• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
• /
• pp.815-820
• /
• 2001

This paper provides an overview of the unreinforced masonry in Australian Standard, especially places the focus on a seismic code. Australia, like Korea, is a country of lower seismicity, and strengthens the code of unreinforced masonry since Newcastle earthquake of magnitude 5.6 in 1989. It is useful in establishing Korean code for unreinforced masonry to compare Australian Standard to Korean.

• Structural Engineering and Mechanics
• /
• 제58권1호
• /
• pp.39-58
• /
• 2016

Since the publication of ACI 318-02, the concrete capacity design (CCD) method has been used to determine the resistance of unreinforced concrete anchors. The regulation of steel-reinforced anchors was proposed in ACI 318-08. Until ACI 318-08, the shear resistance of concrete breakout for an unreinforced anchor during an earthquake was reduced to 75% of the static shear strength, but this reduction has been eliminated since ACI 318-11. In addition, the resistance of a hairpin-reinforced anchor was calculated using only the strength of the steel, and a regulation on the dynamic strength was not given for reinforced anchors. In this study, shaking table tests were performed to evaluate the dynamic shear strength of unreinforced and hairpin-reinforced cast-in-place (CIP) anchors during earthquakes. The anchors used in this study were 30 mm in diameter, with edge distances of 150 mm and embedment depths of 240 mm. The diameter of the hairpin steel was 10 mm. Shaking table tests were carried out on two specimens using the artificial earthquake, based on the United States Nuclear Regulatory Commission (US NRC)'s Regulatory Guide 1.60, and the Northridge earthquake. The experimental results were compared to the current ACI 318 and ETAG 001 design codes.

• Advances in concrete construction
• /
• 제3권4호
• /
• pp.283-293
• /
• 2015

This paper presents the effects of elevated temperatures of $400^{\circ}C$ and $800^{\circ}C$ on the residual compressive strength and failure behaviour of fibre reinforced concretes and comparison is made with that of unreinforced control concrete. Two types of short fibres are used in this study e.g., steel and basalt fibres. The results show that the residual compressive strength capacity of steel fibre reinforced concrete is higher than unreinforced concrete at both elevated temperatures. The basalt fibre reinforced concrete, on the other hand, showed lower strength retention capacity than the control unreinforced concrete. However, the use of hybrid steel-basalt fibre reinforcement recovered the deficiency of basalt fibre reinforced concrete, but still slightly lower than the control and steel fibres reinforced concretes. The use of fibres reduces the spalling and explosive failure of steel, basalt and hybrid steel-basalt fibres reinforced concretes oppose to spalling in deeper regions of ordinary control concrete after exposure to above elevated temperatures. Microscopic observation of steel and basalt fibres surfaces after exposure to above elevated temperatures shows peeling of thin layer from steel surface at $800^{\circ}C$, whereas in the case of basalt fibre formation of Plagioclase mineral crystals on the surface are observed at elevated temperatures.

• 한국구조물진단유지관리공학회 논문집
• /
• 제7권4호
• /
• pp.171-181
• /
• 2003

비균열 무근 콘크리트에 매입된 단일앵커는 연단거리와 콘크리트 강도에 따라 콘크리트 단부파괴, 콘크리트 부서짐파괴, 앵커파괴가 발생한다. 본 연구에서는 연단거리와 콘크리트 강도에 따라 콘크리트 단부파괴, 콘크리트 부서짐파괴, 앵커파괴 발생시 단일앵커의 전단내력평가를 목적으로 한다. 이를 위하여 ACI 318-02와 EOTA 기준의 근거인 CCD (Concrete Capacity Design) 방법과 기존의 앵커 설계기준인 ACI 349-90(45-Degree Cone Method)에 의한 예측값과 실험값을 서로 비교 평가하였다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
• /
• pp.369-374
• /
• 1999

A practical approach of calculating the ultimate strength of composite beams with unreinforced web opening is proposed. In this method, the slab shear contribution at the opening is calculated as the smaller of the shear strength of the slab and the pullout capacity of the shear connectors at the high moment end. A simple interaction equation is used to predict the ultimate strength under simultaneous bending moment and shear force. Strength prediction by the proposed method is compared with previous test results and the predictions by other analytical method. The comparison shows that the proposed method predicts the ultimate capacity with resonable accuracy.

• 콘크리트학회지
• /
• 제7권4호
• /
• pp.71-83
• /
• 1995

• 콘크리트학회논문집
• /
• 제12권5호
• /
• pp.101-110
• /
• 2000

A practical approach of calculating the ultimate strength of composite beams with unreinforced web opning is proposed through shear behavioral tests. In this method, the slab shear contribution at the opening is calculated as the smaller value of the pullout capacity of shear connector at the high moment end and the one way shear capacity of slab. A simple interaction equation is used to predict the ultimate strength under simultaneous bending moment and shear force. Strength prediction by the proposed method is compared with previous test results and the predictions by other analytical methods. The comparison shows that the proposed method predicts the ultimate capacity with resonable accuracy.

• Computers and Concrete
• /
• 제18권2호
• /
• pp.215-233
• /
• 2016

Exterior beam-column joints are structural elements that ensure connection between beams and columns. The joint strength is generally assumed to be governed by the structural element of lowest load capacity (beam or column), however, the joint may be the weakest link. The joint shear behavior is still not well understood due to the influence of several variables, such as geometry of the connection, stress level in the column, concrete strength and longitudinal beam reinforcement. A parametrical study based only on experiments would be impracticable and not necessarily exposes the failure mechanisms. This paper reports on a set of numerical simulations conducted in DIANA$^{(R)}$ software for the investigation of the shear strength of exterior joints. The geometry of the joints and stress level on the column are the variables evaluated. Results have led to empirical expressions that provide the shear strength of unreinforced exterior beam-column joints.

• 한국강구조학회 논문집
• /
• 제26권1호
• /
• pp.11-20
• /
• 2014

2001년 이후 앵커의 설계는 Concrete Capacity Design(CCD) 방법이 적용되고 있는데, 국내 기준에서는 지진하중에 대한 콘크리트의 파열파괴강도를 정적 파괴강도의 75%로 제한하고 있다. 본 연구에서는 무근콘크리트에 매입된 선설치앵커의 동적 전단하중에 대한 콘크리트 파열파괴강도 평가하기 위한 실험을 수행하였다. 이를 위해 직경 20 mm의 앵커에 대해 정적 하중과 동적 편진하중에 대한 실험을 각각 3개의 시험체에 대해 수행하였으며, 앵커의 연단거리는 120 mm를 적용하였다. 동적 실험은 15 cycle의 편진하중을 1 Hz의 속도로 재하하였으며 반복하중단계의 크기를 키워가면서 최종 파괴 시까지 가력하였다. 실험으로부터 동적 전단하중에 의한 콘크리트 파열파괴강도는 정적하중에 의한 것과 거의 같은 파괴강도를 보였다.

• 콘크리트학회지
• /
• 제19권5호
• /
• pp.51-57
• /
• 2007