• 한국건축시공학회지
• /
• 제17권2호
• /
• pp.141-147
• /
• 2017

본 연구는 기존의 에폭시 수지 충전 접착재의 단점을 보완한 마그네시아 실리케이트 인산염을 활용한 무기충전 접착재 개발 연구로서 사소마그네시아와 플라이애시를 기반으로 제1인산칼륨과 붕사를 사용하여 가사시간을 조절한 무기충전 접착재를 개발하고자 하였다. 이를 위하여 먼저 제1인산칼륨의 적정 첨가율을 도출하기 위한 기초실험을 실시하였다. 기초 실험을 바탕으로 적정강도를 취하면서 접착재 위로 인산염 잔존물이 떠오르지 않게 한 적정 첨가율을 도출하였으며, 이후 붕사 첨가율에 따라 본 실험을 실시하였고, 제조된 접착재를 대상으로 가사시간, 휨강도, 압축강도, 접착강도, 인장강도, 가열변화율, 경화수축률, 라돈가스 및 포름알데히드 방출량을 측정하였다. 그 결과 제1인산칼륨의 적정 첨가율은 35%이며, 가사시간 조절을 위해 붕사 첨가율에 따른 가사시간은 약 10분, 15분, 25분으로 나타났다. 휨강도 및 압축강도는 12시간 최소 휨강도 8.0MPa, 최소 압축강도 31.0MPa로 나타났다. 인장강도는 최소 4.1MPa로 나타났으며, 경화수축률은 최대 2.4%, 가열변화율은 최대 -0.3%로 'KS F 4923'(콘크리트 구조물 보수용 에폭시 수지)의 품질기준에 모두 만족하였다. 라돈가스 및 포름알데히드 방출량의 경우 모두 방출량이 검출되지 않았다. 따라서, 마그네시아 실리케이트 인산염을 활용한 무기충전 접착재의 가사시간에 따른 발열시간을 조절한다면 보다 시공성과 안전성을 확보한 무기 충전 접착재를 제조 할 수 있을 것으로 판단된다.

• 한국재료학회지
• /
• 제25권2호
• /
• pp.75-80
• /
• 2015

The carbon dioxide($CO_2$) released while producing building materials is substantial and has been targeted as a leading contributor to global climate change. One of the most typical method to reducing $CO_2$ for building materials is the addition of slag and fly ash, like pozzolan material, while another method is reducing $CO_2$ production by carbon negative cement development. The MgO-based cement was from the low-temperature calcination of magnesite required less energy and emitted less $CO_2$ than the manufacturing of Portland cements. It is also believed that adding reactive MgO to Portland-pozzolan cements could improve their performance and also increase their capacity to absorb atmospheric $CO_2$. In this study, the basic research for magnesia cement using $MgCO_3$ and magnesium silicate ore (serpentine) as main starting materials, as well as silica fume, fly ash and blast furnace slag for the mineral admixture, were carried out for industrial waste material recycling. In order to increase the hydration activity, $MgCl_2$ was also added. To improve hydration activity, $MgCO_3$ and serpentinite were fired at $700^{\circ}C$ and autoclave treatment was conducted. In the case of $MgCO_3$ as starting material, hydration activity was the highest at firing temperature of $700^{\circ}C$. This $MgCO_3$ was completely transferred to MgO after firing. This occurred after the hydration reaction with water MgO was transferred completely to $Mg(OH)_2$ as a hydration product. In the case of using only $MgCO_3$, the compressive strength was 3.5MPa at 28 days. The addition of silica fume enhanced compressive strength to 5.5 MPa. In the composition of $MgCO_3$-serpentine, the addition of pozzolanic materials such as silica fume increased the compression strength. In particular, the addition of $MgCl_2$ compressive strength was increased to 80 MPa.

• The Korean Journal of Ceramics
• /
• 제3권4호
• /
• pp.269-273
• /
• 1997

Chemical composition of cement powder influences the setting time and early compressive strength development. The setting time increases as the amounts of zinc oxide and magnesium oxide are increased. For one day compressive strength development, a cement powder with a composition 90% ZnO, 8% MgO and 2% silica resulted in the highest strength (greater than 1, 090 kg/$\textrm{cm}^2$). Cement-forming liquids also need to be buffered, with both aluminum and zinc ions, for a good consistency and a higher strength of the zinc phosphate cement. These liquids control the setting reactions.

• 자원리싸이클링
• /
• 제16권1호
• /
• pp.37-43
• /
• 2007

본 연구에서는 함수염화마그네슘 탈수를 통하여 마그네슘 용융염전해의 원료 물질인 무수염화마그네슘을 제조하였으며, 탈수는 관상로를 이용하여 $350{\sim}580^{\circ}C$ 범위에서 수행하였다. 함수염화마그네슘을 대기중에서 탈수할 경우 모두 산화마그네슘으로 산화되는 것을 알 수 있었으며, 염화수소가스 분위기에서 탈수시켜 무수염화마그네슘을 제조할 수 있음을 확인하였다. 그리고 탈수 온도와 시간이 증가함에 따라 탈수된 무수염화마그네슘의 결정성이 증가하였다. 염화수소가스 분위기에서 탈수가 일어나는 동안 발생되는 미반응 염화수소가스는 모두 염산으로 회수할 수 있었으며, 회수한 염산은 산화마그네슘으로부터 함수염화마그네슘을 제조하는 데에 재사용 가능할 것으로 판단된다.

• 한국세라믹학회지
• /
• 제19권2호
• /
• pp.139-144
• /
• 1982

This study has examined closely on the various foundamental conditions for the fitting in steatite porcelain as a industrial porcelain of superior quality, and as a decorated porcelain. The materials consisting of the Kyul Sung talc, and the sea water magnesia clinker power which was produced from Sam Hwa-Hwa Sung, as major constituents have been used, and also used Hyup Jin kaolin as clay minerals to give them plasticity. First, the mixture was made of corresponding in the theoretical composition of enstatite with Kyul sung talc and sea water magnesia clinker, and kaolin was added in various kinds of 1%, 2.5% 5%, 10%, and 20% by weight of the mixture. Next, the mixture was fired at the various temperatures from 1330 to 145$0^{\circ}C$. After we examined closely the physical properties and microstructures, we achieved the results that noted from this study were listed below. 1. The addition amount of kaolin should generally be from 5% to 10% by weight of the mixture to give mixture plasticity in steatite porcelain, but preferably about 20% to consider the firing temperature. 2. The temperature of the optimum firing range is from 1390 C to 142$0^{\circ}C$. 3. A case, which the $A_2$ composition had been fired at 142$0^{\circ}C$, showed a good effect in the strength, but showed a bad result in the absorption. Therefore, the specimens of $A_4$ the composition has excellent in properties of matters when the composition is fired at 142$0^{\circ}C$. Also, we consider that the specimens of the $A_5$ composition, which is fired at 139$0^{\circ}C$, is suitable for the $MgO-SiO_2$ porcelain bodies with respect to the various properties.

• 한국세라믹학회지
• /
• 제16권1호
• /
• pp.31-37
• /
• 1979

The middle point of composition within the system $MgO-Al_2O_3-SiO_2$ has been studied for applicability as ceramics dielectrics. A Kyul Sung Tale of high purity, magnesia clinker of Sam-wha chemical company, C.P. aluminium oxide, calcium carbonate, red lead, barium carbonate which was made into frit were used the raw materials. A number of steatite ceramics were prepared under carefully controlled condition and the water absorption, linear shrinkage, power factor, dielectric constant and dielectric loss were measured at elevated temperature. When we used magnesia clinker as flux, the quantity of this flux was 0.05mole, sintering temperature was continued for 2 hrs. at 1, 27$0^{\circ}C$. From this conditions, we could get the data whose power factor was 0.142%, water absorption was zero, linear shrinkage was 8.76%, dielectric constant was 5.63, dielectric loss was 0.00799. When we used red lead as flux, the quantity of this flux was 0.033mole and 0.066mole, sintering temperature was continued for 2hrs. at 1, 26$0^{\circ}C$. From this conditions, we could get the data whose water absorption was zero, linear shrinkage was 8.03%, and 8.48%, power factor was 0.136% and 0.062%, dielectric loss was 0.0072 and 0.0037. When we used barium carbonate made into frit as flux, the quantity of this flux was 0.02mole, sintering temperature was continued for 2hrs. at 1, 27$0^{\circ}C$. From this conditions, we could get the data whose water absoption was zero, linear shrinkage was 8.44%, power factor was 0.138%, dielectric constant was 5.69, dielectric loss was 0.0074.

• 한국세라믹학회지
• /
• 제48권4호
• /
• pp.303-306
• /
• 2011

[ $V_2O_5$ ]doped Karrooite pigments were synthesized by the solid state method to get stabilized brown pigment in oxidation and reduction atmosphere. Optimum substitution condition and limited dopant with $V_2O_5$ for Karrooite pigment was investigated. With calcination at $1250^{\circ}C{\sim}1400^{\circ}C$, compositions were designed varying $V_2O_5$ molar ratio by increasing 0.02mole to the formula $Mg_1-xTi_2-xM_{2x}O_5$(x = 0.01~0.09 mole). Synthesized pigments were analyzed by XRD, Raman spectroscopy and UV-vis. When $V_2O_5$ was doped from 0.01 to 0.05 mole, single phase of Karrooite was observed at temperature $1300^{\circ}C$ and soaking time 4h by Raman spectroscopy. However, it was found that excess $VO_2$ peak appeared with 0.07 and 0.09 mole of $V_2O_5$ doped to $MgTi_2O_5$. This result indicated that the maximum limit of solid solution is 0.05 mole $V_2O_5$. Karrooite pigments were applied as a ceramic pigment to achieve brown colors in lime magnesia glaze and lime barium graze at both of oxidation and reduction atmosphere. CIE color coordinates are $L^*$ = 40.34, $a^*$ = 9.94, $b^*$ = 21.40 in lime magnesia glaze.

• 한국세라믹학회지
• /
• 제20권2호
• /
• pp.99-106
• /
• 1983

This experiment has been carried out for the purpose of investigating the effect of $Ga_2O_3$ and $GeO_2$ additivies on sintering of magnesium oxide over the temperature range of 130$0^{\circ}C$~150$0^{\circ}C$. The effect of calcining temperature on the bulk densities of fired compacts prepared from this material was observed MgO powder has been obtained by calcining extra reagent grade magnesium carbonate(basic fired) at 90$0^{\circ}C$ for 30 minutes $Ga_2O_3$and GeO2 were added in the ratio of 1, 2, and 3 wt% to MgO and mixed with calcined MgO. The specimens were prepared by compression with pressure of $700kg/cm^2$ than fired at 130$0^{\circ}C$~150$0^{\circ}C$ for 0-5hrs. Sintering behaviour and microstructure of the fired specimens were examined. The optimum calcination temperature of magnesium carbonate was 90$0^{\circ}C$. Densification rates obeyed the equation D=K in t+c. Theoretical density in the case of addition of $Ga_2O_3$ was 23.1 kcal/mole in the case of the additive $GeO_2$ was 14.176kcal/mole. This low value would appear to support a machanism of grain boundatry diffusion The range of average grain size in the case of addition of $Ga_2O_3$ and $GeO_2$ was 21$\mu\textrm{m}$-31$\mu\textrm{m}$.

• 한국건축시공학회지
• /
• 제19권5호
• /
• pp.449-456
• /
• 2019

최근 비정형 건축물의 비중이 증가함에 따라 거푸집 재사용이 불가하여 건설폐기물이 증가하고 있는 추세이다. 또한 비정형 건축물 건축 시 생산자의 숙련도에 따라 비정형 패널의 품질이 결정되며 이에 따른 정확한 공사비 측정불가 및 인건비 증대라는 문제점이 있다. 본 연구는 이러한 비정형 건축물의 문제점을 보완하기 위하여 오차율이 적고 작업성이 좋은 최적의 배합을 찾는 것을 목표로 실험을 진행한다.

• 한국건축시공학회지
• /
• 제21권4호
• /
• pp.281-291
• /
• 2021

건설산업의 환경부하를 최소화하기 위해서는 건축 자재의 친환경성을 강화하고 내구수명을 연장하여 신축 및 철거를 최소화의 필요성이 있다. 따라서 이러한 문제점을 개선하기 위해 많은 한옥의 지붕마감 공법이 제안되었지만 현재는 경제성, 무게, 내구성 등의 문제점으로 기존공법을 사용하는 추세이다. 한옥 건물의 지붕재로 사용되는 점토기와의 제조방법에 경주에서 생산된 기와용 점토와 고령토와 S사의 재활용 FNS(Ferro Nickel Slag) 활용하여 문제를 해결하고자 연구를 진행하여 한국전통 점토기와의 개발 특성과 재료를 연구하고 관련 기초자료를 제시한다.