• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.222-223
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• 2014

In this study, industrial by-products including blast furnace slag, incineration ash and waste gypsum were used with recycled fine aggregates to manufacture the zero-cement mortar.The replacement ratio of dihydrate gypsum and anhydrite gypsum was fixed as 0 and 10%, the replacement ratio fo WA1 was fixed as 0.5% and 1.0%, respectively. It could be identified that when the replacement of gypsum was 10% and WA1 of 1.0%, the strength could be in the range of normal strength.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1999.11a
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• pp.137-142
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• 1999

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2001.11a
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• pp.3-9
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• 2001

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.74-81
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• 2019

In this study, to characterize the application of CSA and dihydrate gypsum Utilizing industrial byproducts, we investigated the characteristics of CSA and dihydrate gypsum to investigate the characteristics of Mine Liner according to the addition amount. As a result of compressive strength, length change and absorption rate of mining lime wastewater according to CSA addition amount, up to 30% of CSA showed a positive effect on shrinkage and absorption reduction effect as well as strength at initial age. However, due to excessive use of CSA 50%, it was reduced by 15% compared to OPC due to increase of absorption rate and decrease of cement amount due to over expansion rather than shrinkage compensation and void filling.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.05a
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• pp.237-241
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• 2005

• Journal of the Korean Chemical Society
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• v.24 no.4
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• pp.329-336
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• 1980

A domestic phosphogypsum was calcined in a batch type fluidized bed reactor at various reaction temperatures ranging 90∼180$^{\circ}$ without and with an alkaline additive amounting up to 5% of gypsum, and physical properties of the resultant products were compared following their characterization by X-ray diffraction pattern and DTA. It has been found that dehydration reactions were uniformly carried out in the fluidized bed reactor and only hemihydrate was obtained at 90$^{\circ}$ whereas at higher temperatures dehydration reaction progressed further. When gypsum was charged to the reactor preheated at over 140$^{\circ}$, a considerable degree of dehydration occurred before the reactant reached the initially set reactor temperature and in particular, at over 160$^{\circ}$ most of dehydration reaction was performed prior to the present reactor temperature. However, it has been found that gypsum mostly transforms into hemihydrate around the reactant temperature of 140$^{\circ}$ while transformation into anhydrite mostly occurs around $160^{\circ}C.$ When calcium hydroxide was added to gypsum in the reactor, the optimum physical properties of the calcined product were obtained at the weight ratio of $Ca(OH_2)/P_2O_5$ = 3.2.

• Fire Science and Engineering
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• v.15 no.3
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• pp.55-62
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• 2001

The fire performance evaluation methods in Korea and overseas for interior finish materials were analysed and tested with gypsum board and Plywood by using room corner test not adopted by domestic code until now. The results of gypsum board (thickness:8 mm) and Plywood (thickness:4 mm) applying NFPA 265 and ISO 9705 test respectively are satisfied the assessment criteria. To assess a actual fire performance and classify fire hazard levels for interior finish materials, room-corner test and flame spread models should be adopted in building code and fire code to overcome limitations of current bench-scale test method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.137-138
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• 2013

Nowadays, research about using recycled aggregate as alkali activator has been investigated. By the mechanism of Alkali activation, blast furnace slag's potential hydraulis property would be activated. Thee application of this technique is considered as fit for low strength concrete, so it's suitable in concrete secondary production such as bricks and blocks. Aside alkali activator, sulfate could also activate blast furnace slag's potential hydranlis property. In this research, gypsum(CaSO4·2H2O)has been added with blast furnace slag. Fundamental experiment such as flow and strength has been tested to evalnate effect of gypsum's activation property.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.8-16
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• 2020

As the circulating fluidized bed combustor(CFBC) boilers system to generate electric power increase in order to reduce environmental pollution, a lot of CFBC fly ashes(CFFA) are produced. CFFA has limited use in concrete because it contains free CaO, which can cause cement expansion and rapid initial hydration. In this study, the microstructure and the initial development of compressive strength characteristics were experimentally analyzed to be used as a stimulant to replace natural gypsum by mixing with CFFA and phosphate gypsum to enhance the initial strength of portland blast furnace slag cement. The recycled gypsum was used as flue-gas desulfurization gypsum and phosphate gypsum. Experimental results show that the initial strength development is relatively lower when CFFA and dihydrate gypsum are mixed, but the strength improvement effect of the mixture with CFFA and anhydrous gypsum as an anhydritedII typed crystalized gypsum is similar to that of natural gypsum. As a result, it w as analyzed to have high possibility of use for stimulant of portland blast furnace slag cement.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.06a
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• pp.190-195
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• 2000

현재 미국과 유럽, 일본 등에서는 실내 벽 및 천장 마감재에 관하여 성능 기준 설계에 의한 새로운 평가방법이 활발하게 연구되고 있다. 예를 들면 시험에 소요되는 시간과 경비를 절감하고자 Bench-scale test 결과를 이용하여 화재위험성을 예측하는 내장재의 Performance-based fire safety design에 관한 연구가 진행되고 있다. 한편, 성능기준 화재안전 설계를 적용하기 위하여 현재 사용하는 대부분의 존 모델 프로그램은 공간화재시 가연성 마감재의 발화 및 화염확산 및 위험성을 충분히 고려하지 못하고 있다. (중략)