• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.172-173
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• 2019

In this study, application of ultra high performance concrete(UHPC) with pre-mix binder were presented on civil, architectural and special field. The UHPC can be applied to a variety of site due to its excellent flowability, mechanical properties, impact resistance and fire resistance. It is necessary to apply the pre-mix binder to take into account the productivity and performance improvements of the UHPC.

• Advances in concrete construction
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• 제15권6호
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• pp.391-404
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• 2023

In this study, the modeling of the transverse connection of fully precast steel-UHPC (Ultra-High-Performance Concrete) lightweight composite bridges were conducted. The transverse connection between precast components plays a critical role in the overall performance and safety of the bridge. To achieve an accurate and reliable simulation of the interface behavior, the cohesive model in ABAQUS was employed, considering both bending-tension and compression-shear behaviors. The parameters of the cohesive model are obtained through interface bending and oblique shear tests on UHPC samples with different surface roughness. By validating the numerical simulation against actual joint tests, the effectiveness and accuracy of the proposed model in capturing the interface behavior of the fully precast steel-UHPC lightweight composite bridge were demonstrated.

• Coupled systems mechanics
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• 제12권6호
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• pp.539-555
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• 2023

Although some prediction models have successfully developed for ultra-high performance concrete (UHPC), they do not provide insights and explicit relations between all constituents and its consistency, and compressive strength. In the present study, based on the experimental results, several mathematical models have been evaluated to predict the consistency and the 28-day compressive strength of UHPC. The models used were Linear, Logarithmic, Inverse, Power, Compound, Quadratic, Cubic, Mixed, Sinusoidal and Cosine equations. The applicability and accuracy of these models were investigated using experimental data, which were collected from literature. The comparisons between the models and the experimental results confirm that the majority of models give acceptable prediction with a high accuracy and trivial error rates, except Linear, Mixed, Sinusoidal and Cosine equations. The assessment of the models using numerical methods revealed that the Quadratic and Inverse equations based models provide the highest predictability of the compressive strength at 28 days and consistency, respectively. Hence, they can be used as a reliable tool in mixture design of the UHPC.

• Steel and Composite Structures
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• 제22권2호
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• pp.387-398
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• 2016

In order to evaluate the effects of U shape ultra high performance concrete (UHPC) permanent form on the behaviors of Reinforced Concrete (RC) beam, a full scale RC composite beam is designed and tested with U shape UHPC permanent form and a reference RC beam with same parameters is tested simultaneously for comparison. The effects of the permanent form on the failure mode, cracking strength, ultimate capacity and deformation are studied. Test results shows that the contributions of the U shape UHPC permanent form to the flexural cracking behaviors of RC beam are significant. This study may provide a reference for the design of sustainable RC beam with high durable UHPC permanent form.

• 콘크리트학회논문집
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• 제26권6호
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• pp.771-778
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• 2014

본 연구에서는 하이브리드 강섬유로 보강된 초고성능 콘크리트(UHPC)의 휨거동 특성을 파악하고자 하였다. 부피비 1.5%의 하이브리드 강섬유를 혼입하여 철근비가 0.02 이하인 부재의 실험을 통해 주요 휨거동 특성을 파악하였다. 본 연구결과는 추후 UHPC의 휨강도 산정 모델링에 실제적인 기초실험자료로 활용될 수 있을 것으로 사료된다. 하이브리드 강섬유 보강 UHPC는 균열제어에 효과적이며, 연성지수는 9.2~15.2 범위에 분포하고 있어 우수한 연성거동 특성을 나타낸다. 또한, 순수 휨 구간 내에 스터럽을 배근한 부재의 휨강도는 스터럽을 배근하지 않은 부재의 휨강도와 유사하며, 이 실험연구의 150 mm 간격 정도의 스터럽 배근은 강섬유 배열 및 휨강도에 영향을 미치지 않는다고 판단된다.

• 한국건축시공학회지
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• 제22권3호
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• pp.229-237
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• 2022

초고성능 콘크리트(UHPC)는 낮은 물-바인더비(W/B), 고성능 감수제(SP), 혼화재 및 강섬유(Steel Fiber)의 혼입으로 일반 콘크리트보다 유동성, 강도 등에서 월등히 우수한 성능을 지닌 건설 재료이다. 본 연구에서는 UHPC를 활용하여 기존의 석재 패널을 대체할 수 있는 건축용 외장 패널을 제작하였다. 또한, UHPC의 W/B비 배합별 동일한 혼화제 투입량, 충전재의 혼입량, 소포제 및 강섬유 혼입 유무의 차이로 변수를 가지고 실험을 진행하였다. 평가 항목으로는 콘크리트 압축강도, 휨강도, 충격강도, 흡수율, 내동해성 등 물성 및 내구성 테스트를 진행하였다. 실험결과, 압축강도 최대 115.5MPa, 휨강도 20.3MPa을 확보하였으며 흡수율 1%이내, 충격강도 및 내동해성 평가는 규격 내 겉보기 관찰 결과 이상 없음 결과를 만족하였다.

• Structural Engineering and Mechanics
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• 제82권2호
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• pp.133-149
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• 2022

This study investigates the resistance of sustainable ultra-high performance concrete (UHPC) on steel reinforcement corrosion. For enhancing the sustainability of UHPC, concrete mixes were prepared with ordinary Portland cement main binder, and mixes with moderate to high percentages of blast furnace cement (CEM III), fly ash (FA), and slag cement as partial replacements of the full quantity of the used cement. Linear polarization resistance technique was employed to estimate the electrochemical behavior of the concrete specimens. Results showed that the compressive strength and the resistance of steel to corrosion in marine environments can be enhanced by improving the sustainability of UHPC through incorporation of CEM III, FA, and slag cement. FA replacement of up to 50% with the addition of 15% SF content produced better compressive strength and steel corrosion resistance than slag cement whether with the use of ordinary Portland cement or blast furnace cement as the main binder.

• 한국건설순환자원학회논문집
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• 제6권4호
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• pp.336-341
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• 2018

프리텐션 콘크리트 부재에서 긴장재에 도입된 프리스트레싱힘은 긴장재와 콘크리트의 직접 부착에 의하여 콘크리트에 전달되므로 응력전달길이를 합리적으로 산정하는 것이 중요하다. 프리텐션부재 또는 프리캐스트 부재에 UHPC를 사용하는 경우 품질관리 측면에서 많은 장점이 있다. 따라서, 이 논문은 초고성능 콘크리트를 사용한 프리텐션 부재에 있어서 PS 강연선의 응력전달길이를 구하기 위하여 초고성능 콘크리트의 압축강도, 피복두께, 긴장재의 지름 및 긴장력을 변수로 하여 실험을 진행하고 그 결과를 분석한 내용을 정리한 것이다. 실험 결과에 따르면 초고성능 콘크리트를 사용한 경우 일반 콘크리트에 비하여 응력 전달길이가 크게 감소하였으며, 압축강도 수준이 증가할수록 응력전달길이가 감소하는 것을 확인할 수 있었다. 이는 초고성능 콘크리트의 높은 부착강도에서 비롯되는 것으로 판단된다. 또한, 실험결과와 기존 설계기준의 응력전달길이 산정식을 비교하고, 초고성능 콘크리트 프리텐션 부재의 응력전달길이를 산정할 수 있는 새로운 공식을 제안하였다.

• 콘크리트학회지
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• 제23권5호
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• pp.38-44
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• 2011

• 한국공간구조학회논문집
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• 제18권2호
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• pp.99-108
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• 2018

This paper presents the design, analysis, and experimental evaluations of precast reinforced UHPC (ultra high-performance concrete) beams with a new design concept of non-uniform flexural members. With outstanding mechanical properties of UHPC which can develop the compressive strength up to 200MPa, the tensile strengths up to 8~20MPa and the tensile strain up to 1~5%, a non-uniform structural shape of UHPC flexural beams were optimally designed using three-dimensional finite element analysis. The experiments were carried out and compared with the design strength in order to verify the performance of them. Proposed non-uniform UHPC beams were evaluated by a series of three-point beam loading test as well as estimated by design bending and shear strength of members. The newly designed UHPC beams show excellent performances not only in transverse load capacities but also in deformation capacities.