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Scientific Paper
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Seismic analysis evaluation of IER-Type retaining walls under road embankment conditions considering Korea’s maximum credible earthquake
국내 발생 최대지진을 고려한 도로 성토 조건에서의 IER 지주식 흙막이 내진해석 평가
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ITae Oh, Minsu Seo, SuWon Son
오이태, 서민수, 손수원
- This study investigates the seismic stability of retaining systems used in embankment construction, with a particular focus on a comparative evaluation of …
- This study investigates the seismic stability of retaining systems used in embankment construction, with a particular focus on a comparative evaluation of the Inclined Earth Retaining (IER) method and conventional H-pile retaining walls. Numerical analyses were performed using FLAC2D, incorporating nonlinear soil behavior and interface elements to realistically simulate soil-structure interaction. Ground motion records from the 2016 Gyeongju earthquake were applied to evaluate dynamic responses under embankment heights of 3 m, 5 m, and 7 m. The analysis results show that although the IER system exhibited relatively higher amplification ratios of internal forces under seismic loading, it consistently resulted in the smallest absolute lateral displacements and internal force demands across all analyzed conditions. In contrast, the H-pile retaining system demonstrated significant structural stress responses, even when the pile spacing was reduced. These findings indicate that the IER method provides superior seismic performance and structural efficiency, particularly under higher embankment conditions. The results of this study offer practical insights for the selection and seismic design of retaining wall systems in earthwork engineering. - COLLAPSE
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Seismic analysis evaluation of IER-Type retaining walls under road embankment conditions considering Korea’s maximum credible earthquake
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Technical Notes
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A basic study on the improvement of smoothness evaluation method for asphalt pavement
아스팔트 포장의 평탄성 평가 방법 개선을 위한 기초 연구
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Kyu-dong Jeong, Moon-Sup Lee
정규동, 이문섭
- PrI and IRI, which are the methods of measuring the smoothness of asphalt pavement, were investigated and analyzed. As a result, it …
- PrI and IRI, which are the methods of measuring the smoothness of asphalt pavement, were investigated and analyzed. As a result, it was evaluated that it was appropriate to change from the current PrI to IRI to maintain the continuity of maintenance after the initial quality control and subsequent road pavement was constructed, and to increase the convenience of the driver. Accordingly, in order to apply IRI in Korea, IRI measurement and analysis methods and quality standards suitable for Korean characteristics, measurement equipment certification and calibration standards, and measurement manpower training systems must be prepared. - COLLAPSE
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A basic study on the improvement of smoothness evaluation method for asphalt pavement
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Scientific Paper
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A basic study on carbon emission in the production process of asphalt mixtures
아스팔트 혼합물 생산시 탄소 발생량에 대한 기초 연구
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Kyu-dong Jeong
정규동
- A plan was prepared to measure the amount of electricity and fuel used when producing an asphalt mixture in an asphalt plant. …
- A plan was prepared to measure the amount of electricity and fuel used when producing an asphalt mixture in an asphalt plant. And the amount used in the asphalt plant was measured and the carbon dioxide emission was analyzed using this. As a result, the carbon dioxide emission was 7.7 kgCO2eq/ton for the new asphalt mixture and 10.2 kgCO2eq/ton for the recycled asphalt mixture, which was 1.3 times higher for the recycled asphalt mixture. The emissions from burner fuel use were 3.5 times higher for new asphalt mixtures and 5.6 times higher for recycled asphalt mixtures than for carbon dioxide mixtures according to electricity use. Since electricity consumption is greatly affected not only by production time but also by the time between production operations, it is necessary to increase continuous production time. The carbon emission generated when producing domestic asphalt mixtures applying the research results is 164,454 tCO2eq/year, and it was analyzed that it has an effect of KRW 1.73 billion/year when converted into emission trading prices. - COLLAPSE
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A basic study on carbon emission in the production process of asphalt mixtures
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Technical Notes
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Productivity Improvement Strategies for Recycled Aggregate Production Systems: Focusing on Enhancing Vibrating Screen Performance and Cone Crusher Efficiency
순환골재 생산시스템의 생산성 향상 방안: 스크린 선별성능 향상과 콘크러셔 파쇄 효율 향상을 중심으로
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Kyung Suk Yoo
유경석
- Although the importance of recycled aggregates is growing in line with government resource circulation policies, field operations face significant productivity challenges due …
- Although the importance of recycled aggregates is growing in line with government resource circulation policies, field operations face significant productivity challenges due to screen blinding caused by high-moisture raw materials and reduced crushing efficiency in cone crushers. Therefore, this study proposes technical optimization strategies for the screening and crushing processes, which are critical components of recycled aggregate plants. To enhance screening performance, the study applies dry aggregate feedback injection and variable eccentric shaft control technologies to minimize screen blinding. Furthermore, to boost crushing efficiency, the introduction of a parallel cone crusher system and input distribution control method is suggested to induce choke feeding and improve particle shape. The proposals in this study contribute to ensuring the quality reliability of recycled aggregates and reducing production costs, thereby contributing to achieving the goal of stabilizing aggregate supply. - COLLAPSE
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Productivity Improvement Strategies for Recycled Aggregate Production Systems: Focusing on Enhancing Vibrating Screen Performance and Cone Crusher Efficiency
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Technical Notes
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National policy transformation toward sustainable road infrastructure in the carbon-neutral era
탄소 중립 시대의 지속 가능한 도로 인프라를 향한 국가적 정책 전환
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Chool Seon Rhee
리출선
- This technical note examines the need for a paradigm shift in national road infrastructure policy toward sustainability in the era of carbon …
- This technical note examines the need for a paradigm shift in national road infrastructure policy toward sustainability in the era of carbon neutrality. It challenges the long-standing, conventional reliance on heated asphalt production methods in road construction and maintenance. In particular, it highlights the policy significance of adopting innovative thinking that leverages proven technologies enabling the recycling of reclaimed asphalt pavement through carbon-neutral, non-heated processes. The note further emphasizes the necessity of establishing an “ICON” that can symbolize and catalyze this transformative shift in national policy. - COLLAPSE
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National policy transformation toward sustainable road infrastructure in the carbon-neutral era
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Technical Notes
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Road paving technology in response to climate change
기후환경변화에 대응한 도로 포장기술
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Kihag Kim
김기학
- The spread of road paving has significantly contributed to social and economic development by improving the efficiency of automobile traffic. However, concerns …
- The spread of road paving has significantly contributed to social and economic development by improving the efficiency of automobile traffic. However, concerns have also been raised about the environmental impact of paving, as it is recognized as one of the causes of the heat island phenomenon, environmental pollution, and urban flooding. Consequently, paving has begun to be recognized as a factor that causes environmental burden. A variety of paving technologies related to the environment have been developed. Systematically organizing these technologies from an environmental perspective, analyzing the environmental issues each technology addresses, and clearly assessing its effectiveness are both practical and academically significant. Therefore, this book aims to organize and categorize paving technologies that address specific environmental issues. - COLLAPSE
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Road paving technology in response to climate change
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Scientific Paper
- Comparison of thermal stress of asphalt mixture by means of two different Simple Performance mechanical Test (SPT)
- Ki Hoon Moon
- Low temperature cracking is a crucial distress for actual asphalt pavement constructed in Northern U.S. and Canada. When temperature drops, thermal stresses …
- Low temperature cracking is a crucial distress for actual asphalt pavement constructed in Northern U.S. and Canada. When temperature drops, thermal stresses start to develop in the restrained asphalt pavement layer. When the temperature reaches a critical temperature limit, thermal cracking finally occurs. This thermal stress results of asphalt pavement are used for computing mechanical performance of actual pavement through current AASHTOWare Pavement software. In this paper, extensive analyses and graphical comparison are applied to compute and compare thermal stress results by means of two different Simple Performance mechanical Test (SPT). As experimental approaches, Indirect Tensile Test (IDT) and Bending Beam Rheometer (BBR) creep tests were considered. It is found that thermal stress results computed by means of IDT and BBR mixture creep data are similar, respectively. - COLLAPSE
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Scientific Paper
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Data-driven stability analysis of road slopes with free groundwater
자유지하수를 갖는 도로사면의 데이터 기반 안정성 해석
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Su Min Noh, Tae Young Son, Jae Hwan Lee, Joon Kyu Lee
노수민, 손태영, 이재환, 이준규
- This study investigates the stability of road slopes with a free groundwater surface represented by the Dupuit theory. Slope stability analysis was …
- This study investigates the stability of road slopes with a free groundwater surface represented by the Dupuit theory. Slope stability analysis was performed using a finite element limit analysis based on the strength reduction method. The result of the analysis is presented in terms of the stability factor and the factor of safety, and the effects of groundwater level within the slope, slope angle, soil cohesion, and internal friction angle on the slope stability are examined. A total of 756 factors of safety were obtained from the numerical analyses based on various combinations of these parameters. In addition, a data-driven model is proposed to predict the computed factor of safety. The model combines the XGBoost algorithm of machine learning with the BOHB technique of hyperparameter optimization, enabling fast and accurate prediction of the safety factor for slopes under different groundwater levels. The performance of the proposed model was evaluated in terms of R², RMSE, and MAE, yielding values of 0.998, 0.021, and 0.009, respectively. The contribution of each variable to the prediction is provided by SHAP. - COLLAPSE
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Data-driven stability analysis of road slopes with free groundwater
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Scientific Paper
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Pothole detection and tracking in asphalt pavement using monocular depth estimation
단안깊이추정을 활용한 아스팔트 포장의 포트홀 감지 및 추적
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Changhwan Jang, Byeong-Hun Woo, Jin-Young Seok, Hong Gi Kim
장창환, 우병훈, 석진영, 김홍기
- Recent advances in artificial intelligence (AI) have enabled rapid progress in image-based object detection, with applications extending into infrastructure monitoring. This study …
- Recent advances in artificial intelligence (AI) have enabled rapid progress in image-based object detection, with applications extending into infrastructure monitoring. This study investigates the feasibility of applying Monocular Depth Estimation (MDE) to detect and track potholes in asphalt pavement. Unlike traditional approaches that require absolute depth data and extensive training, MDE provides relative depth information directly from single images, offering a lightweight and efficient alternative. Using the Zoe.D library, one of the most advanced MDE modules, we evaluated pothole detection performance on publicly available datasets. Experimental results demonstrate that MDE can successfully highlight pothole regions under favorable conditions, particularly when images are captured at close range with minimal background noise. However, failures occurred when distant objects such as trees, vehicles, or fences dominated the depth perception, or when reflective surfaces like water introduced noise. In some cases, post-processing adjustments improved the visibility of pothole contours, suggesting that MDE can complement conventional object detection models in multimodal frameworks. Overall, while MDE alone is insufficient for robust pothole detection, its integration with existing detection architectures shows promise for cost-effective, non-intrusive pavement monitoring. This research highlights both the limitations and potential of MDE in construction engineering applications. - COLLAPSE
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Pothole detection and tracking in asphalt pavement using monocular depth estimation
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Scientific Paper
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A study on the mitigation of screen blinding in recycled aggregate production using a variable amplitude system
가변 진폭 시스템을 활용한 순환골재 망 막힘 개선에 관한 연구
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Min Seok Oh, Kyung Suk Yoo
오민석, 유경석
- Although the mandatory use of recycled aggregates is expanding in line with government resource circulation policies, production sites face significant challenges due …
- Although the mandatory use of recycled aggregates is expanding in line with government resource circulation policies, production sites face significant challenges due to high moisture content in raw materials caused by wet processes and weather conditions. High-moisture soil with strong adhesiveness induces screen blinding in vibrating screens, leading to reduced production efficiency and quality degradation. This study applies a variable amplitude vibrating screen system, capable of multi-stage control (Stages 1-6) during operation, to analyze blinding characteristics according to moisture content variations and proposes process optimization strategies. To ensure accuracy, moisture content was measured according to the ASTM D4643 standard, and critical moisture thresholds for each amplitude stage were derived. The results indicated that while conventional low-amplitude operation caused screen blockage under high-moisture conditions , operating at the maximum amplitude suppressed the blinding rate to below 4% even at moisture levels exceeding 17%, thereby enabling continuous production. Furthermore, it was verified that applying amplitude control allows for stable operation even when reducing the screen mesh size from 25 mm to 13 mm without aggravating blinding, thus improving particle separation performance. This study is significant in establishing operational guidelines that allow for active response to high-moisture environments through variable amplitude control. - COLLAPSE
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A study on the mitigation of screen blinding in recycled aggregate production using a variable amplitude system
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Scientific Paper
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Flight path and altitude optimization of drones using deep reinforcement learning for automation of road pavement management
도로포장 관리 자동화를 위한 심층강화학습 활용 드론 비행 경로 및 고도 최적화 연구
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Byeong-Hun Woo, Yongjoo Kim, Kanghun Lee, Ilhwan Kang, Kinam Han, Changhwan Jang
우병훈, 김용주, 이강훈, 강일환, 한기남, 장창환
- This study explored the application of deep reinforcement learning (DRL) to optimize drone flight paths and altitudes for road pavement management automation. …
- This study explored the application of deep reinforcement learning (DRL) to optimize drone flight paths and altitudes for road pavement management automation. While drones have been widely utilized in infrastructure monitoring, research on autonomous flight path optimization in complex terrains remains limited. To address this gap, a simulation approach was carried out using space shuttle radar topography mission (SRTM) data to model a mountainous area near Hantan River Eco-Scenic Complex in South Korea. The simulation space was discretized into a 100×100 grid, and a deep Q-learning (DQL) framework was implemented to train the virtual drone agent. Reward and punishment mechanisms were designed to encourage efficient navigation while avoiding terrain collisions. The simulation demonstrated that after 170 training episodes (early stopped point), the agent successfully learned an optimal 3D trajectory that avoided obstacles and reached the target point. The results confirm the feasibility of DRL for autonomous drone navigation in road pavement management, suggesting that future work should extend to real-world environments with road infrastructure and validate performance in actual autonomous flights. - COLLAPSE
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Flight path and altitude optimization of drones using deep reinforcement learning for automation of road pavement management
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Scientific Paper
- Effect of physical hardening on asphalt material: From binder to mixture
- Ki Hoon Moon
- The significant effect of physical hardening on asphalt binder properties at low temperature is well documented. However, not many studies addressing physical …
- The significant effect of physical hardening on asphalt binder properties at low temperature is well documented. However, not many studies addressing physical hardening in asphalt mixtures crucially. This paper investigates physical hardening effect on asphalt mixtures creep behavior especially at low temperatures. Bending Beam Rheometer (BBR) creep tests were performed on asphalt binder and asphalt mixture beams conditioned at the test temperature for 1h and 24h to quantify physical hardening effects. Both laboratory-prepared and field samples were used. For all tested asphalt binders, the additional conditioning time resulted in significant increase in creep stiffness and in significant reduction in m-values. For asphalt mixtures, much less significant changes are observed, and the type of aggregate appears to be a significant factor. - COLLAPSE
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Scientific Paper
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Statistical data analysis of deformation strength (SD) level of various field asphalt mixtures
현장 아스팔트혼합물 변형강도(SD) 수준의 통계적 분석 연구
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Wonbae Kim, Chaehyeon Kim, Ye-eun Kim, Kyong K. Yun, Kwang W. Kim
김원배, 김채현, 김예은, 윤경구, 김광우
- The deformation strength (SD) was developed to create a load-induced spot deformation which is similar to the one created by …
- The deformation strength (SD) was developed to create a load-induced spot deformation which is similar to the one created by a static wheel, and to measure the material’s resistance against the deformation at high temperatures. The SD is currently used as a mix-design criteria for rut resistance of asphalt pavement mixture. The criteria for the surface course of 2nd class road pavement and of 1st class highway pavement are S D 3.2 MPa and S D 4.25 MPa, respectively, which were set forth by Ministry of Land, Infrastructure and Transport, Republic of Korea. However, not many statistical data of field asphalt mixtures were collected and evaluated yet. Therefore, in this study, random samples of 31 PG64-22 (normal asphalt) mixtures and 18 PG76-22 (polymer-modified asphalt: PMA) mixtures for surface course were collected from nation-wide field sites. Three specimens (100 mm in diameter) were made using a gyratory compactor for measuring SD for each site mixture. The statistical data for SD were analyzed to estimate population mean and standard deviation. Assuming the SD population follows normal distribution, the current process mean of SD ( S D ¯ ) was found for each binder mixture (64-22 and 76-22). Statistical data shows that both SD means satisfied the respective mix-design criterion. The coefficient of variation (Vc) of normal mixes was approximately 10%, which is decent level of variation, and Vc of PMA mixes were found to be 8.63%, which is lower than that of normal mixes. In general, the strength quality in the field mixes was found to be controlled properly in SD point of view. - COLLAPSE
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Statistical data analysis of deformation strength (SD) level of various field asphalt mixtures
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Scientific Paper
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Serviceability properties of warm-mix recycled modified asphalt mixtures
중온 개질 순환 아스팔트 혼합물의 공용 특성 평가
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Wonbae Kim, Woohyun Kim, Kyong K. Yun, Kwang W. Kim
김원배, 김우현, 윤경구, 김광우
- In this study, the serviceability performance of a warm-mix recycled polymer-modified asphalt (WRPMA) mixture, which was produced at 150 ± 5°C using …
- In this study, the serviceability performance of a warm-mix recycled polymer-modified asphalt (WRPMA) mixture, which was produced at 150 ± 5°C using a PG76-22 warm-mix polymer-modified asphalt (WPMA) binder with a rejuvenator (RJ), was evaluated. A 30% of reclaimed asphalt pavement (RAP), heated indirectly to 110°C, virgin binder (WPMA+RJ) at 163 ± 5°C were mixed first, and new aggregates at 163 ± 5°C was added to the first blend and then mixed together in 2nd stage, which is called a stage mixing (SM) technique. A PG76-22 hot-mix PMA (HPMA) mixture was produced at 180 ± 5°C and a warm-mix PMA (WPMA) mixture without RAP was prepared at 150 ± 5°C using the same aggregate grade for comparison with the WRPMA mix. In comparison with the hot and warm mixes, the WRPMA mixes showed identical properties in deformation strength (SD), indirect tensile strength (ITS), tensile strength ratio (TSR) and dynamic stability (DS). The WRPMA mix satisfied the serviceability performance requirements for surface course of heavy vehicle highway pavement. This high performance is result of using the WPMA binder showing a low dynamic viscosity, adequate use of RJ based on GPC test on RAP binder aging, and application SM technique. The WRPMA mixes were used in a field pavement in a 1st class road. It was evaluated that the field pavement mixture showed somewhat lower values compared with the lab mix, but satisfied all the requirements for surface course of heavy vehicle highway pavement. - COLLAPSE
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Serviceability properties of warm-mix recycled modified asphalt mixtures
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Scientific Paper
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Comparative economic assessment of lean concrete and gravel wearing course methods for unpaved road improvement in Lao PDR
라오스 비포장도로 개선을 위한 린콘크리트와 자갈골재층 공법의 경제성 비교 평가
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Il Hwan Kang, Yong Joo Kim, Kang Hun Lee
강일환, 김용주, 이강훈
- This study aims to evaluate and compare the economic feasibility of the lean concrete method (LCM) and the gravel wearing course (GWC) …
- This study aims to evaluate and compare the economic feasibility of the lean concrete method (LCM) and the gravel wearing course (GWC) method for unpaved road improvement in Laos. The analysis incorporates the estimation of construction costs per cubic meter, projection of future inflation rates based on a 10-year review of the Consumer Price Index (CPI) and inflation data, and scenario-based assessments using three economic conditions: optimistic, neutral, and pessimistic. The results show that although the lean concrete method has a higher initial construction cost, its long service life of approximately 25 years leads to significantly lower long-term financial burden. In contrast, the GWC method requires annual reconstruction due to a one-year service life, causing cumulative construction costs to rise rapidly. Across all scenarios, the cumulative cost of the GWC method exceeded the initial lean concrete cost within 2-5 years, with the crossover occurring earlier under the pessimistic scenario. By 2050, cumulative GWC costs reached approximately 0.66 million USD, 0.96 million USD, and 2.47 million USD under the optimistic, neutral, and pessimistic scenarios, respectively, demonstrating a substantially higher long-term expenditure compared with lean concrete. The findings highlight the importance of life-cycle cost considerations rather than initial unit cost in selecting construction methods for rural roads in developing countries such as Laos. - COLLAPSE
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Comparative economic assessment of lean concrete and gravel wearing course methods for unpaved road improvement in Lao PDR
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Scientific Paper
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Proposal of the methodology for selecting a field investigation section and investigation plan for Skid-Resistant pavement
미끄럼방지 포장의 현장 조사구간 선정 및 조사계획 방법론 제안
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Junseong CHOI, SangYum LEE, Jongun Baek
최준성, 이상염, 백종은
- This Study outlines the technical considerations that must be taken into account when selecting survey sections to understand the current status of …
- This Study outlines the technical considerations that must be taken into account when selecting survey sections to understand the current status of skid-resistant pavement in Korea. First, when determining the survey sections, comprehensive considerations are necessary, including road type (national highways, local roads), speed limits, climatic conditions, gradient (5% or more), and risk of skidding accidents. In consideration of these factors, a test section determination methodology based on existing research results is proposed. The methodology was structured after verifying the status change from the initial construction up to the present day using tools like street view, to confirm the performance degradation of skid resistance over the public service period. The appropriate survey period is spring and autumn, and the evaluation of skid resistance performance should use the Grip Number Tester, BPT (British Pendulum Tester), and PFT (Pavement Friction Tester) if necessary. The pavement surface condition should be analyzed through visual inspection (utilizing video-based equipment), and it is appropriate to quantify the degree of damage. The results of the field survey, determined by this survey section methodology, will be utilized to analyze the causes of performance degradation and the correlation between factors using statistical methods (ANOVA, regression analysis), and to establish proposed management standards and maintenance plans for skid-resistant pavement. - COLLAPSE
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Proposal of the methodology for selecting a field investigation section and investigation plan for Skid-Resistant pavement
Journal Informaiton
Journal of the Korean Asphalt Institute
Journal of the Korean Asphalt Institute
KOREAN ASPHALT INSTITUTE
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Tel: +82-02-948-1268 / E-mail: asphaltinstitute@naver.com Copyright© KOREAN ASPHALT INSTITUTE. Powered by APUB
Tel: +82-02-948-1268 / E-mail: asphaltinstitute@naver.com Copyright© KOREAN ASPHALT INSTITUTE. Powered by APUB