RU2543836C1 - Tube-concrete element of circular cross-section with prestressed shell - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: tube-concrete element of circular cross-section with prestressed shell, consisting of steel shell, prestressed or unstressed core inside the shell, besides reinforcement is coiled helically with tension along the outer surface of the shell.

EFFECT: increase of bearing capacity of tube-concrete element, metal saving.

2 dwg

Description

The invention relates to the construction and can be used in the design and construction of residential, public and industrial buildings, structures.

Known pipe element of circular cross-section, consisting of a steel shell and pre-squeezed or uncompressed concrete core inside the shell (Krishan A.L., Melnichuk A.S. Pipe-concrete columns of square section // Housing. 2012. No. 5. P. 19- twenty).

The disadvantages of the known design is that they can work only with small eccentricities of the application of longitudinal force, the bearing capacity quickly decreases with an increase in the eccentricity of the application of compressive load, the concrete used has significant shrinkage and Poisson's ratio lower than that of the steel sheath, which is why without prior compression of the concrete core, a violation of the joint work of the core and the shell during operational loads may occur. Due to the significant longitudinal deformation of the concrete element, the increased strength of the bulk concrete core is not fully used.

Technical results include increasing the bearing capacity of the concrete element, reducing its weight, saving metal, concrete, improving the working conditions of the concrete core and shell.

These technical results are achieved by the fact that on the outer surface of the shell of the pipe-concrete elements of circular cross section in a spiral with tension of the reinforcement.

The cage effect further increases the resistance of concrete to compression inside pipes. But due to shrinkage and different Poisson's ratios of concrete (0.18-0.24) and steel pipe (0.3), in a few years, ordinary concrete can peel off from the inner walls of the pipes. As a result, the adhesion of concrete to the inner surface of the pipes is broken. This can lead to a decrease in bearing capacity under operational loads. Preliminary compression of the shell eliminates the difference in the Poisson's ratios of concrete and the metal shell, increases its bearing capacity while saving metal, provides better joint work of the concrete core and the outer steel shell at operational loads.

Preliminary compression of the shell by winding prestressed reinforcement along the outer surface of the shell in a spiral is more convenient to do in the factory. As prestressed fittings, wire, ropes, tapes can be used. Depending on the requirements for the design, the prestressing reinforcement may or may not have a yield point.

The pipe-concrete element must be reliably protected from fire in case of fire (at a temperature of more than 200 ° C, the prestressing in the reinforcement disappears irrevocably).

The design of the pipe-concrete element of circular cross section with a prestressed shell is illustrated by drawings.

In FIG. 1 shows a longitudinal section 1-1 of a fragment of a pipe-concrete element of circular cross-section with a spiral reinforced tensile reinforcement. In FIG. 2 shows its cross section 2-2.

A pipe-concrete element of circular cross section with a prestressed shell consists of a prestressed shell 1, a pre-compressed or uncompressed concrete core 2 inside the shell, reinforcement 3 wound in a spiral with tension along the outer surface of the shell 1.

Claims (1)

A pipe-concrete element of circular cross section with a prestressed sheath, consisting of a steel sheath, a pre-crimped or uncompressed core inside the sheath, characterized in that the reinforcement is spiral-wound along the outer surface of the sheath in a spiral with tension.

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