• Journal of Technologic Dentistry
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• v.40 no.4
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• pp.201-207
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• 2018

Purpose: The purpose of this study is to evaluate the fitness of lower jaw compete denture with glass fiber. Methods: Lower jaw edentulous model was selected as the master model. Ten study models were produced using Type IV stone(n=10). Lower jaw trial dentures were produced by the wax denture base and artificial teeth. Conventional complete denture (CD) group was fabricated by excluding glass fiber reinforcement (n=5). Glass fiber complete denture (GD) group was fabricated with glass fiber reinforcement (n=5). The lower jaw trial complete denture was invested using a plaster. PMMA resin was injected and curing was performed. The CD and GD groups measured the fit using silicone replica technology. The measured data was verified by t-test. Results: The anterior area of the CD group showed the smallest value. There was a statistically significant difference in the anterior area of the CD group and the GD group (p<0.05), but there was no statistically significant difference in the posterior area (p>0.05). Conclusion : Complete denture with glass fiber showed low fitness and further study is needed to apply it clinically.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.5
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• pp.81-90
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• 2008

This paper concerns the flexural capacity of reinforced concrete beams with ultra-high performance cementitious composites(UHPCC). It was investigated if the existing equations to estimate the flexural capacity of reinforced fiberous concrete beams are applicable with the experiments including lightly reinforced concrete beams. The reinforcing effect when the steel fiber reinforced concrete was used in beams was also estimated. The results showed that the equation to predict the flexural capacity of reinforced steel fiber concrete by ACI 544 committee didn't have a good agreement with the test results and underestimated the flexural capacity in especially lightly reinforced beams with under 1.5% reinforcement ratio. the enhancement of flexural capacity was quite considerable in lightly reinforced beams when the steel fiber reinforced concrete was used. A equation to predict the reinforcing effect of steel fiber in reinforced steel fiber beams was developed. the equation was proposed as a function of both the characteristics of steel fiber and reinforcement ratio.

• Structural Engineering and Mechanics
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• v.22 no.3
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• pp.311-330
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• 2006

Standard compression tests of steel fiber reinforced concrete (SFRC) cylinders are conducted to formulate compressive stress versus compressive strain relationship of SFRC. Axial pullout tests of SFRC specimens are also conducted to explore its tensile stress strain relationship. Cover concrete spalling and reinforcement buckling models developed originally for normal reinforced concrete are modified to extend their application to SFRC. Thus obtained monotonic material models of concrete and reinforcing bars in SFRC members are combined with unloading/reloading loops used in the cyclic models of concrete and reinforcing bars in normal reinforced concrete. The resulting path-dependent cyclic material models are then incorporated in a finite-element based fiber analysis program. The applicability of these models at member level is verified by simulating cyclic lateral loading tests of SFRC columns under constant axial compression. The analysis using the proposed SFRC models yield results that are much closer to the experimental results than the analytical results obtained using the normal reinforced concrete models are.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.375-378
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• 2003

Plastic shrinkage cracking occurs at the exposed surfaces of freshly placed concrete due to consolidation of the concrete mass and rapid evaporation of water from the surface. This so-called shrinkage cracking is a major concern for concrete, especially for flat structural such as pavement, slabs for industrial factories and walls. This study has been performed to obtain the plastic shrinkage properties of hydrophilic fiber reinforced mortar and concrete. The results of tests of the hydrophilic fibers were compared with plain and polypropylene fibers. Test results indicated that hydrophilic poly vinylalcohol fiber reinforcement showed an ability to reduce the total crack area and maximum crack width significantly (as compared to plain and polypropylene fiber reinforcement).

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.547-548
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• 2009

Fiber reinforcement has been being widely used in concrete to enhance the mechanical properties and to reduce the micro-cracking caused by plastic and drying shrinkage. While researches has been focused on the benefits of fiber reinforcement, the properties of fiber reinforced concrete are strongly dependent on the type, shape and the amount of fibers in concrete.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.906-909
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• 2005

The purpose of this paper is to study on the construction of roadbed with environmental friendly soil amendment agent and reinforced fiber. The special amendment agent and fiber used in this study has a function of soil-cement-agent solidification and reinforcement. A series of laboratory experiments including unconfined compressive strength, tensile strength, compaction test were carried out to investigate the physical and mechanical characteristics of roadbed treated by solidifying agent and fiber. The results of this research showed that the roadbed using poor soil could be efficiently constructed by treatment of this amendment agent and fiber.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.415-422
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• 2001

In this paper, the experimental study was carried out in order to compare the mechanical characteristics of multi-layer elastomeric isolation hearings where the reinforceing elements steel plates case and fiber-reinforcement case. Fiber-reinforced isolater which has the same dimension as the steel reinforced isolator had shown better efficiency in effective damping than NRB. The compression test has shown the corresponding results with the theoretical vertical stiffness in the case of flexible reinforcement. The fiber-reinforced isolator will be significantly lighter and could lead to a much less labor intensive manufacturing process.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.6
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• pp.115-123
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• 2002

This study was performed to provide basic data for development and construction of reinforced soil wall that mixed with reinforcements such as calcium carbonate, monofilament fiber. In order to determine proper moisture content and mixing ratio by weight of reinforcement, Poisson's ratio and compressive strength tests for sandy soil had been conducted. Model tests for long-term behavior of reinforced soil wall were carried out to investigate the effect of reinforcement during loads and under static loads. The results of creep and model tests for sandy soil compared with clayey soil. Reinforced sandy soil mixed with calcium carbonate and cement showed brittle rupture by shear but that of mixed with monofilament fiber showed ductile rupture due to the tension force of fiber. It was shown that when age increased, creep strain of reinforced soil under sustained load approached constant values.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.861-864
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• 2008

This study was performanced to investigate the fractural and fatigue behavior of ultra-strength steel fiber reinforcement concrete. The tension softening diagram can describe the post-cracking behavior of concrete in tension. In this paper, Three points bending tests with a notch have been carried out to investigate tensile properties of the steel fiber reinforced concrete(SFRC) according to variation of the height. Poly-linear approximation method combined with FEM analysis is applied to the steel fiber reinforced concrete to determine the tension softening diagrams and also to certify the validity of the method. The simulated load-CMOD curves using the determined softening diagrams though the poly-linear approximation method completely agree with the measured ones.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.665-668
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• 2006

Concrete secondary product that use cement is increasing application from reason of shortening etc.. of construction period in construction site. Manufacture method of construction of this concrete secondary product there is hot-check method, direct spray method, press method, extrusion molding method etc.. Also, I am using reinforcement boating certainly in this process. In most case, We have used asbestos by reinforcement fiber until early 90s but use from human body hurtfulness controversy is felt constraint. Therefore, application of principal parts fiber is increasing. But, to replace asbestos, because must satisfy all lubricating ability, productivity etc.. class, it is the very difficult matter to replace asbestos. In this study, I wished to do Test about asbestos principal parts possibility at extrusion process to charge shape or form making test piece because mixs polypropylene fiber etc. by plan that replace asbestos in cement extrusion molding product and measures bending strength and elasticity.