined. Sirnilarly, the observed results were then analyzed through linear regression. The tests to determine thin-lift density by means of a full-type nuclear density meter also conducted on the overlay layers( about 4. 8cm thickness) above AC pavements at road construction sities in Korea.

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Surface Information Acquisition for Asphalt Concrete Pavement Using Digital Video Camera (디지털 비디오카메라를 이용한 아스팔트 콘크리트 포장 노면 정보획득)

  • Seo, Jeong-Hoon;Seo, Dong-Ju;Lee, Jong-Chool;Lee, Sung-Rock
    • Journal of Korean Society for Geospatial Information Science
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    • v.12 no.3 s.30
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    • pp.51-59
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    • 2004
  • In the study, there has been a sharp upward trend in road maintenance cost as the expansion of road networks increases. Running a pavement management system(PMS) is indispensable for efficient and scientific maintenance of the whole road networks with limited maintenance budgets. With a PMS, a maintenance plan should be drawn up after surface conditions are precisely examined and analyzed. The majority of the present PMSs are run by the fact that experts first examine surface conditions on sites, and then enter results into systems. However, considering the actual circumstances of the present time and the increase in paved road hereafter, it is inefficient that experts examine the whole paved roads in person and long-lasting PMSs can not be kept up. As a result, after analyzing the accuracy of 3-D coordinates representing road surfaces that was decided using multi orientation and digital photogrammetry, the average of standard errors turned out to be 0.0427m on the X-axis, 0.0527m on the Y-axis and 0.1539m on the Z-axis. It was found to be good enough to be put to practical use for maps drawn on scales below 1 :1000, which are being currently made and used within the country, and GIS data.

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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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Effects of Reinforced Pseudo-Plastic Backfill on the Behavior of Ground around Cavity Developed due to Sewer Leakage (하수관 누수에 의해 발생되는 공동 주변 지반의 거동에 대한 가소성유동화토의 보강효과)

  • Oh, Dongwook;Kong, Sukmin;Lee, Daeyoung;Yoo, Yongseon;Lee, Yongjoo
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.12
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    • pp.13-22
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    • 2015
  • Developed ground cavity due to leakage of decrepit old sewer pipe causes ground surface settlement and brittle fracture of pavement. Recently, for 5 years, frequency of occurrence of ground subsidence phenomenon tends to increase rapidly and/or steadily. It is difficult to investigate ground surface settlement and/or subsidence in urban area because most ground surfaces are covered with asphalt or concrete pavement. In this research, therefore, ground surface settlement, influence zone and settlement of sewer pipe were analyzed using finite element method. Not only reinforced effect of pseudo-plastic backfill that is applied to prevent ground surface settlement or subsidence spot, was compared and analyzed using numerical analysis program, but also direct shear test was carried out to determine strength parameters of pseudo-plastic backfill.

Mechanistic-Empirical Guideline for Routine Overweight Truck Traffic Routes (과하중 트럭 운행 도로에 대한 역학적-경험적 지침)

  • Oh, Jeongho
    • Journal of the Society of Disaster Information
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    • v.9 no.1
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    • pp.1-10
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    • 2013
  • The main objective of this research is to develop the Mechanistic-Empirical (M-E) guidelines for evaluating the capacity of existing highways to sustain route overweight truck traffic over a specified performance period due to a growing concern on the impact of increasing overweight truck loads on highways. In this study, a two-stage framework was developed for this purpose. Level I procedure involves the use of pavement evaluation charts to identify the best possible route from among the alternatives considered and to determine what additional tests and analyses are needed as a screening tool. Level II involves the application of the Overweight Truck Route Analysis (OTRA) program to evaluate the structural adequacy of an existing route to carry routine overweight truck traffic over the specified performance period along with estimating asphalt concrete overlay thickness, if necessary.

Behavior of High-elastic Stress Absorbing Interlayer for Reflective Cracking Resistance (고탄성 응력흡수층의 반사균열 저항특성 연구)

  • Park, Tae Soon;Lee, Yo Seop
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3D
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    • pp.445-451
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    • 2006
  • This study was conducted to develop the interlayer mixture that absorbs the stress between the old concrete pavement and the asphalt overlay pavement layer. The elasticity, the flexibility, the consistency and the impermeability is required for high-elastic Stress Absorbing Interlayer(HSAI) to absorb and disperse the stress that causes the flexural and horizontal movements of the joint and the crack. The HSAI developed from foreign product was satisfied with the design criteria. The specimens using the HSAI showed the significant reduction of the reflective crack compared those not using the HSAI. The significance included that the life of shear failure and horizontal displacement resistance increased 4 times. The life of the share failure increased to 5 times and the horizontal displacement increased to 9 times according to the selection of surface course material which showed the excellence of the HSAI.

The Prediction of Remaining Life of Concrete Bridge Decks Using The Reliability Analysis (신뢰도 분석을 통한 고속도로 교량의 바닥판 잔존 수명 예측)

  • Park, Jung-Hee;Lee, Sang-Soon;Kim, Ji-Won;Park, Cheol-Woo;Lee, Dong-Hyun
    • International Journal of Highway Engineering
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    • v.13 no.4
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    • pp.71-79
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    • 2011
  • Korean national highway has been increased 2 times more for the past ten years because of many highway geometric improvements and new routes since 2000. According to the reasons, maintenance cost has been increased continuously. Deterioration of concrete bridge decks caused by asphalt pavement deformation occupies a high proportion of overall bridge management budget. The number of current highway bridges has reached over 7,800 in 2011, and It is difficult to determine to some future budget. This study predicted the remaining life of concrete bridge decks using the reliability analysis based on Weibull distribution. and The expected future maintenance cost was estimated.

Litholohical and Mechanical Characteristics of Crushed Limestone Aggregates (쇄석 골재용 석회암의 암석학적 및 역학적 특성)

  • 진호일;민경원;백환조;연규석
    • Magazine of the Korea Concrete Institute
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    • v.9 no.3
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    • pp.119-126
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    • 1997
  • Recently, duc to highly increased consumption of' ngg~.egatc>s f o ~ . construction. studies have focused on the effective utilization of rock wastes abandoned so far. This study was designed, firstly, to determine t,hc petrological, g'ochemical and mechanical cha~,acte~istics of' crushed limestone aggregates in thc Samhwa district for suitable construction aggregates and, secondly, to offer basic data for cff'ective utilization of low grade limestones. Results of' the petrographic st,udy indicates that the crushed limestone aggregates in the Samhwa district can bo separate4 into two groups, namely f'inc-grained and cowlxcgrained limestones. Dominantly distributed fine-grained limestone containing some dolomite has higher Mgo and $SiO_2$ contents compared to the coarse-graincd limestonr. It, can be classified as medium strength rock by the physical and mcxhanical pi.opertics. I3ased on the size of' mineral grains and chemical compositions, it is suggested that the crushed limestone aggregates in t,his study area would bctkr be u s ~ i for asphalt concr.ctt., road pavement, or railroad ballast materials than for cement concrete.

Correction Coeffecient for Tensile Adhesive Strength of the Bridge Decks Waterproofing Systems with Different Temperature Conditions (온도조건에 따른 교면방수재의 인장접착강도 보정계수에 관한 실험적 연구)

  • Lee, Byung-Duck;Yun, Byung-Sung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.794-797
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    • 2004
  • In this study, tensile adhesive strength(TAS) test was carreid out for evaluated the effects of temperature conditions (-20, -10, 0, 5, 10, 20, 30, $40^{\circ}C$) on the tensile adhesive characteristics about 4 type waterproofing membranes which were commercially used in bridge decks. And, failure appeariences of waterproofing systems in each temperature after TAS test were observed the sawing surfaces of waterproofing systems for whether or not damaged of waterproofing membranes. Also, correction coefficient of TAS with temperature were calculated using 4 type waterproofing membrane. It could be shown that the higher TAS and shear adhesive strength, the lower temperature, regardless of the type of waterproofing membrane. Temperature sensibility of TAS was especially remarkable in epoxy membrane. Failure type was occurred the ductile failure in $30^{\circ}C\;and\;40^{\circ}C$. From these results, it was shown that if ambient temperature above $30^{\circ}C$ maintains for a long time, waterproofing membrane will be deformed by softening. Otherwise, waterproofing membrane in temperature below $20^{\circ}C$ shown that occurred the brittle failure. From the results of visual observation of cutting surface for specimen, the thin waterproofing membranes shown indented by hot aggregate of the asphalt mixtures. Therefore, it could be known that the specification of waterproofing membrane thickness is necessary by waterproofing membrane type. As temperature change varied with pavement depth, the interface temperature was more important than ambient temperature in TAS test. Now, TAS test results were limited only in $-10^{\circ}C\;and\;20^{\circ}C$ temperature, but correction coefficient of TAS by ambient temperature could be used as a solution to deal with this problem.

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