• Korean Journal of Construction Engineering and Management
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• v.6 no.3 s.25
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• pp.128-134
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• 2005

Up to now, the various water proofing methods and materials have been developed. For the water proofing methods, poly-urethane membrane method is one of the commonly used and increase market share in water proofing industry due to it's many advantages. However, in spite of it's many advantages over other water proofing methods, water proofing defect occurs frequently. With this respect, the study investigate water proofing defect causes in roof water proofing. The study investigate 13 water proofing construction site in Sunchon city in oder to find urethane membrane defection causes and their type. As a results of the study, the followings are founded. 1) Among various water proofing defection causes, problems of water remain phenomenon due to surface horizontal level defect which occupy $25\;\%$ of total defect causes is the most commonly occur. 2) The second defect cause which occupy $15\;\%$ of total defect causes is the swell up phenomenon due to surface dry problem. For the prevention of water proofing defection in roof using urethane membrane, the followings are recommended. 1) Faultless surface treatment before using urethane membrane 2) Develop improved urethane membrane material 3) Improve urethane membrane construction technique

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.4
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• pp.348-354
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• 2015

Urethane waterproofing materials which currently being used most commonly in the Korean domestic market have high applicability and construct layers without forming any joints, but under the influence of low temperature and low humidity, as well as the thickness of the applied layer, the curing time of this material may become extended in construction sites. To resolve these issues, a proposed method of using water-hardening type of polyurethane waterproofing materials are being developed. However, there currently lacks any standards or evaluation methods on determining an optimal mixture ratio of water for the water-hardening polyurethane waterproofing materials. Therefore, workers and construction workers are relying on their hands-on-skills and experience to determine this ratio and are not able to obtain a consistent performance quality out of these materials. Therefore, for the establishment of a board applicability of the water-hardening polyurethane waterproofing methods in construction sites, this study objectively analyzes the changes in the performance of these materials depending on the changes of the water mixture ratio and attempts to procure the optimal ratio on the basis of forming a provisionary standard. The study prepares mixtures of varying ratio(no water added, 5, 10, 15, 20, 25, 30, 40 and 50) and conducts comparative analysis respective mixtures' performances and their changes in the physical properties in an objective manner and proposes a provisional optimal value that can serve as a data base that can be used as a reference for future studies.

• Journal of the Korea Institute of Building Construction
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• v.2 no.1
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• pp.139-146
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• 2002

This study deals with the characterizing and the application like as insulation materials in the joint part in concrete surface layer and waterproofing sheet especially for roof slabs. Using steel materials and butil-rubber tape to band waterproofing sheet and concrete surface together before this waterproofing system will be applied. It can be expected to both the curability and the watertightness by coating poly-urethane 2 or 3 times with sheet surface. Therefore this waterproofing system can be possible to protect water without the damage when vapor is going out from concrete and without air pockets because of the difference temperature inside and out. This system particularly consists of air bents and elastic waterproofing sheet considering the physical damage while water can cause purely physical damage. This system is one of the most efficient ways of waterproofing system without air pocket.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.931-934
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• 2008

Polyurethane apply to the waterproof widely. Polyurethane rubbers are prepared that the influences of a thermal aging on the properties are investigated. Polyol and Polyisocyanate were varied ratio in the range mixed by using individual product that was vulcanized by a hot. The waterproofs of Polyurethane were investigated about tensile strength, tear strength and elongation after the thermal Aging for 168, 336, 504 hrs at 70$^{\circ}$C and 80$^{\circ}$C in the air oven. As the increase of the thermal aging time, tensile strength, tear strength and elongation were reduced.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.168-169
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• 2013

In this study, the chemical resistance of polyurea resin waterproofing and anti-corrosion materials that is applied to the social infrastructure was analyzed. The result in this study will be utilizing as a basic data for establishing the quality standards which are able to judge the chemically resistant characteristic of polyurea resin waterproofing and anti-corrosion materials.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.211-212
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• 2016

Due to a lack of objective and adequate study on the physical effects on hydroponic polyurethane waterproofing material water mixture ratio, construction site workers are having to rely on their hands-on experience to determine a mixture ratio, resulting in difficulty of maintaining quality management. Particularly in cases of rooftop exposed type hydroponic polyurethane materials, the varying temperature conditions make it further difficult for quality management control. in this regard, this study conducts tensile strength testing and compares the tensility change rates hydroponic polyurethane waterproofing materials with various water mixture ratios ranging from 0%~50% and exposed to alternating temperature change between -20℃ to 60℃ in the span of 1 hour after curing for 14 days.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.683-692
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• 2020

A joint displacement resistance evaluation method for selecting waterproofing materials in railway bridge decks is proposed. The displacement range for an evaluation is determined by finite element method (FEM) analysis of a load case based on an existing high-speed PSC Girder Box railroad bridge structure. The FEM analysis results were used to calculate the minimum joint displacement range to be applied during testing (approximately 1.5 mm). For the evaluation, four commonly used waterproofing membrane types, cementitious slurry coating (CSC), polyurethane coating system (PCS), self-adhesive asphalt sheet (SAS), and composite asphalt sheet (CAS), were tested, with five specimens of each membrane type. The joint displacement width range conditions, including the minimum displacement range obtained from FEM analysis, were set to be the incrementing interval, from 1.5, 3.0, 4.5, and 6.0 mm. The proposal for the evaluation criteria and the specimen test results demonstrated how the evaluation method is important for the sustainability of high-speed railway bridges.