Supervisor:
Southwest Ordnance Industry Bureau
Organizer:
Chongqing Ordnance Industry Society
Chongqing University of Technology
Chongqing University of Technology
Study on impact resistance of pre stressed confined concrete with a wedge tightened truncated cone
| DOI: | 10.11809/bqzbgcxb2023.06.001 |
| Keywords: | wedge tightened truncated cone; pre stress; confinement; concrete filled steel tube; drop hammer impact |
| Abstract: | A concrete filled steel tube has superior impact resistance. In order to improve the constraining effect of the steel tube on concrete at the elastic stage, this paper designs and prepares pre stressed confined concrete with a wedge tightened truncated cone, thereby completing the active pressure restraint of the steel tube to the concrete. The damage modes of the pre stressed confined concrete, the plain concrete and the conventional steel ferrule confined concrete are compared by using a six meter high drop hammer impact test, and the effect of the main parameters is analyzed. The results show that when the mean pre stress of the confined concrete specimen is greater than 1 MPa, the absorbed energy of the specimen when the initial visible cracks generate is 4 to 20 times that of the plain concrete and the steel ferrule confined concrete. This absorbed energy during the damage is much higher and even more than 40 times that of the plain concrete and the steel ferrule confined concrete. Compared with the damage pattern of the steel ferrule confined concrete, the pre stressed confined concrete has finer damage cracks and better integrity when it is being damaged, which can significantly improve the impact resistance of the high strength concrete. In order to effectively improve the impact resistance of the pre stressed confined concrete, the taper angle of the steel ferrule should not be greater than 3°; the impact resistance of the steel ferrule with a hexagonal truncated cone is better than that with a circle or a square truncated one. The proposed pre stressed confinement form of the wedge tightened truncated cone can be used to improve the impact resistance of a concrete filled steel tube, and can also be applied to protective door layers or bomb shielding layers. |
| Issue: | Vol. 44 No. 6 (2023) |
| Published: | 2023-06-28 |
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