Self-repairing and self-sealing waterproof membrane, for insulating built structures subjected to hydrostatic pressure

Abstract

A self-repairing and self-sealing waterproof membrane, for insulating built structures subjected to hydrostatic pressure, includes a first layer of hermetic polymeric material, which covers a second layer of water-expanding polymeric material, in which additives of polymeric and/or mineral origin are added, arranged in contact with the concrete surface of the structure. The second layer includes a plurality of sublayers which are contiguous and have different expanding actions and mechanical characteristics. The membrane has substantially the shape of a continuous flat sheet, which gives the membrane the appearance of a uniform film, having a thickness between 0.2 and 5.0 mm and being composed of one or more of the following polymers: TPE, TPO, TPU, EVA, EPDM, EPM, HDPE, MDPE, LDPE, PE, PVC and other elastomeric or polymeric polymers, containing optional additions of fillers and other ingredients to give the article the necessary requirements of workability, mechanical strength, and durability.

Claims

1. A self-repairing and self-sealing waterproof membrane, for insulating built structures subjected to hydrostatic pressure, comprising a first layer consisting of a hermetic polymeric material layer, suitable to be arranged in contact with an infiltrated surface of said structure, which covers a second layer of water-expanding polymeric material, in which additives of polymeric and/or mineral origin are added, suitable to be arranged in contact with a concrete surface of said structure, said second layer being composed of at least one first sublayer and one second sublayer, each of said first and second sublayers consisting of a water-expanding polymeric material layer, and which are adjacent and have different expanding actions and mechanical characteristics, said membrane having substantially the shape of a continuous flat sheet, which gives the membrane the appearance of a uniform film, having a thickness comprised between 0.2 and 5.0 mm, each of said first layer and said first and second sublayers are composed of a same compound of polymers selected from one or more of the following polymers: TPE, TPO, TPU, EVA, EPDM, EPM, HDPE, MDPE, LDPE, PE, and PVC, each of said first and second sublayers of said second layer are further composed of a material that is capable of reacting to contact with water by expanding and being incorporated in said compound of polymers, the differentiation of the expanding action between said at least one first sublayer and one second sublayer being obtained by acting on said material that is capable of reacting to contact with water by expanding, wherein said first sublayer has a greater expanding action than said second sublayer in order to increase the water reactivity of the central part of said membrane, and said second sublayer has a smaller expanding action and a greater structural strength than said first sublayer thereby to be adapted to provide a greater dimensional stability than said first sublayer, wherein upon contact with water the swelling force of said first sublayer is developed more greatly and more rapidly in the direction at right angles to said first layer and to said second sublayer, and the expanding force of the first sublayer is contained between the first layer and the second sublayer.

2. The membrane according to claim 1, wherein said second layer is further composed of an additional polymeric layer that is adapted to contain more of the expanding substances incorporated within said first sublayer, preventing the expanding substances from being able to migrate into said second sublayer, in order to keep unchanged over time the expanding characteristics of said first and second sublayers.

3. The membrane according to claim 1, wherein in the presence of a nail or other through segment the different expanding action between said first sublayer and said second sublayer generates an expansion in the direction of said second sublayer that has the function of sealing the nail passage hole, preventing the propagation of water to adjacent surfaces.

4. The membrane according to claim 1, wherein in the presence of water in an overlap region of said first sublayer and said second sublayer, the combined action of said first sublayer and said second sublayer compresses said membrane against said infiltrated surface and said concrete surface, preventing the passage of water through the overlap region.

5. The membrane according to claim 1, wherein said first and second sublayers allow said second sublayer, which is dimensionally more stable than said first sublayer, to couple to an additional porous layer such as a nonwoven fabric.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics and advantages of the disclosure will become better apparent from the detailed description of a particular but not exclusive embodiment illustrated by way of nonlimiting example in the accompanying drawings, wherein:

(2) FIG. 1 is a sectional view of the stratification of the membrane;

(3) FIG. 2 is a stratigraphic view of the applied membrane;

(4) FIG. 3 is a sectional view of the application of the membrane in an overlap region;

(5) FIGS. 4 and 5 are views, similar to the preceding one, of the membrane following the insertion of a nail and following a tear;

(6) FIG. 6 is a view, similar to the preceding one, of the activation of the membrane due to the presence of water in the overlap region; and

(7) FIG. 7 is a view of a variation.

DETAILED DESCRIPTION OF THE DRAWINGS

(8) In the exemplary embodiment that follow, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

(9) With reference to the figures, the numeral 1 designates a self-repairing and self-sealing waterproof membrane, according to the present application, particularly for the insulation of built structures subjected to hydrostatic pressure, which is constituted by a continuous flat sheet which gives it the appearance of a uniform film.

(10) The membrane 1 is constituted by a first layer 2 of hermetic polymeric material, which is arranged in contact with an infiltrated surface 4 that affects said built structure.

(11) The membrane 1 preferably has the shape of a continuous flat sheet with a thickness comprised between 0.2 and 5.0 mm, preferably comprised between 0.5 and 2.0 mm, and can be composed of one or more of the following polymers: TPE, TPO, TPU, EVA, EPDM, EPM, HDPE, MDPE, LDPE, PE, PVC and/or other polymers of an elastomeric or polymeric nature, containing optional additions of fillers and of other ingredients known in the art in order to give the article the necessary requirements of workability, mechanical strength and durability.

(12) The first layer 2 covers a second layer 3 of water-expanding polymeric material placed in direct contact with the concrete surface 5 of said built structure.

(13) The second layer 3 comprises a material that is capable to reacting to contact with water by expanding and is incorporated for example in a compound of polymers of a thermoplastic or elastomeric nature similar to those of the first layer 2.

(14) In order to increase the expanding function of the second layer 3 it is possible to add in the polymeric compound additives of polymeric and/or mineral origin.

(15) This mixture, differently from other expanding materials, such as for example clays, constitutes in itself already a physical barrier and, depending on the percentages of additives that are mixed, allows an expansion of the second layer 3 that is comprised (by way of example) between 100% and 800% of the initial volume.

(16) The second layer 3 is advantageously composed for example of a first sublayer and a second sublayer 3a, 3b, which are contiguous and have different expanding actions.

(17) The differentiation between the first sublayer 3a and the second sublayer 3b can be obtained for example by acting on the ingredients of the composition, in particular on the water-expanding agents and on the additives that allow to control their behavior.

(18) This differentiation allows to control the expanding action of the second layer 3, at the same time maintaining the shape and waterproofing characteristics of said membrane 1; for example, the first sublayer 3a is assigned a greater expanding action than said second sublayer 3b, for example in order to increase the reactivity to water of the central part of the membrane 1.

(19) The differentiation between the expanding action of the first sublayer 3a and of the second sublayer 3b further ensures higher stability of the membrane 1, since in contact with water the expanding force of the first sublayer 3a is contained between the first layer 2 and the second sublayer 3b, both of which have similar mechanical characteristics that allow the membrane 1 to develop its functions while maintaining its shape.

(20) Use of the disclosure of the example described above can therefore be as follows: the use of the first sublayer 3a having a greater expanding action and of the second sublayer 3b having a smaller expanding capacity causes the second sublayer 3b to have a greater structural strength than the first sublayer 3a, which is adapted to give it a better dimensional stability with respect to the first sublayer 3a.

(21) With the sandwich-like embodiment, the expanding force of the first sublayer 3a is in fact contained between the first hermetic layer 2 and the second sublayer 3b.

(22) Upon contact with water, the expanding force of the first sublayer 3a, compressed between the infiltrated surface and the concrete surface, develops more greatly and more rapidly in the direction at right angles to the first layer 2 and to the second sublayer 3b, which, by way of the similar mechanical characteristics, allow the membrane 1 to achieve the above-cited tasks, further ensuring dimensional stability.

(23) In the presence of a nail 7 or of another element that passes through the membrane 1, the different expanding action between the first sublayer 3a and the second sublayer 3b allows to generate, as shown in FIG. 4, an expansion in the direction of the second sublayer 3b that has the function of sealing the nail passage hole.

(24) In particular, the expansion of the second layer 3b that presses against the concrete surface 5 prevents the propagation of the water to the contiguous surfaces.

(25) Thus, if there is water in the overlap region between adjacent membranes 1, as shown in FIG. 5, due to the combined action of the first and second expanding sublayers 3a, 3b, the membrane 1 is compressed against the infiltrated surface 4 and the concrete surface 5, preventing the passage of water through the overlap region.

(26) A further characteristic of the embodiment of the second layer 3 in a first sublayer 3a and a second sublayer 3b is to allow the outermost second sublayer 3b, which is dimensionally more stable than the first sublayer 3a, to mate with an additional porous layer, for example a nonwoven fabric 6, which allows adhesion to the liquid concrete when it is cast in direct contact.

(27) The waterproof membrane 1 can be manufactured in many ways, with known technologies and with commercially available machines.

(28) As mentioned in the introduction, the characteristics and the number of the layers that constitute the second layer 3 shown in the examples can be increased and interchanged for other exemplary embodiments.

(29) Thus, for example, the second layer 3 can be increased further by inserting between the first sublayer and the second sublayer 3a, 3b an additional polymeric layer 3c in order to contain further the expanding substances incorporated in the first sublayer 3a, preventing them from being able to migrate into the second layer 3b.

(30) This is done to keep unchanged over time the expansion characteristics of said first and second sublayers 3a, 3b.

(31) The process can comprise a single step, for example extrusion or coextrusion, or a plurality of steps, which comprise spreading and/or lamination or hot-melt gluing of the individual layers.

(32) It has thus been found that the disclosure has achieved the intended advantages by providing a membrane 1 which allows to waterproof walls, allowing at the same time to be self-repairing in case of accidental cutting or perforation of the membrane 1, self-sealing in the overlap regions created during installation for the joining of contiguous membranes, inhibiting the flow of water that can be created between the membrane 1 and the wall to be waterproofed (migration).

(33) In particular, the expanding agents and the additives that act within the polymeric membrane 1 and in particular within the first and second polymeric sublayers 3a, 3b induce the expansion, at the same time maintaining the shape and waterproofness characteristics of the membrane 1.

(34) Moreover, the differentiation between the first and second sublayers 3a, 3b allows to control the expanding action of the second layer 3 in order to increase the water reactivity of the central part of the membrane 1, at the same time ensuring greater stability of the membrane 1, since upon contact with water the expanding force of the first sublayer 3a is contained between the first layer 2 and the second sublayer 3b, both of which have similar mechanical characteristics which allow the membrane 1 to develop its functions while maintaining its shape.

(35) It has also been found that the membrane 1 allows to provide the hydraulic seal between the overlaps of the deposited membranes, preventing interface migration between the concrete wall and membrane proper.

(36) Furthermore, the membrane 1 does not require heat-sealing or taping or even the addition of external sealing and/or expanding materials for the joining of the several deposited sheets.

(37) Furthermore, the installation of the membrane 1 occurs in a simplified manner and meets the requirements of installation simplicity that are needed in building yards and within work areas, since the unit weight of the membranes is lower than that of most traditional products of the known type.

(38) The materials used, which constitute the individual components of the disclosure, as well as the composition and dimensions of the individual layers, may be parameters that are defined according to the specific requirements.

(39) The several means for performing certain different functions need not certainly coexist only in the illustrated embodiment but can be present per se in many embodiments, including ones that are not illustrated.

(40) The characteristics indicated as advantageous, convenient or the like may also be omitted or be replaced with equivalents.

(41) The disclosures in Italian Patent Application No. MI2015A000403 (102015902338648) from which this application claims priority are incorporated herein by reference.