Study of joint work of shell and core of tube confined concrete elements with strengthened core

Abstract

At the present time, it is necessary to strengthen the economy mode, the resources efficiency and reduce the material consumption in construction. Modern building constructions must meet all the requirements of economy, resource conservation, which are required for construction. The main direction of their development is reducing the cost of steel (14-16%), saving cement (10-12%) and saving forest materials (12-14%). These tasks can be solved, including at the expense of reduction of material content and reduction of the cross-section of structures, due to the rational combination of concrete and steel in their joint work and through the use of high-strength materials. These requirements are satisfied with building constructions from tube confined concrete. With a relatively small cross-section, such structures can withstand significant efforts, while the concrete at the expense of a volumetric stressed state receives stresses that far exceed the prism strength, which saves steel and concrete. Applying high-strength concrete, concrete, compacted by pressing, centrifugation, it is possible to obtain significant cement savings, as due to industrial technological factors of sealing concrete mix significantly increases the concrete strength. It is possible to increase the concrete strength also due to the use of indirect reinforcement, which allows, at low cost of steel, to significantly increase the strength of structures. Improving the well-known effective methods of strengthening concrete in relation to tube confined concrete constructions with strengthened cores suitable for industrialization is an urgent and important task. The purpose of the research presented in this paper was the experimental study of tube confined concrete elements with reinforced in different methods concrete cores; the development of methods for calculating the carrying capacity and the stress-strain state of tube confined concrete elements with strengthened cores.