scholarly journals Concrete-encased CFST structures: behaviour and application

2018 ◽  
Author(s):  
Lin-Hai Han ◽  
Dan-Yang Ma ◽  
Kan Zhou
Keyword(s):  
Fire Resistance ◽  
Composite Structure ◽  
Dynamic Performance ◽  
Steel Tube ◽  
Major Research ◽  
Bond Performance ◽  
High Rise ◽  
Static Performance ◽  
Research Findings ◽  
Subway Stations

Concrete-encased CFST (concrete-filled steel tube) is a kind of composite structure comprised of a CFST component and a reinforced concrete (RC) component. The concrete encased CFST possesses superior ductility and higher stiffness. They are gaining popularity in high-rise buildings, large-span structures, bridges, subway stations and workshops. This paper initially reviews the recent research on concrete-encased CFST structures. The major research findings on bond performance, static performance, dynamic performance and fire resistance are presented. This paper also outlines some construction considerations, such as the utilization of materials, the fabrication of the steel tube, and the methods of casting the inner and outer concrete. Finally, some typical practical projects utilizing concrete-encased CFST members are presented and reviewed.

scholarly journals EXPERIMENTAL STUDY ON BEHAVIOR OF UNPROTECTED FOAMED CONCRETE FILLED STEEL HOLLOW COLUMN UNDER FIRE

2021 ◽  
Vol 12 (2) ◽  
pp. 189-202
Author(s):  
Bishir Kado ◽  
Shahrin Mohammad ◽  
Yeong Huei Lee ◽  
Poi Ngian Shek ◽  
Mariyana Aida Ab Kadir
Keyword(s):  
Fire Resistance ◽  
Applied Load ◽  
Fire Test ◽  
Lightweight Concrete ◽  
Steel Tube ◽  
Load Level ◽  
Exposure Test ◽  
Hollow Section ◽  
High Rise ◽  
Foamed Concrete

Reduction in self-weight and achievement of full fire resistance requirements are some of the important considerations in the design of high-rise structures. Lightweight concrete filled steel tube (CFST) column provides an alternative method to serve these purposes. Recent studies on lightweight CFST columns at ambient temperature have revealed that foamed concrete can be a beneficial and innovative alternative material. Hence, this study investigates the potential of using foamed concrete in circular hollow steel columns for improving fire resistance. A series of nine fire test on circular unfilled hollow and foamed concrete filled hollow section column were carried out. ISO 834 standard fire exposure test were carried out to investigate the structural response of these columns under fire. The main parameters considered are load level and foamed concrete density; foamed concrete density used are 1500 kg/m3 and 1800 kg/m3 at 15%, 20%, and 25% load level. All the columns tested are without any external fire protection, with concentrically applied load under fixed-fixed boundary conditions. The columns dimension was 2400 mm long, 139.7 mm diameter and steel tube thickness of 6 mm. The fire test result showed that foamed concrete increases the fire resistance of steel hollow column up to an additional 16 minutes. The improvement is more at load level above 15%, and the gain in fire resistance is about 71% when 1500 kg/m3 density foamed concrete is used. Generally, foamed concrete filled steel hollow column demonstrate a good structural fire behavior, based on the applied load and foamed concrete density. Also, inward local buckling was averted by filling the steel hollow column with foamed concrete. General method for composite column design in Eurocode 4 adopted to calculate the axial buckling load of 1500 kg/m3 foamed concrete filled columns.  These type of columns can be used for structures like airports, schools, and stadiums; taking the advantage of exposed steel for aesthetic purpose and high fire resistance. It can also be used for high rise structures; taking advantage of high fire resistance and reduction in self-weight of a structure.

Research Advances in Concrete Filled Steel Tube Connection Device

2015 ◽  
Vol 744-746 ◽  
pp. 230-234
Author(s):  
Hong Wei Ren ◽  
Jie Fang Tian ◽  
Qiu Ming Li
Keyword(s):  
Composite Structure ◽  
International Research ◽  
Steel Tube ◽  
Current Situation ◽  
Bridge Structure ◽  
Concrete Filled Steel Tube ◽  
High Rise ◽  
Advantages And Disadvantages ◽  
New Type ◽  
Theory And Experiment

Concrete filled steel tubular structure is a new type of composite structure, widely used in monolayer or multilayer industrial workshop structure column, frame column, all kinds of equipment support and super high-rise building and bridge structure, connection pipe attracted more research on its theory and experiment at home and abroad on the concrete force has carried on the preliminary summary, analysis of the advantages and disadvantages of concrete filled steel tube of various existing connection mode, and illustrates the current situation of domestic and international research on concrete filled steel tube are connected, and finally puts forward some problems in the study.

FIRE RESISTACE OF SHEAR CONNECTORS FOR COMPOSITE BEAMS

2020 ◽  
Vol 92 (6) ◽  
pp. 59-65
Author(s):  
G.P. TONKIH ◽  
◽  
D.A. CHESNOKOV ◽  
◽  
Keyword(s):  
Fire Resistance ◽  
Composite Structure ◽  
Composite Structures ◽  
Composite Beams ◽  
Design Codes ◽  
Connection Strength ◽  
Shear Connectors ◽  
Shear Connection ◽  
Capacity Reduction ◽  
Russian Research

Most of Russian research about composite structure fire resistance are dedicated to the composite slab behavior. The composite beams fire resistance had been never investigated in enough volume: the temperature evaluation within the scope of the actual Russian design codes leads to the significant reduction in the shear connection strength. Meanwhile, there no correlation between the strength decreasing and type of the shear connection. The article provides an overview of the relevant researches and offers some approaches which could take into account bearing capacity reduction of the shear connectors within composite structures design.

scholarly journals Post-fire resistance of concrete filled steel tube columns

2020 ◽  
Vol 988 ◽  
pp. 012036
Author(s):  
Ihssan A Alhatmey ◽  
Talha Ekmekyapar ◽  
Nadheer S Ayoob
Keyword(s):  
Fire Resistance ◽  
Steel Tube ◽  
Concrete Filled Steel Tube

Static and Dynamic Analysis for Tower in a High-Rise Steel Reinforced Concrete Composite Structure

2013 ◽  
Vol 788 ◽  
pp. 558-561
Author(s):  
Jian Qiang Wang ◽  
Wen Tao Ma ◽  
Min Jing Ma
Keyword(s):  
Reinforced Concrete ◽  
Composite Structure ◽  
Linear Time ◽  
Response Spectrum ◽  
Time History ◽  
Vibration Period ◽  
Small Earthquake ◽  
Steel Reinforced Concrete ◽  
Static And Dynamic Analysis ◽  
High Rise

Steel reinforced concrete composite structure which apply in the high-rise buildings, not only save steel, but also have excellent properties in fire prevention, anti-corrosion, and seismic performance, and improve the speed of construction, economic efficiency.This thesis based on the analyse of a steel reinforced concrete composite structure tower and the domestic and foreign experts study use Finite Element Analysis software SAP2000 analyze the dynamic Performance of the structure to draw the inherent vibration period and frequency of the structure. The structure is analyzed to obtain its deformation with different height of the structural elements under a small earthquake. Structure and component in elastic stage when suffur a small earthquake. Using the mode decomposition response spectrum method and method of linear time history analysis, the maximum horizontal displacements of the structural layer, the maximum inter-story displacement and the maximum inter-story displacement angle is obtained to see if the results within a predetermined range.

Influence of Ground Structure on the Seismic Response of Underground Subway Station in Soft Site

2011 ◽  
Vol 368-373 ◽  
pp. 2769-2775 ◽  
Author(s):  
Hui Long ◽  
Guo Xing Chen ◽  
Hai Yang Zhuang
Keyword(s):  
Seismic Response ◽  
Underground Structure ◽  
Outer Part ◽  
Subway Station ◽  
Analysis Model ◽  
Ground Structure ◽  
Element Analysis ◽  
High Rise ◽  
Underground Subway Station ◽  
Subway Stations

This paper selected representative soft site along the subway lines and created two-dimensional overall finite element analysis model about nonlinear dynamic interaction among soil, underground subway station, and ground structure based on Nanjing underground subway station. It explored the seismic response influence of neighboring high-rise structure on the two-layer and three-span island-type underground subway stations. The results showed that the structure near the subway station had a significant constraint effect on the deformation of subway station which is oriented to the structure, and the influence of deformation of subway station which is backward to the structure is related to vibration characteristics of the soil-underground structure interaction system. The influence of neighboring ground structure on the strain stress response of subway station is useful in most part of important nodes. However, this influence is disadvantageous in the outer part of connections of side walls and plates and middle plate-interior column connections.

scholarly journals Dynamic Analysis on RCC and Composite Structure for Uniform and Optimized Section

2021 ◽  
Vol 9 (12) ◽  
pp. 1114-1127
Author(s):  
Ankit Kumar
Keyword(s):  
Dynamic Analysis ◽  
Composite Structure ◽  
Composite Structures ◽  
Response Spectrum ◽  
Steel Structures ◽  
Seismic Zone ◽  
Dead Weight ◽  
Conventional Concrete ◽  
High Rise ◽  
Time Period

Abstract: This study examines the composite structure that is increasing commonly in developing countries. For medium-rise to high-rise building construction, RCC structures is no longer economical due to heavy dead weight, limited span, low natural frequency and hazardous formwork. The majority of commercial buildings are designed and constructed with reinforced concrete, which largely depends on the existence of the constituent materials as well as the quality of the necessary construction skills, and including the usefulness of design standards. Conventional RCC structure is not preferred nowadays for high rise structure. However, composite construction, is a recent development in the construction industry. Concrete-steel composite structures are now very popular due to some outstanding advantages over conventional concrete and steel structures. In the present work, RCC and steel-concrete composite structure are being considered for a Dynamic analysis of a G+25-storey commercial building of uniform and optimized section, located at in seismic zone IV. Response Spectrum analysis method is used to analyze RCC and composite structure, CSI ETABS v19 software is used and various results are compared such as time period, maximum storey displacement, maximum storey stiffness. Maximum storey shear and maximum stoey overturning moment. Keywords: RCC Structure, Composite Structure, Uniform Section, Optimized Section, Shear Connector, Time Period, Storey Displacement, Storey Shear, Storey Stiffness, Response Spectrum method, ETABS

scholarly journals Eye movements in vocabulary research

2021 ◽  
Author(s):  
Ana Pellicer-Sánchez ◽  
Anna Siyanova
Keyword(s):  
Eye Movements ◽  
Eye Tracking ◽  
Future Research ◽  
Auditory Input ◽  
Major Research ◽  
Research Gaps ◽  
Comprehensive Overview ◽  
Formulaic Sequences ◽  
Online Processing ◽  
Research Findings

Abstract The field of vocabulary research is witnessing a growing interest in the use of eye-tracking to investigate topics that have traditionally been examined using offline measures, providing new insights into the processing and learning of vocabulary. During an eye-tracking experiment, participants’ eye movements are recorded while they attend to written or auditory input, resulting in a rich record of online processing behaviour. Because of its many benefits, eye-tracking is becoming a major research technique in vocabulary research. However, before this emerging trend of eye-tracking based vocabulary research continues to proliferate, it is important to step back and reflect on what current studies have shown about the processing and learning of vocabulary, and the ways in which we can use the technique in future research. To this aim, the present paper provides a comprehensive overview of current eye-tracking research findings, both in terms of the processing and learning of single words and formulaic sequences. Current research gaps and potential avenues for future research are also discussed.

A High-Frequency Inverter Based on Double Closed-Loop Control

2012 ◽  
Vol 241-244 ◽  
pp. 509-512
Author(s):  
Lin Yang ◽  
Gen Wang Liu
Keyword(s):  
High Frequency ◽  
Closed Loop ◽  
Control Structure ◽  
Dynamic Performance ◽  
Current Loop ◽  
Closed Loop Control ◽  
Voltage Waveform ◽  
Loop Control ◽  
Static Performance ◽  
Frequency Inverter

In order to improve the dynamic performance of inverter and the output voltage waveform quality, the double-loop control combination with internal current loop and external voltage loop is introduced. The inner loop is used for improving the dynamic performance of the system and rapidly eliminating the effects of load disturbance; the outer loop is used for improving static performance of the system. In the end, MATLAB / Simulink is carried out to build the system model and prove the feasibility of the dual closed-loop control structure in this paper.

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