• Research Article

    A Research on the application status and considerations of warm mix asphalt

    중온아스팔트의 적용현황 및 고려사항에 관한 조사연구

    Sang Gab Cho and Tae Soon Park

    조상갑, 박태순

    This paper provides an extensive literature review especially on Warm Mix Asphalt (WMA) technology. A wide considerations of construction example, current issues ... + READ MORE
    This paper provides an extensive literature review especially on Warm Mix Asphalt (WMA) technology. A wide considerations of construction example, current issues and future research topics on WMA were performed. It is well known that WMA is an environment friendly, next generation asphalt pavement technology. However, due to lack of long-term performance evaluation and corresponding results, more prudent consideration on applying WMA on asphalt pavement field is needed. In addition, more extensive studies on gas ventilation system development, evaluation during WMA production and optimized additives development with application process are crucially recommended. Based on this paper, readers can understand advantages, disadvantages and challenges on WMA well in many specialized areas. - COLLAPSE
    December 2019
  • Research Article

    Investigation of reflection crack reduction methods for improving overlaid asphalt pavement performance on aged concrete pavement

    노후 콘크리트 덧씌우기 아스팔트 포장의 공용성 개선을 위한 반사균열저감 공법조사 연구

    Dong Min Cho, Tae Soon Park and Tae Ho Yoo

    조동민, 박태순, 유태호

    The Reflection Crack is one of the typical destruction when the asphalt pavement is constructed over the old deteriorate concrete pavement. the ... + READ MORE
    The Reflection Crack is one of the typical destruction when the asphalt pavement is constructed over the old deteriorate concrete pavement. the many efforts studies and practical approach has been conducted in order to control and prevent the Reflection Crack. This study presents the results of previous researches that applied to the practise of stress absorbing layer for reflection crack suppression. SAMI and EXTEND SAMI which is suggested method were examined, in terms of site to review the material and construction the effectiveness of these methods. - COLLAPSE
    December 2019
  • Research Article

    Application of simple approximated mathematical approaches for computing relaxation modulus of asphalt binder
    Ki-Hoon Moon
    Low temperature cracking represents one of the crucial distresses in asphalt pavements. When temperature drops, thermal stress develops in restricted pavement layer ... + READ MORE
    Low temperature cracking represents one of the crucial distresses in asphalt pavements. When temperature drops, thermal stress develops in restricted pavement layer then cracking occurs when it reaches at critical temperature level. Due to this reason, thermal stress is recognized as a crucial pavement performance parameter in many pavement agencies in U.S. and Canada. To compute thermal stress, low temperature creep testing is required. After the laboratory work is done, the experimentally computed creep compliance needs to be converted into relaxation modulus then thermal stress can be generated. In this paper, two simple computation approaches for computing relaxation modulus of asphalt mixture from its experimental creep compliance results were introduced. The computation results were compared to the relaxation modulus data computed by the conventional but sophisticated Hopkins and Hamming’s algorithm. It was found that the newly introduced simple inter-conversion approaches provide reliable and reasonable computation results compared to use of the conventional approach. - COLLAPSE
    December 2019
  • Research Article

    A study on effects of hydrated lime on moisture susceptibility of SMA mixtures

    소석회를 첨가한 SMA의 수분 저항 특성 분석

    Kyung-Ha Lee

    이경하

    The objective of this study is to evaluate effects of hydrated lime on SMA mixtures as an anti-stripping agent. The SMA mixtures ... + READ MORE
    The objective of this study is to evaluate effects of hydrated lime on SMA mixtures as an anti-stripping agent. The SMA mixtures containing hydrated lime were evaluated for asphalt mixture properties through indirect tensile strength, tensile strength ratio (TSR), and dynamic immersion test. The results of the IDT test revealed that the indirect tensile strength of mixtures with hydrated lime is 1.2~1.5 times greater than those with anti-stripping agent. And hydrated lime has more influence on strength characteristics of modified asphalt mixtures than those of straight asphalt. The results of TSR test showed that the mixtures with hydrated lime and anti-stripping agent are 1.3~1.5 times more resistant to moisture damage than control mixtures. The results of dynamic immersion test showed that the coverage rate of asphalt in the mixture with hydrated lime and anti-stripping agent is 2.9~3.1 times greater than that of control mixtures. It is considered that the improved moisture resistance of asphalt mixtures with the use of hydrated lime can reduce incidences of various pavement damages caused by stripping. - COLLAPSE
    December 2019
  • Research Article

    A study on the performance improvement of guss asphalt mixture

    구스 아스팔트 혼합물의 성능 개선에 관한 연구

    Young Doo Jang, Tae Soon Park and Jae Sik Lee

    장영두, 박태순, 이재식

    The 3 kinds of guss asphalt binders were satisfied with the domestic design criteria. However, the contents of TLA should be changed ... + READ MORE
    The 3 kinds of guss asphalt binders were satisfied with the domestic design criteria. However, the contents of TLA should be changed large amount depending on the composition of TLA and dust when the results of mix design passing is in accordance with the current standard of the guss asphalt mixture. Therefore, the stability of the guss asphalt is not able to produce consistently. In order to pass the Lueer fluidity and penetration resistance, the working process of the mix design is time consuming. However, type 3 which includes the SBS and gilsonite to make possible to the permit and reduce the time that is satisfied with mix design criteria. The results of this study show that the improvement of the dynamic stability is significant which is twice larger than that of conventional mixture. The new type of SBS maintains consistency of the mixture and reduce the trial and error mix design procedure significantly. - COLLAPSE
    December 2019
  • Research Article

    Characteristics of durability on asphalt mixtures including anti-icing agent

    결빙방지제가 혼입된 아스팔트 혼합물의 내구성 연구

    Mun Jin Cho, Hyun Kook Shin and Kwang Woo Kim

    조문진, 신현국, 김광우

    The main objective of this study is to evaluate the durability of anti-icing asphalt pavement using anti-icing agent (AIA) to mitigate numerous ... + READ MORE
    The main objective of this study is to evaluate the durability of anti-icing asphalt pavement using anti-icing agent (AIA) to mitigate numerous traffic slippery events caused by black ice or unobserved surface ice during winter season. The AIA was incorporated into the three asphalt mixes, a normal dense graded asphalt (DGA) mix, a stone mastic asphalt (SMA) mix and a porous asphalt (PA) mix, because the DGA is most widely appled to the national roads, SMA to expressways and PA to expressway for drainage purpose. To evaluate integrity of serviceability performance, the deformation strength (SD), indirect tensile strength (ITS) and wheel tracking (WT) rut depth of the asphalt mixture with AIA were measured in the laboratory. As a result of the performance test, it was confirmed that the use of AIA did not degrade the durability of the asphalt mixture such as the volume characteristics, deformation strength, indirect tensile strength, and dynamic stability. In conclusions, it is therefore highly expected that the AIA-included asphalt mixture can be successfully applied to the field pavement to reduce traffic accidents by preventing formation of black ice and frozen snowy surface without pavement damages. - COLLAPSE
    December 2019
  • Research Article

    Crack sealing vs crack filling: A state of the art review and analysis
    Mithil Mazumder, Hyun Hwan Kim and Soon-Jae Lee
    The objective of this paper is to evaluate existing literature regarding the practice of pavement crack treatment using crack sealing and crack ... + READ MORE
    The objective of this paper is to evaluate existing literature regarding the practice of pavement crack treatment using crack sealing and crack filling technique. There are two methods of sealing water and other debris out of asphalt pavements: crack sealing and crack filling. Crack sealing uses a router to cut the crack to provide a uniform rectangular reservoir for greater penetration of sealants, thus allowing the sealant material more even contact with the asphalt pavement with less chance for air voids. On the other hand, there is no pavement removed with crack filling treatment. The following topics are discussed in this paper: crack sealing, crack filling, treatment procedure and equipment selection, treatment materials evaluations, material placement, pavement evaluation, Texas and other US states practices and traffic safety issues. The most cost effective practice between crack sealing and filling treatment can be analyzed via the selection of appropriate test sites, computer aided simulation, and life cycle cost analysis. Overall, the literature suggests a comprehensive review of all the known literature and conducted an analytical study of crack sealing and filling practices along with all those factors impacting sealant performance. - COLLAPSE
    December 2019
  • Research Article

    Effects of anti-strip additives on binder stiffness of polymer-modified asphalt mixture
    Sungun Kim, Yeongsam Kim, Wonbae Kim, Kyung-Jin Kim and Kwang Woo Kim
    This study evaluated aging level of polymer-modified asphalt (PMA) binders in SMA mixes, which were prepared using hydrated lime (HL) and liquid ... + READ MORE
    This study evaluated aging level of polymer-modified asphalt (PMA) binders in SMA mixes, which were prepared using hydrated lime (HL) and liquid additives (LA) as anti-strip additive (ASA). The mixes were short-term aged at 185°C and the large molecular size (LMS) was obtained from gel-permeation chromatography (GPC) test. The high-temperature binder stiffness (G*/sin δ) was estimated from LMS and the estimated stiffness was used for aging level comparison. The objective of this study was to analyse age-retardation effect of HL and LA in PMA mixes which were prepared with HL and LA as ASA. The experimental study results showed that HL was effective on retarding oxidation of binders in PMA mixes and the normal mixes, which were used for comparison purpose. However, it was observed that LAs used in this study were not effective on retarding oxidation of binders in both mixes. Therefore, ASA was found to be one of the sources affecting stiffness level of binder in the mix. - COLLAPSE
    December 2019
  • Research Article

    Strength evaluation of HMA and WMA sand asphalt mixtures

    HMA와 WMA 샌드 아스팔트 혼합물 강도특성 연구

    Changjeong Choi, Yeongsam Kim, Kwang Woo Kim and Sungun Kim

    최창정, 김영삼, 김광우, 김성운

    The Sand asphalt mixture (SAM) pavement was developed to provide safe walking condition by virtue of excellent properties such as surface smoothness ... + READ MORE
    The Sand asphalt mixture (SAM) pavement was developed to provide safe walking condition by virtue of excellent properties such as surface smoothness and soft texture, because the SAM is made of fine aggregate without coarse particles with a higher asphalt content. SAM was also designed to show excellent flexibility under freeze conditions and relatively high deformation resistance. Therefore, it can be applied to the pavements of pedestrians, sideway, bicycle road and low volume road with relatively small vehicles in rural area. In this study, the SAM mix design was conducted by adding crumb rubber modifier (CRM) with 7.5% and 10% by binder weight. In addition, two types of SAM i.e., hot-mix sand asphalt mixture (H-SAM) and warm-mix sand asphalt mixture (W-SAM), were prepared and evaluated in this study. The deformation strength (SD), indirect tensile strength (ITS), were evaluated. The low temperature flexural strength (Sf) was measured by three point bending (3PB) test at –10°C. The results showed that the deformation strength and tensile strength of the W-SAM showed similar values to the H-SAM. The flexural strength test presented that Sf of H-SAM was 12% higher than that of W-SAM with W-SAM having similar failure strain. - COLLAPSE
    December 2019
  • Research Article

    A fundamental study on the development of variation control index of asphalt plant aggregate

    아스팔트 플랜트 골재의 변동 관리지수 개발을 위한 기초연구

    Junseong Choi, Kangbin Lee and Jinsoo Kim

    최준성, 이강빈, 김진수

    In this study, the variation control index of asphalt plant aggregates was selected, and the database was constructed by collecting asphalt plant ... + READ MORE
    In this study, the variation control index of asphalt plant aggregates was selected, and the database was constructed by collecting asphalt plant aggregates of Stockpiles and Cold Bins and conducting an indoor experiments. The QM (Quality management) points on the 25 mm, 19 mm, 13 mm, 8 mm Maximum size aggregate of Stockpiles and Cold Bin were selected equally, which affect the quality of asphalt mixture, during Sieve analysis and moisture content measurement. In addition, the statistical variation of the indoor experiment data were compared and analyzed to develop the variation control index of asphalt plant aggregate in the future. - COLLAPSE
    December 2019
  • Research Article

    Evaluation of permanent deformation resistance of asphalt concrete by different temperature conditions using MWTT applying railway track structure
    Il Ho Na, Seung Ho An and Kwang Woo Kim
    Application of asphalt mixture on the railway track is under study in Korea, based on the review of the foreign country's ... + READ MORE
    Application of asphalt mixture on the railway track is under study in Korea, based on the review of the foreign country's experiences in materials, methods and specifications. The asphalt mixture used in railway track should be strong enough against spot deformation (similar to rutting mechanism). The current methods for evaluating of rut resistance of road pavement uses a pressure wheel, slowly tracking on the asphalt mixture slab to measure a final rut depth and dynamic creep rate. However, since the deforming mechanism of asphalt pavement under railway crosstie (sleeper) and temperature environment are different from the road pavement, a test method to measure the deformation resistance of asphalt mixture for railroad pavement should be devised in a different concept. The objective of this study is to initiate a feasibility study of developing a test protocol for measuring deformation resistance of asphalt mixture for railroad pavement. The test concept suggested in this study was found to acquire a positive consideration for railway environment. - COLLAPSE
    December 2019