EP2920380B1

EP2920380B1 - Method for the production of masonry and masonry made with such a production method; a system for the production of masonry and the use of such a system

Info

Publication number: EP2920380B1
Application number: EP13789580.1A
Authority: EP
Inventors: Marek Torbus; Christian Duve
Original assignee: Torbus Marek
Current assignee: Torbus Marek
Priority date: 2012-11-14
Filing date: 2013-11-14
Publication date: 2018-03-14
Anticipated expiration: 2033-11-14
Also published as: EP2920380A1; WO2014076178A1; ES2670940T3; ITBO20120622A1

Description

This invention relates to a method for producing masonry and masonry made with this method according to the generic parts of claims 1 and 9.
In the construction industry, the increase in material and labor costs has led to a growing demand for new and more effective construction methods and building materials.
In order to reduce setting times and therefore the labor costs, bricks with tongue and groove connections have been proposed that facilitate the setting of bricks or building blocks in a line. Such bricks or building blocks are proposed with different geometries and sizes, and of the solid or hollow type, for example with cavities or holes, with the percentage of perforations or holes variable depending on requirements. As is well known, the hollow space percentage of a brick or building block is the ratio expressed as the percentage between the sum of the surface area of the hollow spaces, perforations or cells and the surface area of the top surface orthogonal to the axes of the hollow spaces or perforations.
The bricks or building blocks mentioned above characterized by tongue and groove connections still have to be bound together in any case by means of hydraulic mortars containing cement, similar to the traditional bricks without tongue and groove connections.
The times for the setting of bricks with tongue and groove connections are therefore only slightly shorter due to a simplified alignment, but they prove to be equally as long because the uniform application of the mortar represents a precise procedure and because, in any case, a horizontal laying of the brick is still required.
In the construction industry, in addition to the above-mentioned necessity to reduce building costs, energy-saving measures are becoming increasingly necessary, which require the use of insulating materials that reduce the transfer of heat between the interior space and the exterior.
On the one hand, hollow-type bricks, possibly lighter in ceramic paste, achieve good values for thermal transmittance because the cavity or perforation per se guarantees good thermal insulation. General masonry built with such bricks traditionally requires an additional insulation, namely the so-called "thermal coat", because the ceramic structure of the brick acts as a thermal bridge between the interior and the exterior environment.
Today there are different technologies on the market for producing the so-called "thermal coat" which generally is characterized by a multiple layered panel made out of insulating material layers of different natures. Among the most commonly used insulation materials is rock wool, glass wool, pressed fibers of wood and other plant material, expanded polystyrol and foamed polyurea, phenolic and urethane resins. The latter can also be applied directly to the finished masonry and foamed to the desired thickness. The above-mentioned insulation panels are prefabricated and attached to the masonry and counter-walled. A so-called sandwich structure is thereby achieved, which is characterized by optimal thermal insulating properties but also by the high costs for the attachment thereof because the "thermal coat" and counter-walling represent additional costs compared to the price of traditional masonry walls.
In this regard EP 2 148 018 A2 discloses a method for connecting bricks in order to build up masonry, wherein a liquid expanding connection material i.e. polyurethane is used to connect the bricks, and wherein the connection material is partly arranged in holes of the bricks. DE 85 17 391 U1 discloses a brick with cavities that can be filled with polyurethane foam to exclude the influx of mortar or for heat insolation reasons. CA 2 594 908 A1 describes a method of stabilizing wall structure made of hollow cementitious blocks by introducing a "reinforcing rod" into the hollow cores of the block. Said reinforcing rod is kept in place by an expanding polymer resin. DE 27 14 341 A1 discloses masonry built up from bricks containing cavities. These cavities can be filled with filling material as polyurethane foam. However, the usage of polyurethane is for heat insulation reasons, whereas further cavities of the bricks are filled with reinforced ferroconcrete for mechanical stability reasons. DE 27 14 341 A1 discloses the features of the preambles of claim 1 and claim 9. All these proposals for building masonry are not suitable for solving the drawbacks mentioned.
The object of the invention is to avoid the above-mentioned drawbacks. In particular, it is the object of the invention to reduce the required time for producing masonry. Another object of the invention is to reduce the costs and/or the amount of raw materials required for producing masonry. A further object of the invention is to reduce the costs and/or the amount of raw materials necessary for the thermal insulation. In particular, the aim is to avoid the attachment of the "thermal coat" while achieving, at the same time, the desired insulation.
This object is achieved by a method for producing masonry and masonry made with this method according to claims 1 and 9.
In particular, the object of the invention is achieved by a method for making masonry work, comprising the steps of forming the masonry work by assembling together a plurality of bricks and/or building blocks, the bricks and/or building blocks having a substantially flat and planar outer surface and being provided with joints and/or alignment elements at the contact area between adjacent bricks and/or building blocks which facilitate alignment of the bricks and/or building blocks such that, after construction, the bricks and/or building blocks provide the masonry work with a planar outer surface without substantially any gaps between the adjacent bricks and/or building blocks, and stably bonding together the adjacent bricks and/or building blocks, the bricks and/or building blocks being of the hollow type with a percentage of holes greater than or equal to 15%; wherein the forming step comprises laying the bricks and/or building blocks with the axis (A) of respective perforations, holes or cavities of the bricks and/or building blocks at right angles to the plane (P) of laying, and the bonding step comprises pouring or injecting a polyurethane binder in a liquid form inside all of the perforations, holes or cavities of the bricks and/or building blocks for securely fixing them to each other through a volumetric expansion of the polyurethane binder in a passage-way formed between the perforations, holes or cavities of adjacent bricks and/or building blocks and its solidification from the liquid state to a foamy state inside the perforations, holes or cavities.
An important point of the invention is the fact that bricks and/or building blocks having perforations, holes or cavities which extend through the brick and/or building block or a part thereof are used and that a liquid polyurethane binder is filled into all of these perforations, holes or cavities after the alignment of the stones in a manner that the perforations, holes or cavities are at least in part communicating with each other. The liquid polyurethane binder solidifies and hardens in these perforations, holes or cavities, thereby fixing and stabilizing the building blocks which are laid one upon the other.
It should be noted that the liquid polyurethane binder preferably is injected and especially poured into the cells from above and flows through the communicating cavities of the bricks and/or building blocks due to gravity. According to a further embodiment, an external pressure can be applied for the injection of the liquid polyurethane. When the liquid polyurethane foams up, the bricks and/or building blocks are interconnected in accordance with their aligned arrangement.
According to the invention, the bricks and/or building blocks can advantageously be arranged in a straightened and dry manner without the need of any mortar or cement, which leads to the saving of time and material. Thereby the costs for producing masonry can be reduced significantly.
The bricks and/or building blocks which can be used for the invention have a percentage of holes of between 15% and 70% and preferably of between 15% and 55%. By using bricks and/or building blocks having the aforementioned percentage of holes, it can advantageously be ensured that at least part of the cavities in the bricks and/or building blocks which are arranged during the forming of masonry in a staggered or non-staggered manner are communicating and that the poured or injected polyurethane extends through and interconnects adjacent bricks and/or building blocks.
It should be noted that bricks and/or building blocks which are suitable for implementing the invention can be natural, i.e., naturally occurring, but formed to have a substantially flat and planar outer surface, and/or artificial building blocks, building bricks or building stones being made of sandstone, limestone, granite, slate, marble, tuff, greywacke, rhyolite, red-brick, clinker, lime sandstone, clay or concrete.
Preferably, the polyurethane binder is of the type with at least two components. In this regard, one component is a polyol component, such as a polyhydric alcohol or a mixture of two or more polyhydric alcohols which are able to react with the other component. The polyol component can be selected from the group consisting of: a propoxylated triol with a hydroxyl value in the range of 200 mgKOH/kg to 700 mgKOH/kg, preferably in the range of 250 mgKOH/kg to 630 mgKOH/kg; propoxylated sorbitol with a hydroxyl value in the range of 400 mgKOH/kg to 600 mgKOH/kg, preferably in the range of 480 mgKOH/kg to 530 mgKOH/kg; glycerin as a crosslinking agent with a hydroxyl value of 1830 mgKOH/kg; or mixtures thereof. The second component is an isocyanate component selected from the group consisting of one or a mixture of several polyisocyanates, in particular 4, 4'-Methylendiphenyldiisocyanat or mixtures thereof. The first and second component, when mixed, are suitable for forming a rigid polymer, especially a rigid polyurethane foam.
Typically, a propoxylated triol and/or propoxylated sorbitol with the aforementioned hydroxyl values are the backbone polyols of the polyurethane binder and provide stiffness and long term stability to the polyurethane binder. The cross-linking agent as described above may be used to improve cohesion and adhesion or the like.
In a further embodiment, a weight ratio of the polyol component in relation to the isocyanate component is in the range of 100 : 100 to 100: 250, preferably 100 : 150 to 100 : 230, and more preferably in the range of 100 : 160 to 100 : 200.
The mixing ratio is related to the OH value of the individual polyol blend. The so called isocyanate index is the percentage of isocyanate saturation. As an example, the mixing ratio of 100 : 168, which may be realised in a system using HA 24-310-00, represents an isocyanate index of 113; that is, a 13% excess of isocyanate. In another example, the mixing ratio of 100 : 190 is realised by a system using HI 26-041-00, which represents an isocyanate index of 143. This higher index advantageously provides an improved flame resistance due to the presence of more aromatic cycles. As a further example of the invention, a fixed mixing ratio of 1 : 1 parts by volume, with a typical mixing ratio of 100 : 110 parts by weight is used, which can advantageously be utilised for standard dosing machines for pour-in-place foams, which oftenly use simple piston pumps.
In another further embodiment, the polyurethane binder comprises a flame-retardant selected from the group consisting of halogenated polyetherpolyol with a hydroxyl value in the range of 300 mgKOH/kg to 400 mgKOH/kg, preferably in the range of 330 mgKOH/kg to 370 mgKOH/kg; triethyl phosphate; or mixtures thereof.
As it could be found, a halogenated polyetherpolyol provides high fire-resistance and does not affect thermal insulation and mechanical properties. In contrast, triethyl phosphate is a flame-retardant with a high phosphorus content and low viscosity. This provides high flame-resistant performance to a polyurethane binder as well as providing a good flowability.
In another further embodiment, the polyurethane binder comprises polyether modified polysiloxane and/or polyether-polydimethylsiloxan-copolymer and/or N,N-dibenzylamine, triethylenediamin and/or water.
Polyether modified polysiloxane and/or polyether-polydimethylsiloxan-copolymer are, according to the unvention, used as surfactants for cell regulation and for providing dimensional stability. N,N-dibenzylamine may be used as a tertiary amine catalyst which may have moderate catalytic activity which improves adhesion properties and reduces surface friability. A triethylenediamin component may be used as a catalyst for both gelling and blowing reactions.
In yet another embodiment, the polyurethane binder comprises a blowing agent selected from the group of physical blowing agents, such as hydrocarbons (for example, pentane) and/or fluorinated hydrocarbons (for example 1,1,1,3,3-pentafluorobutane), and chemical blowing agents, such as carboxylic acids (for example formic acid), which releases CO₂ though the reaction with the isocyanate component, to ensure a complete filling of the cavities in which the liquid polyurethane binder is poured.
Preferably, the polyurethane binder comprises fillers, such as natural and/or synthetic fibers, for example glass fibers and/or carbon fibers and/or aramid fibers to enforce the strength of the foamed binder. Not according to the invention is, as shown for example in Fig. 2, that only part of the perforations, holes or cavities or at least the outer perforations, holes or cavities of each brick and/or building block receive the polyurethane binder according to a predetermined or random pattern. In that way, the degree of thermal insulation can advantageously be adjusted according to the requirements. Not according to the invention is, than the masonry can be provided with a thermal insulation element by filling at least the outer perforations, holes or cavities of each brick and/or building block with liquid polyurethane binder which subsequently foams up.
Furthermore, the object of the invention is achieved by masonry work according to claim 9. In particular, this object is achieved by masonry work comprising a plurality of bricks and/or building blocks, the bricks and/or building blocks having a substantially flat and planar outer surface and being provided with joints and/or alignment elements at the contact area between adjacent bricks and/or building blocks which facilitate alignment of the bricks and/or building blocks such that, after construction, the bricks and/or building blocks provide the masonry work with a planar outer surface without substantially any gaps between the adjacent bricks and/or building blocks, the bricks and/or building blocks being of the hollow type with a percentage of holes greater than or equal to 15%; the bricks and/or building blocks assembled with the axis (A) of respective perforations, holes or cavities at right angles to the plane (P) of laying, wherein the bricks and/or building blocks are straightened and are laid dry in a forming step of forming the masonry work, the bricks and/or building blocks being stably bonded together using a polyurethane binder in liquid form poured inside all of the perforations, holes or cavities of the bricks and/or building blocks which are securely fixed to each other through a volumetric expansion of the liquid polyurethane binder in the passage-way formed between the perforations, holes or cavities of adjacent bricks and/or building blocks and its solidification from the liquid state to a foamy state inside the perforations, holes or cavities.
The technical features of the invention according to the above-mentioned objects can be easily determined from the contents of the claims and the advantages of the invention will become clear through the following detailed description. This detailed description will refer to the accompanying drawings which illustrate a manner of realization not according to the invention, which is exemplar only and not limiting, wherein:

Fig. 1 represents, in longitudinal section, a masonry wall, whereby not all perforations, holes or cavities are shown to be filled with the polyurethane binder (whereas having all perforations, holes or cavities filled is essential for the invention)
Fig. 2 is a perspective view of a building block as a component of the masonry of Fig. 1.

In Figure 1, masonry work with reference numeral 1 is shown that is realized by assembling a plurality of building blocks 2 and by permanently bonding adjacent building blocks 2. More precisely, masonry 1 is realized by positioning a plurality of building blocks 2, appropriately offset, side by side and in multiple layers. The layers lying superimposed above each other are placed offset in the traditional manner, e.g., with the second layer of building blocks 2 on the first layer and, compared to the first layer, placed offset by half a length of a building block, the third layer of building blocks 2 lies, viewed perpendicular, exactly over the first layer, the fourth layer over the second layer, etc.
Building blocks 2 are characterized by perforations, holes or cavities with a hollow space percentage over 15%. Preferably, building blocks 2 have a hollow space percentage between 15 and 70%.
Especially preferable are building blocks 2 with a hollow space percentage between 15 and 55%. Preferably building blocks 2 are straightened or aligned to provide a planar outer surface to the masonry work 1, e.g. the dimensions of each building block 2 is guaranteed within narrow tolerances.
That is, the building blocks 2 are configured to have a flat or substantially flat and planar outer surface such that, after the building blocks 2 are arranged in the aforementioned configuration, the resulting structure has an overall flat and planar outer surface. In an advantageous manner, this results in outer surface(s) of the building blocks 2 being formed without substantially any gaps along the joins between adjacent building blocks 2. In comparison with the known art, such a structure results in the expansion of materials being irrelevant. For example, consider the influence of water, and more specifically freezing water, that is disposed inside the gap of the prior art. Such an expansion of the water, due to a decrease in temperature and the transition to ice, causes forces to be experienced within the gap, typically separating the building blocks 2 away from each other, and thus causing damage to the join of the building blocks 2. Providing a flat, substantially flat, or planar outer surface prevents or reduces this damage danger. Equally, the internal portions, such as the perforations, holes or cavities 4, of the building blocks 2 may also be provided with flat, substantially flat, or planar surfaces, when provided in the straightened or aligned configuration, thereby reducing the effect of the expanding polyurethane binder 3 disposed in gaps therebetween in a similar manner.
Masonry 1 does not contain any hydraulic cement mortar because the building blocks 2 are set dry, namely, with the axis A of the perforations, holes or cavities 4 orthogonal on the setting level P and they are bonded together permanently and orthogonal in respect of the setting level P by means of a two or multiple component polyurethane binder 3, for example, which is positioned in the interior of all perforations, holes or cavities 4 of building blocks 2, for example.
The polyurethane binder 3 is added as a fluid into the interior of all perforations, holes or cavities respectively, which represent the inner structure of the building block 2. After a relatively short time, which can vary from a few seconds up to several minutes depending on the quantity and the quality of the catalyst used in the binder formulation, the liquid starts to foam and the volume thereof increases and fills the perforations, holes or cavities 4 of building block 2 and that of the building block(s) 2 positioned above. The foam solidifies by hardening in a short time, typically within a few minutes to several hours, and adheres to the inner surface of the perforations, holes or cavities 4 of building blocks 2; that is, through a volumetric expansion of the polyurethane binder 3 and its solidification from a liquid state to a foamy state inside the perforations, holes or cavities 4.
In other words: the polyurethane binder is injected or poured, for example, into the perforations, holes or cavities 4 of building blocks 2 and hardens within the perforations, holes or cavities 4 following an increase of the volume which is caused by the transition from a fluid condition into a foamy condition.
The above-mentioned process is repeated for every single building block 2 used.
In other words: during the construction of the masonry 1 according to the drywall technique, the amount of liquid polyurethane binder 3 is poured into each building block 2 which is necessary to bond the building block 2 with the building block 2 located above it.
The building time for the masonry 1 is reduced thereby to the positioning times of building blocks 2 and to the time for injecting or pouring in the polyurethane binder 3.
The use of straight-sided bricks and/or building blocks, on the one hand, and the absence of mortar, on the other hand, makes the process of levelling out of bricks and/or building blocks 2 superfluous. In particular, the straight-sided bricks and/or building blocks have side walls which are perpendicular to the base and/or the top of the bricks and/or building blocks.
The stability of the masonry 1 is obtained after a short time, namely in a few minutes to 1-2 hours, with corresponding time-saving in comparison to the setting time of traditional mortar containing cement.
According to the above description, it is possible to foam up all perforations, holes or cavities 4 of each building block 2. The above described panel-like structure formed of polyurethane foam advantageously allows for the dispensing of the "thermal coat" already described in connection with the known technology.
In order to simplify the process of dosing the polyurethane binder 3, portable dosing units can be used which allow the injecting or pouring, for example, of a specific amount of the premixed liquid to produce the foam volume by means of a dosing pump.
The polyurethane binder 3 consists of at least two components - in chemical terms, a polyol or polyalcohol and a polyisocyanate - which react with each other in the presence of suitable catalysts, which accelerate the reaction, and other additives that influence the properties of the polyurethane foam to form the polyurethane.
In general, the polyurethane binder contains a polyol or a mixture of several polyols which are able to react with a polyisocyanate or a mixture of several polyisocyanates to form a hard polymer.

The following table, Table 1, illustrates two examples of materials that may be used as the first component, namely the polyol component, of the polyurethane binder 3. As shown below, the exemplary polyol components have different properties, and it is these different properties that lead to the desired polyurethane binder 3 being produced. The materials given below are represented by the designations HA 24-310-00 and HI 26-041-00.

Table 1

	Dimension	HA 24-310-00	HI 26-041-00
Density	kg/m³	37	112
Compression strength (10% compression)	MPa	0.25	0.86
Bending strength	MPa	0.58	1.22
Tensile strength	MPa	0.33	0.60
Elongation at break	%	12	5
Fire classification	Class	F	E
Thermal conductivity, λ initial (10°C)	W/mK	0.024	0.029

For example, the polyurethane binder 3 can be the product that the company PUR SYSTEMS produces with the designation HA 24-310-00 as the first component and ISO 10-002-00 as the second component. Both components are preferably mixed in the weight ratio 100 : 168, first component to the second component, in order to achieve a polyurethane foam with a bulk density of 38 kg/m³. In a corresponding experiment performed in a beaker, it can be shown that the expansion reaction occurs after 40 seconds upon the initial mixing, and a time at which long chain compounds start to form, i.e., the beginning of solidification, is 155 seconds. A corresponding rise time is 265 seconds.
As another example, the polyurethane binder 3 can be the product that PUR SYSTEMS produces with the HI 26-041-00 as the first component and ISO 10-002-00 as the second component. In this example, both components are mixed in the weight ratio 100 : 190, first component to second component, in order to achieve a polyurethane foam with a bulk density of 125 kg/m³. In a corresponding experiment performed in a beaker, it can be shown that the expansion reaction occurs after 35 seconds upon the initial mixing, and a time at which long chain compounds start to form is 115 seconds. A corresponding rise time is 150 seconds.
Preferably, to achieve a sufficient polyurethane binder 3, a weight ratio of the polyol component in relation to the isocyanate component is in the range of 100 : 100 to 100 : 250, preferably 100 : 150 to 100 : 230, and more preferably in the range of 100 : 160 to 100 : 200.
However, in both examples, there is a delay between the mixing of the components and the initiation of the reaction. This is advantageous in that the polyurethane binder 3 is able to be poured or injected in a liquid form into the perforations, holes or cavities 4, and is subsequently able to "settle" into and effectively fill up the perforations, holes or cavities before beginning to solidify from below to the top of the stacked building blocks.
Accordingly, the solidification occurs from the part of the polyurethane binder 3 that was inserted first. If the polyurethane binder 3 is inserted from the top of the masonry work 1, this means that the polyurethane binder 3 will solidify and bind from the base of the masonry work 1 upwards. In order to achieve the desired starting time, i.e., with a delay, the type(s) and amount(s) of the catalyst(s) are carefully selected when preparing the polyurethane binder 3. This careful selection may lead to any advantageous properties and, in particular, appropriate starting times of the solidification reactions of various polyurethane binders 3. While a delay has been advantageously shown in the examples above, this may not be required or desired. For instance, if the masonry work 1 is rather shallow or small, the delay times above are not required and the initiation of the reaction may be delayed for a shorter amount of time, i.e., shorter than 35-40 seconds. Indeed, in some instances a delay time may not be necessary at all.

In essence, it is the specific constitution of the polyol components, as well as the weight ratios, that provides the polyurethane binder 3 with the desired properties. The following table, Table 2, shows exemplary percentages of used constituents of the components discussed above.

Table 2

Raw Material	Manufacturer		HA 24-310-00	HI 26-041-00
Daltoc R 251	Huntsman	Propoxylated triol, OHZ 250 mgKOH/kg	50.2	24.0
Daltoc R 630	Huntsman	Propoxylated triol, OHZ 630 mgKOH/kg	23.9	55.0
Daltoc R 517	Huntsman	Propoxylated sorbitol, OHZ 510 mgKOH/kg	18.7
Glycerin		Cross-linking agent, OHZ 1830 mgKOH/kg		5.0
Ixol B 251	Solvay	Halogenated polyetherpolyol OHZ 350		7.0
Levagard TEP	Lanxess	Triethyl phosphate		5.0
Tegostab B 8404	Evonik	Polyether modifcated polysiloxane	0.9
Tegostab B 8491	Evonik	Polyether-polydimethylsiloxian-coploymer		2.0
BDMA		N,N-dibenzylamine	2.4
Dacob 33 LV	Air-products	Triethylenediamin		1.0
Water			3.9	1.0

As evident from Table 2, the polyol component can be selected from the group consisting of: a propoxylated triol with a hydroxyl value in the range of 200 mgKOH/kg to 700 mgKOH/kg, preferably in the range of 250 mgKOH/kg to 630 mgKOH/kg; propoxylated sorbitol with a hydroxyl value in the range of 400 mgKOH/kg to 600 mgKOH/kg, preferably in the range of 480 mgKOH/kg to 530 mgKOH/kg; glycerin as a crosslinking agent with a hydroxyl value of 1830 mgKOH/kg; or mixtures thereof.
Typically, a propoxylated tirol, such as Daltoc R 251 or 630, and/or propoxylated sorbitol, such as Daltoc R 517, with the aforementioned hydroxyl values are the backbone polyols of the polyurethane binder 3 and provide stiffness and long term stability to the polyurethane binder 3. The cross-linking agent as described above may be used to improve cohesion and adhesion or the like.
Additionally, the polyisocyanate or isocyanate component can be selected from the group consisting of one or a mixture of several polyisocyanates, in particular 4, 4'-Methylendiphenyldiisocyanat or mixtures thereof.
In a particularly advantageous arrangement, the polyurethane binder 3 comprises a flame-retardant. Such a flame-retardant component may be selected from the group consisting of halogenated polyetherpolyol with a hydroxyl value in the range of 300 mgKOH/kg to 400 mgKOH/kg, preferably in the range of 330 mgKOH/kg to 370 mgKOH/kg; triethyl phosphate; or mixtures thereof. As aforementioned, a halogenated polyetherpolyol, such as Ixol 251, which is a brominated polyetherpolyol, provides high fire-resistance and does not affect thermal insulation and mechanical properties. In contrast, triethyl phosphate, such as Levagard TEP, is a flame retardant with a high phosphorus content and low viscosity. This provides high flame-resistant performance to a polyurethane binder 3 as well as providing a good flowability.
As discussed above with reference to Table 2, HI 26-041-00 is one such example polyurethane binder 3 that includes flame-retardant components, such as Ixol B 251 or Levagard TEP.
An alternative and/or additional arrangement to enable flame-retardant qualities in the polyurethane binder 3 is to use polyisocyanurate (PIR) formulations. These polyisocyanurate polyurethane binders 3 are specific formulations that include a large excess of isocyanate in the presence of special polyisocyanurate catalysts, typically comprising an isocyanate index of between 140-350, more preferably between 180-300. Such an excess of isocyanate provides advantageously an improvement in flame-retardant qualities due to the presence of isocyanurate structures.
Advantageously, however, is the fact that no additional flame-retardant foam is added to the building blocks 2 once the polyurethane binder 3 is injected or poured into the building blocks 2. That is, the polyurethane binder 3 is specially configured, via carefully selecting one of the components listed above or by adjusting the excess of isocyanate, to inherently include flame-retardant properties, and therefore the masonry 1 produced via using this polyurethane binder 3 requires no further flame-retardant foam to be added.
In another configuration, the polyurethane binder 3 comprises polyether modified polysiloxane and/or polyether-polydimethylsiloxan-copolymer and/or N,N-dibenzylamine, triethylenediamin and/or water.
Polyether modified polysiloxane, such as Tegostab B 8404, and/or polyether-polydimethylsiloxan-copolymer, such as Tegostab B 8491, are generally used as surfactants for cell regulation and for providing dimensional stability of the polyurethane binder 3. N,N-dibenzylamine, such as BDMA, may be used as a tertiary amine catalyst which may have moderate catalytic activity which improves adhesion properties and reduces surface friability. A triethylenediamin component, such as Dacob 33 LV, is generally used as a catalyst for both gelling and blowing reactions.
According to one variation, the building blocks 2 are characterized by tongue and groove connection which facilitates the placement in a row.
In yet another embodiment, the polyurethane binder 3 comprises a blowing agent selected from the group of physical blowing agents, such as hydrocarbons (for example, pentane) and/or fluorinated hydrocarbons (for example 1,1,1,3,3-pentafluorobutane), and chemical blowing agents, such as carboxylic acids (for example formic acid), which releases CO₂ though the reaction with the isocyanate component. As is well known, blowing agents cause, in this case, the polyurethane binder 3 to further expand by creating a cellular structure in the polyurethane binder 3. This ensures the strength of the polyurethane binder and ensures that the cavities in which the binder is filled in are completely filled up without any remaining free space.
In the two aforementioned examples of the polyurethane binder 3 (using HA 24-310-00 and HI 26-041-00 as the polyol component), the polyurethane binder 3 may also include a blowing agent. In the examples, the blowing agent operates on the basis of the release of CO₂ from the reaction between the isocyante and/or the polyol component. This may also decrease the bulk density of the polyurethane binder 3, thereby providing yet a further decrease in the thermal conductivity and enhance the insulation effect of the materials to be used.
The polyurethane binder 3 may also comprise fillers, such as natural and/or synthetic fibers, for example glass fibers and/or carbon fibers and/or aramid fibers. The use of such fillers can dramatically alter the properties of the polyurethane binder 3, thereby meaning that the strength or rigidity of the polyurethane binder 3, for example, is improved by the fillers or fibers. Fillers can also increase tensile strength, shear strength and dimensional stability of the polyurethane binder 3, and the fillers may be selected depending upon the desired properties of the polyurethane binder 3.
The invention presented here can obviously be used for industrial purposes, it may moreover be the object of numerous modifications and variations, all of which in turn fall under the invention as defined by the appended claims; furthermore, all details can be replaced by other equivalent technical elements, as long as covered by the invention as defined by the appended claims.

Claims

A method for making masonry work (1), consisting of the steps of forming the masonry work (1) by assembling together a plurality of bricks and/or building blocks (2), the bricks and/or building blocks (2) having a substantially flat and planar outer surface and being provided with joints and/or alignment elements at the contact area between adjacent bricks and/or building blocks (2) which facilitate alignment of the bricks and/or building blocks (2) such that, after construction, the bricks and/or building blocks (2) provide the masonry work (1) with a planar outer surface and substantially without any gaps between the adjacent bricks and/or building blocks (2), and stably bonding together the adjacent bricks and/or building blocks (2); the bricks and/or building blocks (2) being of the hollow type with a percentage of holes greater than or equal to 15%; wherein the forming step comprises laying the bricks and/or building blocks (2) with the axis (A) of respective perforations, holes or cavities (4) of the bricks and/or building blocks (2) at right angles to the plane (P) of laying, wherein the bricks and/or building blocks (2) are straightened and are laid dry in the forming step of forming the masonry work (1),
characterized in that
the bonding step comprises pouring or injecting a polyurethane binder (3) in a liquid form inside all of the perforations, holes or cavities (4) of the bricks and/or building blocks (2) for securely fixing them to each other through a volumetric expansion of the polyurethane binder (3) in a passage-way formed between the perforations, holes or cavities (4) of adjacent bricks and/or building blocks (2) and its solidification from the liquid state to a foamy state inside the perforations, holes or cavities (4).
The method according to claim 1, wherein the bricks and/or building blocks (2) have a percentage of holes of between 15% and 70%, preferably of between 15% and 55%.
The method according to any one of claims 1 to 2, wherein the polyurethane binder (3) is of the type with at least two components, namely a polyol component selected from the group consisting of a propoxylated triol with a hydroxyl value in the range of 200 mgKOH/kg to 700 mgKOH/kg, preferably in the range of 250 mgKOH/kg to 630 mgKOH/kg; propoxylated sorbitol with a hydroxyl value in the range of 400 mgKOH/kg to 600 mgKOH/kg, preferably in the range of 480 mgKOH/kg to 530 mgKOH/kg; glycerin as a crosslinking agent with a hydroxyl value of 1830 mgKOH/kg; or mixtures thereof and an isocyanate component selected from the group consisting of a polyisocyanate or a mixture of several polyisocyanates, in particular 4,4'-Methylendiphenyldiisocyanat or mixtures thereof.
The method according to claim 3, wherein a weight ratio of the polyol component in relation to the isocyanate component is in the range of 100 : 150 to 100 : 230, preferably in the range of 100 : 160 to 100 : 200.
The method according to any one of claims 1 to 4, wherein the polyurethane binder (3) comprises a flame-retardant selected from the group consisting of halogenated polyetherpolyol with a hydroxyl value in the range of 300 mgKOH/kg to 400 mgKOH/kg, preferably in the range of 330 mgKOH/kg to 370 mgKOH/kg; triethyl phosphate; or mixtures thereof.
The method according to any one of claims 1 to 5, wherein the polyurethane binder (3) comprises polyether modified polysiloxane and/or polyether-polydimethylsiloxan-copolymer and/or N,N-dibenzylamine, triethylenediamin and/or water.
The method according to any one of claims 1 to 6, wherein the polyurethane binder (3) comprises a blowing agent selected from the group of physical blowing agents, such as hydrocarbons as for example pentane and/or fluorinated hydrocarbons as for example 1,1,1,3,3-pentafluorobutane, and chemical blowing agents, such as carboxylic acids as for example formic acid, which releases CO₂ though the reaction with the isocyanate component.
The method according to any one of claims 1 to 7, wherein the polyurethane binder (3) comprises fillers, such as natural and/or synthetic fibers as for example glass fibers and/or carbon fibers and/or aramid fibers.
Masonry work (1) consisting of a plurality of bricks and/or building blocks (2), the bricks and/or building blocks (2) having a substantially flat and planar outer surface and provided with joints and/or alignment elements at the contact area between adjacent bricks and/or building blocks (2) which are adapted to facilitate alignment of the bricks and/or building blocks (2) such that, after construction, the bricks and/or building blocks (2) provide the masonry work (1) with a planar outer surface without substantially any gaps between the adjacent bricks and/or building blocks (2), the bricks and/or building blocks (2) being of the hollow type with a percentage of holes greater than or equal to 15%; the bricks and/or building blocks (2) assembled with the axis (A) of respective perforations, holes or cavities (4), at right angles to the plane (P) of laying, wherein the bricks and/or building blocks (2) are straightened and are laid dry in a forming step of forming the masonry work (1),
characterized in that
the bricks and/or building blocks (2) being stably bonded together using a polyurethane binder (3) in a liquid form positioned inside all of the perforations, holes or cavities (4) of the bricks and/or building blocks (2) which are securely fixed to each other through a volumetric expansion of the polyurethane binder (3) in the passage-way formed between the perforations, holes or cavities (4) of adjacent bricks and/or building blocks (2) and its solidification from the liquid state to a foamy state inside the perforations, holes or cavities (4).