• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.109-110
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• 2023

Domestic ultra-hard road repair materials require a lot of time before the road can be opened to traffic. Therefore, in this study, Methyl Methacrylate (MMA) based road repair material was used to improve the above problems. Furthermore, the basic physical properties of MMA-based pavement repair materials are examined to confirm their suitability in concrete pavements. For this study, two types of MMA road repair materials (A type and B type) were selected. Then, the curing of the test specimens prepared for painting was carried out under three conditions. The experimental items were viscosity (drop time) and drying time (set to touch, dry-hard). As a result of the experiment, viscosity (drop time) was faster in type A than in type B. The drying time results were as follows. In the case of set ti touch, both type A and type B dried in about 10 minutes regardless of the curing conditions. In the case of dry-hard, regardless of the curing conditions, A type dried longer than B type, but it dried faster than conventional road repair materials. Therefore, within the scope of this study, it is considered that A type has a high potential for utilization as a road repair material.

• International Journal of Highway Engineering
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• v.18 no.1
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• pp.43-55
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• 2016

PURPOSES : This study aims to develop a repair material that can enhance pavement performance, inducing rapid traffic opening through early strength development and fast setting time by utilizing MgO-based patching materials for repairing road pavements. METHODS : To consider the applicability of MgO-based patching materials for repairing domestic road pavements, first, strength development and setting time of the materials were evaluated, based on MgO to $KH_2PO_4$ ratio, water to binder ratio, and addition ratio of retarder (Borax), by which the optimal mixture ratio of the developed material was obtained. To validate the performance of the developed material as a repair material, the strength(compressive strength and bonding strength) and durability (freezing, thawing, and chloride ion penetration resistance) was checked through testing, and its applicability was evaluated. RESULTS : The results showed that when an MgO-based patching material was used, the condensation time was reduced by 80%, and the compressive strength was enhanced by approximately 300%, as compared to existing cement-based repair materials. In addition, it was observed that the strength (compressive strength and bonding strength) and durability (freezing and thawing, and chloride ion penetration resistance) showed an excellent performance that satisfied the regulations. CONCLUSIONS : The results imply that an emergent repair/restoration could be covered by a rapid-hardening cement to meet the traffic limitation (i.e. the traffic restriction is only several hours for repair treatment). Furthermore, MgO-based patching materials can improve bonding strength and durability compared to existing repair materials.

• International Journal of Highway Engineering
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• v.20 no.2
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• pp.9-17
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• 2018

PURPOSES : The frequency and severity of natural disasters such as torrential rain or typhoons have become increasingly significant worldwide. Events such as summer typhoons and localized torrential downpour can cause severe damages to a residential area and road networks, resulting in serious harm to the daily lives of people, especially in rural areas by isolating residents from road networks. An immediate and emergency repair technology for the collapsed road networks is urgently needed. This study introduces a new technology to repair road bases or slopes. METHODS : The development of new technology for emergency and permanent repair consists of first, packing of cement paste-coated gravel, second, combining appropriate equipment, and third, conducting a field applicability test. In this research, the compressive strength of cement pastecoated gravel, gravel-netting concrete properties, and packing efficiency were determined, and a full scale field mock-up test was carried out. RESULTS : The compressive strength of the cement paste-coated gravel concrete satisfied the required limit for road base of 5 MPa after 7 days. With appropriate netting materials and packing size, gravel-netting concrete was successful up to a slope of 1:1.5. The full scale field mock-up test showed efficiency in the field and penetration resistance performance. CONCLUSIONS : The new technology of emergency and permanent repair for damaged road bases and slopes, introduced in this study, showed satisfactory performance. The technology is expected to be applied in the field when construction procedures and quality specifications are made.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.154-155
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• 2015

This study was to review the basic characteristics in order to evaluate field application of the emergency road repair materials for development of CAC(Calcium Aluminate Composite) usage. The experiment was conducted with two phases of field and laboratory conditions and the laboratory experiment consisted indoor and outdoor tests for compressive and flexural strength. In the result of an experiment, for the compressive strength test, the specimens that cured in the laboratory conditions were not satisfied the requirement of standards, while the specimens that cured in the field conditions were well satisfied with those. For flexural strength test, the result value was satisfied with the requirement on the standards only in outdoor curing condition of laboratory experiment. Based on these results, it is expected that the CAC can be used as an emergency road repair material for field conditions.

• 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.

• International Journal of Highway Engineering
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• v.16 no.4
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• pp.21-33
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• 2014

PURPOSES: The purpose of this study was to break away from the workforce method using cold-mix asphalt mixtures and has a constant quality and has develop repair materials of pre-production asphalt-precast types. METHODS: The selection of the repair material was determined as the results obtained through physical properties of materials and the field applicability. In case of repair materials, values obtained through Marshall stability test & the dynamic stability test & retained stability test as well as the site conditions was considered. In case of adhesive, test results were obtained through examination of the bond strength(tensile, shear) and the field applicability of the adhesive was examined through combined specimens to simulate field applications. RESULTS : According to the results of laboratory tests, in the case of repair materials, Marshall stability and dynamic stability, retained stability of cold-mix reaction type asphalt mixture is the highest. In the case of adhesive, two-component epoxy-urea has a very high bonding strength(tensile, shear) was most excellent. According to the results of field tests, when epoxy-urea was excellent workability. Also, the repair body through actual mock-up test did not occur large deformation and fracture after 12 months. CONCLUSIONS : A suitable repair material is cold-mix reaction type mixture of asphalt-precast, a suitable adhesive is a two-component epoxy-urea.

• Journal of the Korea Institute of Building Construction
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• v.24 no.1
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• pp.35-42
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• 2024

This research explores the potential of methyl methacrylate(MMA) as a material for road repair applications. It specifically examines two MMA formulations, referred to as type A and type B, in relation to their performance on concrete substrates. The evaluation criteria included drying time, tensile bond strength, and resistance to alkali. The condition of the substrate surface was varied across three curing environments: constant temperature and humidity(R), immersion in water(W), and immersion in water with chloride ions(N). The findings indicate that type B MMA exhibits a quicker drying time and superior resistance to alkali compared to type A. While type A demonstrated greater tensile bond strength, it failed to maintain adhesion with the concrete base. Based on the parameters tested in this study, type B MMA emerges as the more favorable option for road repair contexts. Nonetheless, the study underscores the necessity for additional testing on asphalt substrates to fully assess the material's durability and applicability for long-term road maintenance.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.107-108
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• 2023

In this study, the tensile adhesion strength was evaluated according to KS F 4932 to assess the suitability of MMA-based repair materials for concrete roads. Two types of MMA were used. Mortar mock-ups were made and tested for adhesion strength in three different surface conditions: air, water, and salt water. Both showed strengths above the standardized strength of 0.6 MPa. Type B, which has a relatively low adhesion strength, is considered more suitable.

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.43-49
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• 2015

PURPOSES : The objective of this study is to develop new pothole repair materials using polyurethane-modified asphalt binder, and to evaluate them relative to current pothole repair materials in order to improve the performance of repaired asphalt pavement. METHODS : In the laboratory, polyurethane-modified asphalt binder is developed, and then asphalt binder is added to produce pothole repair materials. In order to evaluate the properties of this new pothole repair material, both an indirect tension strength test and a direct tension strength test are performed to measure the material strength and bond strength, respectively. Additionally, the basic material properties are evaluated using the asphalt cold mix manual. The strength characteristics based on curing times are evaluated using a total of 7 types of materials (3 types of current materials, 2 types of new materials, and 2 types of moisture conditioned new materials). The indirect tension strength tests are conducted at 1, 2, 4, 8, 16, and 32 days of curing time. The bond strength between current HMA(Hot Mix Asphalt) and the new materials is evaluated by the direct tension strength test. RESULTS AND CONCLUSIONS : Overall, the new materials show better properties than current materials. Based on the test results, the new materials demonstrate less susceptibility to moisture, faster curing times, and an improved bond strength between HMA and the new materials. Therefore, the use of the new materials reported in this study may lead to enhanced performance of repairs made to asphalt pavement potholes.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.269-272
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• 2005

Epoxy resins are gradually becoming some of the most important and versatile polymers in modem civil engineering. Because epoxy resins have some unigue properties, such as toughness, versatility of viscosity and curing conditions, good handling characteristics, high adhesive strength, inertness, low shrinkage compared to most other thermo-setting resins and concrete, and resistance to chemicals, they have found many applications in construction castings, repair materials, road or bridge deck pavements, coatings, and as structural or non structural adhesives. In this applications, epoxy resins are widely used for polymer concretes, grouting materials, injection glues, and sealants. In this paper, characteristics of deformation of repair material after repaired have been investigated by viscosity of repair material and the width of crack. It is believed that flexural strength of epoxy resin with low viscosity is high because tensile strength is high and elongation at break is low, fracture energy is low.