Axial Compression Mechanical Behavior of Steel Tube Confined Steel-reinforced Concrete(SRC) Stub Columns
|Course||Bridge and Tunnel Engineering|
|Keywords||Tubed steel reinforced concrete columns Axial load carrying capacity Failure mode Shear failure Crushing damage|
Tubed steel reinforced concrete is thin-walled steel outsourcing in steel reinforced concrete columns, replaced with steel stirrups, steel does not directly bear vertical loads, constraints only play the role of core concrete. This paper on the circular tube confined concrete and steel high-strength steel square tube confined high strength concrete axially loaded members were studied and theoretical analysis, specific tasks are as follows: (1) to pipe diameter to thickness ratio and yield strength steel for the main parameters a 11 round steel tube confined axially loaded high strength concrete Experimental Research. The results obtained in this study section within the component failure mode can not be changed. This paper analyzes the same pipe diameter to thickness ratio and yield strength of two kinds of parameters pipe of circular tube confined high strength concrete steel stub columns bearing capacity, ductility, the loading process of the steel stress change, peak load point pipe stress state. Through the test, the specimen obtained in the axial direction of the pressure (kN) and the test piece longitudinal strain (ε) of the curve. The results showed that: the peak specimens in each group were outsourced steel yield point; pipe diameter ratio of the bearing capacity of the specimen had no significant effect; same component mode conditions, high yield strength steel specimens compared with axial bearing capacity high, but the steel yield strength and ductility of the elastic stiffness of the component had no significant effect; With the radius to thickness ratio increase, the ductility decreased. (2) to thickness ratio of the steel pipe, steel pipe aspect ratio as the main parameters of the 12 square tube confined concrete stub columns SRHC Experimental Research. The results show that the high strength concrete and steel pipe is relatively large in the case generous, simply change the tube member can not change the aspect ratio of component failure modes. The presence of steel in the range studied in this paper can not change component failure modes. Through the test, the specimen obtained in the axial direction of the pressure (kN) and the test piece longitudinal strain (ε) of the curve, the test piece of steel in each group the aspect ratio of the capacity of the specimen and the same member of mode conditions, the pipe thickness ratio increased influence on the ductility. (3) step by step according to the test loads determined in the longitudinal outer surface of steel ring strain and strain through stress analysis, the pipe in the test piece when the peak load point is the tube longitudinal stress, hoop stress and the steel tube core concrete confining force, will be in a complex stress state of the steel and concrete of the overall work performance unbundled, steel tube and core concrete interaction relations have been more clear and profound understanding. (4) using the Mohr - Coulomb theory obtained by a member of the shear strength of the formula, and the use of concrete crushing theory obtained by crushing capacity of the member formula, two kinds of formula results are in good agreement with the experimental results, of steel tube confined high strength concrete provides a basis for engineering application.