Find the optimal strengthening core of compressed tube confined concrete elements

Purpose. To identify the best options for strengthening the core of compressed tube confined concrete elements. Methodology. The proposed algorithm for determining the most suitable design solutions for tube confined concrete elements with increased strength. It is based on a comparison of the effectiveness of the coefficients of samples To obtain experimental results that will enable to judge sufficiently on the operation characteristics of these elements in axial compression depending on how the core is strengthened the following groups of samples were designed and manufactured: a) samples of the of high-strength concrete cores; b) samples of core strengthened by longitudinal reinforcement. c) multi-core samples of various types. During experimental studies identified strength and stress-strain state of these samples. The analysis of the obtained values of the efficiency coefficients of studied samples is performed. It will give insight on the rationality of the use of a specific method. Findings. By reinforcing the core by different methods we can significantly increase both core strength and bearing capacity of the tube confined concrete element on the whole. But the effectiveness of the concrete core in this case is somewhat reduced. The highest rate coefficient of efficiency of the tube confined concrete in general mb.cf observed in cores annular section. And the highest rate coefficient of the performance concrete core ηb.cf observed in cores filled with high-strength concrete. In determining how to strengthen the core it must be taken when designing structures, it should be considered individually as a particular operation environment of the construction and its technical and economic properties. Originality. The proposed new structural forms of the tube confined concrete elements with reinforced cores. The influence of various design schemes to deformation, strength and effectiveness of tube confined concrete elements. Practical value. The propositions to determine the most optimal variants of core reinforcement of compressed tube confined concrete elements are given.