• Research Article

    Analysis on Factors Affecting the Moisture Sensitivity Characteristics of Asphalt Mixtures

    아스팔트 혼합물의 수분 민감 특성에 영향을 미치는 인자 분석

    Kyung-Ha Lee

    이경하

    In this study, Influencing factors were investigated by analyzing the moisture sensitivity characteristics of asphalt mixtures. According to the test results, TSR ... + READ MORE
    In this study, Influencing factors were investigated by analyzing the moisture sensitivity characteristics of asphalt mixtures. According to the test results, TSR was judged to be a more reliable test method than residual stability. Limestone aggregates were more resistant to water infiltration than granite. The comparison analysis of the mixture showed that SMA had better moisture sensitivity than dense gade mixtures. A comparative analysis of additives showed that anti-stripping agent was the most resistant to moisture, and hydrated lime was more resistant to moisture than cement. - COLLAPSE
    December 2018
  • Research Article

    Improvement of Local Road Asphalt Pavement Condition Index Considering Crossroads and Traffic Volume Levels

    교통량등급과 교차로구간을 고려한 아스팔트포장 지역도로 공용성지수의 개선방안 연구

    인덕대학교 토목환경공학과

    최준성 · 서주원

    Generally, in case of high traffic volume roads or crossroads, the probability of traffic accidents increases and the frequency of user complaints ... + READ MORE
    Generally, in case of high traffic volume roads or crossroads, the probability of traffic accidents increases and the frequency of user complaints increases. Therefore, it is necessary to raise the maintenance priority of asphalt pavement. On the other hand, Maintenance intervals need to be lowered in areas with very low traffic volumes. In this study, it is proposed that asphalt pavement performance evaluation method would provide reasonable management plans for each section of the local road asphalt pavement with consider crossroads and traffic volume level in addition to existing LrPCI(Local road Pavement Condition Index). This method can consider regional road grades, traffic volume levels and crossroads characteristics of each section. - COLLAPSE
    December 2018
  • Research Article

    Laboratory Evaluation of Modified Recycle Asphalt Mixtures

    개질 재활용 아스팔트 혼합물의 실내 물성 평가

    Ham, Sang Min and Kim, Booil

    함상민 · 김부일

    The purpose of this study is to verify the laboratory properties of the modified recycle asphalt mixtures as a asphalt pavement materials ... + READ MORE
    The purpose of this study is to verify the laboratory properties of the modified recycle asphalt mixtures as a asphalt pavement materials. Indirect tensile strength test at 25°C, dynamic modulus test at five different temperatures(-5°C, 5°C, 21°C, 40°C, 54°C) and repeated indirect tensile fatigue test at 25°C were conducted to evaluate the performance of the modified recycle asphalt mixtures as a asphalt pavement materials. The test results showed that the indirect tensile strength and toughness of the modified recycle asphalt mixtures was over the criteria of the specification of Korea Ministry of Land, Infrastructure, and Transport. Dynamic modulus of the modified recycle asphalt mixtures were bigger than those of the 13mm+PG64-22 typical asphalt mixtures used on Korea asphalt pavement. Repeated indirect tensile fatigue test showed that the fatigue crack resistance of the modified recycle asphalt mixtures was ten times bigger than that of PG64-22 asphalt mixtures. The results of the laboratory tests showed that the potential performance of the modified recycle asphalt mixtures is good enough as a asphalt pavement materials. - COLLAPSE
    December 2018
  • Research Article

    Effect of Anti-stripping Additive on Short-term Aging and Service Life of Asphalt Mixtures

    박리방지제 사용이 아스팔트 혼합물의 단기노화 및 공용수명에 미치는 영향

    Yeongsam Kim, Baesun Dong, Jaewon Jo, Sungun Kim and Kwang W. Kim

    김영삼 · 동배선 · 조재원 · 김성운 · 김광우

    The normal hot-mix asphalt (HMA) mixture is aged significantly during the short-term aging (STA) period if the mixture temperature is higher (i ... + READ MORE
    The normal hot-mix asphalt (HMA) mixture is aged significantly during the short-term aging (STA) period if the mixture temperature is higher (i.e., 180°C or over) than normal (i.e., 160°C) and time is longer than 2 hours. In that case, to control the aging, an anti-oxidant can be used. According to earlier experiences, the hydrated lime (HL), one of the anti-stripping additives (ASA), has known to have a binder age-retarding function in the mixture. Following use of HL for stripping control, the liquid-type ASA (LA) was developed for stripping control too. When the aging is becoming an issue lately for maintaining durability and service life of pavement, the HL is highlighted as one of the premium additives for aging control. Therefore, when HL is added to asphalt mixes for stripping control, it reacts as an age-retarder in addition to ASA function. However, it has not been well known that all ASAs have similar age-retarding function. Many LAs are known to have good stripping control function, but their anti-aging function is not known. Therefore, this study examine the effect of ASA on aging level of asphalt mixture and service life of asphalt mixtures later in the field. The results showed that the HL clearly reduced aging level of binder measured by the large molecular size (LMS) and estimated absolute viscosity (EAV) from the LMS. The EAV of HL mix was the lowest in comparison with the plain (no additive) mix and LA-added mixes in dense grade and SMA mixes. Three of 4 LAs showed almost no anti-aging function and one showed even higher EAV, inducing significantly higher aging. The significant aging was found to cause a service life reduction. According to comparison with field mixture aging level, the 5-year service life reduction of an LA mix due to STA for 1 h at 180°C can be reduced to 1.37 year by using HL, making nearly 4-year service-life extension possible. - COLLAPSE
    December 2018
  • Research Article

    A Study on Drainage Behavior and Permeability Test Method in Porous Asphalt Pavement

    배수성 아스팔트 포장의 배수거동 및 투수시험방법에 관한 연구

    Tae-Soon Park and Sang-Gab Cho

    박태순 · 조상갑

    The Drainage Behavior of Porous Asphalt Pavement is evaluated by in-situ permeability test. The Darcy's law, which is the basic theory ... + READ MORE
    The Drainage Behavior of Porous Asphalt Pavement is evaluated by in-situ permeability test. The Darcy's law, which is the basic theory of the permeability test, can not be applied when calculating the permeability coefficient as a result of the in-situ permeability test, and there is a big difference from the results of the indoor permeability test when the Darcy rule is applied. The present in-situ permeability test method is a variable pore test used for directly measuring and evaluating the permeability function of permeable pavement with 20% or more porosity in the city of Tokyo. As a result of its convenience and rapidity, This method was introduced into the Japanese Asphalt Pavement Association without review. This method has been propagated to the country as it has been transmitted to the present. Based on the results of in-situ and indoor permeability test conducted on the roads A, B and C of the roads where drainage asphalt pavement was installed in Seoul, Drainage behavior of Porous asphalt pavement and in-situ permeability test. - COLLAPSE
    December 2018
  • Research Article

    Mechanical Performance Evaluation of Reclaimed Asphalt Mixture (RAP) under Static and Dynamic Condition
    Ki Hoon Moon and Oh Sun Kwon
    The use of recycled materials in asphalt pavement is common and crucial practice due to economic and environmental benefits. During the past ... + READ MORE
    The use of recycled materials in asphalt pavement is common and crucial practice due to economic and environmental benefits. During the past decades, many research agencies and road authorities have evaluated the impact of adding Reclaimed Asphalt Pavement (RAP) on the field performance of asphalt mixtures. In this study the effect of RAP on the low temperature properties of asphalt mixture is investigated with two different experimental approaches: Bending Beam Rheometer (BBR) mixture creep tests, which are based on static loading, and Dynamic Shear Rheometer (DSR) mixture complex modulus tests, which use dynamic loading. Based on tests results, creep stiffness, thermal stress and complex modulus are derived then compared. The results present that most of the mixtures prepared with RAP have relatively inferior performance compared to virgin mixtures. However, no significant differences in creep stiffness and complex modulus properties are observed beyond a specific RAP amount; this is in the range of 25% to 40%. - COLLAPSE
    December 2018