• Journal of the Korean Ceramic Society
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• v.31 no.9
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• pp.957-968
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• 1994

Manufacturing process of porous glass by the filler method was studied. Commercial soda-lime-silicate glass powder was mixed with inorganic salt as the filler such as KCl, K2SO4, Na2SO4. Sintering shrinkages of mixed powders with the variation of sintering temperature were compared, and the effects of the fillers to shrinkages of mixed powder were increased in the order of Na2SO4${\mu}{\textrm}{m}$ of pore diameter were manufactured when the filler sizes 100~200 ${\mu}{\textrm}{m}$. The open pore volume of porous glass is determined by the quantity of filler and porous glasses having open pore volume between 30 and 70 vol% are available. Available sintering temperature range for preparation of porous glass is from the softening temperature of the glass powder to eutectic melting temperature of DTA curve of mixed powder.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.128-134
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• 2005

This study was performed to evaluate the strength and durability properties of recycled concrete containing water - redispersible copolymer powder(WRP) and blast furnace slag powder(BSP) [RCWS]. Material used were cemente, recycled coarse aggregare, natural fine aggregate, water-redispersible copolymer powder, blast-furnace slag powder. Especially, Water-redispersible powder was used for blending with Inorganic binders such as cemente, gypsum and hydrated lime etc. First of all, Mixed ratio method of RCWS made Two Type. One was called type-1 which used to BSP content 5% and WRP(Water-redispersible powder) content 0%, 1%, 2%, 3%, 4%, 5%, 6%. respectively. Another was called Type-2 which used to BSP(blast furnace slag powder)content 10% and WRP(Water-redispersible powder) content 0%, 1%, 2%, 3%, 4%, 5%, 6%. respectively. According to the experimental results of (RCWS), Incase Type-2 at curing age 28days, Compressive strength, pulse velocity and dynamic modulous of elasticity were shown higher than Type-1 and The more WRP content increasing($0%{\sim}6%$) was the lower Compressive strength, Pulse velocity and Dynamic modulous of elasticity. Water absorption ratio was in the range of $3.85%\;{\sim}\;3.23%$, it was almost equal to Type-1, 2 but Increasing the WRP content($0%{\sim}6%$), The water absorption ratio is decreased.

• KIEAE Journal
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• v.9 no.2
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• pp.65-71
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• 2009

Results from tests for what mixing rate of soil and sand is proper for the rammed earth and for how much additives are optimum are as under. 1) In the test to evaluate what mixing rate of soil and sand is desirable, peptizing property and surface sticking rate are found similar in its degree, but compression strength is found most stable when the ratio of soil and sand mixing shows 30:70 which indicates the best mixing rate of soil and sand. 2) In a test to add hydrated lime, compression strength, peptizing property, and surface sticking rate are found best when the mixing rate of soil and sand shows 23:7. 3) In a test to add sea weeds, the peptizing property goes down at 75% of sea weeds input a little bit more than at 100%, but compression strength shows best at 75% which is thought to be the best rate. 4) In a drop test, more soil powder mixed, the sticking strength gets better and more sands are contained, the sticking strength gets far worse to be scattered in powder type. 5) As concluding all results mentioned in the above item, the most desirable mixing rate of soil, sand, and hydrated lime is found to be 23:7:70 for the rammed earth where compression strength, peptizing property, and surface sticking rate are best.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.2
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• pp.159-166
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• 1999

This study was conducted to investigate the effects of application of the dolomite particle and the shell powder on soil characteristics, dry matter yield and nutritive value of forages in loam soil at the experimental field of National Livestock Research Institute, Suwon, from 1994 to 1996. Application treatments were control, lime, dolomite 0.5, 2.0, 4.0mm, and shell powder in mixed pasture. Rate of dust occurrence was greatly decreased according to dolomite application and the dissolving rate in soil was highest in shell powder application among treatments. Although there was no significant difference, average dry matter yield of forages for 3 years was slightly increased with the application of lime, shell powder, dolomite 0.5mm, 4.0mm, 2.0mm and control in order. Both Ca and Mg contents of forages were no differences among treatments in 1994. However, all treatments were higher than those of control in 1995. And K and Na contents of forages were no differences among treatments. Lime requirement was greatly increased from 2,630 to 6,150kg per ha with the lapse of time. Although soil hardness was optimum level at first, it was likely to become hard little by little after treatments. Solid phase of soil was lowered a little except for control. Organic matter and available $P_2O_5$ contents of soil were highest in shell powder application among treatments, and K, Ca and Mg contents of soil were no differences among treatments. Ca content was increased a little in 1995, but decreased a little in 1996 compared to that of soil before treatments in 1994. AIso, Mg content was lowered than that of soil before experiment in 1995 and 1996. The results demonstrated that use of dolomite and shell powder as lime substitutes could be reduced dust problem and coast pollution as well as soil improvement. Therefore, it is desirable to apply the dolomite and the shell powder every 3 years in loam soil.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.28-34
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• 2004

The old technique of sandblasting which has been used for decoration of glass surface has recently been developed into a powder blasting technique for brittle materials such as glass, silicon and ceramics, capable of producing micro structures larger than 100${\mu}{\textrm}{m}$. In this study, we introduced oblique powder blasting, and investigated the effect of the impacting angle of particles, the scanning times and the stand-off distance on the surface roughness and the weight-loss rate of samples with no mask, and the wall profile and overetching of samples with different mask pattern in powder blasting of soda-lime glass. The varying parameters were the different impact angles between 50$^{\circ}$ and 90$^{\circ}$, scanning times of nozzle up to 40 and the stand-off distances 70mm and 100mm. The widths of mask pattern were 0.2mm, 0.5mm and 1mm. The powder was alumina sharp particles, WA #600. The mass flow rate of powder during the erosion test was fixed constant at 175g/min and the blasting pressure of powder at 0.2Mpa.

• Resources Recycling
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• v.27 no.3
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• pp.58-65
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• 2018

For the recycling of coal ash from the domestic circulating fluidized bed boilers, a lime-based sorbent with 0.2~0.4 mm size was prepared by using limestone powder and CFBC fly ash. Mixing a small amount of slaked lime in the lime-based absorbent lead the formation of calcium silicate on the surface of the particle and the strength of absorbent particle was improved. As a result of comparing the desulfurization characteristics, it was found that the conversion rate was about 10% higher than that of commercially available limestone desulfurization used in the furnace, which is confirmed that it can be used as a desulfurization absorbent.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.509-516
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• 2023

The use of sulfur(S) in concrete has been variously studied as a way to improve salt resistance in concrete. However, sulfur is a solid material and is difficult to powder, which has disadvantages in its usability as an admixture or mixture for cement and concrete. For these problem, polymers such as dicyclopentadiene have been used to modify sulfur, but this also exists in a sticky state after modifying and does not improve the fundamental problem. So, reforming sulfur with slaked lime and the effect on cement hydration was examined by reforming sulfur with slaked lime, and the following conclusions were obtained. Depending on the reaction conditions, slaked lime modified bio-sulfur exists in a slurry state containing unreacted sulfur, unreacted slaked lime, calcium-sulfur(Ca-S) compounds and water. When slaked lime modified bio-sulfur is used as a cement mixture, salt resistance of concrete with slaked lime modified bio-sulfur is to be superior to that of plain concrete. This is believed to be because structure of cement hydrates with slaked lime modified bio-sulfur is to be more dense to that of plain cement hydrates by the continued presence of ettringite and can be used as a cement mixture in concrete.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.2
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• pp.27-34
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• 2008

Recently, owing to the development of industry and improvement of building techniques, concrete structures are becoming larger and higher. This study was performed to analyze hydration reation properties of concrete with binders and admixtures, such as OPC, low heat cement, belite rich cement, slag powder, lime powder and fly ash. To investigate effects of PC type superplasticizer on the hydration, experiments involving FT-IR, XRD, DSC, SEM were analyzed at the curing age 1day, 3days and 28days. The hydration reaction rate of OPC concrete slightly delayed at the curing age 1day, blast furnace slag powder and fly ash were more effective. BRC and LHC concretes can be used for concrete structures in winter season.

• Journal of Power System Engineering
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• v.18 no.3
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• pp.93-99
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• 2014

The purpose of this paper is to manufacture the non-sintered ceramic used lime and industrial waste. The used materials were basalt powder sludge, calcium hydroxide(Ca(OH)2) and additives such as calcium stearate and $TiO_2$. The mixing ratios between Ca(OH)2 and sludge were 5:5, 6:4 and 8:2, respectively. The ceramic forms were pressured by 100, 200 and 300 bar and cured in 14% CO2 for 12 days. The behaviors of compressive strength, specific gravity, water absorption and pH of ceramic form were investigated. The results were compressive strength of over 36 MPa, water absorption of over 8.8%, pH value of over 12.3. And these results satisfied GR F 4006 and 4031 standard.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.106-113
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• 2010

We were tried to draw a conclusions related to additive amount of gypsum in blast furnace slag in the study. In the result, fluidity of concrete decreased with an increase of gypsum and was not satisfied with KS standard in the cases of natural gypsum and limestone sludge more than 2.6% addition. Early compressive strength of concrete containing desulfurized gypsum, fluosilicic acid gypsum and phosphoric acid gypsum were improved respectively but calcined lime sludge and lime powder were not influenced on strength. If available, additive gypsum should be managed less than 2.0% owing to low fluidity. In low temperature, fluosilicic acid gypsum was to advantages on the fluidity while desulfurized gypsum was in high temperature. There also are conclusions that additive gypsum was to be 2.6% in winter and in summer; it's to be fewer than 2.6%.