• 제목/요약/키워드: Compressive property

검색결과 591건 처리시간 0.03초

Prediction of compressive strength of slag concrete using a blended cement hydration model

  • Wang, Xiao-Yong;Lee, Han-Seung
    • Computers and Concrete
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    • 제14권3호
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    • pp.247-262
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    • 2014
  • Partial replacement of Portland cement by slag can reduce the energy consumption and $CO_2$ emission therefore is beneficial to circular economy and sustainable development. Compressive strength is the most important engineering property of concrete. This paper presents a numerical procedure to predict the development of compressive strength of slag blended concrete. This numerical procedure starts with a kinetic hydration model for cement-slag blends by considering the production of calcium hydroxide in cement hydration and its consumption in slag reactions. Reaction degrees of cement slag are obtained as accompanied results from the hydration model. Gel-space ratio of hardening slag blended concrete is determined using reaction degrees of cement and slag, mixing proportions of concrete, and volume stoichiometries of cement hydration and slag reaction. Furthermore, the development of compressive strength is evaluated through Powers' gel-space ratio theory considering the contributions of cement hydration and slag reaction. The proposed model is verified through experimental data on concrete with different water-to-binder ratios and slag substitution ratios.

고성능 콘크리트의 압축강도 추정을 위한 초음파속도식의 검토 (Investigation on the Ultrasonic Pulse Velocity Equation for Estimating Compressive Strength of High Performance Concrete)

  • 이태규;김규용;최경철;강연우;김순묵;김수봉
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 추계 학술논문 발표대회
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    • pp.5-6
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    • 2014
  • For estimating compressive strength of concrete, non-destructive test has conducted generally. It used experimental equation to calculate compressive strength from construction. This study investigated experiment to apply non-destructive test, based on fresh property, compressive strength and ultrasonic pulse velocity of high performance concrete. And it conducted to compare various proposed equation.

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압축강도에 따른 수중불분리 콘크리트의 배합설계에 관한 연구 (A Study on the Mix Design of Antiwashout Underwater Concrete According to Compressive Strength)

  • 조영국
    • 한국건축시공학회지
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    • 제3권3호
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    • pp.91-97
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    • 2003
  • At present, the antiwashout underwater concretes are used as popular construction materials in European countries, the United States and Japan. The water-soluble polymers in the antiwashout underwater concretes provide excellent segregation or washout resistance, self-compaction and self-leveling property to the concretes. The purpose of this study is to recommend to optimum mix proportions of antiwashout underwater concretes according to compressive strength of 300kgf/$\textrm{cm}^2$ to 500kgf/$\textrm{cm}^2$. The antiwashout underwater concretes are prepared with various unit cement content, unit water content, sand-aggregate ratio, unit antiwashout agent and superplasticizer content. And they are tested for flowability, and compressive strength. From the test results, it is possible to recommend the optimum mix proportions of antiwashout underwater concretes according to compressive strengths within the range of 300kgf/$\textrm{cm}^2$ to 500kgf/$\textrm{cm}^2$.

스프링강의 피로크랙진전 특성에 미치는 쇼트피닝 투사속도의 영향 (An Effect of Shot Velocity of Shot-peening on A Property of Growth Behavior of Fatigue Crack for Spring Steel)

  • 박경동;노영석
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2002년도 추계학술대회 논문집
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    • pp.341-346
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    • 2002
  • In this study, an effect that compressive residual stress formed by shot-peening the surface of spring steel(JISG SUP-9) at each shot velocity(1800, 2200, 2600, 3000rpm) on the fatigue crack growth property and threshold stress intensity factor, ${\Delta}K_{th}$, was examined. Followings are the result (1) Compressive residual stress on surface of specimen was determined at each -601 MPa(1800rpm), -638 MPa(2200rpm), -587 MPa (2600rpm), -550 MPa(3000rpm) by shot velocity of shot peening and threshold stress intensity factor, ${\Delta}K_{th}$, fatigue crack growth rate, da/dN, on fatigue crack growth is obstructed by the compressive residual stress was determined at each $5.619\;MPa\sqrt{m}$(Un-peening), $8.319\;MPa\sqrt{m}$(1800rpm), $8.797\;MPa\sqrt{m}$(2200rpm), $7.835\;MPa\sqrt{m}$(2600rpm), $7.352\;MPa\sqrt{m}$(3000rpm) (2) Existing compressive residual stress by effect of shot velocity of shot-peening on relation of crack length. a, and number of cycle, N, was 2 times progressed in case of 2200rpm than specimen of Un-peening on fatigue life. And fatigue life was 1.6 times progressed incase of 3000rpm by Over peening. (3) Fatigue life of Material on Paris' law, $da/dN=C({\Delta}K)^m$, that effect of material constant, C, and fatigue crack growth exponent, m, was influenced by effect of. C and m.

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저융점 개질유황의 산화마그네슘 치환에 따른 모르타르의 역학적 특성 (The Mechanical Property of Mortar According to the MgO Replacement of Low Melting Modified Sulfur)

  • 정병열;문지환;이상수;송하영
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
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    • pp.97-98
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    • 2012
  • This research examined the fundamental property of the MgO as the fundamental study that substituted the MgO in the low melting point modified sulfur mortar to examine the physical properties.In this research, the table floor, flexural strength test, and compressive strength test were performed. And as the replacement ratio increased, the floor showed the tendency to increase. And when being the replacement ratio 3%, the flexural strength and compressive strength made the high strength. In case of being substituted for over 5% they displayed the tendency that the intensity is degraded.

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Effects of thermal aging on mechanical properties of laminated lead and natural rubber bearing

  • Kim, Dookie;Oh, Ju;Do, Jeongyun;Park, Jinyoung
    • Earthquakes and Structures
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    • 제6권2호
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    • pp.127-140
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    • 2014
  • Laminated rubber bearing is very popular base isolation of earthquake engineering pertaining to the passive structural vibration control technologies. Rubber used in fabricating NRB and LRB can be easily attacked by various environmental factors such as oxygen, heat, light, dynamic strain, and organic liquids. Among these factors, this study carried out thermal aging test to investigate the effect of thermal aging on the mechanical properties of laminated rubber bearings in accelerated exposure condition of $70^{\circ}C$ temperature for 168 hours. The compressive-shear test was carried out to identify the variation of compressive and shear properties of the rubber bearings before and after thermal aging. In contrast to tensile strength and elongation tests, the hardness of rubber materials showed the increasing tendency dependent on exposure temperature and period. Based on the test results, the property changes of rubber bearing mainly aged by heat are quantitatively presented.

바이오콘크리트의 물리적 특성에 관한 연구 (A Study on the physical Property of the Bio Concrete)

  • 이종찬;이세현;박영신;박재명
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.509-512
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    • 2006
  • We have many environmental problems by the polluted materials as a results of mechanical development these days. So people want to use building products made from natural things and take a good effect for people from those bio products. We can instance electron wave shelding, far infrared ray and anion emission, and anti-bacterial property as the latest trend of the bio building material. So we had a experiment to investigate how much bio materials affect concrete when we use in the concrete with cement substitution. We tested slump, 7days compressive strength, and air contents for physical properties of bio concrete. The result is that bio concretes with four bio ingredients have proper values comparing with target values for slump and air content but lower compressive strength than plain concrete.

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Mechanical properties of natural fiber-reinforced normal strength and high-fluidity concretes

  • Kim, Joo-Seok;Lee, Hyoung-Ju;Choi, Yeol
    • Computers and Concrete
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    • 제11권6호
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    • pp.531-539
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    • 2013
  • An experimental investigation of mechanical properties of jute fiber-reinforced concrete (JFRC) has been reported for making a suitable construction material in terms of fiber reinforcement. Two jute fiber reinforced concretes, called jute fiber reinforced normal strength concrete (JFRNSC) and jute fiber-reinforced high-fluidity concrete (JFRHFC), were tested in compression, flexure and splitting tension. Compressive, flexural and splitting tensile strengths of specimens were investigated to four levels of jute fiber contents by volume fraction. From the test results, Jute fiber can be successfully used for normal strength concrete (NSC) and high-fluidity concrete (HFC). Particularly, HFC with jute fibers shows relatively higher improvement of strength property than that of normal strength concrete.

석회암 굵은골재 사용 고강도 콘크리트의 역학적 특성 분석에 관한 기초적 연구 (Fundamental Study on the A Mechanical Characteristic of High Strength Concrete Using Lime Stone Coarse Aggregate)

  • 손호정;김기훈;황인성;권오봉;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
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    • pp.65-67
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    • 2011
  • This research analyzed the mechanical properties of high strength concrete produced by limestone aggregate, and summarized the result as follows: Due to the property of unhardened concrete, slump flow value increased more or less according to the increase in LG replacement, but didn't show a big difference while clear tendency of air content couldn't be found. Due to the property of hardened concrete, there appeared an increase in the rate of compressive strength the more LG replacement increased, and the modulus of elasticity also showed a tendency similar to the increase rate of compressive strength.

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굵은 입자 시멘트를 사용한 콘크리트의 강도발현 특성 (Property of Strength Development on the Concrete with Coarse Particle Cement)

  • 노상균;손호정;백대현;정웅성;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
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    • pp.89-91
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    • 2011
  • This paper is to investigate experimentally the property of strength development on the concrete for 5 years according to the change of a replacement rate of coarse particle cement in order to use coarse particle cement with a fineness of 1 900 ㎠/g that is classified during a grinding process of the OPC production. The result is that as the CC replacement rate increased, the compressive strength was decreased proportionally. but the width of strength reduction was reduced as time passed.

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