WO2022243589A1

WO2022243589A1 - System for structural connection at a later stage and method for connecting structures by means of said system

Info

Publication number: WO2022243589A1
Application number: PCT/ES2022/070296
Authority: WO
Inventors: Carles COTS COROMINAS
Original assignee: Concrete Rehabcco Slp
Priority date: 2021-05-15
Filing date: 2022-05-13
Publication date: 2022-11-24
Also published as: ES2928275A1; ES2928275B2

Abstract

The present invention relates to a system for structural connection at a later stage and method for connecting structures by means of said system, wherein the system comprises a plate-like support (3) incorporated in a reinforcement structure (4) and at least one screw (2) threaded into the support (3) that can be placed at different heights, maintaining the clearance between the screw (2) and the support (3) close to zero, and wherein the method comprises the steps of: placing the support (3) next to the existing concrete structure (1) to be repaired, flush with the support plate (3) on the side of the existing structure (1); generating a cavity (5) in the existing structure (1); threading in the screw (2) that is embedded in the cavity (5); restoring the cavity (5) such that the restored material (6) joins the concrete of the existing structure (1) with the support (3) with the screw (2).

Description

A POSTERIORI STRUCTURAL CONNECTION SYSTEM AND METHOD OF CONNECTION OF STRUCTURES THROUGH SAID SYSTEM

DESCRIPTION OBJECT OF THE INVENTION The invention, as expressed in the statement of this specification, refers to a structural connection system a posterior! and method of connecting structures by means of said system, contributing to the function for which it is intended, advantages and characteristics that are described in detail later and that represent an improvement of the current state of the art.

The object of the present invention falls, on the one hand, on a connection system, understood as a set of elements, which, essentially comprising a support in the form of a plate and a retractable screw inserted flush into it, is intended to allow power carry out the subsequent joining of structural elements, that is, existing elements, particularly reinforced, post-stressed or mass concrete structures, with a new reinforcing structure, which can be metallic or mixed or made of other materials, normally for the repair or rehabilitation of the existing structure, a second aspect of the invention being a connection method to carry out said connection between said structures using said connection system.

FIELD OF APPLICATION OF THE INVENTION The field of application of the present invention falls within the construction industry sector, focusing particularly on the field of connection systems between structures.

BACKGROUND OF THE INVENTION

It is common for structures built with concrete of any type to lose resistance capacity for any reason, either due to the increase in the loads to which it will be subjected, due to changes in the regulations required to continue developing its function or for any other reason. other deterioration or structural pathology suffered by the structure over time.

As an alternative to demolition and reconstruction, rehabilitation can be considered based on complementing the original structure with resistant additions that allow the extension of its useful life.

Examples of rehabilitations are:

In bridge structures, the connection between metal beams and concrete decks through connectors executed a posteriori.

In building structures, the subsequent execution of the connection between concrete slabs and metal beams under them.

The subsequent connection is usually made with different types of connectors, among which we can mention stud type connectors, T connectors and others.

The method used up to now is analogous to all types of connectors and consists of the demolition of the alveoli for the location of the connectors, the welded placement of the connectors in the alveoli connecting them The metal structure and the filling of the alveoli with a matrix with characteristics superior to those of the existing concrete.

The objective of the present invention is the development of a connection system and method between said existing structures to be repaired or reinforced and the structures or reinforcement elements improved in several aspects, especially in its adaptability to all types of structures, with or without armor.

On the other hand, as closest documents in reference to the current state of the art, it is worth mentioning the following:

-- Patent JPS598813A, referring to an "ANCHOR CONSTRUCTION METHOD OF INTEGRATING CONCRETE, EPOXY RESIN AND STEEL MATERIAL WHEN BRIDGE BEAM REINFORCING STEEL MATERIAL IS ADHERED UNDER PRESSURE" However, unlike the system and method object of the present invention, this method provides for the use of through bolts with the head of the bolt on the outside of the plate and, furthermore, for fixing it, an alveolus is not made to clean up the part of the concrete structure to be repaired.

- Patent JP2011202419A, referring to a "STRUCTURE AND METHOD FOR JOINING SHAFT MEMBER AND RC MEMBER" which, unlike the system object of the present invention, is not a reinforcement support for the original concrete structure.

- Patent US2015167332, referring to a “REPAIR AND STRENGTHENING SYSTEM FOR REINFORCED CONCRETE STRUCTURE. In this case, unlike the system of the present invention, it does not contemplate the use of retractable screws and, therefore, it is not adaptable to the shape of the alveolus or the framework.

- Patent US2019153728, referring to a "CONCRETE STRUCTURE USING REINFORCING PANEL INCLUDING EMBEDDED REINFORCING GRID AND METHOD OF REPAIRING AND REINFORCING THE SAME", unlike the system object of the present invention, the joining of the piece is done through screws fixed to the original concrete structure.

- Patent W02007/009160A1, referring to a “SHEAR CONNECTOR FOR USE IN A CONCRETE AND STEEL STRUCTURE”.

- Patent US00531129A, referring to a “DECK REPLACEMENT SYSTEM WITH IMPROVED HAUNCH LOCK”.

EXPLANATION OF THE INVENTION

The a posteriori structural connection system and structure connection method by means of said system that the invention proposes are configured as the ideal solution to the aforementioned objective, with the characterizing details that make it possible and that distinguish them conveniently included in the final claims that accompany this description.

Specifically, what the invention proposes, as noted above, is a connection system, or set of connection elements, which, essentially comprising a support in the form of a plate and a screw inserted in said plate in a retractable manner, has as purpose to allow to carry out the union of an existing structural element, which can be reinforced concrete, post-tensioned or in mass, with a new reinforcement structure, which can be metallic or mixed, for example for the repair or rehabilitation of the existing structure, a second aspect of the invention being a connection method to carry out said union between said structures using said connection system .

For this, and more specifically, the a posteriori structural connection system object of the invention essentially comprises a support in the form of a plate, belonging to the new reinforcement structure, and at least one screw threaded to said support in a threaded hole. provided for this purpose, in such a way that the tip of the screw shank can be retracted and placed at different heights with respect to the support plate maintaining a near zero clearance between the screw and the support, since such near zero clearance is essential so that the support acts as structural reinforcement of the damaged concrete structure to be repaired.

For its part, the method of connecting existing concrete structures with new structural reinforcements by using the previously described connection system essentially comprises the following stages:

- The placement of the structure that integrates the support with at least one screw in a retracted position, that is to say with the tip of the screw without exceeding the plate, next to the existing concrete structure to be repaired, in such a way that the The tip of the screw is flush with the plate and on the side of the concrete structure to be repaired.

- Pouring of concrete, preferably by hydro demolition, until generating an alveolus in the concrete structure to be repaired. - Threading of at least one screw until it is embedded in the alveolus generated in the concrete structure to be repaired.

- Restitution of the removed concrete in the alveolus generated in the concrete structure to be repaired with the head of at least one screw inside said alveolus, in such a way that the restored material joins the concrete of the original structure with the support with the screw or threaded screws.

The fact that the screw is retractable, that is, that it can be retracted with respect to the plate, is important in order to be able to adapt to the shape of the alveolus generated, which sometimes exposes the reinforcement (in the case of reinforced concrete). , which prevents moving the screw towards the interior of the alveolus. To avoid this circumstance, the screw or screws of the connection system support can enter the alveolus in a direction perpendicular to the plate or with another azimuth and thus avoid running into the reinforcement.

Optionally, the method comprises a stage of provisionally fixing the support of the connection system to the concrete structure to be repaired in order to keep the plate in the desired position while the other stages are executed. This fixing is not the one that will offer structural resistance.

It is important to point out that the described method has the advantage that a structure can be repaired in stages with it. For example a beam. In this case, the support is placed along the entire length of the structure to be repaired with the screws retracted. Since it is not possible to make an alveolus in the entire area to be repaired because the structure is at risk, a first alveolus is made only in a small part, the screws corresponding to said part are screwed in, and concrete is poured with restitution material. Once dry, a second alveolus is made in the area adjacent to the first one, the screws corresponding to this new position are screwed in, the alveolus is concreted, and so on until the entire extension of the support is covered.

It should be noted that the restitution of the material removed to generate the alveolus in the existing concrete structure to be repaired can be done using micro-concrete, mortars, resins or grouts, in any case, such that they restore the same or greater resistance capacity that it had. the original concrete.

For its part, the threaded screw can be made of any material deemed appropriate.

And, in turn, the demolition or removal of material to generate the alveolus in the structure to be repaired can be carried out by any conventional method such as chipping, drilling, controlled explosion or another method, although, as previously indicated, Preferably, it will be by hydrodemolition.

On the other hand, although the connection system and method of the invention is designed for on-site execution, it can also be carried out in a prefabrication workshop for the rehabilitation of prefabricated structures.

Thus, the problem to be solved is to prolong the useful life of pre-existing structures and/or increase their resistance capacity through the joint work connection of said pre-existing structure and a new reinforcement addendum structure.

This connection between concrete and other structures for joint structural work provides a unique solution to solving the problems of rehabilitation, reinforcement and extension of the useful life of structures.

DESCRIPTION OF THE DRAWINGS

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, a set of drawings is attached to this specification, as an integral part thereof, in which, for illustrative purposes, and not limiting, the following has been represented: figure number 1 a.- Shows a schematic view in elevation and section of a stud-type connector in composite beams of bridges or buildings, as an example of the prior art; Figure number 1 b.- Shows a schematic view in elevation and section of a T-type connector in composite beams of bridges or buildings, as an example of the prior art; Figure number 1 c.- Shows a set of different types of connectors, according to the prior art; Figure number 2.- Shows a schematic view in elevation and section of an example of a structure to be rehabilitated and an example of the connection system object of the invention with the elements it comprises represented separately; Figures number 3-A, 3-B, 3-C, 3-D and 3-E.- Show, in respective schematic elevation and section views, the successive essential stages of the connection method, according to the invention; Y Figures number 4-A, 4-B and 4-G,- Show, in respective schematic sectional views, another example of the stages of the connection method, specifically for staggered repair of a structure,

PREFERRED EMBODIMENT OF THE INVENTION

In view of the described figures, and in accordance with the numbering adopted, it can be seen in them, in addition to some examples of the prior art, a non-limiting embodiment of the structure connection system! after the invention, e! which includes what is described in detail below.

Thus, looking at figure 1-A, an example of the use of a stud-type connector (a) for joining an existing structure (1) with a reinforcing structure (4) is observed. In figure 1-B, An example of the use of a T-type connector (b) is observed, also represented from the front and in profile, for joining an existing structure (1) with a reinforcing structure (4). While, in figure 1-C, different types of connectors (c) are observed, also according to the prior art,

For its part, as can be seen in figure 2, the connection system object of the invention, applicable for joining an existing concrete structure (1) to be repaired, which may or may not be reinforced concrete, with a structure supplementary reinforcement (4), which can be metallic or mixed, essentially comprising a support (3) in the form of a plate, incorporated into the reinforcement structure (4), and at least one screw (2) threaded to said support (3) in a threaded hole (3a) provided for this purpose in the plate constituting the support (3), in such a way that the tip (2a) of! screw stem (2) can be retracted and positioned at different heights with respect to the support plate (3) maintaining a clearance close to zero between the screw (2) and the support (3).

The screw (2) can be metallic, or made of reinforced polymer with or without fibers of any type or ceramic.

The support plate (3) is preferably a metallic or fiber-reinforced polymer sheet of any type, belonging to and integral with the supplementary reinforcement structure (4).

Looking at figures 3-A to 3-E, it can be seen how the connection method of the existing concrete structure (1) with the supplementary reinforcement structure (4) by means of the described connection system essentially comprises the following stages:

- The placement of the reinforcement structure (4) that integrates the support (3) with at least one screw (2) in a retracted position, that is, with the tip (2a) without exceeding the plate (figure 3-A ), and next to the existing concrete structure (1 } to be repaired, in such a way that the tip (2a) of the screw (2) is flush with the support plate (3) and on the side of the existing structure ( 1) of concrete in the area to be repaired (figure 3-B).

- Emptying of concrete, preferably by means of hydrodemolition, until generating an alveolus (5) in the existing concrete structure (1) to be repaired (figure 3-C).

- Threading of at least one screw (2) until it is embedded in the alveolus (5) generated in the existing concrete structure (1) to be repaired (figure 3-D). - Restitution of the concrete removed in the alveolus (5) generated in the existing concrete structure (1) to be repaired with the head (2a) of at least one screw (2) inside said alveolus (5), in such a way that The restored material (6) joins the concrete of the existing structure (1) with the support (3) with the screw (2) or threaded screws.

The screw (2) or screws of the support (3) of the connection system can penetrate the alveolus (5) in a perpendicular direction to the plate of said support (3) or with another azimuth and to avoid running into the armor that, in In the case of reinforced concrete, it can present said alveolus (5).

Optionally, although it has not been represented in the figures, after the stage of placing the support (3), the method comprises a stage of provisional fixing of the support (3) to the existing concrete structure (1) to be repaired to maintain the plate in the desired position while the other steps are executed.

Optionally, the restored material (6) that is incorporated instead of the removed material to generate the alveolus (5) in the existing concrete structure (1) to be repaired can consist of micro concrete, mortars, resins, such as to restore equal to or greater than the resistance capacity of the original concrete and are compatible with said concrete.

And, in turn, the removal of material to generate the alveolus (5) in the existing structure (1) to be repaired can be carried out by hydrodemolition or another conventional method such as chipping, drilling, controlled explosion. Finally, the method can be executed repetitively in some stages to repair an existing structure (1), for example a beam, in a staggered manner, in such a way that, after the stage of placing the support (3) along the entire length of the existing structure (1) to be repaired with the screws (2) retracted, a first alveolus (5) is made only in a small part, the screws (2) corresponding to said part are threaded, concrete is poured with restitution material and, once hardened, a second alveolus is made (5) in an area adjacent to the first one, the screws (2) in said area are screwed in, the alveolus (5) is concreted, and so on until the entire extension of the support (3) is covered. Figures 4-A, 4-B and 4-C show an example of what has been said.

Having sufficiently described the nature of the present invention, as well as the way of putting it into practice, it is not considered necessary to make its explanation more extensive so that any expert in the field understands its scope and the advantages derived from it.

Claims

1 Rear structural connection system! which, applicable for joining an existing concrete structure (1) to be repaired, which may or may not be reinforced concrete, with a supplementary reinforcement structure (4), which may be metallic or mixed, is characterized by comprising a support (3) in the form of a plate, incorporated into the reinforcing structure (4), and at least one screw (2) threaded to said support (3) in a threaded hole (3a) provided for this purpose in the plate constituting the support (3) in such a way that the tip (2a) of the shank of the screw (2) can be retracted and placed at different heights with respect to the support plate (3) maintaining a clearance close to zero between the screw (2) and the support (3).

2.- A posterior structural connection system!, according to claim 1, characterized in that the screw (2) is metallic or reinforced polymer with or without fibers of any type or ceramic,

3.- Rear structural connection system!, according to claim 1 or 2, characterized in that the support plate (3) is a metal sheet or polymer reinforced with fibers of any type, belonging to and integral with the supplementary reinforcement structure (4).

4. Method of connecting structures, by means of a connection system as described in claims 1 to 3, characterized by comprising the following stages:

- Placing the reinforcing structure (4) that integrates the support (3) with at least one screw (2) in a retracted position and next to the existing concrete structure (1) to be repaired, in such a way that the tip (2a) of screw (2) is flush with support plate (3) on frame side existing (1) concrete in the area to be repaired;

- emptying of concrete until generating a cell (5) in the existing structure (1) of concrete to be repaired;

- Threading of at least one screw (2) until it is embedded in the alveolus (5) generated in the existing concrete structure (1) to be repaired;

- Restitution of the concrete removed in the alveolus (5) generated in the existing concrete structure (1) to be repaired with the head (2a) of at least one screw (2) inside said alveolus (5), in such a way that the restored material (6) joins the concrete of the existing structure (1) with the support (3) with the screw (2) or threaded screws;

5. Method of connecting structures, according to claim 4, characterized in that, after the stage of placing the support (3), it comprises a stage of provisional fixing of the support (3) to the existing concrete structure (1) to be repaired. to keep the plate in the desired position while the other stages are executed,

6. Method of connection of structures, according to claim 4 or 5, characterized in that the restored material (6) that is incorporated instead of the removed material to generate the alveolus (5) in the existing concrete structure (1) existing at to repair is micro concrete or mortars or resins, which restore the same or greater resistance capacity than the original concrete and are compatible with said concrete.

7.- Structure connection method, according to any of claims 4 to 6, characterized in that the removal of material to generate the alveolus (5) in the existing structure (1) to be repaired is carried out by hydrodemolition.

8. Method of connecting structures, according to any of claims 4 to 6, characterized in that the removal of material to generate the alveolus (5) in the existing structure (1) to be repaired is carried out by means of chipping, drilling or controlled explosion.

9. Method of connecting structures, according to any of claims 4 to 8, characterized in that after the step of placing the support (3) along the entire length of the existing structure (1) to be repaired with the screws (2) retracted , the following steps are carried out repetitively to repair an existing structure (1) in a staggered manner.