• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.9-12
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• 2007

Recently, research and development related to high strength concrete for the high rise and large scale reinforced concrete building has been actively promoted in worldwide by national and private research project. But, it is reported that violent explosive explosion would be happened when it was exposed in fire. In the existed study, a explosion in a reinforced concrete structure looses the organism by the different contraction and expansion of hardened cement paste and aggregate, and causes crack by thermal stress. In case of the Europe, Japan and America, they have studied the explosion for a long time. However it would hardly study the explosion in domestic, So it is needed base on mechanical properties of fire deterioration in high strength concrete. Therefore, this study is intend as an mechanical properties of specimen to high heating by heating and load test machine and $700^{\circ}C$. As a result, it is willing to propose fundamental data for quick and accurate diagnosis of deteriorated concrete structure by fire damage with experiment according to the design high strength concrete.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.70-73
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• 2001

The layup optimization by genetic algorithm (GA) for the interlaminar strength of laminated composites with free edge is presented. For the calculation of interlaminar stresses of composite laminates with free edges, extended Kantorovich method is applied. In the formulation of GA, repair strategy is adopted for the satisfaction of given constraints. In order to consider the bounded uncertainty of material properties, convex modeling is used. Results of GA optimization with scattered properties are compared with those of optimization with nominal properties. The GA combined with convex modeling can work as a practical tool for maximum interlaminar strength design of laminated composite structures, since uncertainties are always encountered in composite materials and the optimal results can be changed.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.765-768
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• 2005

This study is investigated the strength properties of ALC(Autocalved Lightweight Concrete) using SPS(Stone Powder Sludge), to develop recycling technique of SPS. At a given replacement percent of SPS and addition percent of foam, the results show that its the strength properties are equal or higher than the quartz used in a raw material of ALC, and it is also found that the addition percent of the foam and the strength properties have a certain relation of linear.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.615-620
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• 2000

The strength properties of Light-Weighted Soils(LWS) mixed with Expanded Polystrene(E.P.S) are studied. Test results show that when the initial water contents of dredged soils are under 135% and the cement contents are above 1%, Light-Weight Soils are in the appropriate strength range of 2.0 to 4.0kg/㎠. However, E.P.S contents had a little affects on the strength properties of LWS. In the view of E.P.S diagram's effects on LWS, which have expand ratio of 25, 35, 45 and 60, further studies considering of physical properties of original E.P.S beads are needed.

• Elastomers and Composites
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• v.52 no.1
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• pp.59-68
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• 2017

The effect on the hydrolysis resistance properties by the addition of maleic anhydride grafted EMDM (MA-g-EPDM) and PP (MA-g-PP) to a PA66/GF composite was investigated with respect to the mechanical properties, thermal properties, and morphology. The degree of hydrolysis of the PA66/GF composite was measured using py-GC/MS analysis. When compared to the PA66/GFcomposite in MEG/water solution, the composites where MA-g-EPDM and MA-g-PP were added to PA66/GF showed a higher degree of hydrolysis resistance, impact strength, and thermal properties, whereas their tensile strength, tensile modulus, flexural strength and flexural modulus decreased. As immersion time in the solution increases, the rate of tensile strength drop of the MA-g-PP added composite appeared lower than that of the PA66/MA-g-EPDM/GF and PA66/GF composites. The py-GC/MS analysis confirmed the formation of PA66 hydrolysis reaction by products such as carboxylic acid and alkylamine with increasing immersion time.

• Journal of the Korean Ceramic Society
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• v.43 no.6 s.289
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• pp.351-357
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• 2006

The fabrication process of the honeycomb filter was investigated using synthesized cordierite with the addition of pore former and extrusion additives (either organic matter or graphite). Also, the effect of additives on the resultant properties of honeycomb filter such as porosity, thermal expansion coefficient and mechanical strength were investigated. With increasing the organic matter up to 10 wt%, porosity was increased but compressive strength was decreased. With increasing the graphite content, however, both porosity and compressive strength were increased. The specimen with an optimum processing condition (C-17A30G, sintering at $1150^{\circ}C$) was demonstrated 59% in porosity, 69 MPa in compressive strength, and $2.4{\times}10^{-6}/^{\circ}C\;(25{\sim}1000^{\circ}C$) in thermal expansion coefficient, which physical properties are appropriate for the honeycomb filter applications.

• KSBB Journal
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• v.14 no.4
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• pp.470-475
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• 1999

Several enzyme were applied to Laubholz Bleached Kraft Pulp(LBKP) to evaluate the influence on beatability which was measured in Schopper Riegler value, and the results were compared with untreated pulp. Among the types of enzyme, cellulase was found to be the most effective. Addition of cellulase increased the beatability by 28% at optimum condition. Strength properties such as tensile strength and folding endurance also increased with enzymatic treatment by 12% and 46%, respectively. However, excessive dosage of cellulase had an adverse effect on strength properties in spite of the high beatability. Fibrillization by cellulase and destruction of fiber by excessive reaction was observed by Scanning Electron Microscopy(SEM).

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.651-658
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• 2002

A series of experimental study are performed to evaluate the shear strength and friction properties of fiber-mixed soil as backfill material in reinforced earth wall. In order to evaluate the properties of shear strength the big-size direct shear tests are carried out and on the friction properties, the shear friction tests and the pull-out tests are performed. In the results, when the mixed ratio of the net type fiber is 0.2%, the reinforcement effect was better than the others. Also the reinforcement effect of the net type fiber was larger than that of the line type fiber.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.1-4
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• 2006

Because do placing joint after smallest $1{\sim}3$ day about concrete that is placed beforehand in field, it is difficult that remove laitance happening harden concrete. This laitance happens a problem of bond properties, deterioration in strength. In this research got following conclusion as result that do research about bond properties the way of disposal placing joint. Air Jet is loft interior and exterior. Water Jet appeared that laitance Removal Capacity is superior to dimension within 5%. Deterioration in strength is measured 37% by splitting tensile strength test result by laitance. Deterioration in strength by laitance do more than 30% that removal of laitance is predicted must consist necessarily at concrete horizontality placing joint stroke.

• Fashion & Textile Research Journal
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• v.3 no.4
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• pp.357-361
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• 2001

This paper is concern with the effect of various conditions on mechanical properties of textile fabrics by water soluble resin treatment. Resin treatment of cotton, acetate, viscose rayon, polyester, nylon and acryl fabrics were made by aqueous resin treatment to improve the mechanical properties. The mechanical properties of fabrics, the breaking strength and strain were measured and surface reflectance was measured by color eye. The breaking strength and surface reflectance of fabrics by water soluble resin treatment showed difference by the different treatment concentration. The surface reflectance was increased by water soluble resin treatment. The breaking strength was lower in fabrics with resin treatment than fabrics with none treatment.