• Title, Summary, Keyword: Porous ratio

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Void Ratio and Strength of Porous Polymer Concrete and Initial Growth Properties within Planting Block with Binder Contents (결합재량에 따른 포러스 폴리머 콘크리트의 공극률과 강도 및 식생 블록 내 초기 생장 특성)

  • Sung, Chan-Yong;Kim, Young-Ik
    • Journal of The Korean Society of Agricultural Engineers
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    • v.52 no.6
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    • pp.101-110
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    • 2010
  • This study was performed to evaluate the void ratio and strength of porous polymer concrete used coarse aggregates and unsaturated polyester resin to find optimum mix design of porous polymer concrete for planting block. Also, this study was performed to evaluate the planting properties of herbaceous plant and cool-season grass in porous polymer blocks based on the experimental results of porous polymer concrete to develop environmentally friendly planting blocks. Tests for the void ratio and compressive strength of porous polymer concrete were performed at the curing age 7 days. Also, kinds of plants such as Tall fescue, Perennial ryegrass, Lespedeza and Alfalfa for planting were applied to porous polymer blocks. Within 6 weeks after seed, initial germination ratio, cover view and growth length for planting blocks were estimated by various methods.

An Experimental Study on the Quality Control of Fresh Porous Concrete (굳지않은 포러스콘크리트의 품질관리를 위한 실험적 연구)

  • 이성일;장종호;김재환;강석표;백용관;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.705-710
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    • 2002
  • Recently, there has been for a number of reasons growing interest in the use of porous concrete, and it is used as an ecological material. But, because the valuation methods of the quality on the fresh porous concrete aren't established up till now, it is difficult that the harden porous concrete is made sure of its required quality. This study is to present the measurement method of the void ratio on the fresh porous concrete and to analyze the influence of water-cement ratio and vibrating time on the binder content covered a coarse aggregate. Results of this study were shown as follows; The measurement methods of the void ratio and aggregate-binder weight ratio on the fresh porous concrete can be useful as data for the quality control of fresh porous concrete.

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Void ratio and Strength Properties of Porous Concrete Utilizing Rice Husk Ash and Recycled Aggregate for Planting (식생 적용을 위한 왕겨재와 순환골재를 활용한 포러스 콘크리트의 공극률 및 강도 특성)

  • Kim, Young-Ik;Sung, Chan-Yong
    • Korean Journal of Agricultural Science
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    • v.33 no.2
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    • pp.167-177
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    • 2006
  • This study was performed to evaluate void ratio, compressive and flexural strength, and pH properties according to the admixture ratio of rice husk ash, aggregate size, and neutral treatment time of porous concrete with an admixture of rice husk ash produced as an agricultural by-product. The SEM results for cement mortar with a 5% rice husk ash admixture for the weight of cement formed more C-S-H hydrates due to the $SiO_2$ present in the applied rice husk ash. According to the results of the SEM test, the $SiO_2$ that was a major chemical element of rice husk ash generated a large amount of calcium hydroxide in the early stage of the hydration process of cement leading to the formation of ettringite. The void ratio of porous concrete with an admixture of rice husk ash decreased with increasing admixture ratio of rice husk ash. In addition, the void ratio of porous concrete with an admixture of rice husk ash decreased compared to porous concrete with no admixture of rice husk ash. The compressive and flexural strength of porous concrete with a 5% and 10% admixture ratio of rice husk ash slightly increased compared to concrete with no admixture of rice husk ash. The pH value of porous concrete rapidly decreased immediately after neutral treatment. Then, it gradually increased and decreased again after 14 days. Also, for neutral treatment, the pH value of porous concrete showed appropriate pH levels(less than 9.5) in all mixtures for planting at 28 curing days.

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Effect of Template Size Ratio on Porosity and Strength of Porous Zirconia Ceramics (기공형성제 크기 비(ratio)가 다공질 지르코니아 세라믹스의 기공율과 강도에 미치는 영향)

  • Chae, Su-Ho;Kim, Young-Wook;Song, In-Hyuek;Kim, Hai-Doo;Bae, Ji-Soo
    • Journal of the Korean Ceramic Society
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    • v.45 no.9
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    • pp.537-543
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    • 2008
  • Effect of template size ratio on porosity and mechanical properties of porous zirconia ceramics were investigated using two different size (${\sim}8{\mu}m$ and ${\sim}50{\mu}m$ in diameter) of polymethyl methacrylate-coethylene glycol dimethacrylate (PMMA) microbeads as sacrificial templates. Porosity of the porous zirconia ceramics increased with decreasing the template size ratio ($8{\mu}m: 50{\mu}m$) whereas the compressive and flexural strengths of the porous zirconia ceramics increased with increasing the template size ratio. By controlling the template size ratio, sintering temperature and sintering time, it was possible to produce porous zirconia ceramics with porosities ranging from 57% to 69%. Typical flexural and compressive strength values of porous zirconia ceramics with ${\sim}60%$ porosity were ${\sim}37\;MPa$ and ${\sim}85\;MPa$, respectively.

Hydration, Strength and pH Properties of Porous Concrete Using Rice Husk Ash

  • Kim, Young-Ik;Sung, Chan-Yong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.3
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    • pp.51-60
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    • 2007
  • This study was performed to evaluate void ratio, compressive and flexural strengths, and pH properties according to the content ratio of rice husk ash, aggregate size, and neutral treatment time of porous concrete with content of rice husk ash produced as an agricultural by-product. The SEM results for cement mortar with a 5% rice husk ash for the weight of cement formed more C-S-H hydrates due to the $SiO_2$ of rice husk ash. In the XRD test, cement mortar with a 5% rice husk ash for the weight of cement registered a higher peak point of approximately $2{\theta}=20{\sim}25^{\circ}$ compared to cement mortar without rice husk ash. According to the results of the XRD and SEM tests, the $SiO_2$ that was a major chemical element of rice husk ash generated a large amount of calcium hydroxide in the early stage of the hydration process of cement leading to the formation of ettringite. The void ratio of porous concrete with rice husk ash decreased with increasing content ratio of rice husk ash. In addition, the void ratio of porous concrete with rice husk ash decreased compared to porous concrete without rice husk ash. The compressive and flexural strength of porous concrete with a 5% and 10% content ratio of rice husk ash slightly increased compared to concrete without rice husk ash. The pH value of porous concrete rapidly decreased immediately after neutral treatment. Then, it gradually increased and decreased again after 14 days. However, the pH value was nearly the same regardless of neutral treatment time in 28 curing days. Also, for neutral treatment, the pH value of porous concrete showed appropriate pH levels (less than 9.5) in all mixtures for planting at 28 curing days.

An Experimental Research on the Feature of the Porous Concrete (다공콘크리트의 특성에 관한 실험적 연구)

  • 옥치율;김종주;옥치남
    • Journal of Ocean Engineering and Technology
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    • v.4 no.1
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    • pp.71-80
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    • 1990
  • We experimented the physical property of the porous concrete by changing the water cement ratio, when the aggregate ratios are 1:5 and 1:7 separately. And then we received the results as follows. The bigger, the coarse grading of the porous concrete is, the more sensitive to the water cement ratio, the porous concrete becomes. And if we think over its compressive strength, the coarse aggregate which has 5-15mm width is most appropriate. So we concluded that when its compressive strength, permeability coefficient and its unit weight are $50kg/cm^{2}3cm/sec$ and $1900kg/m^{3}$ respectively, the water cement ratio which has 35-37% width is most appropriate, too. And its compressive strength and unit weight show that they are about a quarter and three quarters respectively about the conventional concrete.

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Analysis of porous micro sandwich plate: Free and forced vibration under magneto-electro-elastic loadings

  • Mohammadimehr, Mehdi;Meskini, Mohammad
    • Advances in nano research
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    • v.8 no.1
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    • pp.69-82
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    • 2020
  • In this study, the free and forced vibration analysis of micro sandwich plate with porous core layer and magneto-electric face sheets based on modified couple stress theory and first order shear deformation theory under simply supported boundary conditions is illustrated. It is noted that the core layer is composed from balsa wood and also piezo magneto-electric facesheets are made of BiTiO3-CoFe2O4. Using Hamilton's principle, the equations of motion for micro sandwich plate are obtained. Also, the Navier's method for simply support boundary condition is used to solve these equations. The effects of applied voltage, magnetic field, length to width ratio, thickness of porous to micro plate thickness ratio, type of porous, coefficient of porous on the frequency ratio are investigated. The numerical results indicate that with increasing of the porous coefficient, the non-dimensional frequency increases. Also, with an increase in the electric potential, the non-dimensional frequency decreases, while and with increasing of the magnetic potential is vice versa.

Influence of Mix Factors and Mixing Ratio of Aggregate on the Strength and Water Permeability of Porous Concrete (포러스 콘크리트의 배합요인 및 골재 혼합비율이 강도 및 투수성능에 미치는 영향)

  • 김무한;김규용;백용관
    • Journal of the Korea Concrete Institute
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    • v.12 no.6
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    • pp.91-98
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    • 2000
  • Porous concrete having continuous voids is gaining more interest as an ecological material. It has several useful functions such as water and air permeability, sound absorption, etc. Its strengths are considerably lower than those of conventional concrete due to the large and continuous voids in it. This study has been carried out to investigate the influence of mix factors and mixture proportion of aggregate on the strengths and water permeability of porous concrete. And it has been carried out to investigate the evaluation of void of porous concrete by the ultra-sonic pulse velocity. The results f this study are as follows: 1) The theoretical void ratio has greater influence than any other factor on the strengths and water permeability of porous concrete. And it is a little affected by the replacement proportion of silica-fume and mixture proportion of aggregate. 2) Because the coefficients of correlation between the void ratio and ultra-sonic pulse velocity were relatively high, it will be possible that the void ratio is predicted by the ultra-sonic pulse velocity.

Planting-Ability Properties of Porous Concrete as Gradation and Void Ratio (포러스콘크리트의 골재입도 및 공극률에 따른 식생능력평가)

  • 윤덕열;김정환;조영수;표구영;박승범
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.243-248
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    • 2002
  • As a notion of environment protection changes throughout the world, construction engineers, as part of the effort to resolve environmental problems, have been actively doing research on environmental friendly porous concrete using large and non-uniform aggregate. Porous Concrete enables water and air to pass through a firmly hardened material and allows required nutrients to reach roots of plants. The purpose of this study is to analyze planting ability when the change of aggregate gradation and void ratio. The results of an experiment from the planting ability of the porous concrete to its influence on the compressive strength are reported in this paper. As a result of the experiment, the compressive strength is higher when the gradation of aggregate is smaller, and it also goes higher when the void ratio gets smaller The planting ability of porous concrete is decided by the germination and the grass length of Indigofera pseudo-tinctoria(IPT). The length of IPT is longer when the gradation of aggregate is greater and the void ratio gets smaller.

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An Experimental Study on Performance in Elevation of Porous Polymer Concrete (투수성 폴리머 콘크리트의 성능 향상에 관한 실험적 연구)

  • Choi, Kyu-Hyung;Lho, Byeong-Cheol;Joo, Myung-Ki;Lee, Bok-Kyu
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.953-956
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    • 2008
  • The purpose of this study is to ascertain the void ratio, permeability coefficient and compressive strength of porous polymer concretes with unsaturated polyester. The porous polymer concretes using unsaturated polyester with polymer binder contents of 3.5, 4.0, 4.5 and 5.5% are prepared, and tested for void ratio, permeability coefficient and compressive strength. As a result, void ratio and permeability coefficient of porous polymer concrete decrease with increasing polymer binder content. However, the compressive strength of porous polymer concrete increase with increasing polymer binder content. The compressive strength of porous polymer concrete decrease with increasing permeability coefficient.

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