• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.399-404
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• 1994

Heavyweight(or High density) concrete, which is generally for shiedling structures, differs from normal weight concrete by having a higher density and special compositions to improve its attenuation properties. There are setting 7 Beam Ports around the reactor of the KMRR Project(Korea Multi-purpose Research Reactor) conducted by the KAERI(Korea Atomic Energy Research Institute). High density(p=5.0t/$\textrm{m}^3$) and Heavyweight(p=3.5t/$\textrm{m}^3$) concrete were placed around the Beam Ports in order to shield radiation. This paper was discussed about construction of High density concrete. High density concrete was placed with method of Preplace Aggregate. Coarse metallic aggregate(steel shot) was used. Boron, boron carbide(B4C), was used to capture effctively the neutrom. The mock-up test was carried out. And the consturction of High density concrete was performed successfully.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.55-60
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• 2002

The columns and The belt wall of Tower Palace III were desined as 800kg/c $m^2$ ultra-high strength concrete. The concrete should meet or exceed the requirements of slump of 23cm, $\sigma$$_{18H}$ of 100kg/c $m^2$, $\sigma$$_{91th}$ of, 800kg/c $m^2$. The concrete mixings with 4 different domestic Silica fumes were investigated. Laboratory tests, the pilot productions of batcher plant and the full-scale mock up tests were performed. As results of site application, all test results are satisfied with the requirements of columns and belt wall.l.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.446-449
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• 2004

Traditional prediction models have been developed with a fixed equation from based on the limited number of data and parameters. If new data is quite different from original data, then the model should update not only its coefficients but also its equation form. However, artificial neural network dose not need a specific equation form. Instead of that, it needs enough input-output data. Also, it can continuously re-train the new data, so that it can conveniently adapt to new data. Therefore, the purpose of this study is to verify faith and application of prediction system of concrete strength using artificial neural networks through mock-up test.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.836-839
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• 1999

Glossy architectural concrete means high qulity concrete which develops marble-like gloss on the surface of concrete. In spite of many benefits of architectural concrete to R.C. structure such as appearance of natural stone, saving of envelope materials and reduction of building weight, the failure of in-situ application of architectural concrete by the absence of knowledge on the physical properties and form work for it can often be found in Korea. This study is to offer the basic materials on the mix proportion, vibrating, curing and treatment of concrete result from the mock up test and in-situ application of architectural concrete to embody high quality architectural concrete in Korea.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.541-544
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• 2006

As the importance of recycled materials is being emphasized more in the Korean construction market, the production Quality has been improved to a significantly high level. Compared to the high quality, however, there are used very limitedly. Among recycled construction materials, recycled aggregates produced through the retreatment of waste concrete are drawing attention because of lack of natural aggregate and heightened consciousness of resource saving and environmental protection and, as a consequence, they are close to natural aggregates in terms of production technology and quality. Despite the high quality and productivity. however, the utilization of recycled aggregates is very low.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.25-28
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• 2006

This study investigated pre-mixed cement combined with ordinary portland cement, BF and SF, in order to manufacture cement binder, which is possible to produce 150MPa ultra high strength concrete. The BF used in this study reduces and control hydration heat. It can also improve concrete fluidity, while AP increases hydration product and accelerates reaction of BF. SF has micro filler effect and makes pozzolanic reaction. It also fabricates high density internal organization. This developed pre-mixed cement can reduce hydration heat and increase hydration product. It is possible to fabricate high density organization and to secure homogeneity. The mock-up test of ultra high strength concrete showed excellent dispersibility and workability and indicated compressive strength more than 150MPa at 28 days.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.33-36
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• 2010

The attention in construction Automation is getting higher since it could be the answer to the lack of skilled labor by decrease in construction population and aging which adversely affects productivity and quality in the construction site. We are on the way to develop a construction automation system adequate for domestic circumstances in Korea; it is called RCA(Robotic-crane based Construction Automation)system. Climbing hydraulic robots system is a part of RCA system and makes Construction factory(CF) climb through the guide rail on the core wall. The safety of climbing hydraulic robots system is at issue due to the overloaded weight of CF. Preventing this issue, present study did the design verification through the structural analysis and the simulation. Mock-up test also was done to analyze the drive performance of climbing hydraulic robots system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.17-20
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• 2008

This study investigated the fundamental properties and cracking shapes of mortar for the floor after Mock-up test with FRP as wastes of crafts. For the flowability of fresh mortar without FRP, it was favorable compared with fresh mortar using FRP, and the drop time at O-Lot was similar to the flowability. For the compressive strength of fresh mortar with FRP, it was increased about 10% compared with plain. The flexible strength was also increased on fresh mortar with FRP. On the cracking shape, there was many penetrated crack in all directions on plain. In the case that FRP was used, it seemed to have excellent resistance to the crack occurrence because there was no directive crack at a limited part.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.274-277
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• 1999

This paper is concerned with estimating the mass of a loose part in the steam generator of a nuclear power plant. Although there is the basic principle known as “Hertz Theory”for estimating mass and energy of a spherical part impacted on an infinite flat plate, the theory is not directly applicable because real plants do not comply with the underlying ideal assumptions. (Say, the steam generator is of a cylindrical and hemisphere shape.) In this work, a practical method is developed based on the basic theory and considering amplitude and energy attenuation effects. Actually, the impact waves propagating along the plate to the sensor locations become significantly different in shape and frequency spectrum from the original waveform due to the plate and surrounding conditions, distance attenuation and damping loss. To show the validity of the present mass estimation algorithm, it has been applied to the mock-up impact test data and also to real plant data. The results show better performance comparing to the conventional Hertz schemes.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.237-242
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• 2004

In design stage of high precision manufacture/inspection FAB building, it is necessary to investigate the vibration allowable limits of high precision equipment and to study a structure dynamic characteristics of C/R and Sub-structure in order to provide a structure vibration environment to satisfy thess allowable limits. The aim of this study is to investigate the dynamic characteristics of PC-Type mock-up structures designed for next TFT LCD FAB through vibration measurement and analysis procedure, therefore, to provide a proper dynamic structure design for high precision manufacture/inspection work process, which satisfy thess allowable limits.