WO2018020075A1 - Connection element for protecting against earthquakes - Google Patents

Connection element for protecting against earthquakes Download PDF

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Publication number
WO2018020075A1
WO2018020075A1 PCT/ES2017/070546 ES2017070546W WO2018020075A1 WO 2018020075 A1 WO2018020075 A1 WO 2018020075A1 ES 2017070546 W ES2017070546 W ES 2017070546W WO 2018020075 A1 WO2018020075 A1 WO 2018020075A1
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WO
WIPO (PCT)
Prior art keywords
connection element
bars
joint
concrete
structural
Prior art date
Application number
PCT/ES2017/070546
Other languages
Spanish (es)
French (fr)
Inventor
José Luis BONET SENACH
Javier PEREIRO BARCELÓ
Alberto NAVARRO GÓMEZ
Original Assignee
Universitat Politècnica De València
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Universitat Politècnica De València filed Critical Universitat Politècnica De València
Priority to MX2019001174A priority Critical patent/MX2019001174A/en
Publication of WO2018020075A1 publication Critical patent/WO2018020075A1/en
Priority to CONC2019/0001508A priority patent/CO2019001508A2/en

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
    • E04H9/00—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate
    • E04H9/02—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
    • E04H9/025—Structures with concrete columns
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D27/00—Foundations as substructures
    • E02D27/32—Foundations for special purposes
    • E02D27/34—Foundations for sinking or earthquake territories
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
    • E04H9/00—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate
    • E04H9/02—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
    • E04H9/021—Bearing, supporting or connecting constructions specially adapted for such buildings

Definitions

  • the present invention relates in general to the field of construction, and more specifically to protection against physical and economic damage to buildings due to seismic movements.
  • This paradigm shift modified the objective of the current seismic design based primarily on the ability of the structure to meet the intended purpose, taking into account the consequences of non-compliance.
  • four levels of behavior are defined depending on the importance of the earthquake (operational, immediate occupation, vital safety and non-collapse), where it is accepted from any type of damage to the total damage of the structure, yes, in In any case, the capacity must be ensured vertical of the structure with the objective of being able to dislodge it in safety conditions after a very rare earthquake.
  • Eurocode 8 of 2004, applicable to the project and construction of civil engineering buildings and works in seismic regions aims to ensure that, in case of earthquakes, human lives are protected, limit the damage and that the structures important for civil protection continue to operate.
  • WO2015100497 discloses a structural damping system suitable for seismic protection in which a jacket provides space for the insertion of SMA rods radially around an axis.
  • this system is relatively complex and expensive to manufacture and the results are not optimal because be an intrinsic part of the reinforced concrete structure of the building.
  • WO9857014 refers to an element to be incorporated into structures intended to modify the vibration frequency of the structure in order to protect its integrity against seismic movement. Said frequency modification is achieved by virtue of the fact that the structural element comprises a piece of shape memory alloy (SMA), which will modify its mechanical properties when external vibration such as that caused by an earthquake occurs. It is a complementary element that, in the absence of said external vibration, does not fulfill any function within the structure of the construction. Therefore it implies an additional cost in the construction of the final structure.
  • SMA shape memory alloy
  • JPH04317446 refers to a composite material in which metal fibers of different characteristics are embedded in concrete: steel in martensitic state, superelastic alloy, as well as shape memory alloys. Said incorporation of metallic fibers gives cement, mortar or concrete the ability to absorb vibrations to some extent. However, simply using such a composite material does not provide completely satisfactory results in terms of the protection of buildings and other constructions against seismic displacements.
  • the prefabricated support of the three models is executed in two phases in a general way.
  • a circular crown is manufactured, either with a conventional concrete at the PNC or GCDP type joints, or by means of an ECC concrete type of simple compressive strength 44 MPa (composed of polyethylene fibers, cement, fine aggregates, water and additives) for the union type HCS.
  • ECC concrete type of simple compressive strength 44 MPa composed of polyethylene fibers, cement, fine aggregates, water and additives
  • the support is longitudinally reinforced with steel bars that extend into the base.
  • the connection between the support and the foundation is made by pods in the foundation filled with ultra high performance concrete (UHPC), in which the steel bars protruding from the base of the support are embedded.
  • UHPC ultra high performance concrete
  • the HCS type model is similar to the PNC type, but incorporating ECC type concrete and form-shaped longitudinal alloy bars (SMA) in the "critical zone" of the support, without these SMA bars getting into the foundation.
  • SMA longitudinal alloy bars
  • the connection between the support and the foundation is made by pods in the foundation filled with ultra high performance concrete (UHPC), in which steel bars are embedded. Said steel bars of the foundation are attached to the SMA bars of the support by connectors.
  • UHPC ultra high performance concrete
  • a connector fixed inside the prefabricated crown of the support (of conventional concrete) and a pedestal made in situ at the base of the support are used.
  • the connection between the support and the foundation is made as follows: The steel bars from the foundation cross the pedestal (without being attached to the pedestal) and are inserted into the support connector, where they connect with the longitudinal bars of the support.
  • the main objective of the invention is to provide a connection element between structural elements that has a high turning capacity, low level of damage after an earthquake, is easy to repair and that gives the overall structure of the recent re-capacity. after the earthquake
  • connection element for the connection between structural elements, the connection element comprising:
  • Figure 1 shows schematically examples of arrangement of a connection element according to preferred embodiments of the invention.
  • Figure 2 shows two comparative graphs depicting the tensile stress strain ratio of an SMA type alloy bar employed in a preferred embodiment of the present invention and in a conventional steel rod.
  • Figure 3 shows two comparative graphs depicting the compression and tensile behavior of a conventional concrete, a high strength concrete and a concrete according to a preferred embodiment of the present invention.
  • Figure 4 shows two comparative graphs representing the drifts obtained with a connection element according to the preferred embodiment of the invention and with a conventional structure according to the prior art.
  • Figure 5 is a view of the preferred embodiment shown in Figure le, with the support attached to the foundation.
  • Figure 6 is a view of the preferred embodiment shown in Figure Id, with the support attached to the foundation.
  • the node shall be understood as "the meeting place between two or more elements constructive in a framework or structure.
  • the knot must be considered as a structural element.
  • stack means the intermediate support of bridges of two or more sections that serves to transmit the loads of the board to the foundation.
  • dasboard means the part of a bridge that directly supports the loads due to the traffic of vehicles or people and transmits them directly or indirectly to the piles, stirrups or walls.
  • support means the structural element of a building structure or industrial building that transmits the loads to the foundation.
  • critical zone the zone of the structural elements that is capable of housing a plastic kneecap.
  • intersection means the meeting surface between the connecting element and the node or other structural element to which it is connected. Said intersection defines a board.
  • the connecting element (1) disclosed has application for the connection of a structural element with another of any section, such as for example a beam with a support in a knot or a support with a foundation of any shape.
  • Figure 8 shows schematically 8 examples of application of the connecting element (1), specifically, the figure shows the connection between a support and an isostatic beam in a node, Figure Ib shows the connection between a support and a continuous beam with sheaths (8) in a knot, the figure shows the sheath type connection (8) between a prefabricated support and a foundation executed in situ, Figure Id shows the calyx type connection (9) between a prefabricated support and a foundation executed in situ, the figure shows the connection between beams and an inner support in the knot, the figure lf shows the connection between a beam and an external support in a knot, the figure lg shows the connection between the beam and a wall and the figure lh shows the connection of the top head of a stack and a board.
  • the connecting element (1) according to the present invention is represented between keys.
  • the bars of SMA (2) are arranged in the longitudinal direction of the structural element beam, support or stack.
  • the SMA bars (2) are arranged so that they cross the intersection between the connecting element and the node or other structural element that is connected.
  • the connecting element (1) can be inserted in any concrete structure, both created in situ and prefabricated.
  • the connection element (1) is arranged in the critical area of the linear structural element (beam, support, bridge stack, etc.).
  • the rest of the linear structural element can be manufactured with a concrete with lower performance than the critical area, in order to reduce the cost of the structural element, as long as its resistant capacity exceeds the criteria set in the corresponding regulations.
  • the length "L" of the connection element (1) will vary depending on the quality of the materials and the mechanical characteristics of the rest of the structure in which the earthquake protection connection element (1) is to be inserted as well as of the required ductility and the characteristics of the earthquakes representative of the region.
  • the connecting element (1) grants a great turning capacity to the area of the structure in which it is incorporated, with minimal damage (easily repairable) and with a capacity to re-structure the structure after the seismic event. All this is achieved thanks to the combination of two materials: concrete of very high or ultra high performance (VHPC or UHPC) (4) and longitudinal bars (2) of alloy with shape memory (SMA) and superelasticity at room temperature, arranged so that they cross the intersection between the connecting element and the knot or other structural element that connects (foundation, wall, board, etc.).
  • VHPC or UHPC concrete is only used in the critical area of the linear element (beam, support, pile, etc.), while the rest of the element can be manufactured with conventional concrete or other type of concrete.
  • the large turning capacity is achieved thanks to the great deformability of SMA. This great deformation could not be mobilized without a concrete with great strength and ductility.
  • Low damage is achieved because the VHPC or UHPC concentrates the damage in a single section (critical section). Said critical section can be placed in any section of the critical area of the element, including the intersection between the connecting element and the node or other structural element. For this reason, it is necessary for the SMA bar to cross said intersection. In figures 5 and 6 two embodiments can be seen with the SMA bars crossing the mentioned intersection. In advanced stages of loading, a large fissure occurs in the area subject to traction, which is joined by the SMA.
  • the invention is based on the combination of the SMA type material with the VHPC or UHPC type concrete (4).
  • an SMA-type material inserted in a conventional concrete would cause it to significantly deteriorate against cyclic loads, caused by an earthquake. Therefore, the great deformability capacity of the SMA could not be used as the energy dissipation is low, since it would hardly enter into the non-linear regime of these bars.
  • using VHPC or UHPC with conventional steel reinforcements has a lower rotational capacity of the patella, less ductility, greater damage and residual deformations, and consequently, a higher repair cost. In both solutions, the local non-buckling condition of the longitudinal reinforcement is not ensured, which limits the ductility and dissipation energy of the structure against earthquakes.
  • the longitudinal bars (2) of alloy (SMA) can be combined with reinforcing bars of fiber reinforced polymers (FRP), for example of glass or carbon fiber, or passive or active bars of conventional steel, in order to reduce the cost of construction.
  • FRP fiber reinforced polymers
  • the damage zone is increased, the self-centering capacity of the structure is reduced, the repair costs are higher and the structure shows a lower dissipation energy. Therefore, the optimal behavior from the point of view of self-centering (lower residual displacements), damage reduction, greater dissipation energy and lower repair costs are found when only longitudinal memory bars (2) with shape memory (SMA) are available in the connection element (1).
  • a conventional steel transverse reinforcement (3) will be provided in the connection element (1) to resist transverse stresses (for example, shear stress).
  • transverse stresses for example, shear stress
  • the amount of transverse reinforcement (3) is not important, which facilitates the commissioning of concrete. This transverse reinforcement (3) will improve the confinement effect of the arranged concrete and consequently its strength and ductility.
  • the earthquake protection connection element (1) according to a preferred embodiment of the invention comprises:
  • SMA shape memory
  • FRP fiber reinforced polymer reinforcement bars
  • connection element (1) connects to connection element (1) and the structural elements.
  • shape memory alloy bars have temperature superelasticity environment, which means that they can recover large deformations when the seismic action disappears.
  • the shape memory alloy of the bars can be selected, for example, from the group consisting of Ni-Ti, Ni-Ti-Nb, Ni-Ti-Cu, Ni-Ti-Fe, Cu-Al-Be, Cu-Al -Ni, Cu-Al-Zn, Mn base alloys and Fe base alloys. More preferably, the shape memory alloy of the bars is Ni-Ti, and even more preferably it is about 50% Ni-50% Ti.
  • the characteristics of the shape memory alloy are that it exhibits superelastity at room temperature, an end temperature of the austenitic transformation (Af) of approximately between -100 ° C and 20 ° C, a Young's modulus of approximately 10,000 - 240000 MPa, a direct tension f and of approximately 150-800 MPa and a transformation strain H of approximately 2-6%.
  • Af austenitic transformation
  • the connecting element (1) may include bars made of other materials such as fiber reinforced polymer bars (FRP), for example of glass or carbon fiber, or passive or active reinforcement of conventional steel.
  • FRP fiber reinforced polymer bars
  • the longitudinal reinforcements will connect the connection element (1) with the structural elements, will have continuity in the structural elements and in the connection element (1).
  • the person skilled in the art will select the most suitable combination according to the necessary performance. More preferably, if the minimum damage, the maximum dissipation energy, the maximum recovery and the minimum repair cost are required, the expert will only have SMA longitudinal bars (2) on the connecting element (1).
  • connection element (1) for earthquake protection.
  • Figure 2 shows the tension-strain strain ratio subjected to a cyclic load of an SMA type alloy bar according to the present invention (upper graph) and of a conventional reinforcing steel rod (lower graph). As can be seen in Figure 2, the residual deformations of the SMA bar are lower with respect to the conventional steel bar.
  • the SMA bars used in the stress-strain test above are Ni-Ti bars having a composition of approximately 50% Ni-50% Ti, super-elasticity at room temperature, an end temperature of the austenitic transformation ( Af) of about -8 ° C, a Young's modulus of about 65,000 MPa, a direct transformation voltage f and about 450-500 MPa and a transformation strain H of about 4%.
  • the concrete used in the connecting element (1) according to the preferred embodiment of the present invention has a very high resistance (between about 100 and about 200 MPa, more preferably between about 110 MPa and about 140 MPa) and a high content of metal fibers (greater than 1%).
  • VHPC very high performance
  • the connecting element (1) For the manufacture of the connecting element (1) according to the present invention it is necessary to manufacture a concrete with very high performance both in compression and in tension with a high content of steel fibers.
  • the range of concretes that have these benefits would go from 110 MPa onwards with a high content of steel fibers. Tests have been carried out with concrete of a lower quality, with steel fibers in their mass from 30 MPa to 80 MPa resulting in unsatisfactory results: greater damage to the piece, skipping of the coating and buckling of the bars due to loss of the coating of the concrete.
  • Figure 3 shows some graphs in which the compression (upper graphic) and tensile (lower graphic) behavior of a conventional concrete (resistance below 50 MPa), a high-strength concrete (between 50 and 80) can be compared MPa) and a concrete according to a preferred embodiment of the present invention (strength between 110 MPa and 140 MPa).
  • a notable difference in performance can be seen between the concrete of the preferred embodiment of the invention and the concrete of the prior art.
  • the step of pouring aggregates comprises pouring the following components into the next order: sand with a particle size of 0.8 rom, sand with a particle size of 0.4 rom, cement and densified silica fume.
  • the waiting and kneading times will vary depending on the type of kneader, the weather conditions and the volume of kneaded concrete.
  • connectors (5) To transmit the forces of conventional steel bars (7) of the structural elements that connect with the SMA bars (2) of the connecting element (1) connectors (5) must be used. These should be able to transmit the efforts without the bar sliding inside, without breaking any of the bars that join and without breaking the connector itself (5).
  • the connector (5) used is a threaded connector in which the thread of the bar will be made in the process of manufacturing it, in order not to modify the mechanical characteristics of the bar by overheating.
  • connection element (1) The groups of structural elements that are connected by means of the connection element (1) according to the present invention can be selected from the group consisting of support-foundation, foundation-pile, beam-foundation, beam-support, stack-board, wall-mount and beam-wall.
  • the structural elements that are connected by the connection element (1) according to the present invention are part of the selected groups in both civil works (eg, bridges) and building constructions. In addition, they can be part of both prefabricated and executed elements in situ.
  • the dry joint consists of direct contact between concrete, while the wet joint consists of a chemical bonding bridge between concrete.
  • the wet joint consists of a chemical bonding bridge between concrete.
  • the chemical bonding bridge in the case of the wet joint can be made by applying, for example, SiKaDur type resins or the like.
  • a joint (6) that is selected from the group consisting of a joint with continuity and a joint without continuity . Both options have been tested and it has been found that the behavior is different. If the seal (6) has no continuity, the critical section of damage occurs in the seal, which opens in the area under tension without causing damage. As for the compressed part, the quality of the concrete causes it to withstand huge compressions, the result of the high position of the neutral fiber due to the large turn that is concentrated in that section.
  • the joint (6) is materialized by concreting in two phases, so that there is a dry joint in a certain section. In this, the tensile strength provided by the metallic fibers of the concrete is dispensed with. This fact causes the maximum load reached to be less than in the case with continuous joint.
  • connection element (1) In joint embodiments without continuity there is no continuity in traction but in compression. That is, the steel fibers do not join the joint (6) of the connection between elements.
  • a specific embodiment of the connection element (1) according to the present invention without continuity in the joint is a sheath type connection (8) between a prefabricated support and an on-site foundation (figures le and 5).
  • the longitudinal and transverse reinforcement is mounted first on both the foundation and the support.
  • the sheaths (8) In the foundation the sheaths (8) are arranged that will serve to connect the prefabricated support with the foundation.
  • the SMA bars connected to the conventional steel bars (7) to be inserted in the foundation sheaths (8) are arranged on the underside of the support.
  • the continuity of the SMA (2) and conventional steel (7) type bars is guaranteed by the arrangement of the connectors (5), both in connection with the foundation and in the prefabricated support.
  • the Ni-Ti bars cross the intersection between the prefabricated support and the upper face of the foundation.
  • the foundation is manufactured on the one hand, and on the other hand the prefabricated support where the concrete is poured taking special care with the critical area of the support in which the Ni-Ti bar has been placed.
  • the connection between the prefabricated support and the foundation is made.
  • an expansive mortar suitable for anchors, fillings and leveling is used, for example of the Sika brand, of the Sika Grout type or similar.
  • a joint bridge of the type SiKaDur or similar can be placed on the joint (6).
  • connection without continuity in the joint (6) is a connection of a hybrid support with a beam in a node without continuity.
  • the longitudinal and transverse reinforcement of the lower support is mounted first.
  • the continuity of the SMA (2) and conventional steel bars (7) is guaranteed by the arrangement of connectors (5).
  • Ni-Ti bars cross the intersection.
  • the formwork of the support prior to the construction of the connecting element (1) (pouring concrete of the UHPC type independently of the rest of the element in the lower support) a concrete with lower performance is poured into the rest of the lower support (for example with a resistance of 80 MPa).
  • the joint (6) between both concrete of the support (H80-UHPC) there is a connecting bridge of the SikaDur type or similar.
  • concrete is poured into the node of the encounter between the lower support and the beam, as well as in the rest of the upper support and the beam. In this case, no joint bridge is available at the junction (6) of the intersection between the hybrid support and the node.
  • the damage zone is greater (the critical section can occur along the critical zone) since a crack occurs at the cost of breaking the tensile concrete , so that the damages are greater than in the case of no continuity of the joint (6), in which the cracking section had already been preformed in a controlled manner.
  • Compression damage is also slightly greater as it is an irregular breakage section caused by tensile damage. However, the maximum load supported in this case is greater.
  • a specific embodiment of the connecting element (1) according to the present invention with continuity in the joint (6) is a chalice type connection (9) between a prefabricated support and a foundation executed in situ ( Figures Id and 6).
  • the longitudinal and transverse reinforcement is mounted first, both in the prefabricated support and in the foundation.
  • the continuity of the SMA (2) and conventional steel bars (7) is guaranteed by the arrangement of connectors (5) arranged in the support prefabricated.
  • the foundation is manufactured. The foundation provides a recess with the same shape as the support and which will serve to insert the support into the foundation.
  • the concrete is poured into the prefabricated support, taking special care with the critical area of the support in which the Ni-Ti bars that are placed across the upper face of the foundation have been placed, once it has been placed the support. This face defines the intersection between the foundation and the prefabricated support. Finally, the connection between the support and the foundation is made (placement and filling of the hole by means of an expansive mortar of the Sika Grout type or similar).
  • connection with continuity in the joint (6) is a connection between a hybrid support and a beam in a knot with continuity.
  • the longitudinal and transverse reinforcement is mounted first on the lower support.
  • the continuity of the SMA (2) and conventional steel bars (7) is guaranteed by the arrangement of connectors (5).
  • Ni-Ti bars cross the intersection.
  • the formwork of the support and the manufacture of the lower support part with a concrete with lower performance (for example, a resistance of 80 MPa) is performed.
  • the UHPC type concrete according to the present invention is poured into the connection zone.
  • the joint (6) between both concrete of the support (H80-UHPC) there is a bridge of SikaDur type or similar.
  • the concrete is poured into the rest of the structure (knot, beam and upper support). In this case, this concrete is poured after pouring the concrete from the connecting element (1) according to the present invention, giving rise to traction continuity by means of steel fibers.
  • the residual drift after a seismic event in the connection element (1) according to the present invention is approximately 15% of the maximum drift, while with conventional structural elements it is approximately 80% of the maximum drift.
  • An additional advantage of the invention is that the manufacturing processes are substantially similar to the usual ones, therefore it can be applied in any construction, prefabricated or on-site, in civil works or buildings, and with any labor force.
  • connection element (1) presents some characteristics of the connection element (1) according to the present invention compared to some known solutions against earthquakes:

Abstract

The present invention relates to a connection element for protecting against earthquakes, for connecting structural elements, which comprises: longitudinal shape memory alloy (SMA) bars having superelasticity at ambient temperature and which are disposed such that they cross the intersection between the connection element and a node or other structural element that is connected; conventional steel transverse reinforcement; very-high performance concrete (VHPC) or ultra-high performance concrete (UHPC) in which the bars are embedded; connectors between the conventional steel bars of the structural elements and the bars of the connection element; and joints between the connection element and the structural elements.

Description

ELEMENTO DE CONEXIÓN DE PROTECCIÓN CONTRA SISMOS  PROTECTION CONNECTION ELEMENT AGAINST SISMS
Campo de la invención Field of the Invention
La presente invención se refiere de forma general al campo de la construcción, y más concretamente a la protección frente a daños físicos y económicos en las construcciones debido a movimientos sísmicos.  The present invention relates in general to the field of construction, and more specifically to protection against physical and economic damage to buildings due to seismic movements.
Antecedentes de la invención Background of the invention
Tradicionalmente, el diseño sísmico de estructuras tenía como objetivo la prevención de las vidas humanas respecto al colapso global o local de las estructuras frente a un terremoto. En los años 60, la "Asociación de Ingenieros Estructurales de California" (SEAOC) manifestó la importancia que tiene la evaluación del daño, tanto en elementos estructurales como no estructurales, en el diseño sísmico de estructuras. A pesar de ello, el diseño sísmico mantuvo los mismos criterios hasta los años 90. Así, los terremotos importantes sucedidos en EEUU y en Japón, a finales de los años 80 y principios de los 90, no significaron pérdidas de vidas importantes pero sí importantes daños y pérdidas económicas. En respuesta a estos hechos, surgió la "Ingeniería Sísmica basada en el Comportamiento" del documento "VISION 2000" publicado por la SEAOC en 1995, como la idea más importante en los últimos años en referencia al diseño sísmico o refuerzo de estructuras. Este cambio de paradigma modificó el objetivo del diseño sísmico actual basado sobre todo en la capacidad de la estructura para cumplir la finalidad prevista, teniendo en cuenta las consecuencias de su incumplimiento. En dicho documento se definen cuatro niveles de comportamiento en función de la importancia del terremoto (operacional, inmediata ocupación, seguridad vital y no colapso) , en donde se acepta desde ningún tipo de daño hasta el daño total de la estructura, eso sí, en todo caso hay que asegurar la capacidad vertical de la estructura con el objetivo de poder desalojarla en condiciones de seguridad tras un terremoto muy poco frecuente . Traditionally, the seismic design of structures was aimed at preventing human lives from the global or local collapse of structures in the face of an earthquake. In the 60s, the "Association of Structural Engineers of California" (SEAOC) expressed the importance of the evaluation of damage, both in structural and non-structural elements, in the seismic design of structures. Despite this, the seismic design maintained the same criteria until the 1990s. Thus, major earthquakes in the US and Japan, in the late 80s and early 90s, did not mean significant but important loss of life. economic damages and losses. In response to these facts, the "Seismic Engineering based on Behavior" of the document "VISION 2000" published by the SEAOC in 1995 emerged as the most important idea in recent years in reference to seismic design or reinforcement of structures. This paradigm shift modified the objective of the current seismic design based primarily on the ability of the structure to meet the intended purpose, taking into account the consequences of non-compliance. In this document four levels of behavior are defined depending on the importance of the earthquake (operational, immediate occupation, vital safety and non-collapse), where it is accepted from any type of damage to the total damage of the structure, yes, in In any case, the capacity must be ensured vertical of the structure with the objective of being able to dislodge it in safety conditions after a very rare earthquake.
En este sentido, el Eurocódigo 8 del 2004, aplicable al proyecto y la construcción de edificios y obras de ingeniería civil en regiones sísmicas, se plantea como objetivo de su aplicación el asegurar que, en caso de terremotos, se protejan las vidas humanas, se limite el daño y que las estructuras importantes para la protección civil continúen operativas.  In this sense, Eurocode 8 of 2004, applicable to the project and construction of civil engineering buildings and works in seismic regions, aims to ensure that, in case of earthquakes, human lives are protected, limit the damage and that the structures important for civil protection continue to operate.
El comportamiento de las estructuras convencionales calculadas en base al Eurocódigo 8 posee inconvenientes que el invento objeto de patente logra suplir. El daño resultante tras un evento sísmico de cierta entidad es elevado y se concentra en las conexiones entre elementos estructurales: el hormigón del recubrimiento estalla, las armaduras comprimidas de acero pandean y la zona de daño formada es muy grande. Como consecuencia, la reparación de estas estructuras, en los casos en que sea posible realizarla, es compleja y costosa. Es más, hay muchos casos en que la deriva residual que presenta la estructura es tal que se debe demoler. Por lo tanto, aspectos como el elevado daño tras un sismo, el coste de reparación, la nula capacidad de auto-recentrado de la estructura, representan unos graves inconvenientes que provocan que el coste del ciclo de vida de estas estructuras sea alto. Además, estas soluciones convencionales no permiten asegurar la funcionalidad de infraestructuras de especial importancia tales como centrales eléctricas, hospitales, suministradoras de agua, etc. después de un sismo.  The behavior of conventional structures calculated on the basis of Eurocode 8 has drawbacks that the invention object of the patent manages to replace. The resulting damage after a seismic event of a certain entity is high and is concentrated in the connections between structural elements: the concrete of the coating explodes, the compressed reinforcements of steel buckling and the area of damage formed is very large. As a consequence, the repair of these structures, in cases where it is possible, is complex and expensive. Moreover, there are many cases in which the residual drift presented by the structure is such that it must be demolished. Therefore, aspects such as the high damage after an earthquake, the cost of repair, the zero capacity of self-re-centering of the structure, represent serious inconveniences that cause the cost of the life cycle of these structures to be high. In addition, these conventional solutions do not allow to ensure the functionality of infrastructures of special importance such as power plants, hospitals, water suppliers, etc. after an earthquake
El documento WO2015100497 da a conocer un sistema de amortiguación estructural adecuado para la protección sísmica en el que una camisa da espacio para la inserción de unas varillas de SMA de forma radial en torno a un eje. Sin embargo, dicho sistema resulta relativamente complejo y costoso de fabricar y los resultados no resultan óptimos al no formar parte intrínseca de la estructura de hormigón armado de la edificación. WO2015100497 discloses a structural damping system suitable for seismic protection in which a jacket provides space for the insertion of SMA rods radially around an axis. However, this system is relatively complex and expensive to manufacture and the results are not optimal because be an intrinsic part of the reinforced concrete structure of the building.
El documento WO9857014 se refiere a un elemento a incorporar en estructuras destinado a modificar la frecuencia de vibración de la estructura con el fin de proteger su integridad frente a un movimiento sísmico. Dicha modificación de la frecuencia se alcanza en virtud de que el elemento estructural comprende una pieza de aleación con memoria de forma (SMA) , la cual modificará sus propiedades mecánicas al producirse una vibración externa como la causada por un terremoto. Se trata de un elemento complementario que, en ausencia de dicha vibración externa, no cumple función alguna dentro de la estructura de la construcción. Por tanto supone un coste adicional en la construcción de la estructura final.  WO9857014 refers to an element to be incorporated into structures intended to modify the vibration frequency of the structure in order to protect its integrity against seismic movement. Said frequency modification is achieved by virtue of the fact that the structural element comprises a piece of shape memory alloy (SMA), which will modify its mechanical properties when external vibration such as that caused by an earthquake occurs. It is a complementary element that, in the absence of said external vibration, does not fulfill any function within the structure of the construction. Therefore it implies an additional cost in the construction of the final structure.
El documento JPH04317446 se refiere a un material compuesto en el que están embebidas en el hormigón fibras metálicas de distintas características: de acero en estado martensítico, de aleación superelástica, así como aleaciones con memoria de forma. Dicha incorporación de fibras metálicas proporciona al cemento, mortero u hormigón la capacidad de absorber las vibraciones en cierta medida. Sin embargo, el uso simplemente de un material compuesto de este tipo no proporciona resultados totalmente satisfactorios en cuanto a la protección de edificaciones y otras construcciones frente a desplazamientos sísmicos.  JPH04317446 refers to a composite material in which metal fibers of different characteristics are embedded in concrete: steel in martensitic state, superelastic alloy, as well as shape memory alloys. Said incorporation of metallic fibers gives cement, mortar or concrete the ability to absorb vibrations to some extent. However, simply using such a composite material does not provide completely satisfactory results in terms of the protection of buildings and other constructions against seismic displacements.
Diversos investigadores han ido proponiendo nuevas soluciones constructivas para proporcionar mejores respuestas ante acciones sísmicas. Concretamente Mostafa Tazarv y M. Saiid Saiidi desarrollaron un proyecto experimental con el objetivo de proponer una nueva generación de pilas de puente que puedan ser construidas en un tiempo relativamente reducido (Accelerated Bridge Construction - ABC) y con una prestación sísmica igual o superior a la de una pila tradicional. Los investigadores publicaron una serie de documentos con información relativa al proyecto: Several researchers have been proposing new constructive solutions to provide better responses to seismic actions. Specifically Mostafa Tazarv and M. Saiid Saiidi developed an experimental project with the aim of proposing a new generation of bridge piles that can be built in a relatively short time (Accelerated Bridge Construction - ABC) and with a seismic performance equal to or greater than from a traditional pile. The researchers published a series of documents with information related to the project:
- Tarzarv M.; Saiidi Saiidi, M. (2015) "UHPC-filled duct connections for accelerated bridge construction of RC columns in high seismic zones" Engineering Structures, 99 (2015) 413-422.  - Tarzarv M .; Saiidi Saiidi, M. (2015) "UHPC-filled duct connections for accelerated bridge construction of RC columns in high seismic zones" Engineering Structures, 99 (2015) 413-422.
Saiidi Saiidi, M. (2015) "Highlights od Recent and Current Bridge Earthquake Engineering at UNR - A few Examples. Tazarv M., Saiidi Saiidi M. (2015) "Low-damage precast columns for accelerated bridge construction in high seismic zones". J Bridge Eng, ASCE, 2015.  Saiidi Saiidi, M. (2015) "Highlights od Recent and Current Bridge Earthquake Engineering at UNR - A few Examples. Tazarv M., Saiidi Saiidi M. (2015)" Low-damage precast columns for accelerated bridge construction in high seismic zones " J Bridge Eng, ASCE, 2015.
- Tazarv M., Saiidi Saiidi M. (2014) "Next Generation of Bridge Columns for Accelerated Bridge Construction in High Seismic Zones". Department of Civil and Environmental Engineering. University of Nevada, Reno. UNR/CCEER 14-06.  - Tazarv M., Saiidi Saiidi M. (2014) "Next Generation of Bridge Columns for Accelerated Bridge Construction in High Seismic Zones". Department of Civil and Environmental Engineering. University of Nevada, Reno. UNR / CCEER 14-06.
Tal y como expone este último documento, en este proyecto de investigación se comparó el comportamiento de una unión convencional entre un soporte realizado in situ y la cimentación, con el de tres nuevas soluciones (modelo tipo PNC, modelo tipo HCS y modelo tipo GCDP) para la unión de un soporte prefabricado con la cimentación, en las que se emplearon según el caso, diferentes tipos de materiales.  As this last document states, in this research project the behavior of a conventional union between a support made in situ and the foundation was compared with that of three new solutions (PNC type model, HCS type model and GCDP type model) for the union of a prefabricated support with the foundation, in which different types of materials were used as appropriate.
El soporte prefabricado de los tres modelos es ejecutado en dos fases de forma general. En primer lugar se fabrica una corona circular, bien con un hormigón convencional en las uniones tipo PNC o GCDP, o bien mediante un hormigón tipo ECC de resistencia a compresión simple 44 MPa (compuesto por fibras de polietileno, cemento, áridos finos, agua y aditivos) para la unión tipo HCS. Una vez se ha situado el soporte en la cimentación, se vierte un hormigón autocompactante en el núcleo de la sección para completar la sección maciza del soporte .  The prefabricated support of the three models is executed in two phases in a general way. First, a circular crown is manufactured, either with a conventional concrete at the PNC or GCDP type joints, or by means of an ECC concrete type of simple compressive strength 44 MPa (composed of polyethylene fibers, cement, fine aggregates, water and additives) for the union type HCS. Once the support has been placed in the foundation, a self-compacting concrete is poured into the core of the section to complete the solid section of the support.
En el modelo tipo PNC, el soporte está reforzado longitudinalmente con barras de acero que se extienden en la base. La conexión entre el soporte y la cimentación se realiza mediante vainas en la cimentación rellenas de hormigón de ultra altas prestaciones (UHPC) , en el que quedan embebidas las barras de acero que sobresalen de la base del soporte. In the PNC type model, the support is longitudinally reinforced with steel bars that extend into the base. The connection between the support and the foundation is made by pods in the foundation filled with ultra high performance concrete (UHPC), in which the steel bars protruding from the base of the support are embedded.
El modelo tipo HCS es similar al tipo PNC, pero incorporando hormigón tipo ECC y barras longitudinales de aleación con memoria de forma (SMA) en la "zona critica" del soporte, sin que dichas barras de SMA lleguen a introducirse en la cimentación. La conexión entre el soporte y la cimentación se realiza mediante vainas en la cimentación rellenas de hormigón de ultra altas prestaciones (UHPC) , en el que quedan embebidas barras de acero. Dichas barras de acero de la cimentación se unen a las barras de SMA del soporte mediante conectores.  The HCS type model is similar to the PNC type, but incorporating ECC type concrete and form-shaped longitudinal alloy bars (SMA) in the "critical zone" of the support, without these SMA bars getting into the foundation. The connection between the support and the foundation is made by pods in the foundation filled with ultra high performance concrete (UHPC), in which steel bars are embedded. Said steel bars of the foundation are attached to the SMA bars of the support by connectors.
En el modelo tipo GCDP se utiliza un conector fijado en el interior de la corona prefabricada del soporte (de hormigón convencional) y un pedestal realizado in situ en la base del soporte. La conexión entre el soporte y la cimentación se realiza de la siguiente manera: Las barras de acero provenientes de la cimentación atraviesan el pedestal (sin quedar adheridas al pedestal) y quedan introducidas en el conector del soporte, en donde se conectan con las barras longitudinales del soporte.  In the GCDP type model, a connector fixed inside the prefabricated crown of the support (of conventional concrete) and a pedestal made in situ at the base of the support are used. The connection between the support and the foundation is made as follows: The steel bars from the foundation cross the pedestal (without being attached to the pedestal) and are inserted into the support connector, where they connect with the longitudinal bars of the support.
Sin embargo, el uso de estas tres nuevas soluciones sigue sin proporcionar resultados totalmente satisfactorios en cuanto a la mejora de prestaciones sísmicas, minimización de daños en la zona crítica de los elementos estructurales, reducción en el coste de reparación, mejora de la resiliencia estructural, protección de edificaciones y otras construcciones frente a desplazamientos sísmicos.  However, the use of these three new solutions still does not provide completely satisfactory results in terms of improving seismic performance, minimizing damage to the critical area of structural elements, reducing repair cost, improving structural resilience, protection of buildings and other constructions against seismic displacements.
Por tanto, sigue existiendo en la técnica la necesidad de una solución alternativa a las conocidas en la técnica anterior que permita construir estructuras sismo-resistentes a un precio asumible a lo largo del ciclo de vida de las mismas que minimice los daños estructurales y asegure la funcionalidad después de un terremoto además de contribuir a la capacidad resistente frente a otro tipo de solicitaciones ( gravitatorias , sobrecarga de uso, viento, etc.) en situaciones no sísmicas. Therefore, there is still a need in the art for an alternative solution to those known in the prior art that allows the construction of earthquake-resistant structures at an acceptable price throughout their life cycle. that minimizes structural damage and ensures functionality after an earthquake in addition to contributing to the resilience against other types of stresses (gravitational, use overload, wind, etc.) in non-seismic situations.
En base al conocimiento y a las normas de diseño actuales, ante un terremoto de alta magnitud, las estructuras o bien colapsan, o bien quedan inservibles debido a sus altas deformaciones remanentes y alto nivel de daño. Por tanto, el objetivo principal de la invención es proporcionar un elemento de conexión entre elementos estructurales que posea una gran capacidad de giro, bajo nivel de daño tras un sismo, sea de fácil reparación y que dote a la estructura global de la capacidad de recentrado tras el sismo.  Based on current knowledge and design standards, in the face of a high magnitude earthquake, the structures either collapse or become unusable due to their high remaining deformations and high level of damage. Therefore, the main objective of the invention is to provide a connection element between structural elements that has a high turning capacity, low level of damage after an earthquake, is easy to repair and that gives the overall structure of the recent re-capacity. after the earthquake
Sumario de la invención Summary of the invention
Para solucionar los problemas de la técnica anterior, en el presente documento se describe un elemento de conexión de protección contra sismos para la conexión entre elementos estructurales, comprendiendo el elemento de conexión:  To solve the problems of the prior art, this document describes an earthquake protection connection element for the connection between structural elements, the connection element comprising:
- barras longitudinales de aleación con memoria de forma (SMA) y con superelasticidad en temperatura ambiente, dispuestas de manera que cruzan la intersección entre el elemento de conexión y el nudo u otro elemento estructural que se conecta;  - longitudinal alloy bars with shape memory (SMA) and with superelasticity at room temperature, arranged so that they cross the intersection between the connecting element and the node or other structural element that is connected;
- armadura transversal, preferiblemente de acero convencional ;  - transverse reinforcement, preferably of conventional steel;
- hormigón de tipo VHPC o UHPC en el que se hallan embebidas las barras de SMA;  - VHPC or UHPC type concrete in which the SMA bars are embedded;
- conectores entre barras de acero convencionales de los elementos estructurales y las barras de SMA del elemento de conexión; y  - connectors between conventional steel bars of the structural elements and the SMA bars of the connecting element; Y
- juntas entre el elemento de conexión y los elementos estructurales . Breve descripción de las figuras - joints between the connection element and the structural elements. Brief description of the figures
La presente invención se entenderá mejor con referencia a las siguientes figuras que ilustran realizaciones preferidas de la invención, proporcionadas a modo de ejemplo, y que no deben interpretarse como limitativas de la invención de ninguna manera.  The present invention will be better understood with reference to the following figures illustrating preferred embodiments of the invention, provided by way of example, and which should not be construed as limiting the invention in any way.
La figura 1 muestra esquemáticamente ejemplos de disposición de un elemento de conexión según realizaciones preferidas de la invención.  Figure 1 shows schematically examples of arrangement of a connection element according to preferred embodiments of the invention.
La figura 2 muestra dos gráficas comparativas que representan la relación tensión-deformación en tracción de una barra de aleación tipo SMA empleada en una realización preferida de la presente invención y en una barra de acero convencional.  Figure 2 shows two comparative graphs depicting the tensile stress strain ratio of an SMA type alloy bar employed in a preferred embodiment of the present invention and in a conventional steel rod.
La figura 3 muestra dos gráficas comparativas que representan el comportamiento en compresión y en tracción de un hormigón convencional, un hormigón de alta resistencia y un hormigón según una realización preferida de la presente invención.  Figure 3 shows two comparative graphs depicting the compression and tensile behavior of a conventional concrete, a high strength concrete and a concrete according to a preferred embodiment of the present invention.
La figura 4 muestra dos gráficas comparativas que representan las derivas obtenidas con un elemento de conexión según la realización preferida de la invención y con una estructura convencional según la técnica anterior.  Figure 4 shows two comparative graphs representing the drifts obtained with a connection element according to the preferred embodiment of the invention and with a conventional structure according to the prior art.
La figura 5 es una vista de la realización preferida representada en la figura le, con el soporte unido a la cimentación .  Figure 5 is a view of the preferred embodiment shown in Figure le, with the support attached to the foundation.
La figura 6 es una vista de la realización preferida representada en la figura Id, con el soporte unido a la cimentación.  Figure 6 is a view of the preferred embodiment shown in Figure Id, with the support attached to the foundation.
Descripción detallada de las realizaciones preferidas Detailed description of the preferred embodiments
A lo largo de la presente descripción se entenderá por nudo" el lugar de encuentro entre dos o más elementos constructivos en un entramado o estructura. El nudo ha de ser considerado como un elemento estructural. Throughout this description, the node shall be understood as "the meeting place between two or more elements constructive in a framework or structure. The knot must be considered as a structural element.
A lo largo de la presente descripción se entenderá por "pila" el apoyo intermedio de puentes de dos o más tramos que sirve para transmitir las cargas del tablero a la cimentación.  Throughout this description, "stack" means the intermediate support of bridges of two or more sections that serves to transmit the loads of the board to the foundation.
A lo largo de la presente descripción se entenderá por "tablero" la parte de un puente que soporta directamente las cargas debidas al tránsito de vehículos o personas y las transmite directa o indirectamente a las pilas, estribos o muros.  Throughout this description, "dashboard" means the part of a bridge that directly supports the loads due to the traffic of vehicles or people and transmits them directly or indirectly to the piles, stirrups or walls.
A lo largo de la presente descripción se entenderá por "soporte" el elemento estructural de una estructura de edificación o nave industrial que transmite las cargas hacia la cimentación.  Throughout this description "support" means the structural element of a building structure or industrial building that transmits the loads to the foundation.
A lo largo de la presente descripción se entenderá por Throughout this description it will be understood as
"zona crítica" la zona de los elementos estructurales que es susceptible de albergar una rótula plástica. "critical zone" the zone of the structural elements that is capable of housing a plastic kneecap.
A lo largo de la presente descripción se entenderá por "intersección" la superficie de encuentro entre el elemento de conexión y el nudo u otro elemento estructural al que se conecta. Dicha intersección define una junta.  Throughout this description "intersection" means the meeting surface between the connecting element and the node or other structural element to which it is connected. Said intersection defines a board.
El elemento de conexión (1) dado a conocer tiene aplicación para la conexión de un elemento estructural con otro de cualquier sección, tal como por ejemplo una viga con un soporte en un nudo o un soporte con una cimentación de forma cualquiera. En la figura 1 se muestran de manera esquemática 8 ejemplos de aplicación del elemento de conexión (1), en concreto, la figura la muestra la conexión entre un soporte y una viga isostática en un nudo, la figura Ib muestra la conexión entre un soporte y una viga continua con vainas (8) en un nudo, la figura le muestra la conexión tipo vainas (8) entre un soporte prefabricado y una cimentación ejecutada in situ, la figura Id muestra la conexión tipo cáliz (9) entre un soporte prefabricado y una cimentación ejecutada in situ, la figura le muestra la conexión entre unas vigas y un soporte interior en el nudo, la figura lf muestra la conexión entre una viga y un soporte exterior en un nudo, la figura lg muestra la conexión entre la viga y un muro y la figura lh muestra la conexión de la cabeza superior de una pila y un tablero. En cada caso, el elemento de conexión (1) según la presente invención se representa entre llaves. Las barras de SMA (2) se disponen en el sentido longitudinal del elemento estructural viga, soporte o pila. Además, según se puede observar en la figura 1, las barras de SMA (2), están dispuestas de manera que cruzan la intersección entre el elemento de conexión y el nudo u otro elemento estructural que se conecta. The connecting element (1) disclosed has application for the connection of a structural element with another of any section, such as for example a beam with a support in a knot or a support with a foundation of any shape. Figure 8 shows schematically 8 examples of application of the connecting element (1), specifically, the figure shows the connection between a support and an isostatic beam in a node, Figure Ib shows the connection between a support and a continuous beam with sheaths (8) in a knot, the figure shows the sheath type connection (8) between a prefabricated support and a foundation executed in situ, Figure Id shows the calyx type connection (9) between a prefabricated support and a foundation executed in situ, the figure shows the connection between beams and an inner support in the knot, the figure lf shows the connection between a beam and an external support in a knot, the figure lg shows the connection between the beam and a wall and the figure lh shows the connection of the top head of a stack and a board. In each case, the connecting element (1) according to the present invention is represented between keys. The bars of SMA (2) are arranged in the longitudinal direction of the structural element beam, support or stack. In addition, as can be seen in Figure 1, the SMA bars (2) are arranged so that they cross the intersection between the connecting element and the node or other structural element that is connected.
El elemento de conexión (1) puede insertarse en cualquier estructura de hormigón, tanto creada in situ como prefabricada. El elemento de conexión (1) se dispone en la zona critica del elemento estructural lineal (viga, soporte, pila de puente, etc.) . El resto del elemento estructural lineal puede fabricarse con un hormigón con prestaciones inferiores al de la zona critica, con la finalidad de reducir el coste del elemento estructural, siempre y cuando su capacidad resistente supere los criterios fijados en la normativa correspondiente. La longitud "L" del elemento de conexión (1) variará en función de la calidad de los materiales y de las características mecánicas del resto de la estructura en la que va a insertarse el elemento de conexión (1) de protección contra sismos así como de la ductilidad requerida y de las características de los terremotos representativos de la región.  The connecting element (1) can be inserted in any concrete structure, both created in situ and prefabricated. The connection element (1) is arranged in the critical area of the linear structural element (beam, support, bridge stack, etc.). The rest of the linear structural element can be manufactured with a concrete with lower performance than the critical area, in order to reduce the cost of the structural element, as long as its resistant capacity exceeds the criteria set in the corresponding regulations. The length "L" of the connection element (1) will vary depending on the quality of the materials and the mechanical characteristics of the rest of the structure in which the earthquake protection connection element (1) is to be inserted as well as of the required ductility and the characteristics of the earthquakes representative of the region.
El elemento de conexión (1) otorga de una gran capacidad de giro a la zona de la estructura en la que se incorpora, con un daño mínimo (fácilmente reparable) y con una capacidad de recentrado de la estructura tras el evento sísmico. Todo esto se logra gracias a la combinación de dos materiales: hormigón de muy altas o ultra altas prestaciones (VHPC o UHPC) (4) y barras longitudinales (2) de aleación con memoria de forma (SMA) y superelasticidad en temperatura ambiente, dispuestas de manera que cruzan la intersección entre el elemento de conexión y el nudo u otro elemento estructural que se conecta (cimentación, muro, tablero, etc.) . Tal y como se puede observar en las figuras, el hormigón VHPC o UHPC solo se utiliza en la zona critica del elemento lineal (viga, soporte, pila, etc.), mientras que el resto del elemento puede fabricarse con hormigón convencional u otro tipo de hormigones. La gran capacidad de giro se consigue gracias a la gran capacidad de deformación de SMA. Esta gran deformación no podría movilizarse sin un hormigón con una gran resistencia y ductilidad. El bajo daño se consigue gracias a que el VHPC o UHPC concentra el daño en una única sección (sección crítica) . Dicha sección crítica se puede situar en cualquier sección de la zona crítica del elemento, incluida la intersección entre el elemento de conexión y el nudo u otro elemento estructural. Por esta razón, es necesario que la barra de SMA cruce dicha intersección. En las figuras 5 y 6 pueden verse dos realizaciones con las barras de SMA cruzando la intersección mencionada. En estados avanzados de carga se produce una gran fisura en la zona sometida a tracción, la cual se une por el SMA. Mientras tanto, en la zona comprimida, debido al alto porcentaje en fibras metálicas y resistencia del hormigón utilizado, el daño es reducido (aunque variable, dependiendo de la junta utilizada) . El bajo coste a lo largo del ciclo de vida de la estructura también es causa directa del bajo daño y de la facilidad de reparación de la estructura tras un sismo de entidad. Por último, el recentrado de la estructura lo provoca el material de tipo SMA, ya que se utiliza SMA superelástico en temperatura ambiente, es decir, capaz de recobrar deformaciones cercanas a cero cuando desaparece la acción sísmica (figura 2a) . Además, el hecho de utilizar un hormigón VHPC o UHPC (4) permite que frente a cargas cíclicas el hormigón no sufra un proceso de degradación (fisuración o salto de recubrimiento) , lo que permite ayudar al material de tipo SMA a reducir los desplazamientos residuales y no pandear localmente. The connecting element (1) grants a great turning capacity to the area of the structure in which it is incorporated, with minimal damage (easily repairable) and with a capacity to re-structure the structure after the seismic event. All this is achieved thanks to the combination of two materials: concrete of very high or ultra high performance (VHPC or UHPC) (4) and longitudinal bars (2) of alloy with shape memory (SMA) and superelasticity at room temperature, arranged so that they cross the intersection between the connecting element and the knot or other structural element that connects (foundation, wall, board, etc.). As can be seen in the figures, VHPC or UHPC concrete is only used in the critical area of the linear element (beam, support, pile, etc.), while the rest of the element can be manufactured with conventional concrete or other type of concrete. The large turning capacity is achieved thanks to the great deformability of SMA. This great deformation could not be mobilized without a concrete with great strength and ductility. Low damage is achieved because the VHPC or UHPC concentrates the damage in a single section (critical section). Said critical section can be placed in any section of the critical area of the element, including the intersection between the connecting element and the node or other structural element. For this reason, it is necessary for the SMA bar to cross said intersection. In figures 5 and 6 two embodiments can be seen with the SMA bars crossing the mentioned intersection. In advanced stages of loading, a large fissure occurs in the area subject to traction, which is joined by the SMA. Meanwhile, in the compressed area, due to the high percentage of metal fibers and strength of the concrete used, the damage is reduced (although variable, depending on the joint used). The low cost throughout the life cycle of the structure is also a direct cause of the low damage and the ease of repair of the structure after a major earthquake. Finally, the re-centering of the structure is caused by the SMA-type material, since super-elastic SMA is used at room temperature, that is, capable of recovering near zero deformations when the seismic action disappears (Figure 2a). In addition, the fact of using a VHPC or UHPC concrete (4) allows that in the case of cyclic loads the concrete does not undergo a degradation process (cracking or skipping coating), which allows the SMA type material to help reduce residual displacements and not buckle locally.
Por tanto, la invención se basa en la combinación del material de tipo SMA con el hormigón de tipo VHPC o UHPC (4) . Por una parte, un material de tipo SMA insertado en un hormigón convencional provocaría que éste se degradara notablemente frente a cargas cíclicas, provocadas por un terremoto. Por lo tanto, no se podría aprovechar la gran capacidad de deformación del SMA siendo la disipación de energía baja, ya que apenas se entraría en el régimen no lineal de estas barras. Por otra parte, utilizar VHPC o UHPC con armaduras convencionales de acero presenta una menor capacidad de giro de la rótula, menor ductilidad, mayor daño y deformaciones residuales, y en consecuencia, un mayor coste de reparación. En ambas soluciones, la condición de no pandeo local de la armadura longitudinal no queda asegurada, lo cual limita la ductilidad y la energía de disipación de la estructura frente a sismos.  Therefore, the invention is based on the combination of the SMA type material with the VHPC or UHPC type concrete (4). On the one hand, an SMA-type material inserted in a conventional concrete would cause it to significantly deteriorate against cyclic loads, caused by an earthquake. Therefore, the great deformability capacity of the SMA could not be used as the energy dissipation is low, since it would hardly enter into the non-linear regime of these bars. On the other hand, using VHPC or UHPC with conventional steel reinforcements has a lower rotational capacity of the patella, less ductility, greater damage and residual deformations, and consequently, a higher repair cost. In both solutions, the local non-buckling condition of the longitudinal reinforcement is not ensured, which limits the ductility and dissipation energy of the structure against earthquakes.
En el elemento de conexión (1) se pueden combinar las barras longitudinales (2) de aleación (SMA) con barras de refuerzo de polímeros reforzados con fibras (FRP), por ejemplo de fibra de vidrio o de carbono, o barras pasivas o activas de acero convencional, con la finalidad de reducir el coste de construcción. En este caso, respecto a la solución de disponer solo barras de SMA, la zona de daño se incrementa, se reduce la capacidad de auto-centrado de la estructura, los costes de reparación son mayores y la estructura muestra una menor energía de disipación. Por todo ello, el comportamiento óptimo desde el punto de vista del auto-centrado (menores desplazamientos residuales), de la reducción de daños, de la mayor energía de disipación y del menor coste de reparación se encuentra cuando se dispone en el elemento de conexión (1) únicamente barras longitudinales (2) de aleación con memoria de forma (SMA) . In the connecting element (1) the longitudinal bars (2) of alloy (SMA) can be combined with reinforcing bars of fiber reinforced polymers (FRP), for example of glass or carbon fiber, or passive or active bars of conventional steel, in order to reduce the cost of construction. In this case, with respect to the solution of having only SMA bars, the damage zone is increased, the self-centering capacity of the structure is reduced, the repair costs are higher and the structure shows a lower dissipation energy. Therefore, the optimal behavior from the point of view of self-centering (lower residual displacements), damage reduction, greater dissipation energy and lower repair costs are found when only longitudinal memory bars (2) with shape memory (SMA) are available in the connection element (1).
Además, en el elemento de conexión (1) se dispondrá una armadura transversal (3) de acero convencional para resistir las solicitaciones transversales (por ejemplo, el esfuerzo cortante) . No obstante, por el hecho de utilizar un hormigón de tipo UHPC o VHPC (4) con alto contenido en fibras de acero da lugar a que la cuantía a disponer de armadura transversal (3) no sea importante, lo que facilita la puesta en obra del hormigón. Esta armadura transversal (3) mejorará el efecto de confinamiento del hormigón dispuesto y en consecuencia su resistencia y ductilidad.  In addition, a conventional steel transverse reinforcement (3) will be provided in the connection element (1) to resist transverse stresses (for example, shear stress). However, due to the use of a UHPC or VHPC type concrete (4) with a high content of steel fibers, the amount of transverse reinforcement (3) is not important, which facilitates the commissioning of concrete. This transverse reinforcement (3) will improve the confinement effect of the arranged concrete and consequently its strength and ductility.
Por tanto, el elemento de conexión (1) de protección contra sismos según una realización preferida de la invención comprende :  Therefore, the earthquake protection connection element (1) according to a preferred embodiment of the invention comprises:
- barras longitudinales (2) de aleación con memoria de forma (SMA) y con supérelasticidad en temperatura ambiente, dispuestas de manera que cruzan la intersección entre el elemento de conexión y el nudo u otro elemento estructural que se conecta, estando dichas barras longitudinales (2) combinadas o no con barras de refuerzo de polímeros reforzados con fibras (FRP) o barras pasivas o activas de acero convencional;  - longitudinal bars (2) of alloy with shape memory (SMA) and with superelasticity at room temperature, arranged so that they cross the intersection between the connecting element and the node or other structural element that is connected, said longitudinal bars ( 2) combined or not with fiber reinforced polymer reinforcement bars (FRP) or passive or active conventional steel bars;
- armadura transversal (3) de acero convencional;  - transverse reinforcement (3) of conventional steel;
- hormigón de tipo VHPC o UHPC (4) en el que se hallan embebidas las barras de SMA;  - VHPC or UHPC type concrete (4) in which the SMA bars are embedded;
- conectores (5) entre barras de acero convencionales de los elementos estructurales y las barras de SMA del elemento de conexión (1); y  - connectors (5) between conventional steel bars of the structural elements and the SMA bars of the connecting element (1); Y
- juntas (6) entre el elemento de conexión (1) y los elementos estructurales.  - joints (6) between the connection element (1) and the structural elements.
Tal como se mencionó anteriormente, las barras de aleación con memoria de forma presentan supérelasticidad a temperatura ambiente, lo que significa que pueden recuperar grandes deformaciones cuando desaparece la acción sísmica. As mentioned earlier, shape memory alloy bars have temperature superelasticity environment, which means that they can recover large deformations when the seismic action disappears.
La aleación con memoria de forma de las barras puede seleccionarse, por ejemplo, del grupo constituido por Ni-Ti, Ni-Ti-Nb, Ni-Ti-Cu, Ni-Ti-Fe, Cu-Al-Be, Cu-Al-Ni, Cu-Al-Zn, aleaciones en base Mn y aleaciones en base Fe. Más preferiblemente, la aleación con memoria de forma de las barras es Ni-Ti, y aún más preferiblemente es 50% Ni - 50% Ti aproximadamente .  The shape memory alloy of the bars can be selected, for example, from the group consisting of Ni-Ti, Ni-Ti-Nb, Ni-Ti-Cu, Ni-Ti-Fe, Cu-Al-Be, Cu-Al -Ni, Cu-Al-Zn, Mn base alloys and Fe base alloys. More preferably, the shape memory alloy of the bars is Ni-Ti, and even more preferably it is about 50% Ni-50% Ti.
Las características de la aleación con memoria de forma son que presenta superelast icidad a temperatura ambiente, una temperatura de finalización de la transformación austenítica (Af) de aproximadamente entre -100°C y 20°C, un módulo de Young de aproximadamente de 10000 - 240000 MPa, una tensión directa fy de aproximadamente de 150 - 800 MPa y una deformación de transformación H de aproximadamente de 2 - 6%.  The characteristics of the shape memory alloy are that it exhibits superelastity at room temperature, an end temperature of the austenitic transformation (Af) of approximately between -100 ° C and 20 ° C, a Young's modulus of approximately 10,000 - 240000 MPa, a direct tension f and of approximately 150-800 MPa and a transformation strain H of approximately 2-6%.
El elemento de conexión (1) puede incluir barras fabricadas con otros materiales como barras de polímeros reforzados con fibras (FRP), por ejemplo de fibra de vidrio o de carbono, o armaduras pasivas o activas de acero convencional. Tal y como entenderá el experto en la técnica, las armaduras longitudinales unirán el elemento de conexión (1) con los elementos estructurales, tendrán continuidad en los elementos estructurales y en el elemento de conexión (1) . El experto en la técnica seleccionará la combinación más adecuada de acuerdo con las prestaciones necesarias. Más preferiblemente, si se requiere el mínimo daño, la máxima energía de disipación, la máxima recuperación y el mínimo coste de reparación, el experto dispondrá únicamente barras longitudinales (2) de SMA en el elemento de conexión (1) .  The connecting element (1) may include bars made of other materials such as fiber reinforced polymer bars (FRP), for example of glass or carbon fiber, or passive or active reinforcement of conventional steel. As the person skilled in the art will understand, the longitudinal reinforcements will connect the connection element (1) with the structural elements, will have continuity in the structural elements and in the connection element (1). The person skilled in the art will select the most suitable combination according to the necessary performance. More preferably, if the minimum damage, the maximum dissipation energy, the maximum recovery and the minimum repair cost are required, the expert will only have SMA longitudinal bars (2) on the connecting element (1).
En todo caso, tal y como entenderá el experto en la técnica, se dispondrá armadura transversal (3) de acero convencional requerida para resistir las solicitaciones transversales (por ejemplo, respecto al esfuerzo cortante) en el elemento de conexión (1) de protección contra sismos. In any case, as will be understood by the person skilled in the art, conventional reinforcement (3) of conventional steel required to resist transverse stresses (for example, with respect to shear stress) will be provided in the connection element (1) for earthquake protection.
En la figura 2 se muestra la relación tensión - deformación en tracción sometida a una carga cíclica de una barra de aleación de tipo SMA según la presente invención (gráfica superior) y de una barra de acero de armado convencional (gráfica inferior) . Tal como puede apreciarse en la figura 2, las deformaciones residuales de la barra de SMA son inferiores con respecto a la barra de acero convencional.  Figure 2 shows the tension-strain strain ratio subjected to a cyclic load of an SMA type alloy bar according to the present invention (upper graph) and of a conventional reinforcing steel rod (lower graph). As can be seen in Figure 2, the residual deformations of the SMA bar are lower with respect to the conventional steel bar.
En concreto, las barras de SMA empleadas en la prueba de tensión - deformación anterior son barras de Ni-Ti que presentan una composición de aproximadamente 50% Ni - 50% Ti, superelasticidad a temperatura ambiente, una temperatura de finalización de la transformación austenítica (Af) de aproximadamente -8°C, un módulo de Young de aproximadamente 65000 MPa, una tensión de transformación directa fy de aproximadamente 450 - 500 MPa y una deformación de transformación H de aproximadamente el 4%. Specifically, the SMA bars used in the stress-strain test above are Ni-Ti bars having a composition of approximately 50% Ni-50% Ti, super-elasticity at room temperature, an end temperature of the austenitic transformation ( Af) of about -8 ° C, a Young's modulus of about 65,000 MPa, a direct transformation voltage f and about 450-500 MPa and a transformation strain H of about 4%.
El hormigón empleado en el elemento de conexión (1) según la realización preferida de la presente invención presenta una resistencia muy alta (de entre aproximadamente 100 y aproximadamente 200 MPa, más preferiblemente entre aproximadamente 110 MPa y aproximadamente 140 MPa) y un alto contenido en fibras metálicas (superior al 1%) .  The concrete used in the connecting element (1) according to the preferred embodiment of the present invention has a very high resistance (between about 100 and about 200 MPa, more preferably between about 110 MPa and about 140 MPa) and a high content of metal fibers (greater than 1%).
Mediante esta alta resistencia se consigue una alta adherencia con las fibras metálicas. Para conseguir esas resistencias tan altas anteriormente mencionadas, se emplea un alto contenido en cemento y también se utiliza humo de sílice. Además, el hormigón resultante es autocompactante debido a que la granulometría tiene un tamaño máximo del árido bajo.  Through this high strength, high adhesion with the metallic fibers is achieved. To achieve these high resistance mentioned above, a high cement content is used and silica smoke is also used. In addition, the resulting concrete is self-compacting because the particle size has a maximum low aggregate size.
Con respecto a la nomenclatura empleada, debe tenerse en cuenta que en la bibliografía existente no es homogénea. Algunos autores clasifican este tipo de hormigones como de "ultra altas prestaciones" (UHPC) a partir de 100 MPa, y otros autores los clasifican como de "muy altas prestaciones" (VHPC) entre 100 y 150 MPa, y de "ultra altas prestaciones" a partir de 150 MPa. Por tanto, en la presente invención se emplean los términos VHPC y UHPC de manera intercambiable para referirse al hormigón empleado en las realizaciones de la presente invención, con una resistencia de entre 100 MPa y 200 MPa, más preferiblemente de entre 110 y 140 MPa. With respect to the nomenclature used, it should be taken into account that in the existing bibliography it is not homogeneous. Some authors classify this type of concrete as "ultra high performance" (UHPC) from 100 MPa, and other authors classify it as "very high performance" (VHPC) between 100 and 150 MPa, and "ultra high performance" from 150 MPa. Therefore, in the present invention the terms VHPC and UHPC are used interchangeably to refer to the concrete employed in the embodiments of the present invention, with a strength of between 100 MPa and 200 MPa, more preferably between 110 and 140 MPa.
Para la fabricación del elemento de conexión (1) según la presente invención resulta necesario fabricar un hormigón con muy altas prestaciones tanto en compresión como en tracción con un alto contenido en fibras de acero. El rango de hormigones que tienen estas prestaciones iría desde los 110 MPa en adelante con un alto contenido en fibras de acero. Se han realizado pruebas con hormigones de una calidad inferior, con fibras de acero en su masa desde 30 MPa hasta 80 MPa dando lugar a resultados insatisfactorios : un daño mayor en la pieza, salto del recubrimiento y pandeo de las barras por pérdida del recubrimiento del hormigón. Se ha descartado en estas pruebas la utilización de un hormigón tipo ECC, por presentar una menor prestación (rigidez, ductilidad, resiliencia y resistencia) respecto a una solución con un hormigón tipo UHPC o VHPC, y porque, de acuerdo con el estado de la técnica, los resultados obtenidos también son insatisfactorios en cuanto al daño producido en la pieza (salto del recubrimiento y pandeo de las barras), lo que implica un mayor coste de la reparación.  For the manufacture of the connecting element (1) according to the present invention it is necessary to manufacture a concrete with very high performance both in compression and in tension with a high content of steel fibers. The range of concretes that have these benefits would go from 110 MPa onwards with a high content of steel fibers. Tests have been carried out with concrete of a lower quality, with steel fibers in their mass from 30 MPa to 80 MPa resulting in unsatisfactory results: greater damage to the piece, skipping of the coating and buckling of the bars due to loss of the coating of the concrete. The use of an ECC type concrete has been ruled out in these tests, as it has a lower performance (stiffness, ductility, resilience and resistance) compared to a solution with a UHPC or VHPC type concrete, and because, according to the state of the technique, the results obtained are also unsatisfactory in terms of damage to the piece (jump of the coating and buckling of the bars), which implies a higher cost of repair.
En la figura 3 se muestran unas gráficas en las que puede compararse el comportamiento en compresión (gráfica superior) y en tracción (gráfica inferior) de un hormigón convencional (resistencia inferior a 50 MPa) , un hormigón de alta resistencia (entre 50 y 80 MPa) y un hormigón según una realización preferida de la presente invención (resistencia de entre 110 MPa y 140 MPa) . Puede apreciarse una diferencia notable en las prestaciones (resistencia y ductilidad) entre el hormigón de la realización preferida de la invención y los hormigones de la técnica anterior. Figure 3 shows some graphs in which the compression (upper graphic) and tensile (lower graphic) behavior of a conventional concrete (resistance below 50 MPa), a high-strength concrete (between 50 and 80) can be compared MPa) and a concrete according to a preferred embodiment of the present invention (strength between 110 MPa and 140 MPa). A notable difference in performance (strength and ductility) can be seen between the concrete of the preferred embodiment of the invention and the concrete of the prior art.
En concreto, el hormigón empleado en las pruebas de compresión y tracción anteriores tiene la composición presentada en la siguiente tabla:  Specifically, the concrete used in the previous compression and tensile tests has the composition presented in the following table:
Figure imgf000018_0001
Figure imgf000018_0001
Para la fabricación del hormigón empleado en la realización preferida se ha seguido el siguiente procedimiento de preparación del hormigón: For the manufacture of the concrete used in the preferred embodiment, the following concrete preparation procedure has been followed:
- humedecer una amasadora;  - moisten a kneader;
- verter áridos de los más gruesos a los más finos;  - pour aggregates from the thickest to the finest;
- pre-mezclar los componentes anteriores durante un minuto ;  - pre-mix the previous components for one minute;
- sin parar la amasadora, añadir agua;  - without stopping the mixer, add water;
- al alcanzar 2 minutos tras terminar la adición de agua, empezar a verter aditivo a ritmo constante;  - when reaching 2 minutes after finishing the addition of water, start pouring additive at a constant rate;
- en el minuto 10 tras terminar la adición de agua empezar a añadir fibras, primero las cortas y después las largas ;  - in the 10th minute after finishing the addition of water, start adding fibers, first cut them and then the long ones;
- en el minuto 23 tras terminar la adición de agua realizar una prueba de cono de Abrams y comprobar que se obtiene como resultado aproximadamente 700 mm de escurrimiento ;  - in the 23rd minute after finishing the water addition, perform an Abrams cone test and verify that approximately 700 mm of runoff is obtained;
- a partir del minuto 25 tras terminar la adición de agua verter el hormigón en los moldes.  - after 25 minutes after finishing the addition of water, pour the concrete into the molds.
Según una realización preferida, la etapa de verter áridos comprende verter los siguientes componentes en el siguiente orden: arena con una granulometría de 0,8 rom, arena con una granulometría de 0,4 rom, cemento y humo de sílice densificado. According to a preferred embodiment, the step of pouring aggregates comprises pouring the following components into the next order: sand with a particle size of 0.8 rom, sand with a particle size of 0.4 rom, cement and densified silica fume.
Tal y como entenderá el experto en la técnica, los tiempos de espera y de amasado variarán en función del tipo de amasadora, las condiciones climatológicas y el volumen de hormigón amasado.  As the person skilled in the art will understand, the waiting and kneading times will vary depending on the type of kneader, the weather conditions and the volume of kneaded concrete.
Para transmitir los esfuerzos de las barras de acero convencionales (7) de los elementos estructurales que conectan con las barras de SMA (2) del elemento de conexión (1) deben utilizarse conectores (5) . Estos deben poder transmitir los esfuerzos sin que la barra deslice en su interior, sin que se rompa ninguna de las barras que unen y sin que se rompa el propio conector (5) .  To transmit the forces of conventional steel bars (7) of the structural elements that connect with the SMA bars (2) of the connecting element (1) connectors (5) must be used. These should be able to transmit the efforts without the bar sliding inside, without breaking any of the bars that join and without breaking the connector itself (5).
Pueden emplearse, por ejemplo, conectores mecánicos de marcas comerciales tales como el modelo MBT de HALFEN, el modelo ZAP screwlock tipo SL de BPI y similares; siempre que se garantice la continuidad de la barra tanto en tracción como en compresión. Según una realización preferida, el conector (5) empleado es un conector roscado en el que la rosca de la barra se realizará en el proceso de fabricación de la misma, con el objetivo de no modificar las características mecánicas de la barra por sobrecalentamiento.  For example, mechanical connectors of trademarks such as the HALFEN MBT model, the BPI screwlock ZAP type SL model and the like can be used; provided that the continuity of the bar is guaranteed both in tension and compression. According to a preferred embodiment, the connector (5) used is a threaded connector in which the thread of the bar will be made in the process of manufacturing it, in order not to modify the mechanical characteristics of the bar by overheating.
Los grupos de elementos estructurales que se conectan mediante el elemento de conexión (1) según la presente invención pueden seleccionarse del grupo constituido por soporte-cimentación, pila-cimentación, viga-cimentación, viga- soporte, pila-tablero, soporte-muro y viga-muro. Los elementos estructurales que se conectan mediante el elemento de conexión (1) según la presente invención forman parte de los grupos seleccionados en realizaciones tanto de obra civil (por ejemplo, puentes) como en edificación. Además, podrán formar parte tanto de elementos prefabricados como ejecutados in situ. La continuidad entre el elemento de conexión (1) y el elemento estructural (viga, soporte o pila) en donde se dispone el elemento de conexión (1) se materializa con una junta (6) seleccionada del grupo constituido por una junta seca y una junta húmeda. La junta seca consiste en el contacto directo entre hormigones, mientras que la junta húmeda consiste en un puente de unión químico entre hormigones. Tal como entenderá el experto en la técnica, en este caso siempre existirá armadura longitudinal para unir el hormigón del elemento de conexión (1) con el hormigón del elemento estructural . The groups of structural elements that are connected by means of the connection element (1) according to the present invention can be selected from the group consisting of support-foundation, foundation-pile, beam-foundation, beam-support, stack-board, wall-mount and beam-wall. The structural elements that are connected by the connection element (1) according to the present invention are part of the selected groups in both civil works (eg, bridges) and building constructions. In addition, they can be part of both prefabricated and executed elements in situ. The continuity between the connection element (1) and the structural element (beam, support or stack) where The connection element (1) is provided with a joint (6) selected from the group consisting of a dry joint and a wet joint. The dry joint consists of direct contact between concrete, while the wet joint consists of a chemical bonding bridge between concrete. As the person skilled in the art will understand, in this case there will always be longitudinal reinforcement for joining the concrete of the connecting element (1) with the concrete of the structural element.
El puente de unión químico en el caso de la junta húmeda puede realizarse mediante la aplicación, por ejemplo, de resinas de tipo SiKaDur o similares.  The chemical bonding bridge in the case of the wet joint can be made by applying, for example, SiKaDur type resins or the like.
Por otro lado, la continuidad en la intersección entre el elemento de conexión (1) y un nudo, cimentación, muro o tablero se ejecuta mediante una junta (6) que se selecciona del grupo constituido por una junta con continuidad y una junta sin continuidad. Se han sometido a prueba ambas opciones y se ha constatado que el comportamiento es distinto. Si la junta (6) no tiene continuidad, la sección crítica de daño se produce en la junta, que se abre en la zona sometida a tracción sin ocasionar daños. En cuanto a la parte comprimida, la calidad del hormigón provoca que pueda soportar enormes compresiones, fruto de la elevada posición de la fibra neutra debido al gran giro que se concentra en esa sección. La junta (6) se materializa realizando el hormigonado en dos fases, de tal forma que existe una junta seca en una determinada sección. En ésta se prescinde de la resistencia a tracción que aportan las fibras metálicas del hormigón. Este hecho provoca que la carga máxima alcanzada sea menor que en el caso con junta con continuidad.  On the other hand, continuity at the intersection between the connecting element (1) and a node, foundation, wall or board is executed by means of a joint (6) that is selected from the group consisting of a joint with continuity and a joint without continuity . Both options have been tested and it has been found that the behavior is different. If the seal (6) has no continuity, the critical section of damage occurs in the seal, which opens in the area under tension without causing damage. As for the compressed part, the quality of the concrete causes it to withstand huge compressions, the result of the high position of the neutral fiber due to the large turn that is concentrated in that section. The joint (6) is materialized by concreting in two phases, so that there is a dry joint in a certain section. In this, the tensile strength provided by the metallic fibers of the concrete is dispensed with. This fact causes the maximum load reached to be less than in the case with continuous joint.
En las realizaciones de junta sin continuidad no existe continuidad en tracción pero sí en compresión. Es decir, las fibras de acero no unen la junta (6) de la conexión entre elementos . Una realización especifica del elemento de conexión (1) según la presente invención sin continuidad en la junta es una conexión tipo vainas (8) entre un soporte prefabricado y una cimentación ejecutada in-situ (figuras le y 5) . En este caso, en primer lugar se monta la armadura longitudinal y transversal tanto en la cimentación como en el soporte. En la cimentación se disponen las vainas (8) que servirán para conectar el soporte prefabricado con la cimentación. En la cara inferior del soporte se disponen las barras de SMA conectadas a las barras de acero convencional (7) que habrá que insertar en las vainas (8) de la cimentación. La continuidad de las barras de tipo SMA (2) y de acero convencional (7) queda garantizada por la disposición de los conectores (5), tanto en la conexión con la cimentación como en el soporte prefabricado. Las barras de Ni-Ti cruzan la intersección entre el soporte prefabricado y la cara superior de la cimentación. A continuación, se fabrica por un lado la cimentación, y por otro lado el soporte prefabricado en donde se vierte el hormigón teniendo especial cuidado con la zona critica del soporte en la que se ha situado la barra de Ni-Ti. Por último, se realiza la conexión entre el soporte prefabricado y la cimentación. Para rellenar el hueco que queda entre la vaina (8) y la barra se emplea un mortero expansivo adecuado para anclajes, rellenos y nivelación, por ejemplo de la marca Sika, de tipo Sika Grout o similar. Por otro lado, en la junta (6) puede colocarse un puente de unión de tipo SiKaDur o similar. In joint embodiments without continuity there is no continuity in traction but in compression. That is, the steel fibers do not join the joint (6) of the connection between elements. A specific embodiment of the connection element (1) according to the present invention without continuity in the joint is a sheath type connection (8) between a prefabricated support and an on-site foundation (figures le and 5). In this case, the longitudinal and transverse reinforcement is mounted first on both the foundation and the support. In the foundation the sheaths (8) are arranged that will serve to connect the prefabricated support with the foundation. The SMA bars connected to the conventional steel bars (7) to be inserted in the foundation sheaths (8) are arranged on the underside of the support. The continuity of the SMA (2) and conventional steel (7) type bars is guaranteed by the arrangement of the connectors (5), both in connection with the foundation and in the prefabricated support. The Ni-Ti bars cross the intersection between the prefabricated support and the upper face of the foundation. Next, the foundation is manufactured on the one hand, and on the other hand the prefabricated support where the concrete is poured taking special care with the critical area of the support in which the Ni-Ti bar has been placed. Finally, the connection between the prefabricated support and the foundation is made. To fill the gap between the sheath (8) and the bar, an expansive mortar suitable for anchors, fillings and leveling is used, for example of the Sika brand, of the Sika Grout type or similar. On the other hand, a joint bridge of the type SiKaDur or similar can be placed on the joint (6).
Otro ejemplo de conexión sin continuidad en la junta (6) es una conexión de un soporte híbrido con una viga en un nudo sin continuidad. En este caso, en primer lugar se monta la armadura longitudinal y transversal del soporte inferior. La continuidad de las barras SMA (2) y de acero convencional (7) se garantiza por la disposición de conectores (5) . Las barras de Ni-Ti cruzan la intersección. A continuación, se realiza el encofrado del soporte, previo a la construcción del elemento de conexión (1) (vertido de hormigón de tipo UHPC de forma independiente al resto del elemento en el soporte inferior) se vierte en el resto del soporte inferior un hormigón con prestaciones inferiores (por ejemplo con una resistencia de 80 MPa) . En la junta (6) entre ambos hormigones del soporte (H80- UHPC) se dispone un puente de unión de tipo SikaDur o similar. Por último, se vierte hormigón en el nudo del encuentro entre soporte inferior y la viga, asi como en el resto del soporte superior y la viga. En este caso, en la junta (6) de la intersección entre el soporte híbrido y el nudo no se dispone de ningún puente de unión. Another example of connection without continuity in the joint (6) is a connection of a hybrid support with a beam in a node without continuity. In this case, the longitudinal and transverse reinforcement of the lower support is mounted first. The continuity of the SMA (2) and conventional steel bars (7) is guaranteed by the arrangement of connectors (5). Ni-Ti bars cross the intersection. Then, the formwork of the support, prior to the construction of the connecting element (1) (pouring concrete of the UHPC type independently of the rest of the element in the lower support) a concrete with lower performance is poured into the rest of the lower support (for example with a resistance of 80 MPa). In the joint (6) between both concrete of the support (H80-UHPC) there is a connecting bridge of the SikaDur type or similar. Finally, concrete is poured into the node of the encounter between the lower support and the beam, as well as in the rest of the upper support and the beam. In this case, no joint bridge is available at the junction (6) of the intersection between the hybrid support and the node.
Por otro lado, en las conexiones con continuidad en la junta (6), la zona de daño es mayor (la sección crítica puede producirse a lo largo de la zona crítica) ya que se produce una fisura a costa de romper el hormigón a tracción, por lo que los daños son mayores que en el caso de sin continuidad de la junta (6), en el que ya se había preformado la sección de fisuración de forma controlada. El daño a compresión también resulta ligeramente mayor al ser una sección de rotura irregular provocada por el daño en tracción. Sin embargo, la carga máxima soportada en este caso es mayor.  On the other hand, in the connections with continuity in the joint (6), the damage zone is greater (the critical section can occur along the critical zone) since a crack occurs at the cost of breaking the tensile concrete , so that the damages are greater than in the case of no continuity of the joint (6), in which the cracking section had already been preformed in a controlled manner. Compression damage is also slightly greater as it is an irregular breakage section caused by tensile damage. However, the maximum load supported in this case is greater.
Este tipo de solución confiere continuidad tanto en tracción como en compresión de la junta (6) . Es decir, las fibras de acero unen la junta (6) de la intersección entre elementos estructurales. Una realización específica del elemento de conexión (1) según la presente invención con continuidad en la junta (6) es una conexión tipo cáliz (9) entre un soporte prefabricado y una cimentación ejecutada in situ (figuras Id y 6) . En este caso, en primer lugar se monta la armadura longitudinal y transversal, tanto en el soporte prefabricado como en la cimentación. La continuidad de las barras SMA (2) y de acero convencional (7) se garantiza por la disposición de conectores (5) dispuestos en el soporte prefabricado. Por un lado, se fabrica la cimentación. En la cimentación se dispone un cajeado con la misma forma que el soporte y que servirá para insertar el soporte en la cimentación. Por otro lado, se vierte el hormigón en el soporte prefabricado, teniendo especial cuidado con la zona critica del soporte en la que se ha situado las barras de Ni- Ti que se disponen cruzando la cara superior de la cimentación, una vez se haya colocado el soporte. Esta cara define la intersección entre la cimentación y el soporte prefabricado. Por último, se realiza la conexión entre el soporte y la cimentación (colocación y relleno del hueco mediante mortero expansivo de tipo Sika Grout o similar) . This type of solution confers continuity in both tension and compression of the joint (6). That is, the steel fibers join the joint (6) of the intersection between structural elements. A specific embodiment of the connecting element (1) according to the present invention with continuity in the joint (6) is a chalice type connection (9) between a prefabricated support and a foundation executed in situ (Figures Id and 6). In this case, the longitudinal and transverse reinforcement is mounted first, both in the prefabricated support and in the foundation. The continuity of the SMA (2) and conventional steel bars (7) is guaranteed by the arrangement of connectors (5) arranged in the support prefabricated. On the one hand, the foundation is manufactured. The foundation provides a recess with the same shape as the support and which will serve to insert the support into the foundation. On the other hand, the concrete is poured into the prefabricated support, taking special care with the critical area of the support in which the Ni-Ti bars that are placed across the upper face of the foundation have been placed, once it has been placed the support. This face defines the intersection between the foundation and the prefabricated support. Finally, the connection between the support and the foundation is made (placement and filling of the hole by means of an expansive mortar of the Sika Grout type or similar).
Otro ejemplo de conexión con continuidad en la junta (6) es una conexión entre un soporte híbrido y una viga en un nudo con continuidad. En este caso, en primer lugar se monta la armadura longitudinal y transversal en el soporte inferior. La continuidad de las barras SMA (2) y de acero convencional (7) se garantiza por la disposición de conectores (5) . Las barras de Ni-Ti cruzan la intersección. A continuación, se realiza el encofrado del soporte y la fabricación de la parte del soporte inferior con un hormigón con prestaciones inferiores (por ejemplo, una resistencia de 80 MPa) . Una vez fraguado el hormigón de 80 MPa, se vierte el hormigón de tipo UHPC según la presente invención en la zona de conexión. Previamente, en la junta (6) entre ambos hormigones del soporte (H80-UHPC) se dispone un puente de unión tipo SikaDur o similar. A continuación, se vierte el hormigón en el resto de la estructura (nudo, viga y soporte superior) . En este caso, este hormigón se vierte después de verter el hormigón del elemento de conexión (1) según la presente invención, dando lugar a la continuidad a tracción mediante las fibras de acero.  Another example of connection with continuity in the joint (6) is a connection between a hybrid support and a beam in a knot with continuity. In this case, the longitudinal and transverse reinforcement is mounted first on the lower support. The continuity of the SMA (2) and conventional steel bars (7) is guaranteed by the arrangement of connectors (5). Ni-Ti bars cross the intersection. Next, the formwork of the support and the manufacture of the lower support part with a concrete with lower performance (for example, a resistance of 80 MPa) is performed. Once the 80 MPa concrete is set, the UHPC type concrete according to the present invention is poured into the connection zone. Previously, in the joint (6) between both concrete of the support (H80-UHPC) there is a bridge of SikaDur type or similar. Then, the concrete is poured into the rest of the structure (knot, beam and upper support). In this case, this concrete is poured after pouring the concrete from the connecting element (1) according to the present invention, giving rise to traction continuity by means of steel fibers.
Se han obtenido experimentalmente de un ensayo las derivas producidas al aplicar una carga lateral cíclica sobre un elemento de conexión (1) según la presente invención de acuerdo con la realización preferida, hormigón tipo UHPC de 121 MPa de resistencia a compresión y barras SMA con las características preferidas, así como sobre un elemento estructural convencional, de hormigón convencional de 34 MPa de resistencia a compresión y barras de acero B500SD. En la figura 4 se muestran los resultados obtenidos en dichos ensayos (gráfica superior: elemento de conexión según la invención, gráfica inferior: elemento estructural convencional) . Puede apreciarse que las derivas máximas obtenidas con el elemento de conexión (1) según la presente invención son el doble que las obtenidas con el elemento estructural convencional. The drifts produced by applying a cyclic lateral load on a connecting element (1) according to the present invention have been experimentally obtained from a test. according to the preferred embodiment, UHPC type concrete of 121 MPa of compressive strength and SMA bars with the preferred characteristics, as well as on a conventional structural element, of conventional concrete of 34 MPa of compressive strength and B500SD steel bars. The results obtained in said tests are shown in Figure 4 (upper graph: connection element according to the invention, lower graph: conventional structural element). It can be seen that the maximum drifts obtained with the connecting element (1) according to the present invention are twice that obtained with the conventional structural element.
También ha podido constatarse que el nivel de daño en el hormigón del elemento de conexión (1) según la presente invención tras un evento sísmico es muy reducido, y que una simple reparación permite recobrar la misma capacidad de resistencia y ductilidad. En concreto, tras reparar el elemento de conexión (1) según la presente invención volvió a realizarse un ensayo de derivas frente a cargas cíclicas, alcanzándose un 95% de la deriva máxima inicial y manteniendo la misma capacidad de resistencia y deriva residual.  It has also been found that the level of damage in the concrete of the connecting element (1) according to the present invention after a seismic event is very low, and that a simple repair allows to recover the same resistance and ductility capacity. Specifically, after repairing the connecting element (1) according to the present invention, a drift test was performed again against cyclic loads, reaching 95% of the initial maximum drift and maintaining the same resistance capacity and residual drift.
La deriva residual tras un evento sísmico en el elemento de conexión (1) según la presente invención es de aproximadamente el 15% de la deriva máxima, mientras que con los elementos estructurales convencionales es de aproximadamente el 80% de la deriva máxima.  The residual drift after a seismic event in the connection element (1) according to the present invention is approximately 15% of the maximum drift, while with conventional structural elements it is approximately 80% of the maximum drift.
Una ventaja adicional de la invención es que los procedimientos de fabricación son sustancialmente similares a los habituales, por lo tanto puede aplicarse en cualquier construcción, prefabricada o in situ, en obra civil o edificación, y con cualquier mano de obra.  An additional advantage of the invention is that the manufacturing processes are substantially similar to the usual ones, therefore it can be applied in any construction, prefabricated or on-site, in civil works or buildings, and with any labor force.
Algunas ventajas proporcionadas por la presente invención se resumen en la siguiente tabla, que presenta algunas características del elemento de conexión (1) según la presente invención en comparación con algunas soluciones conocidas protección contra sismos: Some advantages provided by the present invention are summarized in the following table, which presents some characteristics of the connection element (1) according to the present invention compared to some known solutions against earthquakes:
Parámetro InvenSolu¬ Aisla¬ Tirantes ción ción dores rigidiza- convendores cional Parameter InvenSolu ¬ Isolates ¬ Stiffness torsion mentions
E ecu- Procedimientos Si Si No Si ción constructivos  E ecu- Procedures Yes Yes No Yes constructive
habituales  usual
Mano de obra No No Si No especializada  Labor No No Yes Not specialized
Posible Si Si No No ejecución de la  Possible Yes Yes No No execution of the
solución en la  solution in the
misma obra  same work
Econó¬ Coste económico Si Si No Si mica Economiza la Si No Si Si estructura en Economy ¬ Economic cost Yes Yes No Yes mica Economize the Yes No Yes Yes structure in
su ciclo de  its cycle of
vida  lifetime
Daños Grado alto de No Si No Si tras el daño  Damage High grade of No Yes No Yes after damage
sismo Coste de Baj o Alto Alto Alto reparación ante  earthquake Cost of Low or High High High repair before
un mismo sismo  same earthquake
Derivas Capacidad de Si No No No resi¬ auto-recentrado Drift Ability of Yes No No No self-recent resi ¬
duales de la  dual of the
estructura tras  structure behind
el sismo  quake
Capaci¬ Alta ductilidad Si No No No dad de en las rótulas Capability ¬ High ductility Yes No No Do not give in the kneecaps
giro plásticas formadas plastic spin formed
Aplica- Estructuras ίη Si Si Si Si bilidad situ  Applies- Structures ίη Yes Yes Yes Yes situ bility
Estructuras Si No Si Si prefabricadas  Structures Yes No Yes Yes prefabricated
Invasi- Repercute en el No No No Si bilidad diseño de  Invasive in the No No No Yes bility design of
fachadas  facades
Propensión a No No No Si  Propensity to No No No Yes
eliminar  remove
espacio útil  useful space
Solución convencional: la ductilidad se consigue mediante exigencias de cuantía de armadura longitudinal y mayores disposiciones de armadura transversal en las zonas de encuentro, lo que dificulta la puesta en obra y aumenta los costes. La disipación de energía se genera en gran medida a costa de plastificación de las armaduras de acero y rotura del hormigón, lo que obliga en un futuro a costosas reparaciones o directamente conduce a la demolición y nueva construcción, y a posibles interrupciones de funcionamiento. Se aplica a sistemas de pórticos o duales equivalentes a pórticos. Conventional solution: ductility is achieved through the demands of the amount of longitudinal reinforcement and greater transverse reinforcement arrangements in the meeting areas, which makes it difficult to put it into operation and increases costs. The dissipation of energy is generated largely at the cost of plasticizing steel reinforcement and concrete breakage, which in the future forces costly repairs or directly leads to demolition and new construction, and possible operational interruptions. It applies to portico or dual systems equivalent to porches.
- Aisladores de la cimentación: solución similar a la propuesta por la presente invención, pero que aporta menos rigidez a la estructura, genera movimientos más violentos para el usuario y obliga a mayores labores de mantenimiento y limpieza e inspecciones periódicas.  - Foundation insulators: a solution similar to that proposed by the present invention, but which provides less rigidity to the structure, generates more violent movements for the user and forces more maintenance and cleaning and periodic inspections.
- Tirantes rigidizadores (cruces de San Andrés) : obliga a la construcción de nuevos elementos, cuya posición óptima se da en la zona exterior del edificio. Esto limita la visión hacia el exterior así como la estética del edificio. Si se posicionan en el interior, también coarta los espacios interiores .  - Stiffening braces (crosses of San Andrés): it forces the construction of new elements, whose optimal position is given in the exterior area of the building. This limits the outward vision as well as the aesthetics of the building. If they are positioned inside, it also restricts the interior spaces.
Aunque se ha descrito la presente invención con referencia a realizaciones preferidas de la misma, el experto en la técnica podrá concebir cambios y modificaciones sin por ello apartarse del alcance de las reivindicaciones adjuntas. Although the present invention has been described with reference to preferred embodiments thereof, the person skilled in the art may devise changes and modifications without thereby departing from the scope of the appended claims.

Claims

RE IVINDICACIONES RE IVINDICATIONS
Elemento de conexión (1) de protección contra sismos para la conexión entre elementos estructurales, comprendiendo el elemento de conexión (1) : Connection element (1) for protection against earthquakes for the connection between structural elements, the connection element (1) comprising:
- barras longitudinales - longitudinal bars
(2) de aleación con memoria de forma (SMA) y con superelasticidad en temperatura ambiente, dispuestas de manera que cruzan la intersección entre el elemento de conexión y el nudo u otro elemento estructural que se conecta; (2) of shape memory alloy (SMA) with superelasticity at room temperature, arranged so that they cross the intersection between the connecting element and the knot or other structural element that is connected;
- armadura transversal - transverse armor
(3); (3);
- hormigón de tipo VHPC o UHPC - VHPC or UHPC type concrete
(4) en el que se hallan embebidas las barras de SMA; (4) in which the SMA bars are embedded;
- conectores - connectors
(5) entre barras de acero convencionales (7) de los elementos estructurales y las barras de SMA (2) del elemento de conexión (1); y (5) between conventional steel bars (7) of the structural elements and the SMA bars (2) of the connecting element (1); and
- juntas (6) entre el elemento de conexión (1) y los elementos estructurales. - joints (6) between the connection element (1) and the structural elements.
Elemento de conexión (1) según la reivindicación 1, caracterizado por que la aleación con memoria de forma de las barras se selecciona del grupo constituido por Ni-Ti, Ni-Ti-Nb, Ni-Ti-Cu, Ni-Ti-Fe, Cu-Al-Be, Cu-Al-Ni, Cu-Al- Zn, aleaciones en base Mn y aleaciones en base Fe. Connection element (1) according to claim 1, characterized in that the shape memory alloy of the bars is selected from the group consisting of Ni-Ti, Ni-Ti-Nb, Ni-Ti-Cu, Ni-Ti-Fe , Cu-Al-Be, Cu-Al-Ni, Cu-Al-Zn, Mn-based alloys and Fe-based alloys.
Elemento de conexión (1) según la reivindicación 2, caracterizado por que la aleación con memoria de forma de las barras es Ni-Ti. Connection element (1) according to claim 2, characterized in that the shape memory alloy of the bars is Ni-Ti.
Elemento de conexión (1) según la reivindicación 3, caracterizado por que la aleación con memoria de forma de las barras es 50% Ni - 50% Ti. Connection element (1) according to claim 3, characterized in that the shape memory alloy of the bars is 50% Ni - 50% Ti.
Elemento de conexión (1) según cualquiera de las reivindicaciones anteriores caracterizado por que las barras longitudinales (2) de aleación con memoria de forma (SMA) y con superelasticidad en temperatura ambiente se combinan con una armadura de refuerzo seleccionada del grupo constituido por barras de polímeros reforzados con fibras (FRP), barras pasivas o activas de acero convencional . Connection element (1) according to any of the previous claims characterized in that the longitudinal bars (2) of shape memory alloy (SMA) and with superelasticity at room temperature are combined with a reinforcing reinforcement selected from the group consisting of bars of reinforced polymers fibers (FRP), passive or active bars of conventional steel.
6. Elemento de conexión (1) según cualquiera de las reivindicaciones anteriores caracterizado por que la armadura transversal (3) es de acero convencional. 6. Connection element (1) according to any of the previous claims characterized in that the transverse reinforcement (3) is made of conventional steel.
7. Elemento de conexión (1) según cualquiera de las reivindicaciones anteriores, caracterizado por que el hormigón presenta una resistencia de 100-200 MPa. 7. Connection element (1) according to any of the previous claims, characterized in that the concrete has a resistance of 100-200 MPa.
8. Elemento de conexión (1) según la reivindicación 7, caracterizado por que el hormigón (4) presenta una resistencia de 110 - 140 MPa. 8. Connection element (1) according to claim 7, characterized in that the concrete (4) has a resistance of 110 - 140 MPa.
9. Elemento de conexión (1) según cualquiera de las reivindicaciones anteriores, caracterizado por que el hormigón (4) presenta un contenido en fibras metálicas superior al 1%. 9. Connection element (1) according to any of the previous claims, characterized in that the concrete (4) has a metal fiber content greater than 1%.
10. Elemento de conexión (1) según cualquiera de las reivindicaciones anteriores, caracterizado por que el hormigón (4) es autocompactante . 10. Connection element (1) according to any of the previous claims, characterized in that the concrete (4) is self-compacting.
11. Elemento de conexión (1) según cualquiera de las reivindicaciones anteriores, caracterizado por que el hormigón (4) presenta la siguiente composición: 1000 kg de Cemento tipo CEM 42.5 SR, 184 kg de Agua, 150 kg de Humo de sílice densificado, 310 kg de Arena con una granulometría de 0,4 rom, 575 kg de Arena con una granulometría de 0,8 rom, 28,5 kg de Aditivo tipo Sika 11. Connection element (1) according to any of the previous claims, characterized in that the concrete (4) has the following composition: 1000 kg of CEM 42.5 SR type cement, 184 kg of Water, 150 kg of densified silica fume, 310 kg of Sand with a grain size of 0.4 rom, 575 kg of Sand with a grain size of 0.8 rom, 28.5 kg of Sika type Additive
20HE, 60 kg de Fibra acero tipo Dramix 80/30 BP y 90 kg de Fibra acero tipo Dramix OL 13/0.5. 20HE, 60 kg of Dramix 80/30 BP type steel fiber and 90 kg of Dramix OL 13/0.5 type steel fiber.
12. Elemento de conexión (1) según cualquiera de las reivindicaciones anteriores, caracterizado por que los conectores (5) entre barras de acero convencionales (7) de los elementos estructurales y las barras de SMA (2) del elemento de conexión (1) son conectores mecánicos. 12. Connection element (1) according to any of the previous claims, characterized in that the connectors (5) between conventional steel bars (7) of the structural elements and the SMA bars (2) of the connection element (1) They are mechanical connectors.
13. Elemento de conexión (1) según la reivindicación 12, caracterizado por que el conector mecánico entre el acero convencional y la barra de SMA (2) es de tipo roscado. 13. Connection element (1) according to claim 12, characterized in that the mechanical connector between the steel conventional and the SMA bar (2) is threaded type.
14. Elemento de conexión (1) según cualquiera de las reivindicaciones anteriores, caracterizado por que los elementos estructurales que se conectan se seleccionan del grupo constituido por realizaciones de obra civil y edificación . 14. Connection element (1) according to any of the previous claims, characterized in that the structural elements that are connected are selected from the group consisting of civil works and building works.
15. Elemento de conexión (1) según cualquiera de las reivindicaciones 1 a 13, caracterizado por que los elementos estructurales que se conectan se seleccionan del grupo constituido por elementos prefabricados y elementos ejecutados in situ. 15. Connection element (1) according to any of claims 1 to 13, characterized in that the structural elements that are connected are selected from the group consisting of prefabricated elements and elements executed in situ.
16. Elemento de conexión (1) según cualquiera de las reivindicaciones 1 a 13, caracterizado por que los elementos estructurales que se conectan se seleccionan del grupo constituido por soporte-cimentación, pila- cimentación, viga-cimentación, viga-soporte, pila-tablero, soporte-muro y viga-muro. 16. Connection element (1) according to any of claims 1 to 13, characterized in that the structural elements that are connected are selected from the group consisting of support-foundation, pillar-foundation, beam-foundation, beam-support, pillar- board, wall-support and wall-beam.
17. Elemento de conexión (1) según cualquiera de las reivindicaciones anteriores, caracterizado por que el elemento estructural es un soporte y la junta (6) entre el elemento de conexión (1) y el soporte se selecciona del grupo constituido por una junta seca y una junta húmeda. 17. Connection element (1) according to any of the preceding claims, characterized in that the structural element is a support and the joint (6) between the connection element (1) and the support is selected from the group consisting of a dry joint. and a wet joint.
18. Elemento de conexión (1) según cualquiera de las reivindicaciones anteriores, caracterizado por que el elemento estructural es una viga y la junta (6) entre el elemento de conexión (1) y la viga se selecciona del grupo constituido por una junta seca y una junta húmeda. 18. Connection element (1) according to any of the preceding claims, characterized in that the structural element is a beam and the joint (6) between the connection element (1) and the beam is selected from the group consisting of a dry joint. and a wet joint.
19. Elemento de conexión (1) según cualquiera de las reivindicaciones 1-17, caracterizado por que el elemento estructural es una pila y la junta (6) entre el elemento de conexión (1) y la pila se selecciona del grupo constituido por una junta seca y una junta húmeda. 19. Connection element (1) according to any of claims 1-17, characterized in that the structural element is a pile and the joint (6) between the connection element (1) and the pile is selected from the group consisting of a dry joint and a wet joint.
20. Elemento de conexión (1) según cualquiera de las reivindicaciones 1-17, caracterizado por que el elemento estructural es un nudo y la junta (6) en la intersección entre el elemento de conexión (1) y el nudo se selecciona del grupo constituido por una junta con continuidad y una junta sin continuidad. 20. Connection element (1) according to any of claims 1-17, characterized in that the element structural is a node and the joint (6) at the intersection between the connecting element (1) and the node is selected from the group consisting of a joint with continuity and a joint without continuity.
21. Elemento de conexión (1) según cualquiera de las reivindicaciones 1-17, caracterizado por que el elemento estructural es una cimentación y la junta (6) en la intersección entre el elemento de conexión (1) y la cimentación se selecciona del grupo constituido por una junta con continuidad y una junta sin continuidad. 21. Connection element (1) according to any of claims 1-17, characterized in that the structural element is a foundation and the joint (6) at the intersection between the connection element (1) and the foundation is selected from the group constituted by a board with continuity and a board without continuity.
22. Elemento de conexión (1) según cualquiera de las reivindicaciones 1-17, caracterizado por que el elemento estructural es un tablero y la junta (6) en la intersección entre el elemento de conexión (1) y el tablero se selecciona del grupo constituido por una junta con continuidad y una junta sin continuidad. 22. Connection element (1) according to any of claims 1-17, characterized in that the structural element is a board and the joint (6) at the intersection between the connection element (1) and the board is selected from the group constituted by a board with continuity and a board without continuity.
23. Elemento de conexión (1) según cualquiera de las reivindicaciones 1-17, caracterizado por que el elemento estructural es un muro y la junta (6) en la intersección entre el elemento de conexión (1) y el muro se selecciona del grupo constituido por una junta con continuidad y una junta sin continuidad. 23. Connection element (1) according to any of claims 1-17, characterized in that the structural element is a wall and the joint (6) at the intersection between the connection element (1) and the wall is selected from the group constituted by a board with continuity and a board without continuity.
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