• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.117-117
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• 2007

• International Journal of Internet, Broadcasting and Communication
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• v.6 no.2
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• pp.20-24
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• 2014

These days the large-scale car accidents have often been occurred by overspeeding in disregard of sharp curve, foggy and freezing regions. This paper has proposed the algorithm to calculate the safety speed in real time that can protect the car accidents under these weather and road conditions using Fuzzy reasoning theory. Under raining and snowing, drivers have to slow down the traffic safety speed by 1/3 of the traffic safety speed indicated on the existing speed sign plate based on their decision. So it is difficult to calculate and then observe the safety speed. This paper has performed the simulation that provides the deivers with the optimal safety speed considering the road and weather conditions in real time to improve these problems. We have proved this method can improve more 25% than the existing one.

• International Journal of Highway Engineering
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• v.6 no.4 s.22
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• pp.91-100
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• 2004

This study was Performed to evaluate applicability of color flexible pavement concrete (CFPC) for motorway pavement. Color flexible pavement has been applied to non-motorway pavements, such as pedestrian and bicycle road. Two polymers were used to modify the binder and to strengthen the stiffness of pavement mixture. Waste paper was used to prevent the asphalt of gap-grade mixture from draining. Marshall properties, indirect tensile strength(ITS), tensile strength ratio(TSR) before and after freezing-and-thawing treatment and artificial aging, permanent deformation and fatigue life were measured. Color bituminous concrete mixtures used this study had nearly the same quality in mechanical properties when compared with conventional asphalt concrete mixtures manufactured with AP-3 and all mixtures satisfied with domestic specification for motorway pavement. Therefore, it is proved that the color bituminous concrete used this study can be applied for motorway pavement.

• International Journal of Highway Engineering
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• v.17 no.2
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• pp.79-87
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• 2015

PURPOSES: According to accident statistics for road built in 2004, the ratio of accidents on frozen roads to normal roads is 0.9%, whereas the fatality ratio is 2.7%. The risk of accidents on frozen roads is very high. Measures taken every year to prevent traffic accidents of frozen roads in the winter season are still insufficient. Additionally, measures have been established mainly on rural roads. Therefore, for urban roads, analyses and measures to prevent accidents are lacking. In this study, data on accidents on frozen roads was used to search for the causes behind these accidents and measures to reduce accidents have been recommended. METHODS: In this study, collected data from the TAMS (Traffic Accident Management System), which were collected by the Seoul National Police Agency was used. The data were divided into vehicle, people, and condition of road. The analytical model used here was the Logistic Regression Model, which is frequently used for traffic safety and accident analysis. This study uses the odds ratio analysis to search for variables related to frozen road traffic accidents in each category. A total of 18 out of 47 variables were found to be the causes of accidents. RESULTS: From the results of the comparative analysis of 18 variables, the category of the condition of the road was found to be the most critical. Contrary to expectations, more accidents occurred in clear weather than in other conditions. Accidents on bridges occurred frequently, and its odds ratio was the highest compared with other road types. When BPT is operated, the probability of accidents on frozen roads is lower than in general conditions, and accidents occurred frequently on roads with less than four lanes. CONCLUSIONS : Based on the results of this study, suggestions for reducing the risk of future domestic road accidents in freezing conditions are indicated as follows. First, it is necessary to perform a technical review of the urban road traffic accidents caused by frozen roads. Second, it is necessary to establish criteria for the study of the road environment based on the major causes of road accidents on frozen roads. Third, improvements in urban road environmental factors should be made.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.173-184
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• 2018

As the portable traffic information collection system using probe vehicles spreads, it is becoming possible to collect road hazard information such as portholes, falling objects, and road surface freezing using in-vehicle sensors in addition to existing traffic information. In this study, we developed a integration and decision algorithm that integrates time and space in real time when multiple probe vehicles detect events such as road hazard information based on GPS coordinates. The core function of the algorithm is to determine whether the road hazard information generated at a specific point is the same point from the result of detecting multiple GPS probes with different GPS coordinates, Generating the data, (3) continuously determining whether the generated event data is valid, and (4) ending the event when the road hazard situation ends. For this purpose, the road risk information collected by the probe vehicle was processed in real time to achieve the conditional probability, and the validity of the event was verified by continuously updating the road risk information collected by the probe vehicle. It is considered that the developed hybrid processing algorithm can be applied to probe-based traffic information collection and event information processing such as C-ITS and autonomous driving car in the future.

• International Journal of Highway Engineering
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• v.7 no.3 s.25
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• pp.53-62
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• 2005

Efficient snow-removing work is one of important processes of winter road management. Calcium chloride has been used as a typical deicing agent in Korea. It presents superial performance as snow deicing agents, however it has been known to give serious environmental problem and to deteriorate durability of concrete structure in road by corrosion. The environment-friendly road deicing agents made from the waste material which is liquid phase organic matter that is Ca Mg and reactant of organic acid (nitric acid and propionic acid) have been introduced by number of researchers. They indicated the calcium magnesium salt of organic acids have advantage over the calcium choride in terms of lower production unit cost by resources recycling and can solve environmental problem and durability deterioration of structures. In this study, the deicing performance of calcium magnesium salt of organic acids(CMO) is investigated based on the series of experiments including the test for heat of dissolution, freezing point, ice melting test and ice penetration test.

• International Journal of Highway Engineering
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• v.20 no.3
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• pp.11-18
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• 2018

PURPOSES : Durability of concrete is traditionally based on evaluating the effect of a single deterioration mechanism such as freezing & thawing action, chloride attack, carbonation and chemical attack. In reality, however, concrete structures are subjected to varying environmental exposure conditions which often results in multi-deterioration mechanism occurring. This study presents the experimental results on the durability of concrete incorporating air-cooled slag(AS) and/or water-cooled slag(WS) exposed to multi-deterioration environments of chloride attack and freezing & thawing action. METHODS : In order to evaluate durable performance of concretes exposed to single- and multi-deterioration, relative dynamic modulus of elasticity, mass ratio and compressive strength measurements were performed. RESULTS :It was observed that multi-deterioration severely affected durability of concrete compared with single deterioration irrespective of concrete types. Additionally, the replacement of cement by AS and WS showed a beneficial effect on enhancement of concrete durability. CONCLUSIONS : It is concluded that resistance to single- and/or multi-deterioration of concrete is highly dependent on the types of binder used in the concrete. Showing the a good resistance to multi-deterioration with concrete incorporating AS, it is also concluded that the AS possibly is an option for concrete materials, especially under severe environments.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.91-91
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• 2011

The quality of the surface layer in concrete structures plays an important role in the durability of the concrete. The concrete factory products are made as they improve the appearance of the surface and compressive strength in need. A common criterion to judge the quality of concrete products frequently seen in our daily life appears to be "beauty" in terms of consistent shaping. However, as for most concrete curb in such areas where a large amount of anti-freezing agents(NaCl) and ice and snow melting agents(CaCl2) are spread over roads to ensure road safety during the winter season, since deterioration advances from the surface, scaling is seen on the surface concrete due to deterioration which combined freezing damage and salt damage. Especially, In cold northern districts, the spreading amount of deicing salts increases by regulation of studded tire use, and the scaling of the concrete products, the various parts of concrete structures for roads is increasing in recent years. In this study, L-shape concrete curb were targeted, the permeable form method with the commercial permeable sheet was applied to it and the improvements of the quality were examined. By the permeable form method, surface layers got strengthened, which prevented permeation of the deterioration factor from the outside, and the scaling resistance of the upper surface where the permeable sheet was applied improved exceedingly. It will be expected by applying the permeable form method to various concrete products that frost resistance improves and scaling damage decreases.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.79-89
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• 2005

Field and laboratory investigations were performed for concrete pavement of the Yeongdong Expressway located in western part of the Kangwon Province where lots of the substantially large spatting distresses were found. The spatting distresses were investigated to the naked eye in the field, and splitting tensile strength, air void, and neutralization tests were performed for the cores obtained from the pavement. In addition, load transfers at joints and dynamic bearing capacities at slab centers were measured to identify the lowering of the structural capability of the pavement. It was judged that the investigated concrete slabs were affected by freezing and thawing action because the air voids of the cores were substantially low. Therefore, it was concluded that the low air voids affected the lots of the large spatting distress in the pavement located in the region of cold winter.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.577-580
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• 2006

This paper presents the experimental results of frost durability characteristics including freezing-thawing and de-icing salt scaling of the concrete used for gutter of the road. Mixtures were proportioned with the three level of water-binder ratio (W/B), 0.58, 0.53, and 0.48, and two binder compositions corresponding to Type I cement without any supplementary cementitious materials (OPC) and Type I cement with 30% blast-furnace slag replacement (Slag30). Also, two different solutions of calcium chloride and water that contains 0 and 8g of anhydrous calcium chloride in each 100 mL of solution, respectively, were used to evaluate their effect on the frost durability resistance. Test results showed that the Slag30 mixture exhibited higher durability factor and lower mass loss values than those made with OPC. Among the mixture tested in this work, the mixtures (OPC and Slag30) made with a relatively higher W/B of 0.58 exhibited large amount of the de-icing salt scaling regardless of calcium chloride concentration. Finally, the use of slag can be used effectively in terms of economy and frost durability of the concrete designated for gutter.