There is an increasing need for new materials and methods for rapid but durable repair of concrete. The author outlines the main properties and reports on some aspects of durability derived from laboratory investigation. Micro-fibre reinforced polymer cementitious materials provide early strength materials and can be considered dimensionally stable. Compressive and bonding strengths show a satisfactory strength. Meanwhile, the micro-fibre reinforced polymer cementitious materials had a low permeability which doesn’t allow water vapour to diffuse through the matrix. Details are expected to be given of successful applications on most of all concrete structures.
In this study, repair and reinforcement priority of dam facilities was estimated using dam in-depth inspection assessment score and grade. Multi-Criteria Decision Making was used for decision of priority, and assessment scores and weights of individual facilities were applied as payoff matrix and weight coefficient. The results show that different analysis results can be deducted by various MCDM method even if assessment index and weight coefficient are the same.
This study presents the concept of a multi-functional Tuned Mass Damper (TMD) using piezocomposite element as damping component. This new type of TMD intends to exploit the unused energy produced by the traffic-induced vibrations of the bridge structure for the generation of electric power while fulfilling its natural role of reducing undesirable vibrations in the structure. Since the proposed TMD is still in a development stage, this paper summarizes the concept underlying the mechanism of the TMD.
A video-based non-contact remote displacement measurement system is proposed and developed. The system captures images of the structure and analyzes the image to determine the displacement. Multi-thread computing and adaptive region of interest method is implemented in the system to compute the displacement in real-time. Field test on a real structure has been carried out to evaluate the performance and verify the reliability of the system.
Recently, tunnel constructions have been increased in Korea. According to the increment of tunnel constructions, cases of tunnel collapses also have been increased under tunnel construction . Among these tunnel collapses, after a certain amount of time has elapsed due to excessive displacements on slope of tunnel exit or entrance, cases of tunnel collapse have been increased rapidly. Therefore, the case study was conducted in this study to figure out factors effect on the tunnel collapses due to excessive displacements on tunnel exit or entrance slopes. Base on the case study, the fragmental zone of fault and the rainfall were most important factors on the collapse.
Although researching and developing of safety and maintenance on domestic facilities are important, there is little recent on a comprehensive and integrated survey of actual condition. Therefore this study asserts the necessity of the survey process of actual condition by period planning(short-term, middle-term, long-term). The purpose of this study is to investigate current situation and to suggest the whole process method, and to establish survey process of actual condition on domestic infrastructure facilities and buildings.
Youth Training Facilities is a facility used for youth training activities. Youth Training Facilities is a facility that could be vulnerable to accidents. The purpose of this study is to minimize any accidents through analysing previous inspection data. Should avoid accidents that may occur during training activities through real-time management of the facility.
This study intends to suggest a methodology of normalization of inspected highway bridges damage. The noticeable point is to normalize the amount of the inspected accumulated damage on bridges according to a normalizing scale. The normalized damages represent such a characteristics of the bridges. With the normalized damage data, a future maintenance cost can be estimated that can be applicable for determining long-term maintenance strategy.
According to recent meterological disasters, social awareness for safety of infrastructure is heightened by increasing natural disasters such as Fukushima accident, landslide of Umyeon mountain. Also scale of landslide is increased in Korea but safety review of dam is insufficient. In this study, we reviewed data(reservoir capacity, type of dam, danger map of korea forest service, satellite pictures, geologic map, etc.) and conducted site investigation whose the area is the most dangerous. Based on the results, we choose the most dangerous dam and analysis site close examination, slope stability analysis, scale of debris flow, etc. As a result, we will conduct measures establish on reinforcement and final evaluation of landslide's hazard.
Infrastructure of the Korean construction industry has been rapidly aging in spite of the major qualitative growth over a short period of time for the last fifty years and interest in the social needs for maintenance has been increasing. Consequently, the paradigm of the domestic infrastructure maintenance market is changing and the needs of users are gradually increasing. According to the results of the domestic maintenance survey and analysis, first-class and second-class public structures specified by the 'Special Act on the Safety Control of Public Structures' are showing remarkable results and effects through the enactment and improvement of related laws. In this study, a survey was conducted for the domestic maintenance market and its status and ensuing reactions regarding policy were proposed for future improvement.
In this study, the structural assessment on the effect of differential deformation of HDRB was performed for double deck warren truss bridge. The results show that the differential deformation of HDRB sharply decreases the safety rate of the superstructure of the bridge.
The thermal load must be considered to design cable supported bridges as a variable load. The thermal load recommended by Korean design code might be different to real temperature distribution in the bridges because the thermal load proposed by Korean design code is referred to Eurocode, etc. Therefore this study proposes the temperature distribution of cable supported bridges In Korea based on measurements.
The suspension bridge main cable requires regular maintenance works to control the axial forces of the cable band bolts. A axial forces of a suspension bridge cable band occur reduction phenomenon because of the creep behavior of cable wire, the bolts relaxation, load fluctuation and cable rearrangements with the lapse of time.
It is necessary to introduce a Reoprt Card that utilized in the developed countries for improved aging domestic Infrastructure. To do that, by improving to match the domestic environment, it is necessary to make a reliable accurate evaluation. Korean evaluation grade is, in consideration of both the life cycle of Infrastructure, should comprehensively evaluated by physical and environmental and social point of view is made .
The Goal of research is that decision-making in bridge and tunnel maintenance were estimated by prediction models of condition and value engineering. We developed the software that can be calculated asset values and it’s condition depending on budget scenario by the bridge and tunnel prediction model. It can be determined an optimal budget of facilities and it’s values using prediction model of cost and condition.
This study dealt with the change in the clamping force of bolt in the friction joint depending on the sectional damage of bolt. Based on the study of the clamping axial force of bolt and sectional damage, clamping force of bolt was affected by sectional damage of bolt head. Thus, relationship between clamping axial force of bolt and corrosion damage of bolt should be considered for maintenance of steel structures.
In this study, we conducted a pilot basis for the census debris flow hazard zone is located on the roadside in some national road. Valley part by usage data for 154 points by calculating the risk and damage was also selected for the debris flow prevention research priorities. This databased to be able to systematically manage a debris flow that may occur on the national roadside.
According to the results of case studies on leakage in large scale aquarium structures, the causes have been identified as construction failure of sealant for joint of sealant design failure in acryilic panel and concrete substrate joints. However, as there currently are no standardized design or specifications for such principles, this study proposes a design formulation of a width and depth of sealant when applied to acrylic panels in large scale aquarium structures.
In order to prevent tendon from corrosion and to provide a sufficient bond between tendon and concrete, post-tensioning grout has been used. But, the normal mixture with w/c ratio of 0.40 and add the expansive agent for 1% was not support for specification(BS EN 445) compliance. Thus, it should add some supplementary cementitious materials to improve the properties. Therefore, based on this test result, not only evaluation of bleeding, volume change, fluidity, and compressive strength, but also estimation of the shrinkage of post-tensioning grout under restrained condition remains as a pressing need.