For quantitative assessment of flexural strength by crack condition of PSC sleeper, which is one of the main components of the ballasted track, 9 PSC sleepers used in Gyeongbu high speed railway line were sampled and static bending strength tests were conducted by EN 13230-2. The flexural strength of PSC sleepers with some mesh or longitudinal cracks was lower than that of new sleepers. In particular, the flexural strength of PSC sleepers with mesh-type cracks was less than 40% of the new sleepers’ flexural strength. The flexural strength of uncracked sleepers was similar to that of new sleepers

The old electric transmission tunnel over thirty years old in northern Seoul is operated with Ttukdo substation as its starting point and 41km-length since March, 1980, and the trend is an icrease in embedded electric power structures over thirty years old beyond sixty kilometers. If the corrosion occur in reinforced concrete structures, it is considered as the important factor among deterioration factors .By examing the seventy-two cases of concrete carbonation and covering depth in order to analyze the concrete carbonation of electric power structures over thirth years old in Gangbuk-gu, this paper atempts to analyze carbonation coefficient, remaning service life, and concrete carbonation of old embedded electric power structures for reference to predict the concrete carbonation progress.

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.

This paper presents the applicability and reliability of the crack detection technique of concrete structures developed based on the use of digital image analysis technologies through on - site tests. The problem of aging of infrastructure is a serious threat to the national and national security and there is a growing interest in the development and application of effective inspection and maintenance techniques for related infrastructure. Therefore, instead of the existing traditional manpower-based infrastructure inspection and maintenance techniques, which involve lots of time and money consumption and reliability of results, research using digital image analysis technology is actively being carried out.

In order to establish preventive maintenance and to make a reasonable estimate of the required repair cost for bridges, the related history information of the existing bridge inspection and diagnosis was analyzed. It was analyzed that about 75% of the repair costs were required for the pavement, expansion joining, curb, and railings in the service area of bridges.

In many climatic conditions, there is UV ray, which is called ultraviolet rays, which has the greatest effect on sealing materials. Because UV has high energy, it changes the internal structure of polymer and causes quality deterioration. In addition, temperature, humidity, and rainfall, snowfall, and atmospheric pollutants are also factors to be avoided in maintaining the integrity of the sealant. In this study, we tried to obtain reproducibility by using a composite deterioration test device which can describe the environment of the outside air as a part of the research project to investigate the weather change in the prototype of the structural sealant. The outdoor exposure test result and the composite deterioration test device Correlation analysis. In the future, it will be possible to predict the changes in the physical properties of the structural sealant by applying the composite deterioration test equipment and outdoor exposure test data.

In this study the existing degradation model for the coated steel member is reviewed, and a new model is recalculated with the deterioration index, ‘rusting’ and ‘flaking’ only. In the case of durability evaluation with the two indexes only some considerations are suggested by the comparison of the existing and recalculated degradation model.

This study provides a simple introduction to photo-catalyst technology to degrade the air pollution in urban environment, in particular, NOx gases from automobiles. Moreover, it shows the spray coating technique was applied to effective coating on the surface of asphalt roads by using as-developed integral photocatalyst solution. In order to examine the slip resistance of asphalt surfaces, the BPT (British Pendulum Test) was used under drying and wetting conditions.

This paper applied the concept of risk to prevent disasters in reservoirs and to manage them efficiently. However, there is a lack of information on safety management for small reservoirs managed by local governments. Therefore, considering such a reality, the geotechnical failure mode scenarios have been reduced to five types. In this study, the site investigation was carried out and the geotechnical failure probabilities were calculated based on the results, and then its applicability has been suggested.

In this paper, we developed a predictive model of maintenance and repair cost based on the element-level condition state by using information collected through the inspection/diagnosis of individual bridges for use in maintenance strategy analysis. The reliability of the prediction model can be improved through of big data analysis using various factors and additional data.

For steel structure, corrosion problem can be a major maintenance area. Even with the same steel structure, corrosion damage can be changed depending on the location and form of thes structural member. In this study, rherefore, In order to evaluate the relative corrosion enviornmnet depending on the installed condition of the structural steel member, the corrosion deterioration environment was monitored for the large-size steel frame structure.

This guideline refers to expansion joints with a diameter of 300mm or more. It will check the condition of large-capacity expansion joint, detect abnormal behavior and damage early, take appropriate measures such as repair and replacement, and secure user's safety and smooth traffic flow. And to provide the basic data necessary for the maintenance work of the management subject to be carried out for the purpose of To this end, we investigated and analyzed the existing joint damage, repair and replacement cases, suggested proper repair and replacement methods and preventive maintenance plan.

The maintenance cost is rapidly increasing due to the increased of infrastructures such as railway and port etc., it is necessary management method of facility for measures and extend life. In the case of international infrastructure, in order to asset management to reasonably and effectively, asset management systems were developed for the management of facilities in various countries such as Australia and Canada etc. In this study, to develop the asset management process, the question investigation was conducted on maintenance site personnels for maintenance of the steel structure.

The corrosion is one of the main causes of cable damages. The use of dehumidification system can be an alternative for this issue. Therefore, the authors have been evaluated for efficiency of the cable dehumidification system for the main cables of a suspension bridge. This study was initiated to develop an efficient and economical management strategy to operate the cable dehumidification system for suspension bridges built in the coastal region of South Korea.

In this study, a feed-back system for vulnerable urban area by debris flow is suggested in order to carry out effective maintenance. The feed-back system consists of deriving vulnerable elements, providing structural alternatives, analyzing investigation·inspection and investigating damages.

Because of the characteristics of long-span bridges, the cable tension is considered a critical item in their maintenance. In particular, because the evaluation of the cable tension in a suspension bridge is essential for understanding the general status of the structural system, identifying the initial values of this force in the construction of a bridge and then accurately predicting and comparing its estimated values during traffic use are very important tasks for the maintenance of a suspension bridge. In this paper, to verify the algorithm for estimating the cable tension of hanger cables using the back analysis technique, an ambient vibration test was conducted at a suspension bridge.

Concrete residential structures are being redesigned for maximum space utilization efficiency by including parking lots and other convenience facilities. However, there are increasing problems of leakage due to various environmental and deterioration conditions. This paper proposes the a world-wide-web based professional information sharing system designed to provide solutions, alternatives and technical information for leakage prevention and effective design at the beginning of the construction stage.

In this study, concrete slab with insulation and non-insulated formwork was used to monitor and control its strength using a wireless sensor network with equivalent age method. As a result, the temperature and compressive strength of the structures were monitored without any problems, which revealed a good management tool.

In this study, the results of the load carrying capacity evaluation were compared for old small bridges. From this study, it can be seen that there are bridges in the old bridges that exceed the design load and ensure the bridging performance higher than the rated load. The evaluation results will manage by data that confirms whether the safety of heavy weight vehicles is secured.

This study is the result of the survey on perception and anxiety of high - rise buildings in the general public. As a result of the survey, there was insufficient change in awareness before the construction of high - rise buildings such as landmarks was insufficient (before 2015). However, half of the citizens who felt uneasy that high-rise buildings were likely to collapse due to external influences were close. The anxiety was mainly due to the information of the press or the Internet. It is thought that the cause of anxiety comes from touching negative opinions about the high-rise buildings.