• 제목/요약/키워드: 폴리머콘크리트

검색결과 536건 처리시간 0.025초

굳지 않은 MMA개질 UP 폴리머 콘크리트의 사용가능시간에 미치는 온도와 결합재의 영향 (Effects of Temperature and Binder Components on Working Life of Fresh MMA Modified UP Polymer Concrete)

  • 연정흠;현상훈
    • 한국도로학회논문집
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    • 제14권4호
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    • pp.51-61
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    • 2012
  • PURPOSES : This study deals with the working life of polymer concrete, which is typically used as a repair or overlay material for portland cement concrete pavements. METHODS : In the scope of this study, laboratory testing was conducted on fresh MMA modified UP polymer concrete, which uses an MMA monomer for viscosity adjustment and strength improvement of UP resin. The experimental variables were temperature (-20 to $+20^{\circ}C$) and binder components (MMA, MEKPO, and DMA). RESULTS : The result showed that the optimum binder ratios for polymer concrete production were 12, 11, and 10 wt.% when the MMA contents were 20, 30, and 40 wt.%, respectively. The working life of polymer concrete depending on temperature and binder components could be expressed by a logarithmic functional formula. The coefficient of variation for each binder component was the highest for DMA content while the lowest for MEKPO content. Also, the contents of each binder component for ensuring the working life of 60 minutes were proposed. CONCLUSIONS : Ultimately, the present study derived a linear regression equation estimating 60 minutes working life based on the setting times of each binder component.

폴리머를 이용한 포러스 콘크리트의 동결융해저항성에 관한 연구 (A Study on the Freeze-Thaw Resistance of Porous Concrete Using Polymer)

  • 이상태
    • 한국환경복원기술학회지
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    • 제9권3호
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    • pp.17-25
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    • 2006
  • To increase freeze-thaw resistance of porous concrete, this study examined physical properties of polymer by replacing paste used as a binding material with polymer, using unsaturated polyester and epoxy resin, and changing the mixing ratio of polymer. According to the result of this study, when the mixing ratio of resin paste to aggregates was 11 to 16%, voids volume was 33 to 37% and unit weight was about 1620 to 1720kg/$m^3$. In comparison with previous studies using cement paste, voids volume increased by about 7 to 16%, while unit weight decreased by about 100 to 300kg/$m^3$. Compressive strength was 90 to 155kg/$cm^2$ at the age of 7 days, which was 5-40kg/$cm^2$ bigger than porous concrete using cement paste. From a viewpoint of freeze-thaw resistance, it was identified that pluse velocity fell by 0.23km/sec, about 7% of the original velocity, when the cycle of freeze-thaw was repeated 300 times. In spite of 300 repetitions of the cycle, relative dynamic modulus of elasticity was more than 60%, which suggested that its freeze-thaw resistance was more excellent compared with the result that relative dynamic modulus of elasticity of porous concrete using cement paste was 60 % or less under the condition of 80 repetitions of freeze-thaw cycle.

강섬유 혼입 폴리머 시멘트 고강도 콘크리트 보의 전단거동 (Shear Behavior of Polymer Cement High Strength Concrete Beams Mixed with Steel Fiber)

  • 곽계환;박종건;곽경헌
    • 한국농공학회지
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    • 제44권1호
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    • pp.93-102
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    • 2002
  • Steel fiber and polymer are used widely for reinforcement material of RC structures because of its excellences of the durability, serviceability as well as mechanical properties. The purpose of this study is to investigate the shear behavior of polymer cement high strength concrete beams mixed with steel fiber. The compressive strength of concrete was based on the 100$\times$200 mm cylinder specimens. The compressive strength of concrete are 320$kgf/cm^2$, 436 $kgf/cm^2$ and 520 $kgf/cm^2$ in the 28 days. The static test was carried out to measure the ultimate load, the initial load of flexural and diagonal cracking, crack patterns and fracture modes. Also, load-strain and load-deflection examined. During the test cracks were sketched against the load values according to the growth of crack. result are as follows; (1) The failure modes of the specimens are increased in rigidity and durability with mixing steel fiber and polymer. (2) The load of initial crack was similar a theory of shear-crack strength. (3) The deflection and strain at failure load of Polymer-steel fiber high strength concrete beams were increased, improving the brittleness of the high strength concrete.

휨 하중을 받는 재생 PET 폴리머 콘크리트의 인장크리프 모델 (Tension Creep Model of Recycled PET Polymer Concrete with Flexural Loading)

  • 채영석;태기호
    • 한국안전학회지
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    • 제27권5호
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    • pp.117-125
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    • 2012
  • In recent years, polymer concrete based on polyester resin have been widely generalized and the research of polymer concrete have been actively pursued by the technical innovations. Polymer concrete is a composite consisting of aggregates and an organic resin binder that hardens by polymerization. Polymer concrete are stronger by a factor of three or more in compression, a factor of four to six in tension and flexural and a factor of two in impact when compared with portland cement concrete. In view of the growing use of polymer concrete, it is important to study the physical characteristics of the material, emphasizing the short term properties as well as long term mechanical behavior. If polymer concrete is to be used in flexural load-bearing application such as in beam, it is imperative to understand the deformation of the material under sustained loading conditions. This study is proposed to empirical and mechanical model of polymer concrete tension creep using long-term experimental results and mathematical development. The test results showed that proposed model has been used successfully to predict creep deformations at a stress level that was 20 percent of the ultimate strength and viscoelastic behavior of recycled-PET polymer concrete is linear of stress level up to 30 percent. It is expected that the present model allows more realistic evaluation of varying stresses in polymer concrete structures with a constant loading.

폐유리분말과 재생골재를 사용한 포장용 투수성 폴리머 콘크리트의 공학적 성질 (Engineering Properties of Permeable Polymer Concrete for Pavement using Powdered Waste Glass and Recycled Coarse Aggregate)

  • 성찬용;김태호
    • 한국농공학회논문집
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    • 제53권6호
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    • pp.59-65
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    • 2011
  • This study was performed to evaluate the compressive and flexural strength, void ratio and permeability coefficient used powdered waste glass, $CaCO_3$, recycled coarse aggregate and unsaturated polyester resin to find optimum mix design of permeable polymer concrete for pavement. The compressive and flexural strength of permeable polymer concrete for pavement using powdered waste glass were in the range of 16.8~19.7 MPa and 4.7~6.1 MPa, respectively. it was satisfied the regulation of permeable concrete for pavement (18 MPa and 4.5 MPa). The void ratio and permeability coefficient were decreased with increasing the powdered waste glass, respectively. The void ratio and permeability coefficient were satisfied national regulation of permeable concrete for pavement (8 % and $1{\times}10^{-2}$ cm/s). In addition, this study found out that required amount of binder was decreased with increasing the powdered waste glass. This fact is expected to have economical effects during the use of powdered waste glass in the manufacture of permeable polymer concrete for pavement. Accodingly, the powdered waste glass can be used for permeable concrete material.

FRP-UHPC 복합 보강기법으로 보강된 RC 슬라브의 휨 파괴를 위한 설계 조건 (Flexural Failure Design Criteria for Retrofitted RC Slabs using FRP-UHPC Hybrid System)

  • 김정중;노혁천;마흐무드 레다 타하
    • 복합신소재구조학회 논문집
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    • 제3권2호
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    • pp.11-18
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    • 2012
  • This study proposes flexural failure design criteria of continuous slabs enhanced by a hybrid system of fiber reinforced polymer (FRP) and ultra high performance concrete (UHPC). The proposed hybrid retrofit system is designed to be placed at the top surface of the slabs for flexural strengthening of the sections in both positive and negative moment zones. The enhancing mechanisms of the proposed system for both positive and negative moment regions are presented. The neutral axis of the enhanced sections in positive moment zone at flexural failure is enforced to be in UHPC overlay for preventing the compression in FRP. From this condition, a relationship between design parameters of FRP and UHPC is established. Although the capacity of the proposed retrofit system to enhance flexural strength and ductility is confirmed through experiments of one-way RC slabs having two continuous spans, the retrofitted slabs failed in shear. To prevent this shear failure, a design criteria of flexural failure is proposed.

철근보강 폴리머 콘크리트 인장부재의 인장강성 (Tension Stiffening of Reinforced Polymer Concrete Tension member)

  • 연규석;김남길;조규우;권택정
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2003년도 학술발표논문집
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    • pp.387-390
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    • 2003
  • Direct tensile tests were carried out for the tensile members of steel-reinforced polymer concrete with different steel diameters and steel ratios to figure out the effect of tensile strength of polymer concrete. In the experiments, polymer concrete with $1000kgf/cm^2$ of compressive strength, steel with $5200kgf/cm^2$ of tensile strength, and the tensile members with 100 cm of constant length were used. Experimental results showed that, regardless of steel diameters and steel content, the strain energy exerted by concrete till the initial crack was 14-15% of the total energy till the point of yield: The energy was much larger than the one of high-strength cement concrete. The behaviors of tensile members of steel-reinforced polymer concrete were in relatively good agreement with the model suggested by Gupta-Maestrini (1990), which was idealized by the effective tensile stress-strain relationship of concrete and the load-strain relationship of members, while those showed a big difference from CEB-FIP model and ACI-224 equation suggested for the load-displacement relationship that was defined as the cross sectional stiffness of effective axis. Modified ACI-224 model code about the load-displacement relationship for the tensile members of steel-reinforced polymer concrete and theoretical equation for the polymer concrete tensile stiffness of polymer concrete suggested through the results of this study are expected to be used in an accurate structural analysis and design for the polymer concrete structural members.

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Rigid Core 샌드위치 구조의 초고속 공작기계 베드 적용에 관한 연구 (Application of Sandwich Structure with Rigid Core for High Speed Machine Tool Bed)

  • 서정도;이대길;김태형;박보선;최원선
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.113-116
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    • 2003
  • To maximize the productivity in machining molds and dies, machine tools should operate at high speeds. During the high speed operation of moving frames or spindles, vibration problems are apt to occur if the machine tool structures are made of conventional steel materials with inferior damping characteristics. However, self-excited vibration or chatter is bound to occur during high speed machining when cutting speed exceeds the stability limit of machine tool. Chatter is undesirable because of its adverse effect on surface finish, machining accuracy, and tool lift. Furthermore, chatter is a major cause of reducing production rate because, if no remedy can be found, metal removal rates have to be lowered until vibration-free performances is obtained. Also, the resonant vibration of machine tools frequently occurs when operating frequency approaches one of their natural frequencies because machine tools have several natural frequencies due to their many continuous structural elements. However, these vibration problems are closely related to damping characteristics of machine tool structures. This paper presents the use of polymer concrete and sandwich structures to overcome vibration problems. The polymer concrete has high potential for machine tool bed due to its good damping characteristics with moderate stiffness. In this study, a polymer concrete bed combined with welded steel structure i.e., a hybrid structure was designed and manufactured for a high-speed gantry-type milling. Also. its dynamic characteristics were measured by modal tests.

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충전재가 투수용 폴리머 콘크리트의 공학적 성질에 미치는 영향 (Effects of Filler on Engineering Properties of Permeable Polymer Concrete)

  • 성찬용;정현정;민정기
    • 농업과학연구
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    • 제23권1호
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    • pp.51-60
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    • 1996
  • This study was performed to evaluate the effects of filler on engineering properties of permeable polymer concrete with unsaturated polyester resin. The following conclusions were drawn; 1. The unit weight was in the range of $1.804{\sim}1.919t/m^3$, the weights of those concrete were decreased 17~22% than that of the normal cement concrete. 2. The highest strength was achieved by stone dust filled permeable polymer concrete, it was increased 17% by compressive, 147% by tensile and 188% by bending strength than that of the normal cement concrete, respectively. 3. The ultrasonic pulse velocity was in the range of 2,722~3,060m/sec, which was showed about the same compared to that of the normal cement concrete. Stone dust filled permeable polymer concrete was showed higher pulse velocity. 4. The water permeability was in the range of $3.076{\sim}4.152{\ell}/cm^2/h$, and it was larglely dependent upon the mix design. These concrete can be used to the structures which need water permeability. 5. The compressive strength, tensile strength, bending strength and ultrasonic pulse velocity were largely showed with the increase of unit weight. But, it was decreased with the increase of water permeability, respectively.

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재유화형 분말수지와 고로 슬래그 미분말을 혼입한 폴리머 콘크리트의 압축강도 및 내산성 (Compressive Strength and Acid-Resistant of Polymer Concrete Using Redispersible Polymer and Blast Furance Slag Powder)

  • 김인수;성찬용
    • 한국농공학회논문집
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    • 제50권5호
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    • pp.19-27
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    • 2008
  • This study was performed to evaluate the compressive strength and acid-resistant of polymer concrete using redispersible polymer powder(RPP) and blast furnace slag powder(BSP). Material used were ordinary portlant cement, recycled coarse aggregate, natural fine aggregate, redispersible polymer powder and blast furnace slag powder. The main experimental variables were the substitution ratio of redispersible polymer powder and blast furnace slag powder, when the substitution ratios of RPP were 0, 1, 2, 3, 4, 5 and 6%, and those of BSP were 10%. The compressive strength and acid-resistant of polymer concrete using RPP and BSP were compared with those of ordinary concrete(Basis). When the substitution ratio of RPP was 1%, at age of 28 days, the compressive strength were more higher than those of Basis by 24%, and it was decreased with increasing the RPP content, respectively. Also, the water absorption ratio was decreased with increasing the RPP content. But, the acid-resistant was improved with increasing the RPP content.