• Technical Notes

    Investigation of the relationship between flexural beam test and cantabro test of high polymer modified binder and research cases by applying flexural beam test

    고점도 개질 아스팔트 바인더의 휨 시험과 칸타브로 시험의 연관성 및 휨 시험 적용을 통한 연구사례 조사

    Cho Dong Min, Park Tae Soon, Kang Ii Hwan

    조동민, 박태순, 강일환

    The high polymer modified binder is used in high functional pavement by improving the durability of the asphalt pavement. It can be … + READ MORE
    The high polymer modified binder is used in high functional pavement by improving the durability of the asphalt pavement. It can be applied to pavement in cold regions by gently reforming the binder at low temperatures to improve resistance to thermal cracks. Therefore, when selecting and applying high polymer modified binder, it is required to clearly grasp the compatibility at high and low temperatures and analyze the test methods and results in depth accordingly. This technical note the relationship between the amount of polymer used in the high polymer modified binder and the result of the cantabro test between Flexural Energy and Flexural Stiffness, and introduced an existing research case in which the test was performed and analyzed. The following conclusions could be drawn: (1) As the amount of polymer increases, the Flexural Energy and the toughness tend to increase, and the cantabro loss rate decreases as the amount of polymer and the Flexural Energy increase.(2) The greater the Flexural Energy, the greater the resistance to Flexural fracture, and according to the standards of the Japan Modified Asphalt Association, the Flexural test shall be 0.4 MPa or higher. (3) The correlation between the amount of polymer and the cantabro loss rate of the mixture can be predicted. - COLLAPSE
    18 July 2022
  • Technical Notes

    Construction cases and follow-up observation of reclamation type expansion joint using granulated guss asphalt

    과립형 구스아스팔트를 이용한 매립방식 신축이음 공법의 시공사례와 현장추적조사 결과

    Hyun Yu Kim, Il Hwan Kang, Jung Bum Lee, Young Doo Jang

    김현유, 강일환, 이중범, 장영두

    Expansion joint construction absorbs the amount of expansion and contraction of concrete caused by temperature change, traffic load and vibration, and blocks … + READ MORE
    Expansion joint construction absorbs the amount of expansion and contraction of concrete caused by temperature change, traffic load and vibration, and blocks the stress transfer between concrete structures. In general, the method in which the surface of the construction joint is exposed is used, but the drivability deteriorates and noise and vibration occur. In order to solve this problem, this technical article introduces the reclamation type expansion joint method using granulated guss asphalt, and introduces construction cases and follow up observation results. Granulated guss asphalt can be used by heating only the required amount, and compaction work can be omitted. Construction of the reclamation type expansion joint can improve the drivability by integrating the expansion joint and the pavement layer. As a result of conducting a follow up observation through visual research of two sites (A,B) where general expansion joints were constructed and three sites (C,D,E) where expansion joints were constructed using this method, It was found that there were fewer cracks in the expansion joint, and thus the durability was increased. - COLLAPSE
    18 July 2022
  • Technical Notes

    Performance evaluation of road traffic infrastructure based on meteorological reproduction standard dark room

    기상재현 표준암실 기반 도로교통 인프라 성능평가

    Seung Ho Jeong

    정승호

    As the commercialization of autonomous vehicles become commercialized, the need to establish driving infrastructure in consideration of road safety and traffic operation … + READ MORE
    As the commercialization of autonomous vehicles become commercialized, the need to establish driving infrastructure in consideration of road safety and traffic operation efficiency is emerging. Accordingly, we are taking the lead in creating a safe, autonomous driving environment for future vehicles by evaluating the performance of road traffic infrastructure based on a standard darkroom for meteorological reproduction. - COLLAPSE
    18 July 2022
  • Technical Notes

    A case study on BRT pavement thickness design for Dar es Salaam city in Tanzania using category design method

    Category 포장설계법을 이용한 탄자니아 다레살람시 BRT사업 포장두께 설계 사례 연구

    Yonggu Lee

    이용구

    The Korean pavement design method in the past was structural calculations using the AASHTO pavement design method, and is currently being performed … + READ MORE
    The Korean pavement design method in the past was structural calculations using the AASHTO pavement design method, and is currently being performed using the Korean pavement design method with special program called KPRP (Korea Pavement Research Program) developed by government in order to be suitable for domestic conditions. The Korean pavement design method has three design level with two manners. Pavement design level one (1) and two (2) should be used with KPRP and design level three (3) shall be used with category table method. The Korean pavement design in category does not request to calculate W8.2 (Accumulate Equivalent Single Axle Loading), and the pavement layers and thicknesses are determined by number of vehicles with sub-grade condition. On the other hand, the British pavement design method using the category table is unfamiliar to domestic engineers because pavement layers and thicknesses are determined based on traffic volume, W8.2 and sub-grade condition. Even though the basic system for pavement design is the same, engineers who work abroad for the first time often experience difficulties due to lack of understanding of British pavement design methods. In order to help domestic engineers who will work abroad, this article describes major issues and decisions experienced while carrying out the pavement design for the Tanzania BRT project, as well as opinions on local design methods. Engineers with abundant domestic pavement design experience is judged that it is possible to understand and perform the British pavement design method because the basic system is the same. It is expected that this article will provide domestic engineers with indirect experience and understanding of category design methods in British pavement and hope it will be helpful to many domestic engineers. - COLLAPSE
    18 July 2022
  • Technical Notes

    Quality control of asphalt pavement through cambodia overseas pilot project

    캄보디아 해외 시범사업을 통한 아스팔트 포장 품질관리 사례

    JaeKyu Lim

    임재규

    By comparing and evaluating the physical properties of asphalt road pavement in Cambodia and Korea, Cambodian companies will use it as basic … + READ MORE
    By comparing and evaluating the physical properties of asphalt road pavement in Cambodia and Korea, Cambodian companies will use it as basic data for future efficient management such as road pavement design, quality and maintenance management. The purpose of this study was to examine the pavement status of Cambodia’s asphalt roads through quality control cases based on overseas demonstration projects. The thickness of the asphalt layer was thinner and larger than that of Korea. on the other hand, density is generally similar. Deformation strength test results showed that neither surface layer nor base layer corresponded Korean standards. Marshall stability, flow, retained stability, indirect tension, tenacity, and tensile strength ratios were corresponded Korea’s quality standards, but not enough. The performance analysis of the asphalt core specimens showed that the overall quality standards of Korea were satisfied. However, As the thickness of the asphalt layer is rather thin and the variation is severe, it is necessary to thoroughly manage the construction and the quality fluctuation due to the thickness difference of the surface layer and the base layer will be serious. - COLLAPSE
    18 July 2022
  • Scientific Paper

    A case study on asphalt concrete pavement remodeling methods of aged concrete pavement considering durability, workability, and maintainability

    노후 콘크리트 포장의 내구성, 시공성, 유지관리성을 고려한 아스팔트콘크리트포장 리모델링 검토 사례연구

    Hwasick Ji

    지화식

    Currently, the applied remodeling method for concrete pavement, which is more or less than 20 year of performance period varies project by … + READ MORE
    Currently, the applied remodeling method for concrete pavement, which is more or less than 20 year of performance period varies project by project, due to the absence of the standard design guideline on concrete pavement (cutting/non-cutting and overlay). This study aims to establish remodeling methods for aged concrete pavement according to its site pavement damage conditions, using the design case study, research data, and papers from projects procured by Korea Expressway Corporation. The study found that the overlay method without cutting was advantageous in terms of durability, workability, etc. and that the overlay thickness of 10 cm, was useful for reducing cost and suppressing reflection cracks. The study also surveyed damage level of the existing concrete pavement and determined the corresponding rehabilitation methods. - COLLAPSE
    18 July 2022
  • Scientific Paper

    Analysis of asphalt aging problem of HMA mixture due to the long-time insulated carriage for repair works

    보수용 가열아스팔트 혼합물의 보온・운반에 따른 노화 문제점 분석

    Yeongsam Kim, Sungun Kim, Wonbae Kim, Kwang W. Kim

    김영삼, 김성운, 김원배, 김광우

    The hot-mix asphalt (HMA) mixture is kept in an insulated carriage for repair work for all day long. If the binder in … + READ MORE
    The hot-mix asphalt (HMA) mixture is kept in an insulated carriage for repair work for all day long. If the binder in the mix is severely oxidized due to the hot-temperature for long-time carriage, the repaired pavement will have to loose its service life. Therefore, a dense-graded HMA mix with PG64-22 was kept in 160°C oven for 1, 2, 4, 6 and 8-hour (h) for aging level evaluation. The gel-permeation chromatography (GPC) technique measured the large-molecular size (LMS) ratio of the binder in the mixture without binder recovery. The absolute viscosity (AV) was estimated from the LMS. Since it was found that AV of binder was increased by polynomial function form by the aging time, the estimated AV (EAV) of the binder in HMA mix was significantly increased. It was found that the binder EAV of 3-4 h aged mix was similar to the binder EAV level of 5-year-old asphalt pavement. The service life expressed by aging level can be interpreted as the service life reduction (SLR) of aged mix, which has already been oxidized before in service. Therefore, it was found that the binders of 4~8 h aged mix were significantly aged, and the SLRs were 6~10 years already. When the 8-h aged mix was used for pothole repair, the repaired mix was found to show an increased EAV than the binder EAV of original-pavement mix. Therefore, it is important to coup with the significant binder aging of the repair HMA mix in a carriage chamber. - COLLAPSE
    18 July 2022
  • Scientific Paper

    Basic study on the improvement of cargo vehicle parking capacity and parking correction coefficient in port using literature research method

    항만 화물자동차 주차용량 및 주차보정계수 개선방안에 대한 기초연구

    Jun Seong Choi, Hyeon Ho Jin, Jae Jin Lee

    최준성, 진현호, 이재진

    In recent years, as the cargo volume has increased, the problem of insufficient parking space for lorries in the port has been … + READ MORE
    In recent years, as the cargo volume has increased, the problem of insufficient parking space for lorries in the port has been raised. This is a negative cause that can lead not only to a decrease in cargo liquidity at the port, but also to civil complaints in neighboring areas. In this study, the parking capacity parking correction coefficient used to design the parking space of the lorry will be presented using the literature study method. Through this, we intend to use it to meet the current trend of cargo volume as the main basis for increasing the efficiency of the existing cargo parking lot or expanding the cargo parking lot area. - COLLAPSE
    18 July 2022
  • Scientific Paper

    An analysis of noise reduction effect of hot mix asphalt mixture and asphalt pavement using steel slag

    제강슬래그 골재를 사용한 아스팔트 혼합물 및 아스팔트 포장도로의 소음저감 효과 분석

    DongBok Jang, KyungWon Park

    장동복, 박경원

    To utilize the steel slag aggregates on manufacturing low-noise asphalt pavement, volumetric test on the general mineral aggregates and steel slag aggregates, … + READ MORE
    To utilize the steel slag aggregates on manufacturing low-noise asphalt pavement, volumetric test on the general mineral aggregates and steel slag aggregates, the acoustic absorption test on the two types of mixture, and the roadway noise test on the two types of asphalt pavements were conducted. The study found that the steel slag aggregates have approximately double air voids than the general mineral aggregates, the steel slag asphalt mixture have 9% higher acoustic absorption capacity, and the steel slag asphalt pavement reduces 10 dB roadway noise. Consequently, the steel slag aggregates are more suitalbe for manufacturing the low-noise asphalt pavement. - COLLAPSE
    18 July 2022
  • Scientific Paper

    Performance evaluation of modified asphalt mixture on asphalt concrete pave layer track using railway wheel tracking test

    철도 휠트랙킹 시험을 이용한 아스팔트 콘크리트 도상의 개질아스팔트 성능평가

    Il Ho Na, Kwang Woo Kim, Hyun Hwan Kim

    나일호, 김광우, 김현환

    Asphalt is produced in the refining process of crude oil. So in itself, it's a lot of weakness. In particular, asphalt concrete … + READ MORE
    Asphalt is produced in the refining process of crude oil. So in itself, it's a lot of weakness. In particular, asphalt concrete is a risk of damage because of rutting in high temperatures and brittleness at low temperatures when used in asphalt concrete track by great temperature sensitivity. However, modified asphalt using various additives can prevent the damages like rutting and crack and extend the pavement service life. In particular, polymer-modified asphalt enhances rutting resistance due to improved elasticity at a high service temperature of 60~80°C. This study evaluated polymer-modified asphalt to measure the base strong characteristics and applicability of the asphalt concrete track for railways. - COLLAPSE
    18 July 2022
  • Scientific Paper

    Comparative analysis of stability of high-viscosity porous asphalt binder

    고점도 배수성 아스팔트 바인더의 안정성 비교 분석

    Young Doo Jang, Jae Sik LEE, Dong Kyun Kim

    장영두, 이재식, 김동균

    The porous asphalt binder can be divided into a premix type and a plant mix type according to manufacturing method. The premix … + READ MORE
    The porous asphalt binder can be divided into a premix type and a plant mix type according to manufacturing method. The premix type binder was found to show an unstable pavement quality due to non-homogeneity of the asphalt mixture because of phase separation at a relatively high temperature. Therefore, this study analyzes the engineering characteristics using the physical property test and the PG grade evaluation test of the high-viscosity porous binder used in Korea, and suggests an improvement plan for the stability of the high-viscosity porous binder. - COLLAPSE
    18 July 2022
  • Scientific Paper

    A study on effect of the tangential correction of load-displacement curve for calculation of flexural energy and flexural stiffness

    하중-변위 곡선의 접선 보정이 휨 에너지 및 휨 강성에 미치는 영향 연구

    Tae Soon Park, Il Hwan Kang, Geon Ho Park

    박태순, 강일환, 박건호

    The displacement (d) is used when calculating the flexural energy and flexural stiffness, and is obtained through tangential correction of the load-displacement … + READ MORE
    The displacement (d) is used when calculating the flexural energy and flexural stiffness, and is obtained through tangential correction of the load-displacement curve by flexural beam test. However, the reason for performing tangential correction and the method is not specified in the Japanese and domestic methods and standards. This paper is introduced how to set the tangential correction on load-displacement curve and is conducted to effect of the change of the tangential correction method on the flexural energy and the flexural stiffness. The tangential correction of the load-displacement curve is set by specifying two points at the position before the rise of the load behaves like a linear (case I) and by adjusting the interval between the two points specified when the rise of the load starts to behave like a linear (cases II and III). As the result of analysis, it was confirmed that the displacement (d) was different according to the setting the two points, so that the flexural energy and flexural stiffness were different. Therefore, it is necessary to correct the load in order to reduce the human error in the analysis process of the flexural beam test. - COLLAPSE
    18 July 2022
  • Scientific Paper

    Moisture resistance of recycled warm-mix asphalt mixture using wax-base additive

    Wax계 중온화 첨가제 사용에 따른 중온 순환아스팔트 혼합물의 수분저항 특성

    Yeongsam Kim, Wonbae Kim, Jongsup Lee, Kwang W. Kim, Sungun Kim

    김영삼, 김원배, 이종섭, 김광우, 김성운

    In this study, wax-based warm mix additive, modifier, and RAP (reclaimed asphalt pavement) were used to prepare typical and modified recycled warm … + READ MORE
    In this study, wax-based warm mix additive, modifier, and RAP (reclaimed asphalt pavement) were used to prepare typical and modified recycled warm mix asphalt mixtures. Asphalt mix design was carried out to obtain the optimum asphalt content (OAC) by changing the content of RAP to 15, 30, and 50%. And the specimen was prepared with OAC to evaluate the crack resistance, rutting resistance, and moisture resistance of WMA. It was determined that the warm mix additive used in this study partially rejuvenated the aged binder of RAP and had an effect on the reduction of stiffness, improvement of aging, stripping resistance, and moisture resistance. Furthermore, when applied to the PG 64-22 or PG 76-22 mixture, it was determined that it was necessary to optimize the dosage by the content of RAP. - COLLAPSE
    18 July 2022
  • Scientific Paper

    A preliminary study on the determination of the damage classification in the porous asphalt pavement sections using FWD test

    FWD 시험을 이용한 배수성 아스팔트 구간의 손상등급 결정에 관한 기초연구

    Junseong Choi, Seunghoon Oh, Sangjin Kim, Jangrak Kim, Namgeun Jo

    최준성, 오승훈, 김상진, 김장락, 조남근

    Recently, Korea tried to apply porous asphalt pavement to the test sections of domestic highways. But the framework for structural performance analyses … + READ MORE
    Recently, Korea tried to apply porous asphalt pavement to the test sections of domestic highways. But the framework for structural performance analyses are still insufficient. For the structural performance comparison analysis, the deflection basin of the FWD (Falling Weight Deflectometer) are calculated according to the load and temperature correction factor on the porous pavement and general pavement.It was found that more research is needed to apply the Japanese temperature correction method to Korea and there was no significant difference between the drainage pavement Techniques as a result of the analysis of determining the repair method using the damage index. In a future study, it is need to compared with the corrected deflection data of the seasonal FWD test ​​along with the field damage evaluation results. - COLLAPSE
    18 July 2022
  • Scientific Paper

    Mechanical performance evaluation of taconite aggregate in asphalt pavement construction
    Augusto Cannone Falchetto, Ki Hoon Moon, Sang Gab Cho
    Using alternative aggregate source is essential in asphalt pavement industry not only for saving construction budget but also for mitigating environmental pollution … + READ MORE
    Using alternative aggregate source is essential in asphalt pavement industry not only for saving construction budget but also for mitigating environmental pollution issue. In U.S. northern Minnesota territory, amount of taconite aggregate: a byproduct of taconite mining industries, are produced annually. If taconite aggregate is successfully used as an alternative aggregate source, more economical and environment friendly asphalt mixture can be achieved. Many studies presented the possibility of taconite aggregate application in road construction. In this paper, suitability investigation of using taconite aggregate is performed by means of mechanical test: low temperature Indirect Tensile (IDT) creep test. A parameter for low temperature cracking resistance: creep stiffness (and corresponding relaxation modulus) result, is computed then compared visually. It was found that the asphalt mixture mixed with coarse taconite aggregate and limestone filler presented reasonable mechanical performance compared to the conventional asphalt mixture. This finding provides possibility of taconite aggregate application in actual asphalt pavement construction. - COLLAPSE
    18 July 2022
  • Scientific Paper

    Feasibility analysis of taconite aggregate application by means of composite pavement structure design simulation using MEPDG
    Augusto Cannone Falchetto, Ki Hoon Moon, Sang Gab Cho
    It is well known that application of alternative aggregate material in asphalt pavement area is crucial not for saving construction budget but … + READ MORE
    It is well known that application of alternative aggregate material in asphalt pavement area is crucial not for saving construction budget but for mitigating environmental pollution. Several research efforts: for finding alternative aggregate material, were performed in U.S. during the past decades. One of the research achievements is application of taconite aggregate: a byproduct of taconite mining industries in northern Minnesota, U.S., in asphalt pavement construction. Some studies performed performance evaluation of taconite aggregate added mixture with various mechanical testing procedure. However, not many studies considered pavement design performance simulation, evaluation and comparison in case of taconite aggregate application. In this paper, performance evaluation of taconite aggregate mixture by means of composite pavement design simulation using AASHTOWare-Pavement (MEPDG: Mechanical-Empirical Pavement Design Guide) was considered. Reasonable and comparable pavement performance was found when taconite aggregate is applied compared to the conventional asphalt mixture. - COLLAPSE
    18 July 2022