Bacteriological quality evaluations were carried out for rice rolled in laver(Kimbab), Hamburger, Walnut cake and Chinese noodle (Jajangmyun), which were on sale in April and May 1995, in May and July 1997 and in January 1999, at 20 different resting places on Kyung-Bu, Ho-Nam, Joong-Bu and Young-Dong Highway in Korea. Food poisoning bacteria were not detected. However numerous coliform bacteria were dectected saying that the sanitary condition of foods on sale at resting places of the highways was not hygienic. There exited 8.8 × 10⁴∼6.6 × 10^5 cells/g of coliform bacteria in all the Kimbab sold in 1995. As for Hamburger, 1.8 × 10²∼4.7 × 10⁴ cells/g of coliform bacteria proliferated in all the samples. In 1997, E. coli was found in 16 cases and 21 cases respectively out of 22 Kimbab samples, Hamburger dealing at 7 resting places out of 14 were contaminated with 1.7 × 10²∼1.9 × 10^7 cells/g of coliform bacteria and Hamburgers dealing at 2 resting places were infected by E. coli. In contrast to the Kimbab and Hamburger, all the 6 Walnut cake samples were free from the microbial pollution exhibitory that their hygienic condition was satisfactory. 3 samples out of 6 Jajangmyun were contaminated by 7.1 × 10²∼2.0 × 10³cells/g of coliform bacteria, but E. coli was not detected. Compared Kimbab sold in 1995 and 1997 with 1999, Kimbab sold in it can be said that hygienic control for Kimbab should be performed more strictly during hot season than during cold season. Walnut cake was the safest against microbial contamination, followed by Jajangmyun, Hamburger and Kimbab in decreasing order, indicating that foods with mixed ingredients such as Kimbab and Hamburger were more susceptible to microbial infection, so that a more systematic safety control is needed for such foods during cooking, processing and distribution.

A P/M high speed steel of ASP 30 grade was austenitized, gas quenched and tempered at various conditional. The mechanical properties such as hardness, bend strength and fracture toughness were evaluated after heat treatment. The microstructure and the type and volume fraction of carbides were analyzed by an optical microscope, image analyzer and XRD. The primary carbides after the heat treatment were MC and type. The volume of the total carbide varied from 10 to 15% depending on the austenitizing and tempering temperature. The tempering temperature for maximum hardness was at around 52. But the maximum bend strength was obtained at about 55. The fracture toughness was largely affected by the presence of retained austenite after gas quenching and secondary hardening during tempering.

본 연구에서는 신속하고 편리한 고속도로 유지관리를 위해 주행 중인 차량에서 실시간으로 영상을 수집하고 분석하여 현장의 노면 포장 상태를 모니터링하고 손상을 탐지하는 딥러닝 기반의 고속도로 포장 손상 조사 기술에 대해 소개한다.

In this study, computer simulation was conducted to evaluate the vulnerability of bridge columns under vehicle impact loading. Firstly, the Preliminary Risk Analysis was conducted to determine if the next step is necessary. In the next step, the Simplified Risk Analysis was conducted to determine the level of risk. According to SRA, if the bridge is confirmed in the category of high risk level, the bridge columns were classified into five types based on the slenderness ratios. Finally, using the five types of bridge columns, the deformation of bridge columns were predicted by conducted collision simulations.

Recently, due to record breaking temperature and other factors, bridge expansion joint closing, damage of shoe, narrow distance between abutment and deck is occurred frequently. Therefore, traffic flow was interrupted and vehicle damage was occurred because of expansion joint stick out. In this study, in order to reduce damage of expansion joint and other bridge facilities and to ensure safety of infrastructure, field survey and consulting works are performed for 91 bridges that distance between expansion joint is closed. Based on this study, cause of expansion joint closing are analyzed and maintenance strategy is suggested.

국내 고속도로 구조물 점검은 인력위주로 수행중에 있으나, 관리대상 구조물의 급증으로 인력점검의 한계가 발생함에 따라 4차 산업기술(IoT, 드론, AI, 로봇 등)을 활용한 점검로봇 및 점검장비를 개발하여 고속도로 구조물 점검에 활용할 예정이며, 구조물 상태 자동 평가기술을 개발하여 안전점검의 신뢰성 및 효율성을 향상할 예정이다.

Structures are currently a good condition in highway, with an average age of 14.7years. However, After 10 years, The old structure will be estimated 22% of the total structure. In this study, We have suggested the preventive maintenance methods such as preventive techniques and asset management for the deterioration of future by a lesson of failure cases of developed countries such as the United States.

This Prospect and Technological Prediction established a strategy system for '2050 Future Highway' to propose the direction of the overall development of highway industry and technology and to secure sustainability. It set future tasks to be implemented in the '2050 Future Highway' suitable for the strategy, materialize detailed measures and identify promising future technology. Also, promising future technologies were evaluated for the possibility of successful technological development, creative innovation, significance of each technological element (comprehensive) and the need for governmental investment based on the Delphi research, and from this, top 50 technologies were selected by considering the balance between tasks for future vision system.

Korea Expressway Corporation has been in operation for 50 years. Pavement maintenance, which was initially conducted by manpower, reached its limits due to the increase of highway extension. Therefore, the introduction of the pavement management system in the 1990s was considered. The pavement management system has become the foundation for conducting the budget. In the 2010s, the concentrated maintenance system, which closes traffic for a long time, was being applied to efficiently manage the distressed pavement.

Korea Expressway Corporation has been in operation for 50 years. Bridges have increased due to the construction of expressways. As the use of bridges continued to become obsolete, the organization and budget increased accordingly. Inspection techniques have also been upgraded. In this paper, the changes in the maintenance of expressway bridges are summarized in terms of the status, organization, budget, inspection technique, maintenance and reinforcement, and history management system.

The inspection items of tunnels include road surface breakage and cleaning condition, lane paint condition, lining crack, leakage, corrosion condition, tile cleaning condition, daylight and nighttime optimum illuminance condition, drainage facility damage and cleaning condition, Gangway wall wall and retaining wall abnormality, slope top and side slope condition. However, investigations for maintenance of tunnels mainly consisted of surveying condition and durability of concrete lining due to characteristics of tunnels.

It is important to operate appropriate measurement system of cable bridges for the efficient construction and maintenance. The main results of study on the optimal construction detail method of measurement for individual cable bridge are described. In this paper, the basic guidelines for the cable bridges measurement system is presented such as sensor classification, installation location and performance standard for the installation of the optimal measurement system of cable bridges on expressways.

It is important to operate appropriate measurement system of cable bridges for the efficient construction and maintenance. The main results of study on the optimal construction detail method of measurement for individual cable bridge are described. In this paper, the basic guidelines for the cable bridges measurement system is presented such as sensor classification, installation location and performance standard for the installation of the optimal measurement system of cable bridges on expressways.

본 연구에서는 덕평자연휴게소, 마장프리미엄휴게소, 망향휴게소를 방문하는 관광객을 대상으로 고속도로 휴게소의 테마공간에 대한 만족도가 휴게소에 대한 재방문의도와 추천의도에 미치는 영향을 실증 조사하고자 한다. 조사결과, 독특한 테마로 구성되어있는 ‘화장실’, ‘체험문화공간’, ‘식당’에 대한 만족도가 휴게소에 대한 재방문의도에 긍정적 영향을 미치고 있는 것으로 나타났으며, ‘화장실’과 ‘체험문화공간’은 휴게소에 대한 추천의도에도 긍정적 영향을 미치고 있는 것으로 조사되었다. 이는 고속도로 휴게소의 이색적인 테마공간, 특히 만족도가 가장 높은 테마화장실 조성을 통한 차별화 전략이 고객의 만족도를 제고시키고 긍정적 구전효과를 일으켜 휴게소 운영의 활성화 및 경쟁력을 강화시킬 수 있음을 시사하고 있다.

In this study, field survey was carried out on reinforced earth retaining wall located on the expressway, and the damage type was classified and basic data about the state evaluation method was prepared

The number of expressway structure management is continuously increasing, and the aging of structures is proceeding rapidly. In order to secure the safety of expressway structures, we propose improvement methods such as advancement of structure management system, lifetime improvement methods such as prevention of structure deterioration, and the preemptive reflection of the structure maintenance budget.