• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.1117-1120
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• 2008

In order to develop an Ultra High Performance Concrete (UHPC) suited to the Korean conditions, KICT has carried out several parts of research in the field of UHPC from 2003. KICT developed UHPC which was a structural material exhibiting very remarkable mechanical performances with compressive strength, tensile strength and flexural strength rising up to 200MPa, 15MPa and 35MPa, respectively. In addition, this material presents exceptional durability regard to the very low diffusion and penetration speeds of noxious substances like chloride ions. This 200MPa strength concrete has been effectively adopted for the construction of bridges like Sherbrooke Bridge in Canada in 1997, Sunyu Bridge in Korea in 2002, Meata Bridge in Japan in 2003, Sheperds Guelly Creek Bridge, the first ultra-high strength concrete highway bridge in Australia in 2004 and, more recently in 2005, Mars Hill highway bridge in USA in 2005. The construction of structures using ultra high performance concrete is a worldwide development trend of concrete technology for the construction of advanced facilities in the 21st century.

• Journal of the Korea Concrete Institute
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• v.25 no.3
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• pp.295-304
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• 2013

Ultra-High Performance Concrete (UHPC) has recently been one of the most active research fields in Korea as well as in foreign countries, because it can contribute to a longer life and economic efficiency of structures. Although precast-type UHPC fabricated in a factory is preferable in terms of quality control and reduction of construction period, there exist, even in the precast structure, some parts that need to be cast in-place such as the joints between precast segments. In the cast-in-place UHPC, however, it is probable that an optimum curing condition can hardly be realized in contrast to the factory production. In this study, therefore, the trend of compressive strength development of UHPC was experimentally investigated by assuming various inferior curing conditions that may be anticipated at a construction site. Concrete specimens were fabricated and cured under different conditions with the variables such as curing temperature, delay time before the initiation of curing, duration of curing time and moisture condition. The strengths were compared with those of the specimens cured by standard high temperature steam. Through the analysis of the test results, some minimum requirements for curing have been proposed that are required when the UHPC is cast in-place. It is expected, through this study, that practical use of UHPC in construction sites can be increased.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.94-95
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• 2020

This paper introduces the mix design and performance evaluation of Ultra-High Performance Concrete (UHPC). The concrete mixture is designed to achieve a densely compacted cementitious matrix via the modified Andreasen & Andersen particle packing model. The compressive strengths of UHPC designed by this method reached 154MPa. The relationship between packing theory and compressive strength of UHPC is discussed in this paper.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.208-215
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• 2021

In this study, a customiz ed bridge system was developed for North Korea application. For the application of North Korea, the customized bridge system design, fabrication, and construction performance evaluation were performed using ultra-high performance concrete a compressive strength 120MPa or more and a direct tensile strength 7MPa or more. The comparison of the North Korean truck luggage load(30, 40, 55) and the Korean standard KL-510 load showed that cross-section increased as the load increased. Furthermore, a bridge with a span length of 30m was fabricated with ultra-high performance concrete for the construction performance evaluation. The evaluation of the load condition analysis was performed by a flexural test. The results showed that a bridge with a span length of 30m secured about 167% of sectional performance under initial cracking load conditions and about 134% of load bearing capacity under ultimate load conditions. As a result of economic analysis, the customized bridge system using ultra-high-performance concrete was less than about 11% of the upper construction cost compared to the steel composite girder bridge. Therefore, these results suggest that the price competitiveness can be secured when applying the ultra-high-performance concrete long-span bridge developed through this study.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.93-94
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• 2009

In this paper, the bond performance between prestressing strand and Ultra High Performance Concrete members are verified to collect the basis data of UHPC increased in practical uses recently. Concrete pouring direction, strand location and strand size were the main parameters of UHPC. As a result, the initial bond performances are influenced by all above parameters.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.351-357
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• 2022

In this study, offshore modular pier system using the ultra-high performance concrete was developed for the offshore construction environment. For the application of offshore modular pier system, the design, fabrication, and construction performance evaluation were performed using ultra-high performance concrete a compressive strength 120 MPa or more and a direct tensile strength 7 MPa or more. For offshore piers previously constructed with precast concrete, it was intended to verify the idea and possibility of solving errors due to position or vertical deformation during the driving of the foundation pile part during the construction stage. Furthermore, a offshore modular pier system was fabricated with ultra-high performance concrete for the construction performance evaluation. The results showed that a offshore modular pier system secured about 9 % of sectional performance of load bearing capacity under ultimate load conditions. If the offshore modular pier system developed through this study is utilized in the future, it is judged that competitiveness due to sufficient durability and constructability can be secured.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.357-360
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• 2008

UHPC which was a structural material exhibiting very remarkable mechanical performances with compressive strength, tensile strength and flexural strength rising up to 200MPa, 15MPa and 35MPa, respectively. In addition, this material presents exceptional durability regard to the very low diffusion and penetration speeds of noxious substances like chloride ions This study was carry out to evaluate the effect of flexural behavior according to placement method in UHPC. The results is showing that the placement methods have remarkable influence flexural strength Addition to it is showing that the placement methods made little difference in the first cracking strength but considerable gap up to 2 or 3 times in the ultimate flexural strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.235-236
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• 2009

In this Study, we examined the characteristic of compressive strength according to various curing methods in order to obtain higher strength of UHPC in th e range of 200MPa.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.483-484
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• 2010

In this paper, it was intended to understand the effect of the fiber orientation distribution on the tensile behavior of Intra High Performance Cementitious Composites (UHPCC) and to estimate flow-dependent fiber orientation distribution and the corresponding tensile behavior of UHPCC.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.375-376
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• 2001

건축 기술의 발달과 도시토지 이용의 효율성을 강화하기 위하여 최근에는 초고층 건물이 많이 건설되고 있다. 이러한 초고층 건물은 에너지 절약적인 설계로 높은 기밀성을 가질 뿐 아니라, 외주부 또한 개폐할 수 없는 유리벽에 의하여 구획되므로 자연 환기에 열악한 특성을 지니고 있다. 초고층 건물의 경우 배기시스템으로 중앙집중배기방식을 채택하고 있으며, 중앙배기시스템은 배기입상덕트의 형상 및 규격, 흡출기의 성능, 그리고 기상조건 등 여러 변수들에 의해 영향을 받는다. (중략)