• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.2
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• pp.169-178
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• 2016

The properties of wastes for melting need to be considered to minimize the maintenance of refractory and to discharge the molten slags smoothly from a plasma torch melter. When the nonflammable wastes from nuclear facilities such as concrete debris, glass, sand, etc., are melted, they become acid slags with low basicity since the chemical composition has much more acid oxides than basic oxides. A molten slag does not have good characteristics of discharge and is mainly responsible for the refractory erosion due to its low liquidity. In case of a stationary plasma torch melter with a slant tapping port on the wall, a fixed amount of molten slags remains inside of tapping hole as well as the melter inside after tapping out. Nonmetallic slags keep the temperature higher than melting point of metal because metallic slags located on the bottom of melter by specific gravity difference are simultaneously melted when dual mode plasma torch operates in transferred mode. In order to minimize the refractory erosion, the compatible refractories are selected considering the temperature inside the melter and the melting behavior of slags whether to contact or noncontact with molten slags. An acidic refractory shall not be installed in adjacent to a basic refractory for the resistibility against corrosion.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.957-960
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• 2008

In this study, it was investigated fire resistance properties of high strength concrete column using Engineered Cementitious Composites(ECC) permanent form as a countermeasure for explosive spalling of concrete on fire. As a test result, it was appeared that ECC permanent form is available as fire resistance method of high strength concrete if it is developed manufacturing technique and scheme for application controlling heat penetration through interface of permanent form and high strength concrete, and setting up mix proportion and thickness of ECC.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.170-171
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• 2014

The buildings constructed with steel structure is coated with certified fire resistive material to resist from fire. Coating materials lose their initial performances as time passes, so they need some maintenance. This study is covers standardization of the methods for assessing the durability of SFRM. In Korea, more than 90 percent of SFRM are used indoors. So This study is to decide proper test method through investigation and examination of effect factor to performance of fire-resistant structure and applicable test method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.109-110
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• 2014

The buildings constructed with steel structure is coated with certified fire resistive material to resist from fire. Coating materials lose their initial performances as time passes, so they need some maintenance. This study is covers standardization of the methods for assessing the durability of SFRM. In Korea, more than 90 percent of SFRM are used indoors. So This study is to decide proper test method through investigation and examination of effect factor to performance of fire-resistant structure and applicable test method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.104-105
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• 2013

The buildings constructed with steel structure is coated with certified fire resistive material to resist from fire. Coating materials lose their initial performances as time passes, so they need some maintenance. Fireproof spray-application also loses its performance and this performance loss of thr fireproof spray-application is very important because fire resistance of buildings depends on fireproof spray-application. So this study is to develop Acceleration durability test method of Fireproof spray-application, and use the Certification of fire resistant coating system.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.104-112
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• 2012

This study involves investigating the correlation between variation of internal structure and heating temperature of alkali-activated fire protection materials using fly ash. Dehydration and micro crack thermal expansion occur in cement hydrates of cementitious materials heated by fire. Internal structure difference due to both the dehydration of cement hydrates and pore solution causes and influences changes in the properties of materials. Also, this study is concerned with change in microstructure and dehydration of the alkali-activated fire protection materials at high temperatures. The testing methods of alkali-activated fire protection materials in high temperature properties are make use of TG-DSC and mercury intrusion porosimetry measurements. The study results show that the alkali-activated fire resistant finishing material composed of potassium hydroxide, sodium silicate and fly ash has the high temperature thermal stability. These thermal stability is caused by the ceramic binding capacity induced by alkali activation reaction.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.1
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• pp.9-18
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• 2011

The spalling phenomenon occurs in high-strength concrete when several factors such as sharp temperature increase, high water content, low water/cement ratio and local stress concentration in material combine in the concrete material. On the basis of the factors, the preventing methods from the spalling are known as reduction of temperature increase, preventing of concrete fragmentation and fast drying of internal moisture. In this study, the reduction of temperature increase was proposed as the most effective spalling-preventing method among the spalling-preventing methods. Engineered cementitious composite for fireproof and repair materials was developed in order to protect the new and existing RC structures form exterior deterioration factors such as fire, cloride ion, etc. This study was carried out to estimate the fire-resisting performance of high strength concrete slab or tunnel lining by repaired engineered cementitious composite (ECC) or fiber reinforcement cemetitious composite (FRCC) under fire temperature curve. and them we will descrike the result of HIDA tunnel in Japan.

• The Journal of the Acoustical Society of Korea
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• v.36 no.4
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• pp.247-253
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• 2017

Generally, the vibration characteristics of refractory ceramics are identified by assuming them as isotropic materials. However, in practice, refractory ceramics exhibit anisotropic properties as they are manufactured by pressing ceramic powders along a particular direction. Therefore, in this research, the frequency responses of a refractory ceramic brick along its width, length, and height directions were acquired using finite element analysis by assuming that the ceramics had tetragonal symmetry in their material properties. The validity of the numerical analysis results was verified by comparing them with those from experimental measurements. Based on the frequency response, the thicknesses of the refractory brick along three different directions were estimated using the impact-echo technique. The maximum difference between the estimated and actual thicknesses was observed to be less than 5 %. This result confirms the effectiveness of the impact-echo technique along with anisotropic property characterization to evaluate the thickness of the refractory ceramic.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.935-940
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• 2008

When reinforced concrete is subjected to high temperature as in fire, there is deterioration in its properties of particular importance are loss in compressive strength, cracking and spalling of concrete, destruction of the bond between the cement paste and the aggregates and the gradual deterioration of the hardend cement paste. Assessment of fire-damaged concrete usually starts with visual observation of color change, cracking and spalling of the surface. In this paper, it was reported the trends of research and practical use on the Explosive Spalling Properties and Performance Based of Structural Design of the High-Strength Concrete.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.465-473
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• 2013

In this Study, the performance of precast PSC slabs with fire resistance panel for fire resistance of the tunnel system was evaluated by experimentally. The fire test was performed in fire resistance (electric) furnace according to RABT(Richtlinien fur die Ausstatung und den Betrieb von stra${\beta}$entunneln) time heating temperature curve. The test results showed that the measured temperatures at the t=0 mm depth of PSC slab with precast fire resistance panel during a fire was maximum temperature $367^{\circ}C$, lower than $380^{\circ}C$ (ITA 2004), when damage occurs. Also, at the t=25 mm, the maximum temperature was $239^{\circ}C$, which was lower than the damage temperature of rebar, $250^{\circ}C$. From the results, the use of precast fire resistance panel (t=25 mm) improves fire resistance of PSC structures.