도로포장의 대표적 파손 종류인 균열은 일반적으로 폭이 좁고 기하학적으로 정의하기 어렵기 때문에 균열을 검출하고 유형을 분류 한 후 정량화하기까지 많은 시간이 소요된다. 본 연구의 목적은 균열 검출 이후 단계에서 요구되는 분류 및 정량화 과정을 자동화하 기 위함이다. 이를 위해, 본 연구에서는 균열이 매핑된 포장관리체계용 노면영상을 대상으로 하는 25cm 정사각형의 격자 배치 방법과 차륜 통과 영역 구분을 제시하였다. 각 격자 내 균열 객체의 길이와 진전방향, 인접한 정도 등 시각적 정보에 의한 균열 격자 속성을 정의하고 프로그래밍하여 균열 유형분류와 집계를 자동화하였다. 무작위로 수집된 고속도로 노면영상 자료를 통해 포장형식 별 주요 균열 유형을 분석하였고 차륜 통과 영역에서의 균열률 증가를 수치적으로 확인하였다.

포장상태 평가를 위한 노면영상 촬영은 라인스캔 방식이 주를 이루고 있다. 라인스캔 특성 상, 조사환경이나 장비특성이 달라질 경 우 밝기가 상이한 노면영상을 취득할 수 있고 이는 U-net과 같은 픽셀 단위 segmentation 딥러닝 모델의 균열 자동검출 성능에 영향을 미친다. 본 연구에서는 인공지능 검출 모델의 변경 없이 영상의 밝기 최적화와 morphology 연산기법을 노면영상 전·후처리 방법으로 제시하고 그 효과를 분석하였다. 영상 처리를 통해 과다 검출경향을 보인 이상치들이 제거되었으며 정답으로 간주할 수 있는 전문요 원 분석결과인 GT 균열률과의 상관성 또한 향상됨을 확인하였다.

도로 주행의 안전성 측면에서 타이어-노면간 미끄럼 마찰력은 주행 차량의 제동거리와 직접적인 요인으로 작용한다. 포장재료와 공법은 노출되는 포장 표면에 적절한 노면의 조직(Texture)을 형성하여 노면의 미끄럼 마찰력을 증가시킨다. 도로 표면에 노출되는 사용골재의 크기와 종류를 달리하거나 인위적인 홈을 주어 Macrotexture와 Microtexture를 형성 한다. 형성된 노면 조직은 시간이 경과 됨에 따라 환경하중과 교통하중이 반복 재하되면서 표면마모가 급격히 진행된다. 교통량의 흐름에 따라 마모로 인해 Microtexture 뿐만 아니라 Macrotexture의 노면조직은 매끄러운 표면으로 변해간다. 교통량의 흐름은 다양하다. 교통량 통계자료에 따르면 고속도로 이용차량의 약 70%는 승용차와 같은 2축 1단위로 구성 된 1종 차량이 차지하고 있다. 이는 국내 교통 특성은 포장 마모에 취약한 환경임을 말해주고 있다. 주행 차량들의 좌/ 우 바퀴의 간격과 주행위치의 다른 궤적에 따라 차량바퀴의 횡방향 변동을 원더링(Wandering)이라하는데, 도로포장 분 야에서 교통특성이 포장에 미치는 영향으로 원더링에 대한 연구 많이 진행 되어왔다. 본 연구에서는 실제 고속도로와 시 험도로에서 횡방향 위치별 미끄럼 마찰을 반복 조사하여 차량의 원더링에 따라 미끄럼 마찰저항이 다르게 분포함을 정 량적으로 입증하였다.

In South Korea, the level of Highway Pavement Management System (HPMS) was developed since early 2000. During this time numbers of professional pavement condition monitoring equipment were developed and applied in the actual field. One of the remarkable results is 3D Pavement condition Monitoring profiler vehicle (3DPM) designed and developed in Korea Expressway Corporation Research Division (KECRD). Thanks to this equipment, The surface condition of current pavement can successfully be monitored and proper following management strategy cab be established. However, the inner condition of pavement layer cannot be monitored dur to limitation of 3DPM equipment. In this paper, Bending Beam Rheometer (BBR) mixture creep test was performed to verify the effectiveness of current 3DPM equipment. It was found that the current 3DPM equipment has reasonable feasibility on surveying pavement condition.

Evaluation of low temperature performance of asphalt mixture is significant not only for mitigating transverse thermal cracking but also for preventing potential traffic accidents. In addition, the engineers in pavement agency need to inform the proper pavement section where urgent management is needed. Since early 2000, Korea Expressway Corporation Research Division (KECRD) developed an 3D Pavement condition Monitoring profiler vehicle (3DPM) to survey expressway pavement surface condition precisely. The management of whole expressway network became more precise, effective and efficient than before due to application of 3DPM and HPMS. One thing recommended is: performing extensive mechanical test and corresponding data analysis work procedure to further strengthen the feasibility of current 3DPM approach and HPMS. In this paper two activities were considered: first, the pavement section where the urgent care is recommended is selected by means of 3DPM approach. Then asphalt mixture cores were acquired on that specified section then low temperature fracture test: Semi Circular Bending (SCB) test, was performed. The mechanical parameters, energy release rate and fracture toughness were computed then compared. It is concluded that the current 3DPM approach in KEC can successfully evaluate and analyze selected pavement condition. However, more extensive experimental works are needed to further strengthen the current pavement analyzing approaches.

In this study, data on indication errors within the range of 0 to 10 mm were measured using a dial gauge, which is widely used as a comparative measuring instrument in the field. Using Minitab, a statistical program, measurement conditions were determined during calibration of measuring instruments. Since the P value of the test statistic for the indication error is 0.000 to 0.003, the alternative hypothesis (H1) that no significant difference occurs due to a change in the measurement point at the significance level of 0.05 was adopted.

PURPOSES : The evaluation of the low-temperature performance of an asphalt mixture is crucial for mitigating transverse thermal cracking and preventing traffic accidents on expressways. Engineers in pavement agencies must identify and verify the pavement sections that require urgent management. In early 2000, the research division of the Korea Expressway Corporation developed a three-dimensional (3D) pavement condition monitoring profiler vehicle (3DPM) and an advanced infographic (AIG) highway pavement management system computer program. Owing to these efforts, the management of the entire expressway network has become more precise, effective, and efficient. However, current 3DPM and AIG technologies focus only on the pavement surface and not on the entire pavement layer. Over the years, along with monitoring, further strengthening and verification of the feasibility of current 3DPM and AIG technologies by performing extensive mechanical tests and data analyses have been recommended. METHODS : First, the pavement section that required urgent care was selected using the 3DPM and AIG approaches. Second, asphalt mixture cores were acquired from the specified section, and a low-temperature fracture test, semi- circular bending (SCB) test, was performed. The mechanical parameters, energy-release rate, and fracture toughness were computed and compared. RESULTS : As expected, the asphalt mixture cores acquired from the specified pavement section ( poor condition – bad section) exhibited negative fracture performances compared to the control section (good section). CONCLUSIONS : The current 3DPM and AIG approaches in KEC can successfully evaluate and analyze selected pavement conditions. However, more extensive experimental studies and mathematical analyses are required to further strengthen and upgrade current pavement analysis approaches.

PURPOSES : The numeric-based Highway Pavement Management System (HPMS), along with an advanced three-dimensional pavement condition monitoring profiler vehicle (3DPM), in South Korea has presented remarkable advancements in pavement management since the early 2000. Based on these results, visual distress on pavement surfaces can be easily detected and analyzed. Additionally, the entire expressway pavement surface conditions in South Korea can be easily monitored using the current graphical user interface-based advanced information graphic (AIG) approach. Therefore, a critically negative pavement section can be detected and managed more easily and efficiently. However, the actual mechanical performance of the selected pavement layer still needs to be investigated in a more thorough manner not only to provide more accurate pavement performance results but also to verify the feasibility of the current 3DPM and AIG approaches. In this study, the low-temperature performance of the selected asphalt pavement layer section was evaluated to further verify and strengthen the feasibility of the current 3DPM and AIG approaches developed by the Korea Expressway Corporation. METHODS : Based on 3DPM and AIG approach, the positive and negative-riding-quality road sections were selected, respectively. The asphalt material cores were extracted from each section then bending beam rheometer mixture creep test was performed to measure their low-temperature properties. Based on the experimental results, thermal stress results were computed and visually compared. RESULTS : As expected, the asphalt material from the negative driving performance section presented a poorer low-temperature cracking resistance than that from the positive driving performance section. CONCLUSIONS : Current 3DPM equipment can successfully evaluate expressway surface conditions and the corresponding material performance quality. However, more extensive experimental studies are recommended to verify and strengthen the findings of this study

PURPOSES : In this study, a driving simulation testing equipment was developed to derive the optimal longitudinal tinting that can reduce the lateral vibration of the vehicle. Various types of longitudinal textures and tires were evaluated through simulation testing with the equipment. Based on the results, 3×3×16mm tinning as the optimal longitudinal texture was selected among 8 textures. METHODS : Based on the literature review, the causes of lateral vibration were analyzed, and parts and types for testing equipment development were reviewed. Driving simulation with testing equipment was conducted considering various textures and tires. To verify the test results, finite element analysis was performed under the similar conditions. And field test for two textures was conducted to find the optimal longitudinal texture. RESULTS : Based on the literature review, driving simulation test, finite element analysis and field test, longitudinal texture of 3×3×16mm is show the better performance compared to 7 textures. CONCLUSIONS : 3×3×16mm as longitudinal tinning for fresh concrete is show less lateral vibration than 3×3×12mm.

PURPOSES : This study suggests an estimated texture depth (ETD) equation for concrete pavements, applicable to highway pavement texture, and the measurement method of mean profile depth (MPD) in a longitudinal texture. METHODS : First, we proposed the most suitable ETD equation through the correlation between ETD data and the measured mean texture depth (MTD) data. Second, we suggested a novel MPD measurement method, by checking the error of the ETD data and measured MTD data by the measurement method. RESULTS : The ETD equation presented by Fisco and Plati was considered the most appropriate for the transverse texture. In addition, the correlation between ETD and the measured MTD was good in the longitudinal measurement method. The ETD equation of Fisco and Plati is suitable for longitudinal texture, and the MPD measurement method obtained good results when applied to transverse measurements. To verify the novel measurement method, we confirmed the correlation between the SR and MPD data using a novel method. The correlation for the novel measurement method is 0.7. CONCLUSIONS : Accordingly, the ETD equation presented in the existing literature has a good correlation between ETD data and the measured MTD data, but it did not reflect longitudinal texture data. Therefore, we assumed the ETD equation produced in this study, and suggested the transverse measurement method in the longitudinal texture.

PURPOSES : The Korea Expressway Corporation has been working on an early remodeling project for the Jungbu Expressway, to prepare techniques for the rehabilitation of the old CRCP. In this study, a literature review, field survey, and thickness design using MEPGD were conducted. This is to provide a procedure for the pre-treatment, or repair of the existing pavement in the JungBu Expressway. METHODS : To evaluate the pavement condition of the JungBu Expressway, the existing PMS data were analyzed, and field surveys were conducted for each pavement condition. The SMA overlay thickness design was performed using the pavement thickness design program (MEPGD). In addition, the repair procedure was reviewed considering the characteristics of the old CRCP in Korea. RESULTS : From the analysis of existing PMS, field surveys, and laboratory tests, it was discovered that the old CRCP condition of the Jungbu Expressway was not satisfactory. Using MEPDG, the SMA thicknesses for each scenario were proposed as 5, 8, and 10 cm. In addition, appropriate repair procedures for each distress type(punchpout, multiple repair, re-failure, failure of longitudinal joint, etc.) of damaged CRCP in Korea were proposed. CONCLUSIONS : For the remodeling project of the Jungbu Expressway, appropriate repairs should be performed for each type of distress in the old CRCP. In this study, an appropriate overlay thickness and pre-treatment method are suggested.