RU2211900C2 - Reinforcing unit - Google Patents

Abstract

FIELD: construction industry. SUBSTANCE: reinforcing unit is intended to compensate for loss of prestressing in fittings of building structures. Springy compensators carrying end anchors are placed in reinforcing unit along length of reinforcing unit and come in the form of hollow members of convex- concave closed contour. Concavities of each member are arranged in symmetry relative to longitudinal axis. Fitting between adjacent compensators is interwoven and bent along sinusoid for contact with concavity of each compensator. Elastoplastic inserts can be positioned in cavities of members. EFFECT: raised bearing capacity of compensator, increased functional reliability under any kind of load, expanded application field of reinforcing unit. 1 cl, 12 dwg

Description

 The invention relates to the field of construction, namely to reinforcing elements intended for use in prestressed building structures.

 Known structural solution of the reinforcing element used to compensate for the loss of prestressing in the reinforcement of building structures made of low-modulus materials, containing expansion joints in the form of series of relaxation nodes installed at the ends of the prestressed reinforcement [1]. However, this technical solution does not provide a sufficient effect of prestressing the structure from prestressing reinforcement due to the small reactive forces of the relaxation nodes.

 The closest set of features to the invention is a reinforcing element for preserving the long-term effect of prestressing in the reinforcement, as well as in a structure made of low-modulus material, comprising a housing of a compensator for losses of prestressing in the reinforcement, the ends of which envelope elastic compensators sequentially located in the housing [2].

 In the known technical solution, elastic compensators in the form of successively installed spring-loaded rolling bodies interacting with prestressed reinforcement allow for a long-term preservation of the prestressing effect in the structure due to the summation of the reactive tensile forces of the longitudinal reinforcement.

 However, the use of such reinforcing elements in structures loaded with a dynamic or pulsating load is not possible due to the insufficient rigidity of the compensators for prestress losses in the reinforcement, their deformability under alternating oscillations, a certain “fluctuation” forms in the structure over time. The use of such reinforcing elements in prestressed bimodule structures, for example, steel-polymer concrete beams, as well as when reinforcing operating structures, causes great technological and structural difficulties in mounting the compensator body at the end sections of the structure.

 The problem to which the invention is directed, is to increase the bearing capacity of the compensator, ensuring its guaranteed reliability under all types of loads, as well as expanding the scope of its use.

 The technical result is achieved through the use of the elastic properties of hollow convex concave elements of a closed loop with significant elasticity and a non-linear nature of deformation, and due to non-linear deformation, the layout of alternating shapes of these elements along the length of the tensioned reinforcement, as well as the use of elastoplastic inserts in the cavities of convex concave elements, high damping properties that persist for a long time in both dynamic and pulse uyuschih loads.

 The essence of the invention lies in the fact that in the reinforcing element containing the reinforcement, which interacts with sequentially located elastic compensators for the loss of prestressing in the reinforcement, and the end anchor, elastic compensators are installed along the length of the reinforcing element having an additional end anchor and are made in the form of hollow convex-closed closed elements contours, the concavities of each of which are located symmetrically with respect to the longitudinal axis, while the reinforcement between the neighbor they are interlaced by compensators, bent along a sinusoid relative to the longitudinal axis with the possibility of contacting with the concavity of each compensator. Moreover, inserts of elastoplastic material can be placed in the cavities of the elastic convex-concave elements.

 The implementation of compensators for prestress losses in the form of hollow elements of a convex-closed closed loop, the concavities of which, having the possibility of contacting with the reinforcement, are symmetrically located relative to the longitudinal axis, allows one to obtain new properties in comparison with the known technical solution, consisting in the creation of sufficiently large reactive forces capable of maintaining prestressed reinforcement initially created tension forces and thereby compensate for voltage losses by Caused by creep and relaxation of both the base material of the structure and the reinforcement itself; Also, due to nonlinear deformation and the arrangement of alternating shapes of convex-concave elements along the length of prestressed reinforcement, as well as the use of inserts of elastoplastic material, high damping properties are created in the cavities of these loops that persist over time under dynamic or pulsating loads.

 In FIG. 1 shows a reinforcing element with compensators for prestress losses in reinforcement, general view; in FIG. 2, 3, 4 - embodiments of the reinforcing element with compensators in a perspective view; figure 5, 6, 7 - embodiments of the compensators, a General view and in a perspective view; in Fig.8 is a section along aa in Fig.1; figure 9 is a section along BB in figure 2; figure 10 is an embodiment of a reinforcing element provided with elastoplastic inserts placed in the cavities of the compensators; figure 11 is a section along bb in figure 10; on Fig - the same, for one of the options for the reinforcing element provided with elastoplastic inserts placed in the cavities of the compensators.

 The reinforcing element contains at least two longitudinal rods 1, which interact with other expansion joints 2 using end anchors 3. The elastic expansion joints 2 are made in the form of hollow elements of a convex concave contour, and the contour can be outlined, for example, in the form of four convex (concave) faces 4, three - 5, two convex (concave) faces 6. Elastic compensators 2 can be equipped with elastoplastic inserts 7 located in the cavities of the compensators 2.

 Assembly of the reinforcing element is as follows. At least two longitudinal reinforcing bars 1 are joined at the end sections by anchors 3. Then, at a certain section along the length of the reinforcing element between the rods 1, compensators 2 are installed so that their concavities are in contact with the rods 1, and the rods 1 in turn between adjacent compensators 2 must be mutually intertwined, that is, each individual reinforcing bar 1 is bent relative to the longitudinal axis of the reinforcing element along a sinusoid. Moreover, this principle of bending of the rods 1 is performed for the reinforcing element with any shape of the elastic compensators 2, regardless of the number of rods 1 and manufacturing options for reinforcing elements.

 The cavity of the elastic compensators 2 can be filled with an elastoplastic material 7 before installation between the reinforcing bars 1 or after the assembly of the reinforcing element, as well as before the creation of prestressing in the reinforcement of the building structure (not shown) or after the prestressing in the reinforcement.

 The reinforcing element operates as follows. To create a preliminary compression of a building structure (not shown), the reinforcing bars 1 are tensioned with a jack connected to the end anchor 3. When the reinforcing bars 1 are tensioned, the compensators 2 installed with a certain step along the reinforcing element begin to deform, as a result of which the reinforcing bars are additionally lengthen and acquire a powerful reactive force (potential energy) at the end anchors 3, interacting with a compressible building structure (not shown). A powerful reactive force at the end anchors 3 is formed by summing the reactive forces from each crimp compensator 2.

при А=0,028...0,2 (м);
Т*=0,5...3,0 (м),
где А - амплитуда;
Т* - длина полуволны.In the process of tensioning the reinforcing bars 1 for the end anchors 3, the compensators 2 begin to deform, since the reinforcing bars 1, curved in a sinusoid, compress the compensators 2 according to the function:

at A = 0.028 ... 0.2 (m);
T * = 0.5 ... 3.0 (m),
where A is the amplitude;
T * is the half-wavelength.

 The total reactive force at the end anchors 3, necessary for compressing the building structure, or rather, to create a prestress opposite in sign to the stresses from the external load, depends on the number of installed compensators 2. The magnitude of the total reactive effort can also be varied by placing in the cavities of the compensators 2 inserts 7 of elastoplastic material.

 After tensioning the reinforcing bars 1 to the required prestress value, they are fastened and fixed in the building structure (not shown) by known methods, which can significantly increase the load-bearing capacity of the structure, reduce its deformability and crack formation from external (static, dynamic, pulsating) loads.

 The decrease in the initial created reactive compression forces of the building structure, or rather, the shortening of the reinforcing bars, can occur due to creep of the material of the building structure, stress relaxation in the reinforcing bars 1, and other technological and operational factors. Compensators 2, made in the form of elastic elements of a convex concave closed loop, instantly respond to the deformability of prestressed reinforcing bars 1 and will for a long time preserve the specified effect of prestressing in the building structure. Due to the filling of the cavities of the compensators 2 with inserts 7 made of an elastoplastic material, the reinforcing element acquires additional advantages in comparison with the well-known technical solutions — increased damping properties, as a result of which the reinforcing element can be used as a damper for its intended purpose.

 The invention allows to increase and maintain the compression effect of building structures from low-modulus materials with long creep properties for a long time, while maximizing the use of the strength properties of prestressed reinforcement; reduce resonance phenomena from the action of mobile, pulsating, dynamic loads. It can be used in hanging building structures, in bridge spans, for equipment with vibrational phenomena, and other types of structures as dampers.

Sources of information
1. Auth. St. USSR 1244259, class E 04 C 3/18. Bull. 26, 1986.

 2. Auth. St. USSR 1268691, class E 04 C 5/08. Bull. 41, 1986.

Claims (2)

 1. The reinforcing element containing reinforcement, interacting with sequentially located elastic compensators for prestress losses in the reinforcement, and an end anchor, characterized in that the elastic compensators are installed along the length of the reinforcing element having an additional end anchor and are made in the form of hollow elements of a convex closed loop, concavity each of which is located symmetrically relative to the longitudinal axis, while the reinforcement between adjacent expansion joints is intertwined chickpea in a sinusoid relative to the longitudinal axis with the possibility of contacting with the concavity of each compensator.  2. The reinforcing element according to claim 1, characterized in that elastoplastic inserts are placed in the cavities of the elastic convex-concave elements.

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