• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.73-74
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• 2017

In this study, unlike high flowing concrete, using glass bubble to develop self-compacting concrete(hereinafter referred to as "SCC") with excellent filler performance by evaluating both flowability and yield stress, viscosity An experiment was conducted. Experimental results show that when 1 kg of glass bubbles are used, it is effective in stabilizing the physical properties of concrete, reducing the yield stress and viscosity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.75-76
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• 2019

The purpose of this study is to achieving a sufficient fluidity without segregation for normal strength grade concrete mixture. therefore in this research, by analyzing the various superplasticizer dosages on the concrete mixture, the segregation range was analyzed to provide a proper concrete mix design with sufficient fluidity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.27-30
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• 2002

Contemporary architecture calls for a wide range of surface textures and treatments. A surface compatible with the architect's design may vary from a glass-smooth finish to one requiring special sculptured ornamentation. These surfaces require many different types of form sheathing and lining. The purpose of study development new design form and made elaborateness shape. Easy to used in field that architecture finish material not used expect effective reduce of working hours, personnel expenses, architecture finish material, cost. After this, building wall apply a variety shape in concrete surface.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.115-116
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• 2016

Numerous of free-form buildings come up with external appearances using various types of free-form panels. If the panel types produced, transport and installation order and maintenance history are not properly managed, it is difficult to complete a given project successfully. For free-form building projects that satisfy 5 factors (proper time, place, price, product and quantity), a supply chain management technique is applied for distribution management of free-form concrete panels. In addition, the study listed the whole production process of free-form concrete panels and any necessary information, and suggested a basic model for the management. The study result will be a great help in effective distribution management of free-form panels for free-form building projects.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.33-34
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• 2018

Currently, free-form building has been increased worldwide. However, as a finishing material of free-form building, the production of free-form concrete panels(FCPs) spends lots of cost and efforts since it is difficult to reuse the FCP formwork and lots of workers are needed to make free-form curve. In addition, the technology to produce the FCP economically and easily is insufficient. Therefore, the objective of this study is a basic study regarding production management for developing free-form concrete panels. To achieve the objective, the property of FCP and condition for effective production management and production process are analyzed. The results of this study can utilize to develop the algorithm for FCP production management.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.54-55
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• 2018

Reinforced concrete is a building material that is generally used in modern society. Securing the performance of reinforced concrete is directly connected to the durability and longevity of the building. One of the major factors that deteriorate the durability of concrete is harmful ion. Recently, the quality and improvement method of reinforced concrete for penetration of harmful ion has been studied. In this study, the bead type ion exchange resin is substituted for 0%, 3%, and 6% of the fine aggregate volume in the mortar. The speciments underwent underwater curing and were checked for compressive strengths of 3 days and 28 days. From the results of compressive strength, it can be seen that the higher the substitution ratio of the ion exchange resin, the lower the early strength and long-term strength development, especially the early strength development.

• Computers and Concrete
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• v.16 no.4
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• pp.531-544
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• 2015

The objective of this study was to examine the effect of repair mortar on the dynamic properties such as natural frequencies, mode shape and damping ratios of two story single span scale reinforced concrete building. To this end, two story single span scale reinforced concrete building having dimensions of 150 cm (width), 150 cm (length) and 135 cm (height) was constructed. Workmanship defects such as separation of material, faulty vibration application and bad gradation of the structure were properly evaluated. Dynamic properties of damaged structure were experimentally determined using Operational Modal Analysis (OMA). Detected defects in the structure were fixed by plastering with repair mortar. Dynamic properties of repaired structure were reevaluated by using the OMA method. Finite element software called Abaqus was used to numerically determine dynamic properties of the structure. Structure modeled as solid was subjected to Linear Perturbation Frequency Method. The changes in dynamic properties of structure after the repair process were comparatively studied by evaluating experimental and numerical results.

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.375-381
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• 2015

In this study, high performance concrete of C60 and C80 were applied to a super tall building and those had satisfactory properties of fresh and hardened concrete to the requirements even changes according to time. Especially the evaluation and analysis of the relation of the rheological properties and puMPability of high performance concrete, C60-14 which was applied to the height of from 500m to 575m in the building, was carried out bymeasuring pumping pressure and pumping speed, testing concrete properties at before and after pumping. As results, themax. pumping pressure showed increase of 5% at every 25m higher pumping and the average pumping speed showed the above $25m^3$ per hour whichmeans proper productivity. Additionally it was verified that the loss of slump flow after pumping was increased according to plastic viscosity values and the increment of temperature through concrete pumping.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.585-588
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• 2006

The environment-friendly building material, photocatalyst/scoria/loess concrete, was prepared using scoria and loess (which have merits as building materials) and photocatalyst (which has the functions to compose the environmental contaminants and of self cleaning). In order to apply this material as a building material, the compressive and flexible strengths, and water absorptivity (which have been set by Korea Industrial Standard) were measured. The optimum mixing ratio of photocatalyst/scoria/loess concrete was obtained at the condition of $393kg/m^3$ of coarse aggregate, $802kg/m^3$ of fine aggregate in case of scoria, $80kg/m^3$ of loess, $12kg/m^3$ of photocatalyst, $400kg/m^3$ of cement, and $2kg/m^3$ of AE water reducing agent. The photocatalyst/scoria/loess concrete prepared by above mixing ratio of raw materials showed 25 MPa of compressive strength, $3.8{\sim}4.6$ MPa of flexible strength and $11.4{\sim}12.0%$ of water absorptivity, indicating that the quality of this material was suitable for Korea Industrial Standard (more than 21 MPa for compressive strength, more than 2.0 MPa for flexible strength in case of lightweight aggregate, and less than 15 % for water absorptivity in case of clay brick) for using as a building material.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.31-34
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• 2009

Large outrigger elements tie the concrete core to perimeter columns, significantly increasing the building's lateral stiffness as well as its resistance to overturning due to wind. The outriggers are deep elements, and large tie forces are resisted by top and bottom heavy longitudinal reinforcing and vertical ties. To reduce construction costs, all primary reinforcing bars in outrigger levels are SD500. Further, concrete strengths of 80MPa have been specified for outrigger elements. However, the reductions in the amount of concrete and reinforcement steel are more increased in tall building. With these backgrounds, 80MPa high strength concrete outrigger system using post tension method is developed. Significant economic savings can be made by reducing the element sizes and material content. The developed outrigger system is designed using strut-and-tie models. In addition, four 1/4-scale test specimens were selected from the same prototype structure. The results from the tests are confirmed that the structural behaviors of the developed outrigger member have better capacities than those of a conventional method.