scholarly journals Behaviour of FRP Confined Concrete Cylinders: Experimental Investigation and Strength Model

2016 ◽  
Vol 60 (4) ◽  
pp. 647-660 ◽  
Author(s):  
Mahfoud Touhari ◽  
◽  
Ratiba Mitiche-Kettab ◽  
Keyword(s):  
Experimental Investigation ◽  
Confined Concrete ◽  
Strength Model ◽  
Concrete Cylinders

The Effect of Confinement Method and Specimen End Condition on Behavior of FRP-Confined Concrete under Concentric Compression

2013 ◽  
Vol 351-352 ◽  
pp. 650-653 ◽  
Author(s):  
Thomas Vincent ◽  
Togay Ozbakkloglu
Keyword(s):  
Experimental Investigation ◽  
Cross Sections ◽  
Fiber Reinforced Polymer ◽  
Confined Concrete ◽  
Fiber Reinforced ◽  
Compressive Behavior ◽  
Stress Strain ◽  
Reinforced Polymer ◽  
Concrete Cylinders ◽  
Frp Tubes

This paper presents an experimental investigation on the influence of confinement method and specimen end condition on axial compressive behavior of fiber reinforced polymer (FRP)-confined concrete. A total of 12 aramid FRP (AFRP)-confined concrete specimens with circular cross-sections were tested. Half of these specimens were manufactured as concrete-filled FRP tubes (CFFTs) and the remaining half were FRP-wrapped concrete cylinders. The effect of specimen end condition was examined on both CFFTs and FRP-wrapped specimens. This parameter was selected to study the influence of loading the FRP jacket on the axial compressive behavior. In this paper the experimentally recorded stress-strain relationships are presented graphically and key experimental outcomes discussed. The results indicate that the performance of FRP-wrapped specimens is similar to that of CFFT specimens and the influence of specimen end condition is negligible.

Cyclic Behavior of Concrete Confined by Active and Passive Jackets

2010 ◽  
Author(s):  
Eunsoo Choi ◽  
Yeon-Wook Kim ◽  
Young-Soo Chung ◽  
Hong-Taek Kim ◽  
Baik-Soon Cho
Keyword(s):  
Shape Memory ◽  
Compressive Loading ◽  
Volumetric Strain ◽  
Confined Concrete ◽  
Cyclic Behavior ◽  
Temperature Hysteresis ◽  
Plastic Strains ◽  
Carbon Fiber Reinforce Polymer ◽  
Concrete Cylinders ◽  
Loading Tests

Shape memory alloy (SMA) wire jackets for concrete are distinct from the conventional jackets of steel or FRP since they provide active confinement that can be easily archived due to the shape memory effect of SMAs. This study uses NiTiNb SMA wires of 1.0 mm diameter to confine concrete cylinder with the dimension of 300 mm × 150 mm (L × D). The NiTiNb SMAs have a relative wider temperature hysteresis than NiTi SMAs and, thus, are more applicable for severe temperature-variation environment which civil structures are exposed to. Steel jackets of passive confinement are also prepared to compare the cyclic behavior of active and passive confined concrete cylinders. For this purpose, monotonic and cyclic compressive loading tests are conducted to obtain axial and circumferential strain. The both of strains are used to estimate volumetric strains of concrete cylinders. Also, plastic strains from cyclic behavior are also estimated. For the NiTiNb SMA jacketed cylinders, the monotonic axial behavior differs from the envelope of cyclic behavior; this should be studied in future. The plastic strains of the active confined concrete show a similar trend to those of the passive confinement. The trend of plastic strain of this study does not match with that of CFRP (Carbon Fiber Reinforce Polymer) jackets. For the volumetric strain, the active jackets of the NiTiNb SMA wires provide more energy dissipation than the passive jacket of steel.

scholarly journals Uniaxial Compressive Behavior of Concrete Columns Confined with Superelastic Shape Memory Alloy Wires

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1227 ◽  
Author(s):  
Chenkai Hong ◽  
Hui Qian ◽  
Gangbing Song
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Seismic Design ◽  
Large Deformations ◽  
Axial Loading ◽  
Concrete Columns ◽  
Confined Concrete ◽  
Loading Capacity ◽  
Compressive Behavior ◽  
Concrete Cylinders

Superelastic shape memory alloy (SMA) exhibits the ability to undergo large deformations before reverting back to its undeformed shape following the removal of the load. This unique property underlies its great potential in the seismic design and retrofitting of structure members. In this paper, superelastic SMA wires were utilized to confine concrete cylinders to enhance their axial compressive behavior. The axial carrying and deformation capacities of SMA-confined concrete cylinders are assessed by uniaxial compression testing on a total of eight SMA-confined concrete columns and one unconfined column. The influence of the amount of SMA and the prestrain level of SMA wires, as well as the reinforcing mode, on the axial carrying and deformation capacity of confined concrete columns were considered. The analysis focuses on the axial carrying capacity and deformation performance of concrete columns reinforced with superelastic SMA under different loading conditions. Based on the experimental data and analysis results, it is found that superelastic SMA wires can increase the axial loading capacity and enhance deformation performance of concrete columns. Under the same loading condition, the ultimate bearing capacity of SMA-confined concrete columns increases as the increasing of the amount of SMA wire. The results of this study verify the effectiveness of superelastic SMA in enhancing the loading capacity and deformation behavior of concrete cylinders.

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