scholarly journals Long-Term Creep and Shrinkage Behavior of Concrete-Filled Steel Tube

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 295
Author(s):  
Doan-Binh Nguyen ◽  
Wei-Sheng Lin ◽  
Wen-Cheng Liao
Keyword(s):  
Stress Transfer ◽  
Shrinkage Strain ◽  
Steel Tube ◽  
Vertical Stress ◽  
Concrete Core ◽  
Concrete Filled Steel Tube ◽  
Structural Applications ◽  
Term Creep ◽  
Creep And Shrinkage

A concrete-filled steel tube (CFT) combines the advantages of concrete and steel in construction and structural applications. However, research on the time-dependent deformation of the CFT under long-term sustained loading are still limited, particularly for stress transfer between the steel tube and concrete due to creep. This study investigated the creep behavior of CFT over a long period of 400 days. The creep and shrinkage strain of CFT was significantly lower than those of concrete that was not confined within a steel tube. The vertical strains of the steel tube and concrete core were almost identical, and it was shown that they were well bonded and acted as a composite. The vertical stress of steel increased by 32.7%, whereas the vertical stress of concrete decreased by 15.8% at 375 days. The stress transfer is notable and cannot be neglected in CFT design. Moreover, the results of creep and shrinkage were compared to prediction values of the B4 model and B4-TW model to verify their validity.

Experiment Study on Cyclic Behavior of Concrete Filled Steel Tube (CFST) Column-Reinforced Concrete (RC) Beam Connections

2009 ◽  
Vol 417-418 ◽  
pp. 833-836 ◽  
Author(s):  
Qing Xiang Wang ◽  
Shi Run Liu
Keyword(s):  
Reinforced Concrete ◽  
Tube Wall ◽  
Plastic Hinge ◽  
Steel Tube ◽  
Reinforced Concrete Beams ◽  
Cyclic Behavior ◽  
Concrete Core ◽  
Concrete Filled Steel Tube ◽  
Steel Bars ◽  
Moment Resisting

The test results of six connections under cyclic loading are presented in the paper. Each test specimen was properly designed to model the interior joint of a moment resisting frame, and was identically comprised of three parts that including the circular concrete filled steel tube columns, the reinforced concrete beams, and the short fabricated connection stubs. Energy dissipation was designed to occur in the beams during a severe earthquake. Steel bars which were embedded into concrete core and welded to the connection stubs, were used to transfer the force distributed by the reinforcing bars of concrete beam to the concrete core. The results indicated that the embedded steel bars were very efficient in eliminating the stress concentration on the tube wall and there was no visible deformation occurred on the tube wall until the collapse of the specimen. Furthermore, the connection of each specimen had enough capacity and thus the plastic hinge appeared in the beams. As results, the ductility of this new type structure directly depended on the RC beams.

On Deformation Charting for Concrete Filled Steel Tube Columns Concrete Core and Steel Shell

2018 ◽  
Vol 878 ◽  
pp. 126-131 ◽  
Author(s):  
Anatoly L. Krishan ◽  
Elvira P. Chernyshova ◽  
Rustam R. Sabirov
Keyword(s):  
Steel Tube ◽  
Steel Shell ◽  
Concrete Core ◽  
New Approach ◽  
Concrete Filled Steel Tube ◽  
The Real ◽  
Side Pressure ◽  
Core Function ◽  
Cfst Columns ◽  
Major Factors

New approach to creating deformation charts for concrete core and steel shell of round CFST columns is offered. For creating such charts the power resistance of short central the compressed concrete filled steel tube element is considered. At the same time two major factors are considered. First, the steel shell and the concrete core function under conditions of complex tension. Secondly, at step-by-step strengthening of axial deformations the side pressure upon concrete core and steel shell constantly changes. As a result coordinates of parametrical points of deformation charts for concrete and steel change. Such approach allows describing the real intense deformed condition of concrete filled steel tube columns more precisely.

scholarly journals Bearing Capacity of Concrete-Filled Steel Tube Column Sections under Long-Term Loading

2019 ◽  
Vol 8 (10) ◽  
pp. 3530-3536
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Steel Tube ◽  
Design Methods ◽  
Contribution Ratio ◽  
Concrete Filled Steel Tube ◽  
Numerical Example ◽  
European Code

This article presents the design methods for concrete filled circular columns subjected to long-term axial compression and bending. . There are two approaches: stress-based and strain-based for formulations. Both approaches are specified in Russian Code, SP 266.1325800.2016, and in European Code, EN 1994-1-1:2004. A numerical example shows the procedures to calculate the strength of a given column according to two different Codes, the influence of parameters such as steel contribution ratio, relative slenderness to the results in two methods are consider.

scholarly journals The influence of physical ageing on the in-plane shear creep compliance of 5HS C/PPS

2019 ◽  
Vol 24 (2) ◽  
pp. 197-220
Author(s):  
E. R. Pierik ◽  
W. J. B. Grouve ◽  
M. van Drongelen ◽  
R. Akkerman
Keyword(s):  
Creep Compliance ◽  
Superposition Principle ◽  
Woven Fabric ◽  
Tensile Creep ◽  
Physical Ageing ◽  
Creep Response ◽  
Structural Applications ◽  
Term Creep ◽  
Over Time

Abstract Thermoplastic polymer-matrix composites, such as carbon woven fabric reinforced poly(phenylene sulphide) (C/PPS), are increasingly used in the aircraft industry. Primary structural applications, however, are limited due to uncertainty concerning the long-term behaviour. Recent work indicated a progressive creep response over time, which would render these materials unusable for such applications. However, the effect of physical ageing was neglected, which is well known to alleviate the creep behaviour and hence physical ageing is rigorously included in this study on the long-term creep response of C/PPS. Short-term tensile creep tests in the bias direction were performed at temperatures of 50, 60, 65, 70, 75 and 80$^{\circ}\mbox{C}$ C ∘ to obtain a master curve using the time–temperature superposition principle. Ordinary horizontal shifting failed to produce a smooth curve and therefore three alternative approaches were used and compared. The physical ageing rate was, however, characterised with horizontal shifting only at 50$^{\circ}\mbox{C}$ C ∘ and was implemented by means of the effective time theory (Struik, 1977) to correct the momentary master curves for the influence of physical ageing. The resulting predictions are more realistic and demonstrate that the structural changes in a material reduce the creep rate over time. Hence, the long-term creep compliance tends to increase asymptotically towards a finite value, in contrast to the unbounded momentary response.

Shrinkage Behavior of CFST Members Stored in Natural Environments

2017 ◽  
Vol 730 ◽  
pp. 418-422
Author(s):  
Wei Wei Lu ◽  
Yong Qing Yang
Keyword(s):  
Strain Difference ◽  
Shrinkage Strain ◽  
Steel Tube ◽  
Natural Environments ◽  
Concrete Shrinkage ◽  
Expansive Additive ◽  
Core Concrete ◽  
Shrinkage Behavior ◽  
Better Than

To provide reasonable guidance for CFST practical structures in design and construction, shrinkage test of concrete-filled steel tube (CFST) members in natural environments was presented. In order to acquire some knowledge regarding the influence of the interaction between the steel tube and core concrete during concrete shrinkage, ordinary concrete (OC) specimens exposed to the atmosphere were also performed in this test. The experimental results have been compared with predicted shrinkage strains obtained from the CEB-FIP1990 model, B3 model, GL2000 model, ACI 209 model. The research results show that the measured shrinkage strains of CFST specimens presents characteristics of seasonal variation under the influence of natural environments. Although expansive additive is added in the concrete mix, there is still strain difference between the steel tube and core concrete. The influence of steel ratio on the shrinkage behavior of CFST is unclear. The value of CFST shrinkage strain is about 50% of the OC shrinkage strain. For the early-age shrinkage of CFST, the predicted result by the ACI209 model is better than the other three models. The CEB-FIP1990 model is recommended to be used to predict the long-term shrinkage behavior of CFST.

Sign in / Sign up

Export Citation Format

Share Document