• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.717-722
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• 2002

The results of an experiment on the water purification of the porous concrete and its influence on the compressive strength are reported in this paper. Two different sizes of coarse aggregate of 5-10, and 10-20mm, and three absolute volume ratios of paste to aggregate of 30, 40 and 50 percent for a given size of aggregate were used. For the compressive strength, the concrete with the aggregate size of 5-10mm showed much higher strength than that with the aggregate size of 10-20mm. But, the compressive strength is higher when the ratio of paste to aggregate is smaller. In the water purification experiment, the amount of attached an organism on the porous concrete surface indirectly is examined by measuring the consumption of the Dissolved Oxygen (DO). The ability of the water purification is evaluated by the removal amount of the Total Phosphorus(T-P) and Total Nitrogen(T-N). The ability of the removal of the T-N and T-P in the test water is superior to a porous concrete with a smaller size of aggregate and a higher void content. These results are owing to a large specific surface area of the specimen. As a result, porous concrete using by-products has sufficient performance of water purification.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.568-571
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• 2004

This research estimated the physical. mechanical characteristic and the character of sound absorption according to target void ratio of porous concrete and the mixing ratio of recycled aggregate for the valid utilization of recycled aggregate using waste concrete and sound reduction out of a road, a railway, a residential street, and a downtown area. As a result of the test, compressive strength tended to be a radical strength fall when target void ratio was $25\%$ and contents of recycled aggregate exceeded over $50\%$. Also, the character of sound absorption of porous concrete which used recycled aggregate using waste concrete was the most excellent when target void ratio was $25\%$, and the influence by contents of recycled aggregate was trivial. Therefore, when the strength and the character of sound absorption of porous concrete are considered, it is proved valid that proper target void ratio was $25\%$ and contents of recycled aggregate using waste concrete was $50\%$ or so.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.677-682
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• 2000

Porous concrete is defined as d type of concrete for which the fine aggregate component the matrix is entirely omitted. Although it had been used as a building material in Europe for over 60 years, low strength and high void ratio limited its application in the past. In recent years, however high void ratio of concrete has been recognized again and can be used as an environmental conscious material, for example, parking lots, draining light-traffic-volume pavements and as sea water purifying material. The result of an experiment on the void ratio of fiber reinforced porous concrete and its influence on the compressive strength and permeability relationship of concrete are reported in this paper. One-sized coarse aggregate of 5-10mm, and three absolute content of fiber(steel fiber, polyprophylen fiber) were used. The result of measured void ratio, permeability coefficient and compressive strength show a small variation. Void ratio, permeability coefficient and compressive strength of fiber reinforced porous concrete depend on contents of fiber and absolute volume ratios of paste to aggregate.

• 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.

• 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.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.3
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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.

• 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.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.4
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• pp.51-59
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• 2007

Recently, concrete has been made porous and used for sound absorption, water permeation, vegetation and water purification according to void characteristics. Many studies are carried out on the utilization of sewage sludge, fly ash and waste concrete to reduce the environmental load. This study was performed to evaluate the void, strength, relationship between void and strength, permeability and chemical resistance properties of porous polymer concrete for pavement with different fillers. An unsaturated polyester resin was used as a binder, crushed stone and natural sand were used as an aggregate and bottom ash, fly ash and blast furnace slag were used as fillers. The mix proportions were determined to satisfy the requirement for the permeability coefficient, $1{\times}10^{-2}$ cm/s for general permeable cement concrete pavement in Korea. The void ratios of porous polymer concrete with fillers were in the range of $18{\sim}23%$. The compressive strength and flexural load of porous polymer concrete with fillers were in the range of $19{\sim}22$ MPa and $18{\sim}24$ KN, respectively. The permeability coefficients of porous polymer concrete with fillers were in the range of $5.5{\times}10^{-1}{\sim}9.7{\times}10^{-2}$ cm/s. At the sulfuric acid resistance, the weight reduction ratios of porous polymer concrete immersed during 8-week in 5% $H_{2}SO_{4}$ were in the range of $1.08{\sim}3.56%$.