• Computers and Concrete
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• v.10 no.2
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• pp.105-119
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• 2012

This paper presents the mix composition and production method that was applied to an extruded Ductile Fiber Reinforced Cement Composite (DFRCC) panel, as well as the flexural performance, represented by deformation hardening behavior with multiple cracking. The effect of fiber distribution characteristics on the flexural behavior of the panel is also addressed. In order to demonstrate the fiber distribution effect, a series of experiments and analyses, including a sectional image analysis and micromechanical analysis, was performed. From the experimental and analysis results, it was found that the flexural behavior of the panel was highly affected by a slight variation in the mix composition. In terms of the average fiber orientation, the fiber distribution was found to be similar to that derived under the assumption of a two-dimensional random distribution, irrespective of the mix composition. In contrast, the probability density function for the fiber orientation was measured to vary depending on the mix composition.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.11
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• pp.3-10
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• 2018

Cladding that finishes the exterior of a building could enhance the value of the building, and shape control is an important factor. With the recent development of 3D printing, cementitious claddings were printed by 3D printer in China, U.S.A and elsewhere. On the other hand, the structural safety of the exterior panel should be examined, as casualties occur when the exterior panel fails due to typhoon or impact. Cement-based cladding is reinforced by wire mesh to improve safety. Introducing 3D printing composite system with polymer and cement, makes it possible to produce claddings fast and accurate. Prior to the development of 3D printing cementitious cladding, the major parameters influencing the optimal shape were identified based on structural performance. The wind load, joint, and bond behavior between polymer and cement were considered. Polymer laminate shape, order, and thickness were variables, and finite element analysis was performed.

• Advances in concrete construction
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• v.13 no.2
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• pp.153-162
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• 2022

Prefabricated exterior wall panel is the main non-load-bearing component of assembly building, which affects the comprehensive performance of thermal insulation and durability of the building. It is of great significance to develop new prefabricated exterior wall panel with durable and lightweight characteristics for the development of energy-saving and assembly building. In the prefabricated sandwich insulation hanging wall panel, the selection of material for the outer layer and the arrangement of the connector of the inner and outer wall layers affect the mechanical performance and durability of the wall panels. In this paper, high performance cement-based composites (HPFRC) are used in the outer layer of the new type wall panel. FRP bars are used as the interface connector. Through experiments and analysis, the influence of the arrangement of connectors on the mechanical behaviors of thin-walled composite wall panel and the panel with window openings under two working conditions are investigated. The failure modes and the role of connectors of thin-walled composite wallboard are analyzed. The influence of the thickness of the wall layer and their combination on the strain growth of the control section, the initial crack resistance, the ultimate bearing capacity and the deformation of the wall panels are analyzed. The research work provides a technical reference for the engineering design of the light-weight thin-walled and durable composite sandwich wall panel.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.498-505
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• 2022

In this study, as a result of eva lua ting the quality properties of Living Concrete, the flow of the table showed a tendency to decrease as the mixing ratio of ocher increased. Compressive strength was found to decrease with increasing loess mixing ratio. Density properties were evaluated for weight reduction, As a result of comparison with the panel using cement as a comparison group, the density was measured to be a bout 20 % lower than that of the cement panel, and it is judged that it is less affected by the load and can be installed in the structure. As a result of evaluating the panel temperature reduction, there was a difference in the temperature reduction with time. It is judged that the panel planted with moss has a lower temperature than the panel without moss, so it is judged that it can be used in a vertical greening system.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.49-52
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• 2006

Extrusion concrete panel is made by extrusion of high viscosity paste. The high viscosity paste is made by mix of cement, silica, reinforced fiber and thickening agent in the dry mixer and wet mixer subsequently, extrusion in the extruder, and curing in the normal steam curer and high pressure steam curer subsequently. To increase a flexural strength of the panel, it is used inorganic fiber as like asbestos. But it was known that the asbestos was harmful to human being lately, in the domestic area it is restricted usage in the construction materials. So, it is demanded the alternative material for asbestos in the extrusion concrete panel. This study is to investigate that the sepiolite is possible to be the alternative of asbestos. The 3 types of sepiolite is applied to the extrusion concrete panel. To investigate the properties of the panel with sepiolite, it is compared the control with asbestos in the flexural strength, the specific density and the spot compressive strength. From the test results, it was found that the panel with sepiolite B is higher than the control with asbestos in the flexural strength and in the density.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1273-1278
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• 2007

The cement-asphalt mortar is a mixture of cement and asphalt emulsion, and is utilized as a underpouring materials for the railway track which is used to fill under slab panel space so as to provide a stabilized track support and a tool for reduction of noise and vibration. To increase the workability of grouting, this study investigates the effect of temperature on cement-asphalt mortar by analyzing its physical and mechanical properties before/after hardening according to the temperature (10, 15, 20, 25, $30^{\circ}C$). According to the test results, it is found that as for the physical property of fresh cement-asphalt mortar the more mixture temperature become higher or lower, the more fluidity become worse. But by increasing reducing agent amount and its unit quantity, the required fluidity is met. The compressive strength as physical property of hardened cement-asphalt mortar become lower when temperature is lower but taking it by and large the physical properties of cement-asphalt mortar before/after hardening aren't so affected by temperature and well satisfy the requirement. And it has proved that rate of expansion and freezing and thawing resistance aren't affected by temperature.

• Journal of the Korea Institute of Building Construction
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• v.4 no.3
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• pp.93-100
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• 2004

In recent years, it has widely been studied on the light-weight composites for the purpose of the large space and thermal insulation of building structures. The purpose of this study is to evaluate the properties of light-weight composites made by binders as cement, resin and polymer cement slurry. The concrete composites are prepared with various conditions such as polymer-cement ratio, void-filling ratio, type of resin, filler content and light-weight aggregate content, tested for thermal conductivity. From the test results, the thermal conductivity of concrete composites with the binder of cement tends to decrease with increasing polymer-cement ratio, and to increase with increasing void-filling ratio. The thermal conductivity of concrete composites with the binder of resin are markedly affected by the light-weight aggregate content, type of resin and filler content. The composites made by polymer-modified concrete and polymer cement slurry have a good thermal insulation property. From the this study, we can recommend the proper mix proportions for thermal insulation Panel or concrete. Expecially. the thermal conductivity of concrete composites made by polyurethane resin is almost the same as that of the conventional expanded polystyrene resin.

• KCI Concrete Journal
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• v.12 no.1
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• pp.47-56
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• 2000

Once a structure fabricated with mass concrete is in a form of wall such as retaining wall, side walls of a concrete caisson and so on, cracks induced by hydration heat have been known to be governed by exterior restraints which are mainly related to the boundary conditions of the structure. However, it is thought that the degree of restraints can be alleviated considerably only if a lift height of concrete placement or a panel size of the wall is selected properly before construction. As a way of minimizing thermal cracking commonly observed in massive wall-typed structure, this study aimed at evaluating effects of geometrical configuration on the temperature rise and thermal stress through parametric study. Evaluation of the effect was also performed for cement types using anti-sulphate cement, blast furnace slag cement and cement blended with two mineral admixture and one ordinary Portland Cement. so called ternary blended cement. As a result of analytical study, it was found that a lift height of concrete placement is the most important factor in controlling thermal cracking in massive wall, and the increase of a lift height is not always positive to the crack occurrence as not expected.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.23-27
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• 1999

The measurement of thr high-temperature strains is one of the challenging subjects in mechanical engineering. For the precise measurement, proper high-temperature strain gauge, cement and skilled technique are needed. In this paper, a high-temperature strain measurement is performed for the perfectly flat CRT. As this CRT is structurally very weak, cracking of the panel frequently occurs during the heat cycle in the furnace. From the measured strain variations of the panel with tension shadow mask, the crack behavior can be explained.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1379-1382
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• 2006

Recently, the method of the apartment building design has been changed from wall type structures to moment structures. With like this reason dry walls are used plentifully. Especially, the gypsum board was used from previously plentifully however the weak point of it is difficult to maintain because it weak strength. For the improvement of gypsum board, light weight concrete panel using cement board is used recently. As this study is the research of the series t on the development of non-hearing light weight concrete Panel using bottom ash, the Purpose of this study is to obtain basic data for application in the field. The results are that the structure 1 satisfies domestic standard concerned with sound insulation between households at the laboratory and field test.