• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.107-108
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• 2019

The interlayer noise of the apartment house is a typical problem that reduces the quality of the residential environment. Therefore, many researchers have developed soundproofing materials that blocks noise between floors. However, most development technologies do not have the noise cut-off effect felt by residents, and may also have a defect in long-term deflection. In this respect, this study developed high-performance interlayer soundproofing material that can overcome existing problems. The developed technology has the noise reduction effect experienced by the residents and it has high durability without long-term deflection. Therefore, high-performance interlayer soundproofing material is expected to contribute to reducing disputes over noise between floors of apartment residents.

• International Journal of Concrete Structures and Materials
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• v.10 no.3
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• pp.271-295
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• 2016

In this study, an extensive literature review has been conducted on the material characterization of UHPC and its potential for large-scale field applicability. The successful production of ultra-high performance concrete (UHPC) depends on its material ingredients and mixture proportioning, which leads to denser and relatively more homogenous particle packing. A database was compiled from various research and field studies around the world on the mechanical and durability performance of UHPC. It is shown that UHPC provides a viable and long-term solution for improved sustainable construction owing to its ultrahigh strength properties, improved fatigue behavior and very low porosity, leading to excellent resistance against aggressive environments. The literature review revealed that the curing regimes and fiber dosage are the main factors that control the mechanical and durability properties of UHPC. Currently, the applications of UHPC in construction are very limited due to its higher initial cost, lack of contractor experience and the absence of widely accepted design provisions. However, sustained research progress in producing UHPC using locally available materials under normal curing conditions should reduce its material cost. Current challenges regarding the implementation of UHPC in full-scale structures are highlighted. This study strives to assist engineers, consultants, contractors and other construction industry stakeholders to better understand the unique characteristics and capabilities of UHPC, which should demystify this resilient and sustainable construction material.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.433-439
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• 2023

In this study, the bonding performance of repair materials was evaluated on concrete repair surface to develop concrete repair materials based on UHPC (Ultra High Performance Concrete) which has high mechanical and durability performance. The ten test variables were applied considering the roughness and wet condition of the concrete surface subject to repair, the addition of polymer, and the use PP and PVA fibers in repair materials. The addition of the polymer caused a significant decrease in strength, which was thought to be due to the effect of the additional super plasticizer used to adjust workability. Also, flow was reduced by up to 13.8 % with the use of plastic-based fibers. As a result of evaluating the bond strength of the repair material considering the condition of the surface subject to repair, it was thought that in the case of using UHPC-based repair material, high bonding performance could be secured without any additional surface treatment as long as the surface of the base material was sound. In addition, UHPC-based repair materials showed high bonding performance even when the attachment surface was wet. In the future, research will be conducted on shot-crete application and gradient pouring for the development of UHPC-based repair materials, and continuous improvement in the repair material mixing property will be carried out to ensure economic efficiency and performance as a concrete structural repair material.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.37-40
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• 2005

High Performance Concrete(HPC) has been widely used in high-rise building. The HPC has several benefits including high strength, high fluidity and high durability. However. spatting is susceptible to occur in HPC and HPC also tends to be deteriorated in the side of fire resistance performance at fire. This paper focuses on the analysis of the temperature history and residual compressive strength with finishing material, in order to protect HPC from sudden-high-temperature, which is one of the main reason spatting occurs. Test results show that spalling occurs in all specimens. The most serious spalling took placed in HPC covering fire enduring spray-on material, whose covering thickness is 20mm but temperature history indicates that fire enduring spray effectively protected HPC from fire for more than 2hours. In addition, residual compressive strength ratio of HPC using fire enduring paint was more than $90\%$ of original strength, thus minimizing spatting and indicating significant fire resistance performance.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.311-321
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• 2021

Many studies have been performed on hybrid fiber reinforced concrete for years, which is to improve some of the weak material properties of concrete. Studies on characteristics of hybrid fiber reinforced concrete using amorphous steel fiber and organic fiber, however, yet remain to be done. The purpose of this research is to evaluate the compressive and tensile behaviors and then propose a material model of high performance hybrid fiber reinforced concrete using amorphous steel fiber and polyamide fiber. For this purpose, the high performance hybrid fiber reinforced concretes were made according to their total volume fraction of 1.0% for target compressive strength of 40MPa and 60MPa, respectively, and then the compressive and tensile behaviors of those were evaluated. Also, based on the experimental results of the high performance hybrid fiber reinforced concrete and mortar, each material model for the compressive and tensile behavior was suggested. It was found that the experimental results and the proposed models corresponded relatively well.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.33-38
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• 2005

It is applied in the high quality equipment construction by introduction of this high duality treating technology (ozone treating, activated carbon treating, high quality oxidation treating, UV treating etc.)waterproofing or corrosion proof method caused secondary economy damage of operation discontinuance and high quality treating equipment for applying existent waterproofing method that corrosion proof ability (ozone resistance performance, chemical resistance etc.) and abrasion resistance performance by comprehension insufficiency of user and designer. Therefor, In this study, we will analyze problem of waterproofing and corrosion material of existing construction application by high quality treating, and measure physical performance change by various condition. It is required to waterproofing and corrosion system and application of the field valuation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.8-10
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• 2013

Inorganic binding material was made by recycled resource and its applicability as pile-filling material was examined. The result was that the material had same liquidity with the liquidity of OPC and high reactivity with site soil. According to dynamic/static loading tests by site test-construction, the inorganic binding material met both design bearing capacity and settlement. Since the inorganic binding material showed same or better performance than OPC, the utilization possibility of the inorganic binding material made of recycled resource as pile-filling material was verified.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.137-138
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• 2012

Domestic construction materials market was about 65 trillion won and it occupied 45% level of total construction cost by 2007. In addition, due to the recent rapid rise of crude oil and iron ore price, fluctuation of raw material cost has a great influence to the cost of construction industry. This means that smooth performance is closely related to construction materials. And among them, because of high putting rate of metal materials, it can be seen that the fluctuation of metal material prices is an important variables. So in this study, for the pre-study to analyze the impact of metallic material prices to construction cost, the researcher analyzed a causal relationship between metal material prices and construction cost.

• Journal of the Korea Institute of Building Construction
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• v.18 no.1
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• pp.41-49
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• 2018

The purpose of this study is to develop a floor mortar construction technique which has high strength and inherent mechanical properties and does not cause cracks due to shrinkage after construction. It has been demonstrated that compressive strength, bending strength, flow with floor mortar, and crack reduction performance. As a result, it was confirmed that the developed floor mortar had the same or better performance comparing with the existing foreign products. The results of this experiment can be used as a validation material for high performance and high flowable mortar construction technology with excellent material performance, economical efficiency and construction ability by securing the required performance as floor mortar and selecting the optimal formulation.

• Advances in concrete construction
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• v.9 no.5
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• pp.459-467
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• 2020

Mechanical and thermal properties of composite sandwich wall panels are affected by changes in their external environment. Humidity and temperature changes induce stress on wall panels and their core connectors. Under the action of ambient temperature, temperature on the outer layer of the wall panel changes greatly, while that on the inner layer only changes slightly. As a result, stress concentration exists at the intersection of the connector and the wall blade. In this paper, temperature field and stress field distribution of UHPC-RW-RC (Ultra-High Performance Concrete - Rock Wool - Reinforced Concrete) wall panel under high temperature-sprinkling and heating-freezing conditions were investigated by using the general finite element software ABAQUS. Additionally, design of the connection between the wall panel and the main structure is proposed. Findings may serve as a scientific reference for design of high performance composite sandwich wall panels.