• Title/Summary/Keyword: 고 내구성 내화재

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A Study on the Properties of Fire Endurance and Spalling of High Performance RC Column with the Finishing and Covering Material (고성능 RC 기둥의 마감재 변화에 따른 폭열 및 내화특성에 관한 연구)

  • Han, Cheon-Goo;Hwang, Yin-Seong;Ji, Suk-Won;Kim, Kyoung-Min
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.2
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    • pp.143-152
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    • 2006
  • High performance concrete(HPC) has been widely used in high-rise building. The HPC has several benefits including high strength, high fluidity and high durability. However, spalling is susceptible to occur in HPC and HPC also tends to be deteriorated in the side of fire resistance performance at fire. This paper investigated the spalling prevention of high performance RC column. Control concrete showed severe failure and a case of concrete with fire enduring spraying material exhibited more severe spalling failure than even control concrete. In addition, concrete with fire enduring paint reported the most favorable spalling resistance effect for preventing spall, compared with other concrete covered with finishing materials, such as fire enduring spraying material, gypsum board, marble board and fire enduring PC board. Meanwhile, concrete adding 0.1% of PP fiber demonstrated spalling resistance performance after 3hours load bearing test.

Estimation on the Durability of High-Strength Concrete using Metakaolin (Metakaolin 혼합 고강도 콘크리트의 내구특성 예측)

  • Lee, Sang-Ho;Moon, Han-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.2
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    • pp.173-180
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    • 2005
  • Metakaolin is a cementitious material for producing high-strength concrete. This material is now used as substitute for silica-fume. In this paper, we did the mechanical and durability test such as compressive/tensile/flexural strength test, chloride ion diffusion, chemical attack and repeated freezing and thawing, carbonation test. In the mechanical tests, 10~15% for binder is optimum substitute rate. And, in the chloride ion diffusion test, according to the increase of substitute of metakaolin & silica-fume for binder, the diffusion coefficient was more reduced. In the chemical attack test, by the filler effect of fine powder such metakaolin and silica-fume, the resistance is more excellent than normal concrete. In the other durability test, the concrete using metakaolin also compared with those of silica-fume substitute concrete. Through these tests, we recognized that metakaolin can be used as a substitute for silica-fume.

A Hardening Properties of Eco-Friendly SCW Grouting Material (친환경 SCW공법용 그라우팅재의 경화특성)

  • Jo, Jung-Kyu;Park, In-Wook;Mun, Kyung-Ju;Hyung, Won-Gil
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.2
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    • pp.109-115
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    • 2018
  • Since the current method of SCW cement milk pouring method uses one to one ratio of cement milk with OPC, there are some problems such as drying shrinkage, increased cost, difficulty of controlling mix proportions for various conditions of applied soil, and precipitation of $Cr^{6+}$ due to the excessively used cement. Specifically, in aspect of sustainability issues of cement manufacturing, the consumption of cement should be reduced. Hence, in this research, as a replacement of cement for SCW method, blast furnace slag with sulfate or alkali as a stimulant, and expansive admixture were used. By using blast furnace slag as a hardening composite of SCW, there are many advantages such as free controllable mix proportions, rapid setting time with less mud occurrence, less cost with less energy for mixing, constant strength development, and less precipitation of $Cr^{6+}$. Regarding the alternative composites for SCW, in this research, durability and chloride resistance were evaluated.

A Study on the Eco-Friendly Durable Pre-Painting for Concrete Structure (콘크리트 구조물의 친환경 내구성 도장에 관한 기초 연구)

  • Jo, Byung Wan;Choi, Ji Sun;Lee, Seong Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.2
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    • pp.110-116
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    • 2013
  • A concrete structure has become bigger and higher because of development of construction technology and a change in construction environment. Also it tends to focus on repairing, reinforcement and exterior in harmony with environment for structure maintenance and performance improvement. The research is about eco friendly durable painting applicable to concrete structure using civil and architecture. it purpose to improve external beauties and durable problems due to flexibility by variation of temperature, adhesion of exterior wall, crack and delamination in existing organic and mineral painting. For those problems, we made a eco friendly pre-paint that is made with preliminary treatment mixture as a highly enriched waterproof agent and adhesive increasing agent in preprocessing mixture. Then we performed an experiment on durability of prevention neutralization of concrete, durability abrasion, hiding power, adhesion, temperature resistance and resistance to chemical attack. The result of an experiment shows that hiding power is over 0.96 in standard test, durability abrasion test got higher value 1mg than water paint 75mg and tensile strength is 6 times higher than standard waterproof specification.

A Study on the Change of Strength of FRP Member Immersed in Chemical Solution (화학약품용액에 침지한 FRP 부재의 강도 변화에 대한 연구)

  • Kim, Ho-Sun;Kim, Woo-Jong;Jang, Hwa-Sup;Kwak, Kae-Hwan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.6
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    • pp.117-123
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    • 2010
  • If FRP materials that have been known as high durability materials are exposed to harmful environmental factors, deterioration and characteristics of materials can be reduced due to chemical reaction such as hydrolysis. Therefore, to use FRP materials as building major materials, it is important to exactly grasp dynamic properties by use condition. Accordingly, this study stored FRP materials in a strong acid and alkali compound solution for a certain period to conduct simulation for acute or chronic, extreme changes by chemicals, and conducted a test for compressive, tensile, shear and bending strength to analyze changes in strength by kinds and storage days of chemicals. In conclusion, the study findings indicate excellent chemical resistance of FRP materials.