• 한국도로학회:학술대회논문집
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• 2009.11a
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• pp.501-504
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• 2009

• 한국도로학회:학술대회논문집
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• 2009.11a
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• pp.413-416
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• 2009

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.4 s.22
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• pp.77-84
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• 2002

Recently, damage of pavement represented by crack is depened by the increase of traffic demand up to ten million and wight, and interest about the efficient management of pavement is being increased gradually according to the growth of maintenance expense of road surface. In this study, the possibility of application for acquisition of crack information was tested by appling DCRP and digital image processing technique and measuring crack on road surface precisely. Based on this, objective and efficient road surface measurement was planned and done. Measuring crack width, acquire result of comparative high accuracy. So, it is considered that it can be utilized as plan draft data for deterioration estimation and repair reinforcement work of pavement.

• Journal of the Korea Institute of Building Construction
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• v.17 no.4
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• pp.341-348
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• 2017

The performance degradation of concrete pavement by winter deicer is very serious in Korea, and its maintenance and rehabilitation brings a high expense. Therefore, a suitable method for rehabilitation of such concrete pavement and repair material of proper performance are required. In this study, the properties of compressive strength, ability to resist chloride ion penetration, and properties of dry shrinkage of magnesium phosphate ceramics were assessed to evaluate its applicability as a repair material for concrete pavement in Korea. As a result, the mortar flow showed a normal level of 190 mm, but the viscosity was high and the self-flow ability was poor. The setting time was 12 minutes, leading very rapid-hardening, and thus a prompt work was required. The compressive strength of mortar was 38.4MPa in 2 hours, 73.8MPa in 24 hours, and 111.0MPa in 28 days, showing a significant level. As a result of the test to chloride ion penetration resistance, mortar showed 143 Coulombs, and concrete showed 172.6 Coulombs, which fell under very low level. The drying shrinkage of MPC concrete in 40 days was below $60{\times}10-6$, and comparing with normal cement concrete, it showed the level below 1/10 of other concrete to secure an excellent volume stability. As above, magnesium phosphate ceramics has excellent strength performance, chloride ion penetration resistance, and volume stability, and this in the future shall be used in construction under the consideration of working time or workability, requiring further improvement for such performance.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.3
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• pp.41-49
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• 2015

The repair of manhole raise has been caused much construction times and disruption of traffic flow, serious environmental pollution from crushed construction wastes, and budget waste due to the repeated repair construction works. In order to overcome such problems, we have developed the new manhole repairing composite structures by using a glass fiber-reinforced polymer (GFRP) pipe, which can raise manhole to the regular height of the overlayed road pavement with rapid construction and minimum traffic jams. This environmental-friendly technology is method completed by the methyl methacrylate monomer (MMA) double wide flanged GFRP pipe composite structures in order to raise manhole to the regular height. In this paper, two kinds of the compressive strength tests of MMA mortar composites were conducted and evaluated by a general compressive strength test, and compressive strength test after freezing-thawing resistance test. It was found that this MMA mortar composites will be used for the application of the double wide flanged GFRP pipe composite structures.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.836-841
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• 2012

The repair of road pavement and manhole has been resulted long construction times and traffic jams, environmental pollution from construction wastes, and budget waste due to excessive construction costs. In order to resolve such problems, we have developed the new construction method using C-ring, which can fix and raise the manhole securely. This technology is the method by driving in a wedge after inserting C-ring and expanding it in order to raise manhole to the regular height. This has been approved by the test reports of KOLAS(Korea Laboratory Accreditation Scheme), and was confirmed safety, durability and reliabilty in result. In this paper we approved this technology was able to short working times to around 20% and construction costs to around 50% with compare other construction methods. Also, environmental pollution and civil complaints will be prevented because there will be no longer any noises, vibrations, dust, or construction wastes.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.271-272
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• 2021

The maintenance and repair work of sidewalk block pavement is a construction that requires a large amount of budget to be invested every year. It is important to establish an appropriate standards for estimating construction cost to ensure proper budgeting and quality. In this study, the standards for estimating the cost of maintenance and construction work for sidewalk blocks that can be applied to the construction volume classified according to the site conditions, construction type, and equipment use differentiated from new construction was established. As a result, the daily construction volume was presented by reflecting excavator and truck as equipment in the combination of paver and common worker. The re-installation was applied by separating the construction volume of sections with general blocks and induction/raised blocks based on the installation of sidewalk blocks after demolition. Generally if block cutting is necessary, the precision construction conditions using a cutting machine were taken into consideration to secure the construction quality. In addition, it has been revised to apply classified construction volume into A and B-Type depending on the park and site conditions.

• Journal of the Korea Concrete Institute
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• v.25 no.1
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• pp.11-18
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• 2013

Cement concrete pavement offers long-term service life and excellent applicability for heavy traffic. It is easier to purchase and more durable and economical than the asphalt pavement. However, it is difficult to repair and rehabilitate compared to the asphalt pavement when it comes to the maintenance problem. Since the crack is the main reason of the damage of concrete pavement, it is necessary to control the early and long-term crack in the concrete pavement. In this experimental study, the basic performance tests have been carried out to investigate the effect of hybrid fibers which were composed of micro fibers with small diameter and high aspect ratio and macro fibers with large diameter and low aspect ratio on the concrete pavement, in which lower water ratio and larger aggregates were used compared to the general concrete mixture. The test results showed that the flexural strength and toughness of concrete pavement mixture have been increased with the use of hybrid fibers in the concrete pavement mixture, even though they were less effective compared to the normal concrete mixture. It was found that the hybrid fibers were effective to control the early shrinkage of the concrete pavement which is one of the main reasons of the damage in the concrete pavement.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.341-344
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• 2006

The waste glasses among plenty of wastes put out lately is limited in recycling and reusing, and the phenomenon hasn't been improved quite much. And besides, the recycling rate shows the 70.1%, relatively low. These waste glasses is currently used for road pavement materials, interior and exterior decorating materials in architecture, road painting meterials, auxiliary lagging materials for heat-retaining, coldness-retaining and soundproofing, and glass bottles. 30% of waste glasses powder is, however, not reused pratically. Therefore, in this research, we operated some tests including flow of mortar mixed with waste glasses powder, setting time, rheology and compressive strength to utilize waste glasses powder put out in the precess of recycling for admixture for repair mortar. As a result, we've found out that we can utilize waste glasses powder for admixture for repair mortar.

• Smart Structures and Systems
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• v.14 no.3
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• pp.469-477
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• 2014

As a kind of intelligent materials, conductive asphalt concrete has a broad application prospect including melting ice and snow on the pavement, closing cracks in asphalt concrete, sensing pavement damage, and so on. Conductive pavement will be suffered from fatigue failure as conventional pavement in the process of service, and this fatigue damage of internal structure can be induced by electrical signal output. The characteristics of electrical signal variation of conductive asphalt concrete in the process of fatigue cracking were researched in this paper. The whole process was clearly divided into three stages according to resistance changes, and the development of fatigue damage wasn't obvious in stage I and stage II, while in stage III, the synchronicity between the resistance and damage began to appear. Thus, fatigue damage variable D and initial damage value $D_0$ represented by the functions of resistance were introduced in stage III. After calculating the initial damage value $D_0$ under different stress levels, it was concluded that the initial damage value $D_0$ had no noticeable change, just ranged between 0.24 and 0.25. This value represented a critical point which could be used to inform the repair time of early fatigue damage in the conductive asphalt pavement.