• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.2
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• pp.74-80
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• 2011

In this study, it is evaluated on the properties of mechanical performance, autogenous shrinkage and chloride resistance for application of high performance concrete for bridge deck overlay used slag powder and fly ash as a representative by-product of industrialization. According to test results, it is evaluated that the durability of concrete is improved the properties of chloride resistance, autogenous shrinkage and alkali aggregate reaction by using hydraulic mineral admixtures. It is considered to have a green construction and an economic feasibility on recycling of by-product as a improved concrete for durability and efficiency in materials and constructions.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.3
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• pp.239-246
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• 2014

High volume slag concrete is attracting new attention and are thought to have promising potential for industrial applications, partly due to the climate debate, but especially due to their very low heat of hydration and their good durability in chemically aggressive environments. However, High volume slag concretes tend to have slower strength development especially. In this study, the effect of anhydrite ($CaSO_4$) on the mechanical and durability performance of high volume slag concrete were investigated. The main variables were anhydrite contents (0, 4, 6, 8, 10%). Test results show that 4~8% anhydrite concrete have improved engineering properties (hydration, compressive strength, shrinkage, creep, carbonation) as control concrete at early ages.

• Computers and Concrete
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• v.30 no.6
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• pp.421-432
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• 2022

Recently, the interminable ozone depletion and the global warming concerns has led to construction industries to seek for construction materials which are eco-friendly. Regarding this, Geopolymer Concrete (GPC) is getting great interest from researchers and scientists, since it can operate by-product waste to replace cement which can lead to the reduction of greenhouse gas emission through its production. Also, compared to ordinary concrete, geopolymer concrete belongs improved mechanical and durability properties. In spite of its positive properties, the practical use of geopolymer concrete is currently limited. This is primarily owing to the scarce structural, design and application knowledge. This study investigates the Mechanical and Durability of Geopolymer Concrete Containing Fibers and Recycled Aggregate. Mixtures of elastoplastic fiber reinforced geopolymer concrete with partial replacement of recycled coarse aggregate in different proportions of 10, 20, 30, and 40% with natural aggregate were fabricated. On the other hand, geopolymer concrete of 100% natural aggregate was prepared as a control specimen. To consider both strength and durability properties and to evaluate the combined effect of recycled coarse aggregate and elastoplastic fiber, an elastoplastic fiber with the ratio of 0.4% and 0.8% were incorporated. The highest compressive strength achieved was 35 MPa when the incorporation of recycled aggregates was 10% with the inclusion of 0.4% elastoplastic fiber. From the result, it was noticed that incorporation of 10% recycled aggregate with 0.8% of the elastoplastic fiber is the perfect combination that can give a GPC having enhanced tensile strength. When specimens exposed to freezing-thawing condition, the physical appearance, compressive strength, weight loss, and ultrasonic pulse velocity of the samples was investigated. In general, all specimens tested performed resistance to freezing thawing. the obtained results indicated that combination of recycled aggregate and elastoplastic fiber up to some extent could be achieved a geopolymer concrete that can replace conventional concrete.

• 보존과학연구
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• s.22
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• pp.133-154
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• 2001

Stone cultural properties, exposed in natural environment, is deteriorated by many weathering reasons for a long time. It is necessary to treat of consolidation and water-repellent on the surface because of the conservation of stone cultural properties. We was treated the specimen [granite(Hwangdung-suk), sandstone, marble(in JeongSeon)] by synthesis resin of DWR-Ⅲ, SI2121 and fluoropolymer, and tested on the durability, water-repellent, color stability and luster generation etc. In the result of this study, DWR-Ⅲ and fluoropolymer is superior to the waterrepellent, durability of salt and acid rain. SI2121 is superior to the penetration because of lower viscosity, but the water-repellent is inferior to the others. After the treatment of chemicals, the color-variation make an appearance but luster-generation doesn’t. With the passage of time, the color of specimen was got better because of the ‘washing’ phenomenon for ultra-violet, salt etc.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.76-82
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• 2006

High-strength, High-durability concrete appearance was embossed by benevolence who quality for each raw material that become factor that is direct in concrete manufacture and the special quality is very important and request properties of matter were also strengthened more. Specially, natural resources of good quality were abundant past in occasion of aggregate and unlike concrete request strength past that the importance was less relatively the quality enemy than cement because is also not big, importance of aggregate quality great veried as concrete strength and request properties of matter about durability are strengthened more on extreme displacement. Mixing four who is original and mixs special quality examination of domestic three Four-Stick Games by Chaechwiwon and age Four-Stick Games and crushed sand examined concrete quality characteristic that use mortar and concrete quality characteristic, special quality of North Korea sun guardian mountain three Four-Stick Games that is imported from the North Korea, North Korea sun guardian mountain three Four-Stick Games etc..

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.92-97
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• 2008

To survive in outdoor environments, photovoltaic modules rely on packaging materials to provide requisite durability. We analyzed the properties of encapsulant materials that are important for photovoltaic module packaging. The properties of Ethylene Vinyl Acetate(EVA) sheet in photovoltaic encapsulant materials have to meet conditions that are high optical transmittance, good adhesion and high cross-linking rate. The objective of this paper is to understand the property evaluation methods of EVA sheet. Through this research, we could confirm that properties of EVA sheet have an effect on durability and operating efficiency of photovoltaic module.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.146-152
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• 1996

Polypropylene fiber reinforced mortar and concrete as civil material or architectural material have been used in America and British etc, and have been researched. Polypropylene fibers have many advantages in many points ; in economical costs, chemical stability and durability. It has been reported that polypropylene fiber can control restrained tensile stresses and cracks and increase toughness, resistance to impact, corrosion, fatigue and durability. This study has been performed to obtain the properties of polypropylene fiber reinforced concrete such as compressive strength, flexural strength, toughness, slump, drying shrinkage crack and drying shrinkage characteristics. The test variables are fiber contents, fiber length, fiber types, and so on. From the results of this study, we can expect the effects of the admixtures of polypropylene fiber about strength and drying shrinkage properties in concrete and mortar.

• Journal of the Korean Ceramic Society
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• v.46 no.4
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• pp.365-371
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• 2009

It is well known that the properties of concrete such as the compressive strength, water permeability, water tightness and durability are affected by micro-structure in hardened cement paste. Especially, for durability of concrete, watertightness of cementitious materials is the most critical property among various properties. Recently, many types of materials as organic and/or inorganic materials are used for watertightness of concrete. In this study, The effect of Stearic Acid at $0.5\;wt%{\sim}3.0\;wt%$ adding ratios on the hydration and watertightness property of cement were investigated. And we also discussed the changing of microstructure in hardened cement paste by addition of Stearic Acid. Cement paste with Stearic Acid showed improvement of watertightness by reducing of cement total pore volume and decomposition of Stearic Acid.

• Economic and Environmental Geology
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• v.32 no.2
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• pp.203-208
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• 1999

The main objective of this study is to suggest a new assessment method of the influence of weathering due to salt crystallization on the engineering property of rock. For this purpose, various sources of salt and salt crystallization were investigated, and artificially accelerated weathering tests were carried out. In natural envionment, weathering rate is very slow and weathering process involves complex mechanisms. Therefore artificial weathering test is essential for systematic analysis. Arificial weathering test is defined as test which controls weathering rate and agents by controlling arificial environmental condition. In this study, salt crystallization test was selected among various artificial weathering test methods, for its important role in weathering. Change of various stone properties were detexted. The change of physical properties by salt crystallization were observed as follows : 72% in Brazilian tensile strength and 72% in Slake durability. These results explain the importance of salt crystallization in the mechanical behaviour and properties of stone.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.8
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• pp.1139-1148
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• 1999

This paper discussed the assessment of hand of denim fabrics finished by enzymatic hydrolysis. The semantic differential scale established using the database collected from university students. Analyzing the subjective rating by common factor analysis with oblimin rotation five factors expressing the hand were induced. Factor one was the surface property related to the surface roughness or softness Factor two was the durability which was related to the compactness and bearing strength Factor three was the sense of weight which was related to the thickness and weight. The moisture related properties and the sense of shape recovery were the forth and fifth factors respectively. the evaluations on the surface property weight and moisture related properties were similar by men and women However the shape recovery and the durability were evaluated differently. Surface and weight related properties were important factors judging the hand of fabrics by both group.