Experimental Study Of Steel High-strength Reinforced Concrete Columns At Early Age

The application of high-strength concrete is more and more common in the construction engineering. When concrete structure is being constructed, the concrete is at early age and can’t meet design requirements of strength and other mechanical index. So, the structure is prone to safety and quality accident. The force on the concrete in the early stage will have a certain impact on the whole structure’s performance during the using stage. Therefore, study on mechanical behavior of high-strength concrete structural members at early age has a significant theoretical and practical value to the construction and the durability of reinforced concrete structure. The C80steel reinforced high-strength concrete columns under eccentric compression and axial compression are systematically studied through experimental, finite element simulation and theoretical research in this paper. The main content of this article is as follows:(1) Monotonic loading tests on7C80steel reinforced high-strength concrete columns under eccentric compression and4C80steel reinforced high-strength concrete columns under axial compression at early age were done to analyze bearing capacity, deformation characteristics, fracture distribution laws, failure pattern, etc. And then, the influence of early force on the later strength and stiffness of the column was concluded.(2) ABAQUS software was used to do simulation analysis. The results of finite element analysis about the stress of section steel, steel bars and concrete were in good agreement with the experimental results. Based on the results above, the influence of eccentricity, flange thickness of section steel and thickness of protective layer on ultimate bearing capacity of early age steel reinforced high-strength concrete columns was analyzed.(3) With the comparison of the theoretical calculation formula in "Technical specification for steel reinforced composite structures"(JGJ138-2001),"Technical Specification for Steel-Reinforced Concrete Structures"(YB9082-2006) and this paper, and the comparison of calculated results and test results, some design suggestions and the advice on the formula used for the calculation of normal section’s bearing capacity of early-age high-strength concrete column which was under axial compression were given in this essay.