• Title/Summary/Keyword: concrete durability.

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Freezing and Thawing Properties of Polypropylene Fiber Reinforced Eco-concrete (폴리프로필렌 섬유보강 에코콘크리트의 동결융해 특성)

  • Sung Chan-Yong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.2
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    • pp.59-66
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    • 2006
  • This study is performed to evaluate freezing and thawing properties of polypropylene fiber reinforced eco-concrete using soil, natural coarse aggregate, soil compound and polypropylene fiber. The mass loss ratio is decreased with increasing the content of natural coarse aggregate and soil compound, but it is increased with increasing the content of polypropylene fiber. The ultrasonic pulse velocity, dynamic modulus of elasticity and durability factor are increased with increasing the content of natural coarse aggregate and soil compound, but it is decreased with increasing the content of polypropylene fiber. The mass loss ratio, ultrasonic pulse velocity, dynamic modulus of elasticity and durability factor are $1.49{\sim}3.32%,\;1,870{\sim}2,465\;m/s,\;77X10^2{\sim}225X10^2\;MPa\;and\;84.6{\sim}92.8$ after freezing and thawing 300 cycles, respectively. These eco-concrete can be used for environment-friendly side walk and farm road.

A study on the fatigue performance of repaired concrete structure. (콘크리트 균열보수부의 내피로성능에 관한 연구)

  • Kwon Yong Joo;Kang Dong Soo;Kim Kyu Yong;Park Sung Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.535-538
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    • 2005
  • The problem of the crack which occures from the reinforced concrete structure. could be caused by the complexed factors. When the crack happen, it caused fatal blemish to manage and maintain the structure such as structural problem, licking, spalling, viewing Even though they study and work hard to solve this kind of problem in the world, there are no countermeasure for perfect prevention of crack. After the crack checked out, a method of repair-reinforcement has been sutdied and operated actively. In this experiment, studied durability of repair material. Experiment wave and durability of epoxy and urethane's were shown good result, and micro cement's durability displayed result that is not good. Result of a repeat tired experiment displayed result that micro cement is bad.

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Durability Life Prediction of Concrete Subjected to Freezing-Thawing and Chloride Attack (동결융해와 염해에 따른 복합열화를 고려한 콘크리트의 내구수명 예측)

  • Hwang, Hyo-Jae;Park, Dong-Cheon;Oh, Sang-Gyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.11a
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    • pp.97-101
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    • 2008
  • As the number of concrete building structures in marine environment increases, it is important to study and predict the durability and the compound deterioration of the concrete which is exposed in both chloride and freezing-thawing damage. The concrete's resistance against freezing and thawing is tested based on KS F 2456, while its chloride ion diffusion coefficient is evaluated based on NT BUILD 492. In result, the more exposure to freezing and thawing process, the shorter life it gets, due to the increased amount of chloride ion diffusion coefficient.

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Improved Durability Performances in Cement Mortar with Rice Husk Ash

  • Saraswathy, Velu;Karthick, Subbiah;Kwon, Seung-Jun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.2 no.1
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    • pp.66-73
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    • 2014
  • Currently many researches have been performed for enhancing durability of concrete. Rice husk ash has several advantages like early strength of concrete and dense pore structure. A calcium silicate hydrate (CSH) gel around the cement particles due to pozzolanic reaction of rice husk can increase the strength of concrete against cracking. Very limitedly a systematic and detailed investigation on the corrosion performance of rice husk ash and silica fume blended concrete is performed. A realistic approach has been made through compressive strength, bond strength, and split tensile strength etc. Corrosion performance was also evaluated rapid chloride ion penetration test (RCPT) and impressed voltage test, and the results were discussed in the paper.

The Durability Evaluation of Concrete using CFBC-ash Binder (발전소 부산물 활용 결합재를 이용한 콘크리트의 내구성 평가)

  • Lim, Gwi-Hwan;Kang, Yong-Hak
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.259-260
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    • 2018
  • This study evaluated the compressive strength, freeze-thaw and sulfate resistance characteristics of concrete using CFBC-Ash. The CFBC-Ash was adjusted to a particle size of 75 ㎛ or less and using by increasing the fineness of powder through milling. As a result, it was confirmed that the concrete using CFBC-Ash shows a high compressive strength, durability. Also, it is confirmed that CFBC-ash can be used as a concrete binder.

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A study on Improving the Durability of the Base Concrete Using Blast Furnace Slag (고로슬래그를 활용한 바탕콘크리트 내구성 향상에 대한 연구)

  • Jang, Yong;Kang, Ye-Jin;Lee, Dong-Oun;Kim, Dae-Geon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.11a
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    • pp.36-37
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    • 2021
  • When the final finish of a building is designed with base concrete, complex deterioration occurs due to the harsh environment such as shrinkage and expansion due to external temperature changes, freezing and thawing, and the use of calcium chloride due to snow accumulation. Therefore, the pozzolanic reaction mechanism of blast furnace slag is clearly identified, and the causal relationship between the material properties and performance of the blast furnace slag is identified to present guidelines for mixing high-durability concrete.

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A Study on the Properties of Promoted High Durability Concrete Applied to Coastal Landfill Underground Structures (고내구성 콘크리트(PHDC)의 해안가 매립지 지하구조물의 현장적용 특성에 관한 연구)

  • Kim, Woo-Jae;Khil, Bae-Su;Kim, Do-Su;Kim, Sung-Su;Jung, Sang-Jin;Lee, Han-Seung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.153-154
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    • 2009
  • This study examined the field applicability of promoted high durability concrete (PHDC) developed for improving the chloride penetration resistance of coastal landfill underground structures. PHDC was found superior to conventional concrete containing slag in watertightness, crack resistance, and chloride penetration resistance required in coastal landfill underground structures. It was also more workable in field application, and easier to control the quality. This study investigated the strength development, crack resistance, and chloride penetration resistance of PHDC, and performed life evaluation of underground concrete structures of coastal landfill using the Life 365 program.

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Self Cleaning and Durability of Silicate Impregnant of Concrete (콘크리트 침투성 표면보호재의 자기세정 및 내구특성)

  • Song, Hun;Chu, Yong-Sik;Lee, Jong-Kyu
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.433-436
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    • 2008
  • Deterioration in the concrete structure are due to carbonation, chloride ion attack and frost attack. Therefore, concrete structure is needed to surface protection for increase durability using silicate impregnants. Thus, this study is concerned with self-cleaning and durability of silicate hydrophilic impregnants of concrete structure using lithium and potassium silicates. From the experimental test results, lithium and potassium silicates have a good properties as a carbonation resistance. Lithium and potassium silicates make good use of hydrophilic impregnants of concrete structures.

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Effect of fly ash and GGBS combination on mechanical and durability properties of GPC

  • Mallikarjuna Rao, Goriparthi;Gunneswara Rao, T.D.
    • Advances in concrete construction
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    • v.5 no.4
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    • pp.313-330
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    • 2017
  • Geopolymer is a sustainable concrete, replaces traditional cement concrete using alternative sustainable construction materials as binders and alkaline solution as alkaline activator. This paper presents the strength characteristics of geopolymer concrete (GPC) developed with fly ash and GGBS as binders, combined Sodium silicate ($Na_2SiO_3$) and Sodium Hydroxide (NaOH) solution as alkaline activators. The parameters considered in this research work are proportions of fly ash and GGBS (70-30 and 50-50), curing conditions (Outdoor curing and oven curing at $600^{\circ}C$ for 24 hours), two grades of concrete (GPC20 and GPC50). The mechanical properties such as compressive strength, split tensile strength and flexural strength along with durability characteristics were determined. For studying the durability characteristics of geopolymer concrete 5% $H_2SO_4$ solutions was used and the specimens were immersed up to an exposure period of 56 days. The main parameters considered in this study were Acid Mass Loss Factor (AMLF), Acid Strength Loss Factor (ASLF) and products of degradation. The results conclude that GPC with sufficient strength can be developed even under Outdoor curing using fly ash and GGBS combination i.e., without the need for any heat curing.