• Steel and Composite Structures
• /
• 제45권1호
• /
• pp.51-66
• /
• 2022

This paper presents the axial compression behavior of partially encased composite (PEC) columns using H-shaped structural steel. In the experimental program, a total of eight PEC columns with H-shaped steel sections of different flange and web slenderness ratios were tested to investigate the interactive mechanism between steel and concrete. The test results showed that the PEC columns could sustain the load well beyond the peak load provided that the flange slenderness ratio was not greater than five. In addition, the previous analytical model was extended to predict the axial load-strain relationships of the PEC columns with H-shaped steel sections. A good agreement between the predicted load-strain relationships and test data was observed. Using the analytical model, the effects of compressive strength of concrete (21 to 69 MPa), yield strength of steel (245 to 525 MPa), slenderness ratio of flange (4 to 10), and slenderness ratio of web (10 to 25) on the interactive mechanism (K_h = confinement factor for highly confined concrete and K_w = reduction factor for steel web) and ductility index (DI = ratio between strain at peak load and strain at proportional load) were assessed. The numerical results showed that the slenderness of steel flange and yield strength of steel significantly influenced the compression behavior of the PEC columns.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2005년도 학술발표회 논문집
• /
• pp.300-307
• /
• 2005

Steel Reinforced Concrete (SRC) composite column has several advantage such as excellent durability, rapid construction, reduction of column section. Due to these aspect, applications of SRC columns to bridge piers are continuously increasing. For the design of relatively large SRC columns for bridge piers, it is necessary to check the current design provisions which were based on small section having higher steel ratio. In this study, seven concrete encased composite columns were fabricated and static tests were performed. Embedded steel members were a H-shape rolled beam and a partially filled steel tube. Based on the test results, the ultimate strength according to section details and local behavior were estimated. For the analysis of inelastic behavior of the SRC column, the cracked section stiffness of the columns was evaluated and compared with calculations. The stiffness of the cracked section showed that 25% of the initial value and this stiffness reduction occurred at 85% of the ultimate load in the experiments.

• 한국강구조학회 논문집
• /
• 제25권6호
• /
• pp.635-647
• /
• 2013

PSRC 기둥은 앵글을 콘크리트에 매입시킨 기둥으로, 단면의 외곽 코너에 배치되는 앵글이 기둥의 휨-압축에 저항한다. 본 연구에서는 KBC 2009에 따라 압축력을 가한 기둥에 대하여 횡방향 반복가력 실험을 통하여 내진성능을 검증하였다. 기둥 종류, 연속후프근 적용, 앵글에 스터드 적용을 실험 변수로 고려하였으며, 2/3 스케일을 갖는 한 개의 SRC 합성기둥과 세 개의 PSRC 합성기둥을 실험하였다. 실험결과, KBC 2009로 예측한 PSRC 합성기둥의 하중재하능력은 실험결과와 잘 일치하였으며, 변형능력과 에너지 소산에 있어서 우수한 성능을 보여주었다. PSRC 합성기둥은 반복하중으로 인한 콘크리트 피복 탈락 이후, 앵글 및 주철근의 좌굴에 의해 실험체의 하중재하능력이 감소하였다. 특히, 연속후프근을 적용한 PSRC 합성기둥은 앵글의 조기 국부좌굴이 억제되어 기존 PSRC 합성기둥에 비해 연성능력이 향상되었다.

• 한국강구조학회 논문집
• /
• 제27권1호
• /
• pp.43-52
• /
• 2015

구조물의 기둥은 층에 따라 받는 내력이 상이함에도 시공의 오차를 줄이고 구조설계의 편의를 위해 상부층부터 하부층의 기둥단면은 동일하게 설계되고 있다. 그럼에도 불가피하게 상하부의 기둥의 단면이 상이하는 경우가 발생된다. 예를들어 초고층 구조물 또는 증축 및 보수에 의해 기둥을 보강할 경우이다. 이렇듯. 선 기둥과 후 피복이 되는 기둥을 피복충전형 콘크리트 충전기둥이라 할 때, 가력조건이 다르므로 재하상태를 나뉘어 구조적 안정성을 확인할 필요가 있다. 그럼에도 국내외적으로 가력조건에 따른 합성기둥에 대한 내력과 변형연구는 전무한 상태에 있다. 따라서 본 연구에서는 구조실험을 통해 가력조건 및 콘크리트 강도, 피복두께 변화에 의한 피복충전형 콘크리트 각형 기둥의 내력과 거동을 분석하였다.

• Steel and Composite Structures
• /
• 제32권1호
• /
• pp.111-126
• /
• 2019

This paper deals with experimental investigation and modeling of the static behavior of a novel RCS beam-column exterior joint. The studied joint detail is a through-column type in which an H steel profile totally embedded inside RC column is directly welded to the steel beam. The H steel profile was covered by two supplementary plates in the joint area in order to avoid the stirrups resisting shear in the joint area. Two full-scale through-column-type RCS joints were tested under static loading. The objectives of the tests were to examine the connection performance and to highlight the contribution of two supplementary plates on the shear resistance of the joint. A reliable nonlinear 3D finite element model was developed using ABAQUS software to predict the response and behavior of the studied RCS joint. An extensive parametric study was performed to investigate the influences of the stirrups, the encased profile length and supplementary plate length on the behavior of the studied RCS joint.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
• /
• pp.613-616
• /
• 2003

Steel-concrete composite columns are used extensively in modern buildings. Extensive research on composite columns in which structural steel are in concrete have been carried out. In-filled composite columns, however have received limited attention compared to encased columns. In this paper, interrelationship of parameters is examined into analyzing and comparing with data through ABAQUS program and experiment on concrete filled tubular column under axial load and propriety of model is checked out by FEM analysis. The main variations of this paper are width-thickness ratio of the section(B/t =33.3, 38.9, 44.4), concrete strength($f_{ck}$=240, 360kgf/$\textrm{cm}^2$), and width-length ratio($L_o$/B=8.0, 10.0, 12.0, 15.0, 20.0). The ultimate value obtained through analysis is compared with test value and calculated by design code of other countries and previous studies.

• KIEAE Journal
• /
• 제10권6호
• /
• pp.159-165
• /
• 2010

The composite frame system suggested in this paper consists of steel reinforced concrete beam encased with structural tee and precast concrete column. This system has advantages such as reduction of materials, CO2 emissions and waste. To commercialize the new composite frame system, it is necessary to develop connections that can effectively connect each member. Therefore, a hybrid connection that has steel type connection and reinforced concrete together is utilized to connect easily at the composite frame system. To evaluate the structural performance of the composite frame system, an experimental investigation is presented. In this study, the flexural moment capacity of the composite frame was determined using the strain compatibility approach. The strain compatibility approach can be used to predict the flexural moment capacity at each limit state. As a result, all elements of the beam to column connection are represented to fully interact between each other. The specimens show errors of -1.9% in the yield limit state and 0.9% at the maximum load limit state. Also, testing shows that beam to column connections have characteristics of semi-rigid connection as per Eurocode 3.

• 한국강구조학회 논문집
• /
• 제26권1호
• /
• pp.31-42
• /
• 2014

본 연구에서는 콘크리트충전 각형강관에 구조용 피복콘크리트를 적용한 합성기둥에 대하여 연구하였다. 1/3~1/2 축소모델의 편심 압축실험체 4개와 중심압축실험체 1개를 제작하여 압축실험을 수행하였다. 실험 변수는 피복콘크리트의 강섬유 첨가여부, 편심거리, 기둥 길이, 그리고 횡보강 상세이다. 일부 실험체에서 최대강도 도달 후 피복콘크리트의 탈락으로 인한 강도저하가 발생하였으나 모든 실험체는 현행 설계기준(KBC 2009)에 의한 휨 압축 강도 및 공칭 압축강도를 초과하는 하중재하능력을 보였다.

• 한국강구조학회 논문집
• /
• 제25권2호
• /
• pp.209-222
• /
• 2013

800MPa급 강재와 100MPa급 콘크리트를 적용한 매입형 합성기둥에 대하여 편심압축실험을 수행하였다. 강재단면의 모멘트팔길이와 변형(응력)을 증가시켜 고강도강재의 성능활용을 극대화할 수 있도록, ㄱ형 강재단면을 네 모서리에 집중 배치한 후, 래티스철근, 링크철근, 띠판을 이용하여 일체화하였다. 이 경우 강재단면의 강력한 횡구속효과로 인해 심부콘크리트의 성능도 개선된다. 실험결과 ㄱ형 강재 매입형 기둥은 H형 강재 매입형 기둥에 비하여 최대강도와 유효휨강성이 1.4배 이상 증가하였다.

• Steel and Composite Structures
• /
• 제17권6호
• /
• pp.835-850
• /
• 2014

The fire resistance of composite steel and concrete structures may be determined by using the simplified methods provided in EN 1994-1-2. For the particular situations not covered by the standard, an advanced calculation model might be applied, using special purpose programs for the analysis of structures in fire. The validation of these programs has always been an important issue for software developers, but also for designers and authorities. Clause 4.4.4 from EN 1994-1-2 refers to the validation of the advanced calculation models and states that these models must be validated through relevant test results. The paper presents the calculation of fire resistance of the composite columns in a high-rise building built in Romania, and focusses on the validation of the calculation model (computer program SAFIR), for this particular case. This validation, asked by the Romanian authorities, considers the available experimental results of a fire test, performed on a similar composite steel-concrete column.