Construction process of anti-seismic masonry wall

Abstract

Disclosed herein is a construction process for an anti-seismic wall comprising the steps of constructing rows and columns of masonry elements (1) with bricks or other construction material blocks and connecting one to the other with an adhesive (2). According to the invention, the bonding step of the building blocks is carried out by means of an adhesive in the presence of an elastic material. The elastic material is interposed between the masonry elements (1) and converts the masonry with frangible behavior into an element with ductile behavior adapted to withstand the forces of an earthquake. The invention can be adapted to all types of masonry elements.

Description

[0001] The present invention relates to masonry walls (brickwork pieces), and more particularly to the construction process of walls made of bricks or similar blocks and configured to have seismic characteristics.

[0002] Construction and related industries have existed since humans became sedentary. Since the beginning of agriculture, humans have started building houses, which are more comfortable than caves, accessible in plain areas, and where they can live with their own families, thus also enjoying a certain sense of family intimacy.

[0003] At first, houses and buildings were usually huts constructed using widely available materials such as, for example, straw and mud, which are still used today in some hot regions, mainly in the construction of the Third World. Straw represents the structural element, while mud serves as a binder to hold the straw together and, once dried, makes the resulting structure harder to obtain a stable form and a certain robustness against major adverse weather conditions. However, wind and rain can represent a danger for this type of building, and this type of building is basically unable to resist the influence of external temperatures.

[0004] Another construction material that is still in use and has a very ancient origin is wood, in which logs and their parts that are dovetailed and / or joined to each other or wooden boards nailed to each other are used. The structure obtained in this way is very strong, and as shown, for example, in Northern Europe where this type of structure is still widely used, the structure is resistant to temperature changes with a moderate final heat loss and can be easily heated. The main drawback of these buildings is the high fire risk because wood can burn easily: for example, in 1906, the city of San Francisco was destroyed by a fire that occurred after a strong earthquake, and the fire killed more people than the earthquake itself.

[0005] Later, bricks were discovered. Bricks are blocks of solid inert material - usually glazed clay - that are stacked on top of each other and bonded together by a binder to form a wall. Similar to bricks are blocks of cementitious materials, expanded concrete, and other similar materials, which are also composites. Over time, lime, concrete, and gypsum have been mainly used as binders.

[0006] Concrete, i.e., a slurry consisting of water, cement, and inert materials, is also used in the presence of metal reinforcing bars to produce so-called reinforced concrete, which can also be used in buildings, although the thermal insulation effect of reinforced concrete is extremely poor, which results in high air-conditioning costs and / or requires the walls made of reinforced concrete to be coated with a layer of thermal insulation material such as, for example, expanded polystyrene (so-called thermal insulation coating) plastered and painted at the end of construction.

[0007] A good building must be stable and strong, protected from rain, wind, and hot and cold climates, and must be fire-resistant to prevent the risk of fire, and must withstand the loads to which it is subjected.

[0008] Another hidden danger that has been seriously damaging the stability of buildings is the instability of the ground on which the buildings are constructed. In particular, landslides, subsidence, and earthquakes still represent important causes of building damage or even collapse. While it is relatively simple to be aware of subsidence and react over time to counteract its negative effects (in the worst case scenario, demolish the building and rebuild it in a more suitable area), this is not possible for landslides and earthquakes. In particular, earthquakes are sudden phenomena that are almost never predictable because there are many causes, a wide area of influence, and they therefore usually affect a large number of buildings, often creating a real emergency.

[0009] The energy generated during an earthquake is highly variable, as is the location of the so-called earthquake epicenter. Two main magnitudes have been established to determine the energy generated by an earthquake: the Richter magnitude and the Mercalli intensity scale. The Richter magnitude is directly related to the amount of energy actually released, while the Mercalli intensity scale is related to the macroscopic effects of the earthquake. The Mercalli intensity scale is divided into 12 degrees, from degree 1 to degree 12, where degree 1 refers to an earthquake that is only detected by instruments and no one can sense, and in the case of degree 12, there is destruction of every object, few survivors, damage to the ground, destructive tsunamis, and displacement of the earth's crust.

[0010] While the Richter magnitude is rated only based on the earthquake and is not affected by humans in any way, the Mercalli intensity scale can be rated to a large extent based on human actions, such that two earthquakes that record the same score on the Richter magnitude may produce very different scores on the Mercalli intensity scale. For example, an earthquake that scores 8 on the Mercalli intensity scale in an area where no preventive measures are provided may score 5 in an area where preventive measures have been taken to build earthquake-resistant buildings, even if they have the same score on the Richter magnitude. In some particularly earthquake-prone regions of the world, such as Japan, earthquake-resistant buildings have been built, where the number of victims has been significantly reduced and the damage to the building complex is less. After some particularly severe events, such as the Marche earthquake in 1997, the L'Aquila earthquake in 2009, and the Amatrice earthquake in 2016, Italy has promoted earthquake-resistant buildings more vigorously compared to the past, also from a regulatory perspective. This is having an impact: it is sufficient to consider the case of the 2016 earthquake, which also extended to the Marche, where in 1997 there had already been an earthquake and therefore in areas where more earthquake-resistant buildings had been built, there were fewer losses and no victims compared to areas where such steps had not been taken. Then, technical regulations have also developed in this direction.

[0011] Basically, there are currently two known methods for constructing earthquake-resistant buildings.

[0012] Based on the first approach, it is necessary to construct a significantly rigid structure that does not undergo swaying even in the presence of very strong forces and actually responds to earthquakes in a completely (or almost completely) inelastic manner so as not to have the movement of that structure during an earthquake. In fact, the swaying generated by the earthquake on the building is almost completely absorbed by the structure, thus not being able to impart significant movement.

[0013] Based on the second approach, which is very widely used in Japan, the exact opposite criterion is followed: the elasticity of the constructed workpiece is very high, and the forces released on the buildings constructed in this way cause very large swaying. However, due to the elasticity of the structure itself, even if it causes very significant movement, it will not lead to the fracture and failure of the structure and will at most cause the movement of the objects (including furniture) housed in the rooms without collapse or failure.

[0014] A major problem is also being able to retrofit structures that are not yet earthquake-resistant. This is particularly important in countries such as Italy, where the building heritage was mainly constructed before the introduction of earthquake-resistant measures, and moreover, the building heritage is widely protected and thus most of the building heritage cannot be demolished and rebuilt but can only be adjusted from the perspective of earthquake resistance.

[0015] However, in both cases, both load-bearing and non-load-bearing masonries are structures with poor ductility and brittle characteristics, which poorly withstand any stress other than the simple compression caused by vertical loads. In the case of an earthquake, stresses occur in many different directions, which requires simultaneous resistance to shear stress, tensile stress, and bending stress.

[0016] In addition, the masonry may even tend to react against the load-bearing structure, thus at least partially reducing the earthquake resistance capacity.

[0017] Generally, masonry is constructed by blocks, bricks, etc., which are bonded to each other by mortar, mainly based on cement or film adhesives: thus, the masonry is an element with poor ductility.

[0018] The fundamental problem of the present invention is to provide a masonry for buildings that overcomes the above-mentioned drawbacks and allows for improved seismic resistance to be obtained by constructing a ductile or elastic masonry, which reduces the risk of collapse in the event of an earthquake. Furthermore, it should be remembered that a ductile or elastic masonry is suitable for being properly connected to the building load-bearing structure (beams, columns, decks, etc.) and that this masonry will be useful if it collaborates with the said building load-bearing structure in the event of an earthquake, thereby simultaneously improving the elasticity / ductility and stiffness of the construction workpiece and further absorbing and damping seismic energy.

[0019] EP 3 037 599 discloses a reinforced block with reinforcing bars in order to increase the mechanical and static resistance of the block. The block is made of lightweight cement via autoclaving. In this patent, the insertion of an undefined "liner" inserted into the gap located between one block and another is mentioned. According to the description and the drawings, these liners have the function of covering the gap that may exist between one block and another and is created by a hydraulic binder. In this way, the said liners compensate for the forces generated in the case of wall bending. There is no mention at all of the material of these liners, so it is not clear whether the liners are made of an elastic material or a rigid or semi-rigid material. In any case, it is clear that the liners are inserts.

[0020] US2016 / 0 194 867 discloses the use of rubber parts as inserts in structures made of bricks or, in any case, made of masonry in order to compensate for swaying in the event of an earthquake.

[0021] Volume 351 of Construction and building materials by Dhir Prateek Kumar et al., published by Elsevier on 6 September 2022, reports data from experiments on masonry structures having mortar and rubber joints between bricks, subjecting the said masonry structures to load cycles in order to verify the energy dissipation due to these joints.

[0022] EP 0 005 814 discloses a bonding device for bricks, usually made of a fibrous material. However, in the bonding device, polystyrene beads are also considered.

[0023] EP 0 625 617 discloses the insertion of strips of material suitable for improving the thermal insulation of buildings.

[0024] JP 2001-254534 discloses the insertion of a filler for a joint made of an elastic material in order to improve the seismic characteristics of a wall.

[0025] These objects are achieved by a process for constructing a masonry wall, said masonry wall comprising masonry elements joined by an adhesive, characterized in that, in addition to said adhesive, in at least a part of the mutually connecting gaps located between the respective masonry elements, one or more binders / adhesives (binders / adhesives of polymeric nature) are inserted, said binder / adhesive having, once polymerized, an elongation at break of > 30%, preferably > 60%, even more preferably > 90%, most preferably > 150% (measured according to standard DIN 53504). The dependent claims describe preferred features of the invention.

[0026] It is very important that this material with elastic properties has a certain thickness suitable for allowing the ductility characteristics of the masonry in the case of an earthquake.

[0027] Likewise, it is important that this material has a suitable ability to make the masonry resist stresses in each different direction, and thus also has the ability to withstand shear, traction and bending stresses in addition to compressive stresses.

[0028] The thickness of the elastic material is crucial because the thickness of the elastic material together with the degree of elasticity of the material used determines the ductility / elasticity of the entire masonry. Additionally, said thickness is mainly crucial for the connections in the vertical plane - additionally, this connection is usually not constructed or only minimally constructed - and also serves to improve the transfer of forces between the individual elements of the masonry, thus avoiding the concentration of loads caused by both the irregularities of the masonry elements and the inevitable misalignments during the setting phase.

[0029] This can be achieved by a binder / adhesive (binder / adhesive of elastomeric nature) which, once polymerized, has elastic properties and a suitable thickness, and the ability to withstand not only vertical loads (and thus compression), but also shear, traction and bending stresses which typically occur during an earthquake.

[0030] The additional features and advantages of the invention will anyway be more easily understood from the following detailed description of a preferred embodiment, which is given by way of illustration and not of limitation and is illustrated in the accompanying drawings, in which:

[0031] Figure 1 A graph of displacement in millimeters against shear strength is shown for a first sample of masonry elements obtained based on a process according to the invention;

[0032] Figure 1A Shows data related to the Figure 1 tests;

[0033] Figure 2Shows a graph of shear strength against displacement in millimeters for a second sample of a masonry element obtained based on the process according to the present invention;

[0034] Figure 2A Shows data related to the Figure 2 tests;

[0035] Figure 3 Shows an example of the connection of a full masonry element based on the process according to the present invention;

[0036] Figure 4 Highlights the soft cord of the elastic adhesive in the drawing / Figure 3 ;

[0037] Figure 5 Shows a graph of shear strength against displacement in millimeters for samples of masonry elements from sample 5 to sample 10 obtained based on the process according to the present invention;

[0038] Figure 5A Shows data related to the Figure 5 tests;

[0039] Figures 6 to 10 Shows different examples of connections on the horizontal and vertical planes of different types of masonry elements that can be obtained using an elastic binder / adhesive; and

[0040] Figure 11 Shows a masonry wall obtained based on the process according to the present invention.

[0041] As observed, the present invention includes connecting the individual elements that make up the masonry (blocks, bricks, etc.) to each other, thereby inserting a binder / adhesive with elastic properties of a certain thickness - possibly different in vertical and horizontal connections - between said individual elements. In addition, this elastic material must allow sufficient strength to be obtained to resist the typical stresses of an earthquake, such as shear, traction, and bending stresses in addition to compression. The simplest and most direct method for achieving this is to use a binder / adhesive (binder / adhesive of elastomeric nature) that has elastic properties and bonding properties once polymerized. When applied at the construction site, this binder / adhesive will be required (mainly for connections on the horizontal plane) and in order to have a certain thickness, the masonry elements are kept spaced apart by specific means until the binder / adhesive of elastomeric nature has time to polymerize, at least to prevent the binder / adhesive from being squeezed during the realization of the masonry.

[0042] Undoubtedly, in order to ensure good adhesion between the binder / adhesive and the masonry element, it is also possible to use anchoring materials (so-called primers) or other means achievable by those skilled in the art. For example, depending on the expected final thickness of the elastic material, a certain excess of binder / adhesive is set and a certain extrusion is carried out in the case of improved adhesion.

[0043] Even in the known case where bands, strips or elastic inserts are inserted - among which closed-cell or mixed-cell foam materials can be mentioned - it is also possible to advantageously use an elastic adhesive / binder for the connection on the vertical plane, thus actually giving rise to another embodiment of the present invention.

[0044] In order to withstand earthquakes, in addition to the characteristics of the elastic material - hardness, modulus and elongation at break - which will be disclosed hereinafter and assumed to be the main reference parameters, the bonding characteristics, width, length (which are crucial for the purpose of bonding between individual blocks) and thickness (which are crucial for the purpose of elastic behavior) are also important.

[0045] Each actual solution shows its own advantages and requires adjustment within the reach of those skilled in the art anyway.

[0046] In order to obtain better cooperation for seismic resistance, the masonry including the masonry element and the interposed elastic material can also be properly interconnected with the load-bearing structure of the construction workpiece through a kind of pre-compression. The above pre-compression allows better cooperation for seismic resistance between the so-called structural components (beams, columns, decks, etc.) and the masonry. The pre-compression can be obtained by specific means, such as by inserting expandable materials or even by mechanical pre-compression actions, which are aimed at inserting both expandable materials and non-expandable materials into the formed gaps, or are equally aimed at inserting compression materials, which once released cause the desired pre-compression of the masonry. Advantageously, this pre-compression must occur considering the polymerization time of the elastic adhesive that can be used at the construction site. Then, the cooperation between the structure and the masonry is obtained.

[0047] The masonry with elastic behavior obtained according to the present invention can also be effectively connected to the ceiling (connected to the upper beams and decks), thus determining beneficial effects for the following reasons:

[0048] · Even in cooperation, the elastic behavior of the masonry allows possible bending of the upper deck or beam;

[0049] · The connection between the masonry and the ceiling allows box-shaped enclosure, thus increasing the stiffness of the construction workpiece without losing the ductility caused by the elasticity of the masonry;

[0050] · The connection between the masonry and the ceiling strongly contributes to preventing the overturning of the masonry, also in the case where the forces act perpendicular to the plane of the masonry ("out of plane").

[0051] In certain seismic situations, and considering the characteristics of the masonry elements, in the past, the insertion of an elastic bonding adhesive into the vertical joints was considered unnecessary.

[0052] However, as achieved by this insertion, the homogeneity of the stress transfer and the prevention of load concentration in the plane are very important. In addition, although beyond the purpose of the present invention, an improvement in terms of sound insulation is produced in this way. Additionally, the insertion of an elastic bonding adhesive of a certain thickness can be carried out for groups of elements and not necessarily for each individual element.

[0053] The masonry wall obtained according to the present invention is suitable for being combined and further strengthened according to the prior art.

[0054] For example, the masonry wall can be strengthened by the most suitable materials, also making use of the holes of the masonry elements and also considering the type of steel reinforcement that is most elastically compatible with the masonry modified according to the present invention, and, for example, the masonry wall can generally be connected even according to an angle in the most suitable way, or the masonry wall may be affected by tie rods.

[0055] Returning to the preferred solution, which provides for the use of an elastic binder / adhesive of polymeric nature, not to be confused with the so-called elastic mortars, which actually exhibit a very moderate elasticity; on the contrary, said elastic binder / adhesive is an adhesive typically used to obtain an adhesive action on surfaces that can usually undergo elongation and elastic deformation. Generally, the binder / adhesive of polymeric nature (although it can also contain mineral fillers and / or various types of additives) must have an elongation at break of > 30%, preferably > 60%, even more preferably > 90%, most preferably > 150% (measured according to standard DIN 53504). The binder / adhesive of polymeric nature is usually a commercially available compound. Some of the binder / adhesives of polymeric nature are polyurethanes, polysilanes (or also silane-modified), silicone-based or mixtures. As can be inferred from the studies carried out, the so-called MS polymers would seem to be certainly suitable. Some examples of the following commercially available materials are only for illustrative purposes and are not intended to be exhaustive: the Sikaflex series of Sika Schweiz; Mapesil AC, Mapeflex MS45, Mapeflex PU 45FT of Mapei; the MS Spray F vehicle of Fratelli Zucchini; SP 101 of Henkel Clear Fix, Hybrifix, HighTack (high tack) of Den Braven; Dowsil 895, Dowsil 776, Dowsil 896 of DOW; SiMP-Seal (seal) 55, SiMP CLEAR (clear), SiMP HIGH TACK (high tack) of NPT, etc. In addition to adjuncts, additives and fillers, the possible materials and the possible combinations of different polymeric materials are also very diverse and, taking into account the specific needs, allow to obtain products with the most suitable characteristics. To keep the individual elements spaced apart by the desired amount in the horizontal plane, an elastic material with the function of a spacer can be added, as better explained below.

[0056] Both in the practice of the present invention and based on the preferred embodiment, a binder / adhesive or elastic adhesive with high elastic characteristics means a material having characteristics that generally fall within the following limits:

[0057]

[0058]

[0059] It is desired to more precisely identify the elastic properties of suitable materials, and it is sufficient to refer to the data of Shore hardness A (measured according to standard DIN 53505) and the modulus at 100% elongation (measured according to standard DIN 53504) and set the range from the narrowest to the widest. The fractions of both hardness and modulus at 100% elongation are shown, since hardness and modulus are not always homogeneous with each other, but they must both be characteristics.

[0060] Regarding hardness:

[0061] · Shore hardness A from 46 to 54

[0062] · Shore hardness A from 38 to 57

[0063] · Shore hardness A from 25 to 60

[0064] · Shore hardness A from 15 to 65.

[0065] Regarding the modulus at 100% elongation:

[0066] · Modulus at 100% elongation from 0.9 N / mm 2 to 3 N / mm 2

[0067] · Modulus at 100% elongation from 0.6 N / mm 2 to 4 N / mm 2

[0068] · Modulus at 100% elongation from 0.3 N / mm 2 to 40 N / mm 2 .

[0069] More specifically, Figure 3 (Exemplary picture) shows three stacked concrete blocks 1 representing a masonry element, the blocks being arranged in parallel lines in a horizontal plane and staggered in a vertical plane (see Figure 11 ). The masonry element can be a clay brick or concrete (hollow if required) or a stone, wood or plastic material block, solid or preferably hollow, having a percentage of voids between 30% and 60%, preferably between 35% and 55%, more preferably between 40% and 50%. In the Figure 3 example, the masonry element 1 is bonded to each other by two cords 2 (or strips) of an elastic binder having a certain thickness 2.

[0070] Figure 4 The cords 2 of the binder inserted between the blocks 1 to form the masonry are shown in an exemplary manner.

[0071] Regarding the thickness of the elastic material, the present invention provides the following:

[0072] · In the horizontal plane:

[0073] ○ Average thickness from 1 mm to 12 mm

[0074] ○ Average thickness from 2 mm to 8 mm

[0075] ○ Average thickness from 2.5 mm to 5 mm

[0076] · In the vertical plane

[0077] ○ Average thickness from 0 mm to 6 mm

[0078] ○ Average thickness from 0.5 mm to 4 mm

[0079] ○ Average thickness from 1 mm to 3 mm

[0080] As can be observed from the previously reported values, the thickness of the elastic material in the vertical plane is lower than that in the horizontal plane. The previously reported values are averages because the masonry units have a certain irregularity, which is compensated for by the thickness variation of the elastic material. This thickness variation that is adapted to and compensates for the irregularities and setting defects of the masonry elements allows for improved force transfer mainly in the vertical joints, which are usually completely neglected, in the event of an earthquake, thus avoiding concentrated loads.

[0081] The width, surface, and thickness of the elastic bonding adhesive can be adjusted based on the characteristics of the substantially hollow and shaped masonry elements and also based on the need to resist earthquakes, usually in relation to the geographical area of the location where the building is being constructed or repaired and the masonry elements. In the case of using an elastic adhesive, during the construction of the masonry, the use of spacers can be provided, which can also be used to maintain correct alignment during the construction phase. The spacers can also be made of an elastic material (wherein the elasticity preferably falls within the range of the parameters reported in this document and can be appropriately differentiated to adjust the response to earthquakes in different planes) to prevent the elastic adhesive from being squeezed during the construction of the wall. If this is the case, they can be removed, or partially removed once the setting and / or polymerization of the elastic adhesive is complete. One advantage resulting from the use of a binder / adhesive of polymer nature compared to traditional concrete mortar is a significantly higher tensile strength. In fact, the tensile strength of the mentioned binder / adhesive of polymer nature is typically about 5 to 10 times that of traditional concrete mortar.

[0082] The above-mentioned elastic spacers can also include a polymer material with closed-cell or mixed-cell foaming (so-called foam).

[0083] Another possibility of maintaining a gap between masonry elements while avoiding squeezing is to use a binder / adhesive with a high alcohol thickness / viscosity and density even before polymerization. This can be achieved using specific products or by mixing on-site at the construction site with suitable fillers and / or extenders and / or additives that also increase the alcohol thickness / viscosity. Due to the higher and different contributions of the binder / adhesive during the setting phase of the masonry elements, these products can be used to build the masonry with or without the previously mentioned spacers or by using the spacers differently. It is also possible to change the density (alcohol thickness / viscosity) of the binder / adhesive on-site as needed. For example, the same binder / adhesive can be used to reduce the alcohol thickness / viscosity when in direct contact with the material to be bonded (almost acting as a primer), and loaded to increase the alcohol thickness / viscosity when the binder / adhesive must at least partially support or allow the alignment of the masonry elements.

[0084] Obviously, the binder can also be applied in a manner different from that Figures 6 to 10 depicted in Figures 6 to 10 and only represents some examples, and the binder can be applied on the contact surface of the masonry 1 in the most diverse ways and with a greater or smaller width, selected according to the application conditions, the geometry of the masonry elements, and the type of building intended to be constructed. It is also necessary to consider that in vertical joints, the binder / adhesive is prone to being squeezed by the expected amount and expanding, without experiencing the uncontrolled squeezing that occurs in horizontal joints under the influence of the weight of the masonry elements in the absence of spacers.

[0085] Figure 6 In addition to the cord 2, a button 3 of the elastomeric binder in an exemplary arrangement is also shown, where the cord 2 is arranged in a (horizontal) plane, and the button 3 is arranged in a (vertical) plane at 90° to this (horizontal) plane.

[0086] Figure 7 A cord 2 of the elastomeric binder in an alternative arrangement is shown.

[0087] Figure 8 A cord 2 of the elastomeric binder based on another alternative arrangement is shown.

[0088] Figure 9 A button 3 of the elastomeric binder and a cord 2 of the elastomeric material are shown.

[0089] Figure 10 A cord 2 of the elastomeric binder according to another alternative arrangement is shown.

[0090] Finally, Figure 11Figure 5 obtained based on the process according to the present invention is shown. The number and dimensions of the cords or strips 2 and both the buttons or strips located on the horizontal and vertical planes can have an infinite number of solutions and combinations while also considering the voids (in the case of hollow), dimensions, structural requirements, etc. of the masonry elements. Similarly, and highly relevant to the present invention, the thickness of the elastic material can be modified as needed, and the thickness of the elastic material, as described, must be significant mainly on the horizontal plane.

[0091] Experiments and tests

[0092] Various experiments were conducted to determine the resistance and deformation (or displacement) behavior of the masonry elements connected to the elastic material.

[0093] In fact, the resistance and synchronous deformation measurements highly represent the ability of the masonry to resist earthquakes in which shear, traction, bending, and compressive forces occur simultaneously.

[0094] At the same time, the ability of the masonry to twist, absorb, and dissipate seismic energy and return to its original position is also important for earthquake resistance.

[0095] For these experiments, as the elastic adhesive, "MS polymer" was used - this "MS polymer" has elastic properties and at the same time has adhesive properties - thus varying the arrangement amount, adhesive surface, thickness, hardness, and application direction of the shear force of the elastic adhesive.

[0096] The purpose of the tests was mainly to evaluate the behavior of the elastic adhesive under extreme conditions. In this first step of the experimental tests, the characteristics of the masonry elements (blocks, bricks, etc.) were ignored and the experiment was prevented from being affected by the possible fragility of the masonry elements themselves; therefore, high-resistance solid concrete blocks were used, such as Figure 3 and Figure 4 the concrete blocks represented in.

[0097] Roughly as Figure 3 tests were conducted by gluing three 10×10×10 cm small cubes with the "cord" of MS polymer in.

[0098] Two side blocks were laid and the central block was pushed to conduct the resistance and synchronous deformation (or displacement) tests.

[0099] In the following text and the drawings, the resistance will be designated as "shear strength" because the shear strength component seems to be the main one, but there are also tensile, bending, and compressive strength components. This is because, during the experiment, the side blocks were simply laid without being fixed, and in fact, this may cause torsion with bending, traction, and compressive forces in addition to the shear force.

[0100] In the case stated herein, the resistance measurements carried out in the experiments (and generally identified as "shear strength" within the scope of this document) appear to be highly relevant and represent the stresses that actually occur in various planes and in various directions during an earthquake.

[0101] Various tests were carried out to verify the differences due to thickness, hardness, and the adhesive surface, as well as the direction of application of the shear strength compared to the direction of the soft cords of the MS polymer.

[0102] These disclosures are tests that allow us to determine the effectiveness and reasonableness of the present invention that can be adapted to various combinations, however, all these combinations are within the reach of an expert in the field.

[0103] Sample n.1

[0104] Three 10×10×10 cm concrete cubes were glued using an MS polymer characterized by a hardness of 43 Shore A, and were joined by 2 soft cords with a length of 10 cm and a width of approximately 1.6 cm, 32 cm on each side 2 (equal to 32%). The thickness of the MS polymer soft cords was 5.5 mm. Figure 4 as in).

[0105] To determine the shear behavior, two side blocks were fixed, and an increasing pressure was applied to the central block. Thus, the central block resisted the increasing pressure but was displaced. The pressure was applied parallel to the direction of the glued soft cords. Then the resistance and displacement (from which the deformation was derived) were measured. The sample was subjected to two shear force cycles, thus sensing the displacement and therefore the deformation:

[0106] - The first cycle was interrupted when the increase in the shear force score stopped at 4.8 kg / cm 2 and the maximum displacement was 8.1 mm. Such a displacement means that the elastic material has undergone a deformation of 147%;

[0107] - After checking that it had almost completely returned to the starting position (elastic return > 90%), the test was repeated, giving a shear force score similar to the first test: shear strength 4.8 kg / cm 2 and displacement 8.5 mm (deformation approximately 155%).

[0108] Furthermore, at the end of the second cycle, the central block almost returned to the starting position in an incredible way: elastic return > 90%. The results are graphically shown in Figure 1 .

[0109] Sample n.2

[0110] As in the case of sample n.1, an MS polymer characterized by a Shore A hardness of 43 was used to glue together three 10×10×10 cm concrete cubes, joined by two MS polymer cords with a gluing surface of 10 cm in length, approximately 2 cm in width and 40 cm on each side (equal to 40%), and a thickness of the MS polymer cords of 5 mm. In this case, 2 the images of Figure 3 and Figure 4 are also valid as a reference.

[0111] To determine the shear behavior, two side blocks were fixed and an increasing pressure was applied to the central block, so that the central block resisted the increasing pressure but was displaced. The pressure was applied parallel to the direction of the gluing cords. Then, the resistance and the displacement (from which the deformation was derived) were measured.

[0112] This second test was also carried out to evaluate the potential resistance to multiple seismic cycles. For this purpose, the load was initially rather moderate and was gradually increased.

[0113] The results are reported in Figure 2 .

[0114] Initially, eleven loading and unloading cycles were performed, in which the shear load reached 1.9 kg / cm 2 , and the displacement reached 1.6 mm (deformation 32%), without any differences being observed (for simplicity, only cycle n.11 is plotted in Figure 2 ).

[0115] Subsequently, five cycles (12 to 16) were performed, increasing the shear strength to 2.9 kg / cm 2 , with a maximum displacement of 2.9 mm (deformation 58%). The blocks always returned to their position (for simplicity, only cycle n.16 is plotted in Figure 2 ).

[0116] Then, four additional cycles (17 to 20) were performed, increasing the shear strength to 3.85 kg / cm 2 and with a maximum displacement of 4.1 mm (deformation 82%). Although the deformation increased under stress, the return was almost always close to 100% (for simplicity, only cycle n.20 is reported in Figure 2 ).

[0117] Subsequently, cycle n.21 was pushed to the maximum pressure allowed by the equipment of 7.7 kg / cm with a displacement of 10.37 mm (deformation 207%). For simplicity, only cycle n.20 is illustrated in Figure 2 .

[0118] After this cycle, the central block does not return to its position: at a deformation of more than 200%, the return is about 80%.

[0119] Therefore, a new cycle is performed up to 7.1 kg / cm 2 where the displacement is 11.1 mm (deformation 222%) (see Figure 2 , cycle n.22).

[0120] After this further cycle, the return is about 60%.

[0121] Sample n.3

[0122] Three 10×10×10 cm concrete cubes are glued using an MS polymer characterized by a hardness of 43 Shore A and are joined by three MS polymer cords with a length of 10 cm, a width of about 2 cm, and a bonding surface of 60 cm per side 2 (equal to 60%), with the MS polymer cords having a height of 2.2 mm, so that the distance between the blocks is 2.2 mm. The gluing pattern and pictures ( Figure 3 and Figure 4 ) are still schematically valid.

[0123] To determine the shear behavior, two side blocks are fixed and an increasing pressure is applied to the central block, so that the central block resists the increasing pressure but is displaced. The pressure is applied parallel to the direction of the gluing cords. Then, the resistance and displacement (from which the deformation is derived) are measured.

[0124] This third sample was also potentially affected by multiple seismic cycles. For this purpose, the load was initially rather moderate and was gradually increased.

[0125] Initially, six loading and unloading cycles were performed, where the shear load reached 2.6 kg / cm 2 and the displacement reached 1.15 mm (deformation 52%). The elastic return was close to 100%.

[0126] Second time, three cycles were performed, increasing the shear stress to 3.2 kg / cm 2 and the maximum displacement was 1.4 mm (deformation 64%). The elastic return was again close to 100%.

[0127] After that, eight additional cycles were performed, increasing the shear stress to 3.85 kg / cm 2 and the maximum displacement was 1.75 mm (deformation 79%). The elastic return was still close to 100%.

[0128] Subsequently, three additional cycles were performed, increasing the shear stress to 4.5 kg / cm 2And the maximum displacement is 1.85 mm (84% deformation). The elastic return remains close to 100%.

[0129] Subsequently, four additional cycles were performed, increasing the shear stress to 5.1 kg / cm 2 and the displacement was 2.3 mm (104% deformation). The elastic return remained close to 100%.

[0130] Then, three additional cycles were performed, increasing the shear stress to 5.75 kg / cm 2 and increasing the displacement to 2.53 mm (115% deformation). The return remained 100%.

[0131] Three cycles were performed, increasing the shear stress to 6.4 kg / cm 2 and increasing the displacement to 3 mm (150% deformation). The elastic return remained close to 100%.

[0132] Three additional cycles were performed, increasing the shear stress to 7.7 kg / cm 2 and increasing the displacement to 3.9 mm (177% deformation). The elastic return did not deviate from 100%.

[0133] In the case of two additional cycles, the shear stress was increased to 9 kg / cm 2 and the displacement was increased to 4.9 mm (223% deformation), and the elastic return remained close to 100%.

[0134] At the end of another cycle, the stress reached 7.3 kg / cm 2 , and the gluing failed. Therefore, what puts the elastic binder / adhesive in crisis is not the deformation problem, but the gluing problem. On the other hand, it should be considered that the shear strength like the one found is very high and may be impractically high for the purposes of this application.

[0135] It can be inferred that as long as the elastic binder / adhesive used remains within an elongation rate of 100% to 200%, the elastic binder / adhesive can withstand many, which can be a large number of seismic cycles.

[0136] A total of thirty-six cycles. No graph was plotted because the behavior was the same as that found in the previous samples.

[0137] Sample n.4

[0138] Three 10×10×10 cm concrete cubes were glued using an MS polymer characterized by a hardness of 43 Shore A, through a length of 10 cm, a width of approximately 0.6 cm, 24 cm per side 2Four MS polymer cords with a bonding surface (equal to 24%) are connected. The thickness of the MS polymer cords is 10 mm. Figure 3 and Figure 4 The gluing patterns and pictures in

[0139] remain valid. To determine the shear behavior, two side blocks were fixed and increasing pressure was applied to the central block, so that the central block was subjected to increasing pressure but was displaced. The pressure was applied parallel to the direction of the glued cord. Then the resistance and displacement (from which the deformation was derived) were measured.

[0140] This fourth sample was also potentially affected by various seismic cycles. For this purpose, the load was initially rather moderate and was gradually increased.

[0141] First, three loading and unloading cycles were performed, in which the shear load reached 2.4 kg / cm 2 and the displacement reached 6 mm (deformation 60%). The elastic return was close to 100%.

[0142] Then, three cycles were performed to increase the shear stress to 3.2 kg / cm 2 and to increase the displacement to 8.4 mm (deformation 84%). The elastic return was close to 100%.

[0143] Then, two additional cycles were performed to increase the shear stress to reach 3.85 kg / cm 2 and to increase the displacement to 10.9 mm (deformation 109%). The elastic return was again close to 100%.

[0144] Subsequently, another cycle was performed to increase the shear stress to reach 4.15 kg / cm 2 and to increase the displacement to 13 mm (deformation 130%). The elastic return remained close to 100%.

[0145] Then, the test had to be interrupted because the instrument did not allow displacement readings greater than 13 mm.

[0146] Samples 5 to 10

[0147] Three 4×4×6 cm concrete prisms were glued using an MS polymer characterized by a hardness between 38 Shore A and 50 Shore A, and were connected by cords with a length of 6 cm, and variable width, thickness and bonding surface as indicated in each test report. Although the dimensions were different, the gluing patterns and pictures ( Figure 3 and Figure 4 ) remained schematically valid.

[0148] To determine the shear / deformation behavior, two side prisms were fixed and an increasing pressure was applied to the central prism, so that the central prism was subjected to an increasing pressure but was displaced. Different from the tests on Samples 1 to 4, the pressure was applied perpendicular to the direction of the glued cord. Then, the resistance and displacement (from which the deformation was derived) were measured.

[0149] In this case, an experiment on the shear strength was carried out such that the pressure caused the glued cord to break, and readings were taken until possible breakage ([[]] Figure 5 )

[0150] It can be easily understood from the foregoing description, the shear strength score, and the deformation capacity that the masonry results obtained in this way are in themselves particularly suitable for withstanding the forces generated by an earthquake and applied simultaneously in several directions and acting on the masonry itself.

[0151] Furthermore, if properly connected to the load-bearing structure, the masonry wall so constructed is also suitable for cooperating in enhancing the seismic strength, both as an elastic element and as an element that increases the stiffness of the masonry wall in the case of connection to the structure, thereby creating a ribbed or box-shaped closed connection between the structural elements. It is easily understood that by applying this technology, each individual and simple repair intervention can provide an opportunity to enhance the seismic resistance of the entire building structure. Incidentally, it should be expected that even without additional measures, the buildings obtained by the process according to the present invention have important seismic characteristics that can resist large earthquake events anyway, even individually.

[0152] The present invention is also suitable for the case of repairing existing buildings, constructing new interior walls and floors, or demolishing and reconstructing a part of the peripheral walls, so that the robustness and safety of the building heritage are significantly increased in terms of seismic resistance.

[0153] In any case, it must be understood that the present invention should not be considered limited to the specific arrangements disclosed above, which only represent some possible exemplary embodiments, but several modifications are possible without departing from the scope of protection of the invention itself as defined by the appended claims, all of which are within the reach of a person skilled in the art.

Claims

1. A construction process of a masonry wall, the masonry wall comprising masonry elements connected by an adhesive, characterized in that, In at least a part of the interconnected spaces located between the respective masonry elements, in addition to the binder, one or more binders / adhesives (binders / adhesives of polymeric nature) are interposed, which, once polymerized, have an elongation at break of > 30%, preferably > 60%, even more preferably > 90%, most preferably > 150% (measured according to standard DIN 53504).

2. The process according to claim 1, characterized in that, The elastic adhesive of polymeric matrix nature is selected from the group comprising polyurethanes, polysilanes, silane-modified polymers, siloxanes and MS polymers.

3. The process according to any one of claims 1 or 2, characterized in that, During the stage of masonry construction, spacers are used in order to allow the elastic adhesive to be applied with the desired thickness before polymerization occurs and, at the same time, to achieve proper alignment without being squeezed.

4. The process according to claim 3, characterized in that, The spacers are also made of an elastic material having similar or different elastic characteristics compared to the elastic characteristics of the elastic adhesive, in order to diversify the response to earthquakes in different planes.

5. The process according to any one of claims 2 to 4, characterized in that, The process also uses an elastic binder / adhesive of polymeric nature having a high alcohol thickness or viscosity obtained by adding fillers and / or extenders and / or additives.

6. The process according to claim 4, characterized in that, The elastic material interposed between the masonry elements has a polymeric nature and may include closed-cell or mixed-cell foam materials.

7. The process according to any one of the preceding claims, characterized in that, Average thickness of the polymeric binder interposed between the masonry elements: Comprises between: · In the horizontal plane: 1 mm to 12 mm, preferably 2 mm to 8 mm, and most preferably 2.5 mm to 5 mm · In the vertical plane: 0 mm to 6 mm, preferably 0.5 mm to 4 mm, most preferably 1 mm to 3 mm.

8. The process according to any one of the preceding claims, characterized in that, The elastic binder interposed between the masonry elements has a hardness characteristic expressed in Shore A, which comprises between: 15 and 65, preferably 25 and 60, more preferably 38 and 57, and most preferably 46 and 54.

9. The process according to any one of the preceding claims, characterized in that, The elastic binder interposed between the masonry elements, once polymerized, has a modulus characteristic of 100%, which comprises between: 0.3 N / mm 2 and 40 N / mm 2 , preferably 0.6 N / mm 2 and 4 N / mm 2 , most preferably 0.9 N / mm 2 and 3 N / mm 2 , measured according to standard DIN 53504.

10. The process according to any one of the preceding claims, characterized in that, The obtained masonry, whether or not structural, is connected by pre-compression to other elements of the construction workpiece, whether or not structural.

11. The process according to any one of the preceding claims, characterized in that, The masonry elements are clay bricks or hollow concrete bricks, the void percentage of which comprises between 30% and 60%, preferably between 35% and 55%, more preferably between 40% and 50%.

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