• 한국지반신소재학회논문집
• /
• 제6권3호
• /
• pp.1-7
• /
• 2007

풍화토의 특성은 다양한 풍화환경, 풍화도 및 영향인자에 따른 거동의 특이성 때문에 정밀한 접근에 있어서 한계를 가진다. 특히 국내 외의 연구는 퇴적토에 집중되어 있고 풍화토의 역학적 거동을 퇴적토의 관점에서 분석하려 하기 때문에 이러한 결과가 풍화토의 실제 거동과 일치하는지 판단하는데 무리가 있다. 본 연구에서는 인공적으로 풍화도를 변화시키는 실험의 초보단계로서 온도 변화에 따른 강도변화 특성을 규명하고자 한다. 이를 위하여 동결 융해 반복작용 후의 시료를 대상으로 실내시험을 실시하여 풍화도에 대한 화강풍화토의 모암별, 지역별, 특성변화를 살펴보았다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
• /
• pp.689-692
• /
• 2008

본 연구는 친환경 콘크리트의 개발을 위하여 시멘트 대체재료인 혼화재료로서 황토, 슬래그 및 PET보강섬유를 혼입한 콘크리트의 역학적 특성을 분석하는데 목적이 있다. 이를 위하여 콘크리트(SC), 황토콘크리트(HTC), 황토 및 PET보강섬유가 혼입된 시험체(HTPC)를 대상으로 재령별 압축강도 실험을 실시하였으며, 시험체의 장기특성을 분석하기 위한 크리프 및 건조수축 실험을 실시하였다. 실험결과, 재령별 압축강도는 시험체 별로 큰 차이를 나타내지 않았으나, HTC 시험체의 압축강도가 가장 큰 것으로 나타났으며, 크리프 및 건조수축의 실험결과 HTC 시험체의 장기특성이 가장 우수한 것으로 판명되었다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2015년도 추계 학술논문 발표대회
• /
• pp.9-10
• /
• 2015

Waste Concrete Powder will be generated during the manufacture of construction waste as recycled aggregate Waste concrete. The main component of the waste concrete Powder is a silica-based composition 51% SiO₂, waste concrete cement-based composition Al₂O₃ 10%, CaO 26% component are contained. The material is silica sand of PHC piles should experiment by replacing the Waste Concrete Powder. The compressive strength results are as follows. 25% when the Silica was replaced 32.5Mpa, when 50% have replaced 43.4Mpa, when 75% have replaced 45.3Mpa was measured. Compared with the non-replaced test sample it appears that the strength increases. Therefore, it is determined that the practical use of the PHC piles by replacing silica via this experiment is possible.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 추계 학술발표회
• /
• pp.772-781
• /
• 2010

In this study, a revegetation reinforced earth retaining wall to strengthen the strength than construction and make up for the weakness; eco-friendly part, of the existing facilities is new construction method. The special attention is that Eco-Metal reinforced retaining wall is not use concret. Before test construction on the scene, the stability of Eco-Metal reinforced retaining wall was checked by an experiment with a model and numerical analysis. The result of an experiment with a model was that the loaded tensile stress 40.2KN/m was more than long-term design tensile strength 29.4KN/m at Geogrid and a safety factor of numerical analysis was 1.14.

• 한국공작기계학회논문집
• /
• 제12권1호
• /
• pp.78-83
• /
• 2003

Electro-rheological(ER) fluids are suspensions in which rheological properties show an abrupt change with variation of electric fields. We modeled the parallel-plates relating to ER-Valve system and yielded shear stress according to the strength of electric field. The purpose of the present study is to examine the flow characteristics of ER fluids according to the strength of electric field between parallel-plates. Then the steady relationship between pressure drop and flow rate of the ER fluids between parallel-plates under application of an electric fields was measured. The pressure drop and flow rates of ER fluids under the application of electric fields for steady flow were measured. For the experiment, we used the ER fluids, 35w% zeolite having hydrous particles and differential pressure gauge. This test reviewed experiment for the special changes of ER fluids in the steady flow condition.

• 한국강구조학회 논문집
• /
• 제11권1호통권38호
• /
• pp.89-98
• /
• 1999

본 연구는 콘크리트충전 각형강관 기둥의 중심 및 편심압축 실험을 통해 비탄성역에서의 좌굴내력을 구하고, 그 결과를 비교 분석하여 기둥의 각 변수에 따른 내력 및 변형능력에 미치는 영향을 종합적으로 파악하며, 각국의 규준식과 비교하여 새로운 내력식을 제안하여 콘크리트충전 각형강관 기둥을 이용한 고층구조시스템의 개발에 필요한 구조역학적 정보를 제공하고, 향후 국내의 콘크리트충전 강관구조 규준 제정에 필요한 기초 자료를 제시하는데 그 목적이 있다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
• /
• pp.135-140
• /
• 1999

The size effect of axial compressive strength of concrete in notched specimens was experimentally investigated. Based on the concept of the fracture mechanics and size effect law, theoretical studies for axial compressive failure of concrete were reviewed, and two failure modes of concrete specimen under compression were discussed. In this study, experiment of axial compressive failure, which is one of the two failure modes, was carried out by using double cantilever fracture specimens. By varying the slenderness of cantilevers and the eccentricity of applied loads with respect to the axis of each cantilever, the size effect of axial compressive strength of concrete was investigated, and predicted by Bazant's size effect law. The test results show that size effect appears conspicuously for all series of specimens. For the eccentricity of loads, the influence of tensile and compressive stress at the notch tip are significant and so that the size effect is varied. In other words, if the influence of tensile stress at the notch tip grows up, the size effect of concrete increases. And the fact that the fracture process zone must be sufficiently secured for more accurate experiment was affirmed.

• International Journal of Concrete Structures and Materials
• /
• 제10권1호
• /
• pp.29-37
• /
• 2016

The paper presents a research project on the tensile properties of RPC mixed with both steel and polypropylene fibers after exposure to $20-900^{\circ}C$. The direct and the indirect tensile strength (in bending) were measured through tensile experiment on dog-bone specimens and bending experiment on $40{\times}40{\times}160mm$ prisms. RPC microstructure was analyzed using scanning electron microscope. The results indicate that, steel fibers can significantly improve the tensile performance of hybrid fiber-reinforced RPC, whereas polypropylene fibers have no obvious effect on the tensile performance. With increasing temperature, the flexural and axial tensile strength of hybrid fiber-reinforced RPC substantially decrease linearly, which attributes to the deteriorating microstructure. Based on the experimental results, equations are established to express the decay of the flexural and tensile strength with increasing temperature.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
• /
• pp.485-488
• /
• 2003

The results of an experiment on the sound absorption of the porous concrete using recycled aggregates and its influence on the compressive strength are reported in this paper. The content of recycled aggregate of 0, 10, 30, 50 and 70%, and the design void ratio of 30 percent for a given size of aggregate were used. In the compressive strength, an aggregate of the size of 5~13mm is much higher strength than that of the 13~20mm, In sound absorption experiment, the sound absorption ratio was is subjected to decreased as the content of recycled aggregates was increased. As a result, Porous concrete using recycled aggregates and by-products sufficiently have the performance of sound absorption.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
• /
• pp.489-492
• /
• 2003

The results of an experiment on the sound absorption of the porous concrete and its influence on the compressive strength are reported in this paper. Two different sizes of coarse aggregate of 5~13, 13~20mm, and the design void ratio of 20, 25 and 30 percent for a given size of aggregate were used. In the compressive strength, an aggregate of the size of 5~13mm is much higher strength than that of the 13~20mm, In the sound absorption experiment, the size of aggregate of 5~l0mm is much higher sound absorption than that of the 13~20mm. The sound absorption ratio was increased as the design void ratio. As a result, Porous concrete sufficiently have the performance of sound absorption.