scholarly journals Study on Large Eccentric Compression Resistance of Steel Fiber Recycled Concrete Columns

2018 ◽  
Vol 07 (03) ◽  
pp. 313-320 ◽  
Author(s):  
丹丹 程
2021 ◽  
pp. 136943322110093
Author(s):  
Zhenzhen Liu ◽  
Yiyan Lu ◽  
Shan Li ◽  
Jiancong Liao

A comprehensive study of the shear characteristics of steel fiber reinforced recycled concrete-filled steel tube (SRCFST) columns is conducted. 50 CFST stub columns are tested with the variables of steel tube diameter-thickness ratio ( D/t), shear span-to-depth ratio (λ), axial compression ratio ( n), and concrete mix. Two types of cements, three recycled aggregate percentages, three water-cement ratios, and three steel fiber contents are considered in design of concrete mixes. The experimental results show that SRCFST columns present the coincident shear behavior of the ordinary CFST columns. As λ is increased, shear resistance shows a downtrend, while the flexural strength presents an increasing trend. Imposing axial compression or thickening steel tube contributes to an adequate safety margin in plastic period. Based on the contributions superposition method, a predicted model of the shear capacity of SRCFST columns is proposed in consideration of shear-span ratio, axial compression, and self-stress.


2020 ◽  
Vol 23 (10) ◽  
pp. 2018-2029
Author(s):  
Hongbing Li ◽  
Fangbo Wu ◽  
Liangtao Bu ◽  
Yong Liu ◽  
Jiang Yao

In this study, the mechanical properties and failure characteristics of steel reactive powder concrete columns with different strength grades were investigated through compression testing. Six steel reactive powder concrete columns were tested; three columns underwent axial compression testing and three columns underwent eccentric compression testing. The results of the axial compression testing showed that steel and reactive powder concrete could work cooperatively at the initial stage, and the final column failure mode was primarily splitting failure at the end of the column, with the formation of a main crack in the longitudinal direction extending to the middle of the column. The results of the eccentric compression testing showed that the eccentrically loaded steel reactive powder concrete columns had comparatively strong deformability. The columns presented ductile failure mode under the eccentric load with 0.2 eccentricity. The final failure of the column involved a sudden increase in the horizontal crack width on the tension side, the steel flange on the tension side reached the yield state, the reactive powder concrete in the middle of the compressive side was crushed, and the reactive powder concrete surface layer burst open and partially spalled off. According to the test results and with reference to the relevant standards, equations for calculating the approximate ultimate bearing capacities of axially and eccentrically compressed reactive powder concrete columns were proposed.


2020 ◽  
Vol 24 (1) ◽  
pp. 25-41
Author(s):  
Weichang Pei ◽  
Daiyu Wang ◽  
Xuan Wang ◽  
Zhenyu Wang

Fiber-reinforced polymer tube–confined steel fiber–reinforced concrete column is a novel composite column proposed recently, which consists of a traditional steel-reinforced concrete column and an external glass fiber–reinforced plastic tube for lateral confinement. In order to investigate the axial compression behavior of steel fiber–reinforced concrete columns, a total of 16 square specimens were fabricated and tested under axial monotonic and cyclic compressive loading. Three different configurations of inner shaped steels, including cross-shaped, box-shaped with wielding, and box-shaped without wielding were considered. Two thicknesses of glass fiber–reinforced concrete tubes were also considered as the main experimental parameters. On the basis of test results, a thorough analysis of the failure process based on strain analysis was discussed. The test results showed that steel fiber–reinforced concrete columns exhibited higher ductility and load capacity compared with fiber-reinforced plastic–confined plain concrete columns. Two quantitative indexes were proposed to measure the confinement of steel fiber–reinforced concretes. The axial cyclic mechanical behaviors were discussed through comparative analysis with monotonic behaviors. The remnant strains and modulus of the cyclic behaviors were also discussed.


2011 ◽  
Vol 71-78 ◽  
pp. 4203-4206
Author(s):  
Le Zhou ◽  
Hong Tao Liu

For the further study of bearing compressive capacity of GFRP tube filled with SHC(steel-reinforced high-strength concrete)columns subjected to eccentric compression, and analysis its whole bearing compressive process under eccentric compression. Based on the flat section assumption finite strip method, the calculating program of bearing eccentric compressive capacity of GFRP tube filled with SHC columns is proposed according to existing retrofit theory and related technical procedures. The relation curves of load-deformation is gotten using this calculating program, at the same time it can get the effect curves of concrete strength, slenderness ratio, eccentricity and containing bone rate to load-deformation. Calculations show that the ultimate bearing compressive capacity of composite column decreases with the increase of slenderness ratio, and elastic stage of component curve gradually shortens and stiffness gradually loses; The ultimate bearing compressive capacity of composite columns decreases with the increase of eccentricity; component ductility improves; the ultimate bearing compressive capacity of composite columns increases with the increase of concrete strength. The calculated results agree well with the experimental results and this study provides a basis for practical design.


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