In this study, We evaluated the flexural behavior of high performance fiber reinforced cementitious composite (HPFRCC) with single steel fibers. to do this, we considered different types of steel fibers such as hooked, twisted and straight fibers. Test results indicated the flexural performance tends to increase as the incorporation rate of steel fiber increases and when the length of the fiber is long and at the high volume fractions(vf of 2.0) the flexural high performance was reduced.

본 연구는 음의 포아송비 거동을 가지는 격자체의 구조부재 보강재로의 적용이 가능한지에 대한 검토를 수행하였다. 콘크리트를 포함한 일반적인 재료는 외부 하중의 작용 시 양의 포아송비 거동을 가진다. 이러한 콘크리트의 역학적 거동을 음의 포아송비 특성을 가지는 금 속 격자체가 구속함으로써 콘크리트의 강성을 증대시킬 수 있음을 이론적으로 확인하였다. 또한 실제 건설산업에 적용이 가능한 수준의 음의 포아송비 거동을 가지는 격자체의 형식을 제시, 역학적 거동 특성을 수치 해석적으로 검토하였다.

This study examined the effects of the embedded auxetic grating structures by design on numerical analysis. Compressive tests were performed and the results showed the effectiveness of auxetic grating structures for the enhancements of stiffness.

The mechanical properties were evaluated to examine the optimum adding amount of AC and UT viscosity agent by mixing two viscosity agent according to the adding ratio. When the ratio of AC and UT viscosity agent was 5:5, It was most suited for high-fluidity concrete with low binders by increasing workability and effect of reducing viscosity.

The flowability and compressive strength were evaluated to examine the effect of biner mixing ratio on the high-fluidity concrete with low binders. When the binder mixing ratio (OPC, BFS, FA) was 7:2:1, It was most suited for high-fluidity concrete with low binders by increasing workability and compressive strength.

In recent years, in order to reduce self-weight of structural elements, the use of SCP(Steel Concrete Plate) is getting increased. Since SCP has complicated sectional shape and includes large amount of studs, the use of shrinkage reduction concrete is required. Therefore, in this study, to prevent the restrained shrinkage behavior by stud, the effects of using expansive agent (EA) and shrinkage reducing agent (SRA) was investigated.

In order to reduce self-weight of structural elements, the use of SCP(Steel Concrete Plate) is getting increased. Since SCP has complicated sectional shape and includes large amount of studs, the use of high-filling concrete is required. Therefore, in this study, It was evaluated the filling performance of filling concrete for SCP module according to our mix proportion. Resultingly, the concrete effectively filled the large-sized SCP module.

This study performed gas-gun propelled projectile impact tests with high strength steel fiber reinforced concrete. Also, from the impact tests, failure modes and protection performances of HIgh Performance Concrete which is reinforced by steel fibers were assessed. High strength steel fiber reinforced concrete showed excellent protection performances against impact loads.

This study examined the effects of the embedded auxetic grating structures by design on numerical analysis. Compressive tests were performed and the results showed the effectiveness of auxetic grating structures for the enhancements of stiffness.

The mechanical properties were evaluated to examine the optimum adding amount of AC and UT viscosity agent by mixing two viscosity agent according to the adding ratio. When the ratio of AC and UT viscosity agent was 5:5, It was most suited for high-fluidity concrete with low binders by increasing workability and effect of reducing viscosity.

The flowability and compressive strength were evaluated to examine the effect of biner mixing ratio on the high-fluidity concrete with low binders. When the binder mixing ratio (OPC, BFS, FA) was 7:2:1, It was most suited for high-fluidity concrete with low binders by increasing workability and compressive strength.

In recent years, in order to reduce self-weight of structural elements, the use of SCP(Steel Concrete Plate) is getting increased. Since SCP has complicated sectional shape and includes large amount of studs, the use of shrinkage reduction concrete is required. Therefore, in this study, to prevent the restrained shrinkage behavior by stud, the effects of using expansive agent (EA) and shrinkage reducing agent (SRA) was investigated.

In order to reduce self-weight of structural elements, the use of SCP(Steel Concrete Plate) is getting increased. Since SCP has complicated sectional shape and includes large amount of studs, the use of high-filling concrete is required. Therefore, in this study, It was evaluated the filling performance of filling concrete for SCP module according to our mix proportion. Resultingly, the concrete effectively filled the large-sized SCP module.

This paper presents an experimental study on the improvement of ductile and flexural strength for high performance fiber reinforced cementitous composites (HPFRCC). The test was evaluated by compressive and flexural behavior of HPFRCC(compressive strength : 180 MPa) according to aspect ratio and volume contents of steel fiber. The flexural strength was increased by aspect ratio near 100 or increasing volume contents of steel fiber while there is no clearly result on the compressive strength.

공공시설물의 대형화 및 도심지로의 인구 밀집화에 따라 충돌 또는 폭발과 같은 하중조건 하에서의 구조물 방호성능의 중요성이 대두되고 있다. 그러나 구조물의 방호설계 및 시공에 있어서 필수적이라 할 수 있는 구조 재료 또는 자재에 대한 방호성능 평가기준은 현재 정 립되어 있지 않은 실정이다. 따라서 본 연구에서는 구조용 자재의 내충격 성능평가 기준 개발 연구의 일환으로 가스건을 사용한 발사체 충격 파 괴시험을 콘크리트 시험체에서 수행함과 동시에, 다양한 접촉식 계측 센서의 적용 가능성을 확인하고자 하였다. 또한, 충격 파괴시험을 통해 일반 콘크리트 및 강섬유가 보강된 초고성능콘크리트의 파괴모드 및 방호성능에 대한 평가를 수행하였다. 실험 수행 결과, 접촉식 계측센서 중 LVDT 변위계의 적용 가능성을 확인하였으며, UHPC의 경우 혼입된 보강섬유의 효과로 인해 일반 콘크리트에 비해 우수한 방호성능을 보여주 었다.

In this study, We evaluated the applicability of high performance fiber reinforced cementitious composite (HPFRCC) with compressive strength of 180, 140 and 100 MPa and identical contents in steel fiber. The analysis of the flexure tensile behavior showed that HPRFCC presents deflection hardening after the initiation of cracks and exhibits higher energy absorbing capacity with high compressive strength.

To assess the protection performance and the applicability as protective materials of high performance fiber reinforced cementitious composites(HPFRCC), this study performed the impact tests with 40 mm gas-gun propelled projectile crash machine. From this study, it has observed that both high compressive strength of cement matrix and fiber reinforcement are beneficial for the improvement of impact resistance.