• Scientific Paper

    A study on the improvement of asphalt concrete construction guidelines

    아스팔트 콘크리트 포장 시공 기준 개선 방안

    Kyu-Dong Jeong, Sung-Do Hwang

    정규동, 황성도

    Standard specifications, MOLIT-related guidelines, and specialized specifications were compared with each other to improve the asphalt pavement construction standard. As a result, … + READ MORE
    Standard specifications, MOLIT-related guidelines, and specialized specifications were compared with each other to improve the asphalt pavement construction standard. As a result, the following conclusions were obtained. Since most of the domestic specialized specifications apply KCS, it was judged that KCS needs to be revised to improve the construction quality of asphalt pavement. In order to improve the quality of tact coat, KCS needs to be revised by reflecting the MOLIT guidelines on the standard of emulsion asphalt (such as emulsion asphalt to prevent tact coat peeling). In order to reduce the occurrence of potholes in asphalt pavement, it is necessary to include the pavement air-voids standard by reflecting the MOLIT guidelines. Research is needed to revise the current PrI standard to an IRI standard that is highly related to the driver's driving ability and has high precision. - COLLAPSE
    31 December 2024
  • Scientific Paper

    A study on improvement of asphalt plant checklist

    아스팔트 플랜트 점검 개선 방안

    Kyu-dong Jeong

    정규동

    In order to prepare a plan to improve the inspection standards of asphalt plants, the ‘Asphalt plant checklist’ included in MOLIT’s ‘Construction … + READ MORE
    In order to prepare a plan to improve the inspection standards of asphalt plants, the ‘Asphalt plant checklist’ included in MOLIT’s ‘Construction Work Quality Management Business Guidelines’ was reviewed. It was compared with the related standards of asphalt plants, and the following conclusions were obtained. For effective inspection of asphalt plants, it is necessary to prepare standards in consideration of production products such as SMA, porous asphalt mixtures in addition to dense-graded asphalt mixtures. In the material quality inspection, it is necessary to revise the standards that is difficult to apply, such as the once-a-day sieve test for cold-bin aggregates and once-a-month asphalt quality test for plants. It is necessary to check the lab and job-mix design and check it as a test production to check the suitability of production management. It is also necessary to prepare an inspection management system for asphalt plants to conduct joint inspections, and to increase efficiency by using the inspection results for approval of other sites. - COLLAPSE
    31 December 2024
  • Scientific Paper

    A study on the effect of physical properties on Indonesian natural asphalt binder produced by foaming equipment

    기포 장치에 의한 기포 발생이 인도네시아 천연 아스팔트 바인더의 물리적 특성에 미치는 영향 연구

    Ilhwan Kang, YongJoo Kim, Kanghun Lee, Harmein Rahman, Fanny Tri Novitasari Siregar, Raihan Arditama Harnedi

    강일환, 김용주, 이강훈, 하르메인 라흐만, 파니 뜨리 노비따사리 시레가르, 라이한 아르디따마 하르네디

    This study is conducted to investigate the effect of physical properties for Indonesian natural asphalt binder(Asbuton) before and after foaming mechanical foaming … + READ MORE
    This study is conducted to investigate the effect of physical properties for Indonesian natural asphalt binder(Asbuton) before and after foaming mechanical foaming equipment. Two types of Indonesian natural asphalt binders (Asbuton PG70 and Asbuton PG76) are selected with one Indonesian conventional asphalt binder (Pen 60-70) as a comparison. The laboratory physical properties tests are conducted in compliance with Indonesian standards ‘Spesifikasi Umum 2018 (Revisi 2)’. Asbuton PG76 is excluded as it did not meet the high-temperature performance grade criteria. The foaming characteristic test and MSCR (Multiple Stress Creep Recovery) test are conducted to compare physical properties of Indonesian natural asphalt binder and conventional asphalt binder before and after foaming. Based on the limited test results, Asbuton PG70 exhibited an OWC (Optimum water content) similar to Pen6070 in the foaming characteristic test, with a relatively longer foaming retention time. The physical properties change due to foaming effect is not observed and the same trend is found in the MSCR test. Therefore, Asbuton PG70 is more suitable to harmonize foamed asphalt technology in Indonesia. Further research through foamed asphalt mixtures using Indonesian natural asphalt binder would be conducted for the future. - COLLAPSE
    31 December 2024
  • Technical Notes

    Case study on the production and application of convenience facilities for road maintenance site workers

    도로 유지보수 현장근로자를 위한 편의시설 제작 및 현장적용사례

    In Woo Shin, Kyong Il Ko, Hyun kuk Shin, Dong Min. Cho

    신인우, 고경일, 신현국, 조동민

    The working conditions of workers in the construction industry are much worse than those of other industries. In particular, in the case … + READ MORE
    The working conditions of workers in the construction industry are much worse than those of other industries. In particular, in the case of road pavement maintenance, most of the work is done outdoors, and most of the convenience facilities that should be provided to guarantee the minimum basic rights of field workers, such as restrooms, break rooms, and restaurants, are not installed in the working environment of construction sites. Many road pavement maintenance workers are exposed to very poor and vulnerable environments, such as eating and relieving themselves on the road while being exposed to dust and sand. In this study, we introduce the TOTAL safety vehicle and mobile shelter, which were introduced to improve the vulnerable working conditions of field workers. The TOTAL safety vehicle is equipped with welfare facilities and safety equipment to enable workers to use safety and convenience facilities, and the mobile shelter is a large bus that is modified to provide welfare spaces such as rest areas and restrooms for field workers, so that it can be used at maintenance sites and new road construction sites. By installing this mobile convenience facility on site, it is expected to not only guarantee the minimum basic rights of road pavement maintenance construction site workers, but also help solve the labor shortage phenomenon (aging) caused by the avoidance of the construction industry by encouraging work motivation, producing excellent products, preventing construction workers from leaving for other jobs, and improving the working environment for female workers. - COLLAPSE
    31 December 2024
  • Technical Notes

    A study on the development of Medium-Temperature Asphalt Paving Technology to Promote Green Road Paving in Indonesia

    인도네시아 녹색 도로 포장 촉진을 위한 중온 아스팔트 포장 기술 개발 연구

    Jaekyu Lim

    임재규

    In order to reduce carbon dioxide emissions on the road, we are selecting domestically produced medium-temperature additives and conducting a pilot project. … + READ MORE
    In order to reduce carbon dioxide emissions on the road, we are selecting domestically produced medium-temperature additives and conducting a pilot project. By applying medium-temperature heated asphalt technology that is manufactured at a temperature about 30 degrees lower than that of existing asphalt, we can achieve a carbon reduction effect of about 20% or more compared to existing asphalt, and reduce fuel costs and electricity usage by about 70% during the construction process. - COLLAPSE
    31 December 2024
  • Technical Notes

    A study on material properties for application of color asphalt pavement

    칼라 아스팔트 포장의 적용을 위한 재료적 특성 고찰

    Il-Ho Na, Hye min Park, Seung wan Son, Hyun hwan Kim

    나일호, 박혜민, 손승완, 김현환

    Color asphalt is used for natural harmony with the road and surrounding environment, mainly applied to parks and tourist attractions. Color asphalt … + READ MORE
    Color asphalt is used for natural harmony with the road and surrounding environment, mainly applied to parks and tourist attractions. Color asphalt pavement can be paved in various colors for appearance and safety by adding pigments to the asphalt mixture or painting it. It is mainly used on sidewalks to contribute to creating a variety of colors for uniform urban roads. However, in South Korea, while color asphalt pavement for sidewalks is relatively widely used, color asphalt pavement for roads is not yet commonly applied. This is because, in the case of sidewalks or bicycle lanes, heavy loads are not generated compared to vehicles, but to be used as a traffic road, it must exhibit the same level of public performance as asphalt pavement for general roads. Therefore, we analyzed cases to improve public performance and raise the level of color pollution prevention technology for applying color asphalt pavement for general roads. Also, if visibility is secured through this, it is expected to reduce human losses related to traffic accidents such as bus-only lanes and children's protection zones, and reduce public complaints, thereby it is possible to improve public satisfaction considering national happiness. - COLLAPSE
    31 December 2024
  • Technical Notes

    Significance of SD difference due to size error of loading head dimension

    하중봉의 치수 오차로 인한 변형강도 차이 분석

    Kwang Woo Kim

    김광우

    This article dealt with significant difference in SD values due to size variation of loading head dimension. There are two major … + READ MORE
    This article dealt with significant difference in SD values due to size variation of loading head dimension. There are two major errors in loading head dimension; one is in diameter (D) of loading head, and another is in radius (r) of round cut at the bottom edge. If the D is smaller than standard size, the SD was found to be resulted in larger values, and if r is smaller than normal size, the SD was found to be also greater values. The acceptable D and r are suggested to be 40 ± 0.05 mm and r = 10 ± 0.03 mm, respectively. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Evaluation of the moisture content of soil in recycled aggregates using electrical conductivity

    전기전도도를 활용한 순환골재에 포함된 토사의 함수비 평가

    Kyung Suk Yoo

    유경석

    The depletion of natural aggregates has necessitated the exploration of alternative materials, leading to extensive research on recycled aggregates. A critical issue … + READ MORE
    The depletion of natural aggregates has necessitated the exploration of alternative materials, leading to extensive research on recycled aggregates. A critical issue during the production of recycled aggregates with high moisture content is screen clogging, which significantly impacts efficiency. This study aims to predict the moisture content using electrical conductivity. An appropriate electrical conductivity sensor was selected, and both laboratory and field experiments were conducted to measure electrical conductivity and evaluate the moisture content of recycled aggregate. The analysis revealed a strong correlation between electrical conductivity and moisture content, resulting in a moisture content prediction equation. Validation of the proposed equation demonstrated that actual moisture content was 0.10-0.82% higher than the predicted values. Future studies are recommended to examine the relationship between moisture content and screen clogging in vibrating screens. The findings suggest that leveraging electrical conductivity measurements for moisture content evaluation and quantitatively assessing screen clogging can significantly enhance the production efficiency of recycled aggregates. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Traffic volume estimation based on weather and foot traffic using LSTM for efficient asphalt pavement management: A case study of Jung-gu, Seoul

    아스팔트포장관리 효율화를 위한 LSTM 활용 날씨 및 유동인구에 따른 교통량 추정: 서울시 중구를 기준으로

    Byeong-Hun Woo, Dong-Ho Yoo, Jae-Soon Choi

    우병훈, 유동호, 최재순

    This study utilized the Long Short-Term Memory (LSTM) model to estimate traffic volume in Jung-gu, Seoul, using weather and foot traffic data. … + READ MORE
    This study utilized the Long Short-Term Memory (LSTM) model to estimate traffic volume in Jung-gu, Seoul, using weather and foot traffic data. The input variables included average temperature (°C), average relative humidity (%), sunlight (MJ/m2), maximum foot traffic, and minimum foot traffic, while the target variable was set as daily traffic volume. This study utilized a total of 1,400 days of time-series data collected from January 1, 2020, to October 31, 2024. During the training process, 500 epochs were optimized using the gradient descent method, with the initial loss value of 0.49 decreasing sharply to 0.15. The test results demonstrated that the model successfully captured the trends in traffic volume, producing predictions within a reasonable range. For example, on a specific day when the actual traffic volume was 640,000, the LSTM model predicted values ranging from 360,000 to 1,000,000, validating its reliability in range-based estimation. This study confirmed that traffic volume estimation is feasible even when using indirect variables, such as weather and foot traffic data. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Asphalt pavement pothole detection using a 3 channel based bayesian-convolutional neural network

    3채널 베이스 Bayesian-Convolutional Neural Network를 활용한 아스팔트 포장 포트홀 추적 연구

    Byeong-Hun Woo, Dong-Ho Yoo, Jae-Soon Choi

    우병훈, 유동호, 최재순

    This study presents an approach for detecting potholes in asphalt pavements using a 3-channel based Bayesian-Convolutional Neural Network (BCNN). The BCNN leverages … + READ MORE
    This study presents an approach for detecting potholes in asphalt pavements using a 3-channel based Bayesian-Convolutional Neural Network (BCNN). The BCNN leverages Bayesian inference to model the uncertainty in the weights, helping prevent overfitting and ensuring robust performance, even with limited data. BCNN was trained using RGB color-scale images and achieved remarkable accuracy in identifying potholes amidst complex environments containing shadows, vehicles, and other noise. The evaluation metrics for the BCNN showed a precision of 99.36%, a recall of 98.68%, and an F1 score of 99.02%. These results were validated against both test and validation datasets with varying levels of complexity. The findings demonstrate that BCNN provides a reliable method for detecting pavement defects, outperforming traditional CNN approaches, particularly in noisy environments. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Evaluation of Field Applicability of Synthetic Fiber-Reinforced Shotcrete through Fiber Output Amount Calculation

    합성 섬유보강 숏크리트의 혼입량 산출을 통한 현장 적용성 평가

    Kyung Suk Yoo, JangTae Kim, JaeSoon Choi

    유경석, 김장태, 최재순

    In previous studies, the quality characteristics of various synthetic fiber-reinforced shotcrete materials were evaluated to enhance their applicability in field conditions, and … + READ MORE
    In previous studies, the quality characteristics of various synthetic fiber-reinforced shotcrete materials were evaluated to enhance their applicability in field conditions, and optimal fiber incorporation rates were calculated. This research advances these studies by evaluating the field applicability of PET fiber-reinforced shotcrete, determining design input amounts and incorporation rates, and analyzing constructability, cost-effectiveness, environmental impact, and safety. Adjustments were made considering the bond load and drawing stress of PET fibers compared to steel fibers, resulting in a correction factor of 11.7%. The final fiber dosage was set at 8 kg/m3 after considering particle number and rebound rate. The constructability assessment showed that PET fibers do not cause floating and have significantly less clumping, enabling uniform construction performance. Economic analysis revealed a cost reduction of 34.1% compared to steel fibers. CO2 emissions were reduced by 25.6% with PET fibers and 55.3% with recycled PET fibers compared to steel fibers. Additionally, the human safety and fire resistance performances were also found to be superior. Based on these results, PET fiber-reinforced shotcrete is expected to be highly applicable in various tunnel construction sites. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Analyses for finding better test property for estimating serviceability characteristics of asphalt mixtures

    아스팔트 혼합물의 공용특성과 상관성이 높은 시험특성 분석

    Wonbae Kim, Yeongsam Kim, Sungjin Lee, Kwang W. Kim

    김원배, 김영삼, 이성진, 김광우

    The rut and crack are two most-typical damage patterns in asphalt pavement, and they are induced due to the change of binder … + READ MORE
    The rut and crack are two most-typical damage patterns in asphalt pavement, and they are induced due to the change of binder stiffness under loading at different temperature. Two test properties used for evaluating rutting resistance at 60°C in this study are wheel tracking (WT) rut depth and strength against deformation (SD). The test property used for evaluating crack resistance is indirect tensile strength (ITS) at 25°C. In addition, Marshall stability (MS) was used as another high-temperature property. Regression analyses were performed to evaluate correlation between two properties each other among the four using various asphalt mixtures. The rut resistance represented by rut depth of WT showed a good correlation with SD with R2 ≒ 0.90 on average. The regressions between ITS and SD, and ITS and WT showed R2 ≒ 0.61 and 0.69 on average, respectively. The reason why one property showed good correlation with another among the three is that those properties are related with binder stiffness. It is well known fact that the mixture with higher stiffness binder showed higher rut resistance and good tensile property. On the other hands, all three regressions between MS and WT, MS and SD, and MS and ITS showed poor correlations with R2 ≒ 0.2 on average. Therefore, it was found that the MS is not the property showing good relation with any performance of asphalt mixture. It was concluded that the WT results could be reliably estimated by SD. Although SD showed somewhat noticeable correlation with ITS, it should be studied further for practical application for estimation of tensile property by SD. However, it is better not to use Marshall stability as a serviceability index of asphalt mixture. - COLLAPSE
    31 December 2024
  • Scientific Paper

    A study on predictive models for identifying risk-areas to mitigate drunk driving accident damage

    음주사고 피해경감을 위한 음주사고취약지역 예측 모델에 관한 연구

    MinSeok Oh, JaeSoon Choi

    오민석, 최재순

    This study aims to develop a predictive model for identifying risk areas to mitigate the damage caused by drunk driving accidents. Using … + READ MORE
    This study aims to develop a predictive model for identifying risk areas to mitigate the damage caused by drunk driving accidents. Using drunk driving accident data from the TAAS database, the RandomForest algorithm was applied to estimate the probability of severe accidents for each autonomous district in Seoul. A risk map of Seoul’s districts was created based on the estimates. For High-Risk Areas, the importance of accident-related variables was analyzed to identify the underlying causes of accidents. The findings of this study are expected to contribute to identifying key risk factors of drunk driving accidents and devising effective measures for accident prevention. It is anticipated that further utilization of machine learning algorithms will enhance the model’s performance and provide more effective solutions for preventing severe accidents caused by drunk driving. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Analysis of the severity of traffic accidents on the highway by age group of offered drivers using machine learning techniques

    머신러닝기법을 이용한 가해운전자 연령대별 고속도로 내 교통사고 심각도 분석

    Minseo Cho, JaeSoon Choi

    조민서, 최재순

    Recently, due to aging in our country, not only the elderly population but also accidents caused by elderly drivers are increasing. To … + READ MORE
    Recently, due to aging in our country, not only the elderly population but also accidents caused by elderly drivers are increasing. To this end, various policies are being implemented, but research on analyzing factors affecting actual accidents involving elderly drivers is very lacking. Meanwhile, machine-learning and deep-learning technology, one of the AI ​​technologies in all fields of engineering, has recently developed significantly, and research cases utilizing various data are rapidly increasing. Taking these points into consideration, this study aims to use machine-learning techniques to identify various factors that affect traffic accidents, including elderly drivers. For this purpose, accident data on 9 highway routes from 2014 to 2022 were collected and analyzed, and influence factors by age were derived. There are four machine-learning algorithms used in impact analysis: AdaBoost, XGBoost, Random Forest, and SVM. The algorithm most suitable for this analysis was selected through comparison of results. Also, we paid attention to recent climate change phenomena and conducted impact analysis under specific climate conditions. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Fundamental study of new port classification system using data analysis of port wharves

    항만부두 데이터분석을 통한 항만부두 새로운 분류방법 기초연구

    JunSeong Choi, SeungHoon Oh, JaeJin Lee, JinSeong Seo

    최준성, 오승훈, 이재진, 서진성

    Currently, ports lack dedicated truck parking spaces, leading to illegal parking and increased traffic accident risks. Due to the need to supply … + READ MORE
    Currently, ports lack dedicated truck parking spaces, leading to illegal parking and increased traffic accident risks. Due to the need to supply asphalt-paved parking lots exclusively for cargo vehicles, previous studies have proposed classification methods considering one entire target on the 14 national trade ports each. However, the existing port classification method targeting the entire port has a problem. When designing the wharf of a new port step by step, the asphalt-paved parking lot may be designed either undersized or oversized after surveying similar facilities. Therefore, to design the asphalt-paved parking lot exclusively for cargo vehicles through an appropriate survey of similar facilities, this study conducted data analysis to develop a new port classification method for referring to similar facilities when designing the wharf of a new port. This study aims to analyze the limitations of existing entire–port standard classification methods by analyzing data from 380 wharves based on four port-specific factors: quay length, yard area, berthing capacity, and cargo handling capacity. Port Wharves were classified using the mean and standard deviation quality control concept. - COLLAPSE
    31 December 2024
  • Scientific Paper

    A predictive model for the permittivity of asphalt pavements using support vector regression

    Support Vector Regression을 이용한 아스팔트포장의 유전율 예측모델

    Chan Ho Song, Yun Jeong Kim, Joon Kyu Lee

    송찬호, 김윤정, 이준규

    In order to effectively apply ground penetrating radar technology for the quality control of asphalt pavements, a comprehensive understanding of the permittivity … + READ MORE
    In order to effectively apply ground penetrating radar technology for the quality control of asphalt pavements, a comprehensive understanding of the permittivity of the pavement is essential. This study aims to predict the permittivity of asphalt pavements based on material properties using support vector regression, a type of machine learning model. The predictive performance of the proposed model indicates that the Radial Basis Function kernel exhibits superior outcomes compared to the other three kernels. The results underscore the potential of the support vector regression technique as a promising tool for estimating the permittivity of asphalt pavements. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Sensitivity analysis of factors influencing the settlement of buried pipes installed beneath roads using explainable machine learning techniques

    해석가능한 머신러닝 기법을 이용한 도로 하부 지반에 설치된 매립관 침하의 영향요소에 대한 민감도 연구

    Yongjin Choi, SuWon Son

    최용진, 손수원

    The buried pipes, which are the core of modern urban infrastructure, play a crucial role in supplying essential resources such as water, … + READ MORE
    The buried pipes, which are the core of modern urban infrastructure, play a crucial role in supplying essential resources such as water, electricity, telecommunications, and gas. These pipes are installed beneath roads and must maintain long-term stability, however various factors can lead to collapse incidents. This study aims to analyze the important factors influencing the settlement behavior of buried pipes under roads and to provide foundational data to improve pipe design and management. The study conducted a sensitivity analysis of the effects of ground settlement volume, subcharge load, pipe diameter, and thickness on pipe settlement using numerical analysis. Linear regression and XGBoost with SHapley Additive exPlanations (SHAP) models were employed for the analysis. The results indicate that subcharge load and ground subsidence volume had the most significant impact on pipe settlement, while pipe diameter and thickness had relatively minor effects. These results present that subcharge load and ground settlement volume should be important considerations in the design of buried pipes.evaluated which external factors had the greatest influence on the settlement of the buried pipe. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Evaluation of the feasibility of epoxy asphalt mixtures for domestic pavement applications

    에폭시 아스팔트 혼합물의 국내 도로포장 적용성 검토

    Geon Ho Park, Sung Hyeon Park, Tae Soon Park, Jeoung Nam Son

    박건호, 박성현, 박태순, 손정남

    As living standards improve, environmental considerations in road pavement have gained attention alongside functional requirements. Epoxy asphalt, known for its high stiffness, … + READ MORE
    As living standards improve, environmental considerations in road pavement have gained attention alongside functional requirements. Epoxy asphalt, known for its high stiffness, durability, and waterproofing, is widely used in orthotropic steel deck bridges. This study compared a domestic epoxy asphalt with Chemco’s established product to evaluate its suitability for both bridge and general road pavements. Laboratory tests on various asphalt mixtures showed that Product B performs as well as or better than Product A. These results suggest that Product B can be effectively applied to diverse asphalt mixtures, contributing to the development of durable, high-performance road pavements. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Thermal stress computation of asphalt mixture using simple power law transfer function approach
    Ki Hoon Moon
    It is well recognized that low temperature cracking is one of the crucial distresses on asphalt pavement. When low temperature cracking happens, … + READ MORE
    It is well recognized that low temperature cracking is one of the crucial distresses on asphalt pavement. When low temperature cracking happens, easy infiltration of water and moisture can be happened. Then this can lead significant pavement distresses such as huge macro cracks, pot hole issues and pavement deflections. It is well known that Thermal Stress (TS) can be a successful and reliable parameter on low temperature performance evaluation of given asphalt material however, the computation process is complex. In this paper, a simple computation method of TS was introduced. Based on the recommendations in this paper, many pavement agencies can easily compute TS results from the current asphalt material mechanical testing method. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Relaxation modulus comparison of tank and modified asphalt binder by means of experimental and simple numerical approaches
    Ki Hoon Moon
    For bituminous material such as asphalt pavement material, low temperature cracking is one of significant distresses. During the cold session, several macro … + READ MORE
    For bituminous material such as asphalt pavement material, low temperature cracking is one of significant distresses. During the cold session, several macro cracks can be occurred due to too brittle characteristic of asphalt material. To evaluate the level of brittleness of given asphalt binder, low temperature creep test is widely used. In this low temperature creep test of asphalt material, creep stiffness is computed and this value can be converted into relaxation modulus: one of significant criteria for evaluating low temperature performance of asphalt binder, with various mathematical approaches. In this paper, relaxation modulus of modified asphalt binder with two different mathematical approaches, was computed, analyzed then compared. It was found that the two different computation methods can successfully provide upper and lower bounds of relaxation modulus of given asphalt binder. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Rut characteristics of open-graded friction course (OGFC) asphalt mixtures

    개립마찰포장용 아스팔트 혼합물의 소성변형 특성연구

    Wonbae Kim, Jaewon Jo, Kwang W. Kim

    김원배, 조재원, 김광우

    The objective of this study was to evaluate rut resistance characteristics of open-graded friction course (OGFC) asphalt mixtures. Two maximum size aggregates … + READ MORE
    The objective of this study was to evaluate rut resistance characteristics of open-graded friction course (OGFC) asphalt mixtures. Two maximum size aggregates (10 mm and 13 mm) with three polymer-modified asphalt mixtures were used to prepare OGFC asphalt mixtures for the strength against deformation (SD) and asphalt pavement analyser (APA) tests. Three polymers included LDPE (low-density polyethylene), CRM (crumb rubber modifier) and SBS (styrene-butadiene-styrene). Six OGFC mix specimens were prepared at optimum asphalt content with the air void ratio of 16.2~17.3% using gyratory compactor. The SD test results showed that LDPE mixes showed approximately 4.2 MPa on average, while CRM and SBS mixes showed 3.6 MPa and 2.7 MPa, on average, respectively. APA test results was similar to those of SD; rut depths of LDPE, CRM and SBS mixtures being 1.35 mm, 3.5 mm, and 4.2 mm, on average, respectively. Therefore, the OGFC mixes using LDPE was found to show strong rut resistance properties in both tests, although SD was slightly lower than 4.25 MPa, which is the minimum limit of 1st class highway dense-grade asphalt pavement in Korea. Since OGFC specimen has air void ratio of 16-17%, which is 4 times greater than dense-grade specimen, instead of applying the dense-grade property limit directly to OGFC, it is suggested to prepare reasonable limits for OGFC mixes in the future. The regression analysis between APA rut depth and SD showed that the two properties has relatively high correlation with R2 > 0.81. Therefore, it will be possible to use SD for estimation for OGFC rut resistance by SD after further studies. - COLLAPSE
    31 December 2024
  • Scientific Paper

    Feasibility study of Non Contact Digital Ski (NCDS) application on asphalt pavement construction for improving smoothness purpose
    Ki Hoon Moon
    Recently, improving driving quality on asphalt pavement layer became more crucial compared to the conventional pavement construction quality management. For past decades, … + READ MORE
    Recently, improving driving quality on asphalt pavement layer became more crucial compared to the conventional pavement construction quality management. For past decades, many pavement quipment companies tried to improve the surface smoothness on asphalt pavement layer. One of the achievements is Non Contact Digital Ski (NCDS) technology : a piece of modern pavement surface levelling equipment. In this paper, the feasibility of NCDS on actual asphalt pavement construction was considered visually. As an experimental work, the International Roughness Index (IRI, m/km) was tested, measured, analyzed then compared. It was found that the NCDS technology provided better pavement smoothness results compared to the conventional construction surface smoothing method. - COLLAPSE
    31 December 2024