MULTILAYER MEMBRANE FOR CONSTRUCTION

Abstract

A multilayer membrane may be suitable for construction, and/ir adapted to be installed between a wall of a seat obtained in the ground and a concrete structure. The multilayer membrane may include: a first layer including thermoplastic polymeric material, impermeable or substantially impermeable to water; a second layer including thermoplastic polymeric material, impermeable or substantially impermeable to methane gas and/or radon gas and/or volatile organic compounds (VOC), fixed to the first layer and adapted to be positioned, when the membrane is installed, between the first layer and a concrete structure.

Claims

1. A multilayer membrane suitable for construction, adapted to be installed between a wall of a seat obtained in the ground and a concrete structure, the membrane comprising: a first layer comprising thermoplastic polymeric material, impermeable or substantially impermeable to water; a second layer comprising thermoplastic polymeric material, impermeable or substantially impermeable to methane gas and/or radon gas and/or one or more volatile organic compounds, fixed to the first layer and adapted to be positioned, when the membrane is installed, between the first layer and a concrete structure.

2. The membrane of claim 1, wherein the first layer and the second layer are made, at least at their contact surfaces, of the same material, or of materials whose chemical composition allows its union by fusion.

3. The membrane of claim 1, wherein the first layer is made of polyethylene or of a polyolefin mixture.

4. The membrane of claim 1, wherein the second layer has a permeability to methane gas lower than 40 cm.sup.3/(24 h*m.sup.2*atm) and/or a permeability to radon gas lower than 10 cm.sup.3/(24 h*m.sup.2*atm).

5. The membrane of claim 1, wherein the second layer has a multilayer structure comprising: a third layer comprising thermoplastic polymeric material impermeable or substantially impermeable to water; a fourth layer comprising thermoplastic polymeric material impermeable or substantially impermeable to methane gas and/or to radon gas and/or one or more volatile organic compounds, positioned between the third layer and the first layer; a fifth layer comprising of thermoplastic polymeric material impermeable or substantially impermeable to water, positioned between the fourth layer and said first layer.

6. The membrane of claim 5, wherein the fifth layer is fixed directly to the first layer.

7. The membrane of claim 5, wherein the third layer is made of polyethylene.

8. The membrane of claim 5, wherein the fourth layer is made of polyamide, polypropylene, polyethylene terephthalate, or ethylene vinyl alcohol.

9. The membrane of claim 5, wherein the fifth layer is made of low density polyethylene, linear low-density polyethylene, or high-density polyethylene.

10. The membrane of claim 5, wherein the fourth layer has a melting temperature higher than that of the fifth layer.

11. The membrane of claim 5, further comprising: a sixth layer comprising thermoplastic polymeric material impermeable or substantially impermeable to methane gas and/or to radon gas and/or to one or more volatile organic compounds, interposed between the fourth layer and the fifth layer.

12. The membrane of claim 11, wherein the sixth layer is made of ethylene vinyl alcohol.

13. The membrane of claim 11, further comprising: a seventh layer comprising thermoplastic polymeric material impermeable or substantially impermeable to methane gas and/or to radon gas and/or to one or more volatiles organic compounds, interposed between the sixth layer and the fifth layer.

14. The membrane of claim 13, wherein the seventh layer has a melting temperature higher than that of the fifth layer.

15. The membrane of claim 13, wherein the seventh layer is made of polyamide or polyethylene terephthalatc.

16. The membrane of claim 13, further comprising, between the seventh layer and the fifth layer: a series of three layers similar to the fourth layer, sixth layer, and seventh layer, arranged in this order.

17. The membrane of claim 5, wherein the third layer and fourth layer are fixed to each other by a first bonding layer arranged between the two.

18. The membrane of claim 5, wherein the fifth layer is fixed to the layer immediately superposed on it opposite to the first layer, by a second bonding layer.

19. The membrane of claim 1, further comprising: an adherence layer layer associated with said second layer and adapted to be positioned, when the membrane is installed, between the second layer and a concrete structure cast on the membrane, to increase the adhesion of the concrete structure, once solidified, with the membrane.

20. The membrane of claim 1, further comprising: a drainage layer fixed to the first layer on the opposite side of the second layer, and adapted to be positioned, when the membrane is installed, in contact with the wall of a seat obtained in the ground, to drain possible liquids present in the seat.

21. The membrane of claim 1, wherein the first layer comprises or is an anti-pressure layer adapted to be positioned, when the membrane is installed, in contact with the wall of a seat formed in the ground, to reduce the pressure on the membrane of possible liquid escaping from the wall.

Description

[0088] The features and advantages of the present invention will be more apparent from the following description, which is to be understood as exemplifying and not limiting, with reference to the appended schematic drawings, wherein:

[0089] FIG. 1 is a schematic perspective view of a portion of a first embodiment of a membrane according to the invention;

[0090] FIG. 2 is a schematic side elevation view of a portion of the membrane of FIG. 1;

[0091] FIG. 3 is a schematic side elevation view of a portion of a second embodiment of a membrane according to the invention;

[0092] FIG. 4 is a schematic side elevation view of a portion of a third embodiment of a membrane according to the invention;

[0093] FIG. 5 is a schematic side elevation view of a portion of a first embodiment of the second layer of a membrane according to the invention;

[0094] FIG. 6 is a schematic side elevation view of a portion of a second embodiment of the second layer of a membrane according to the invention;

[0095] FIG. 7 is a schematic side elevation view of a portion of a fourth embodiment of a membrane according to the invention;

[0096] FIG. 8 is a schematic side elevation view of a portion of a fifth embodiment of a membrane according to the invention;

[0097] FIG. 9 is a schematic side elevation view of a portion of a sixth embodiment of a membrane according to the invention;

[0098] FIG. 10 is a schematic side elevation view of a portion of the membrane of FIG. 7 installed according to a first laying method;

[0099] FIG. 11 is a schematic side elevation view of a portion of the membrane of FIG. 1 installed according to a second laying method.

[0100] With reference to the appended Figures, the number 1 generally indicates a multilayer membrane for construction, adapted to be installed between a wall 8a of a seat 8 obtained in the ground 9 and a concrete structure 5.

[0101] The concrete structure 5 can be, for example, a building, a containment pit for a hydrocarbon tank, the tank of a landfill, etc.

[0102] As will be better explained below, the membrane 100 according to the invention, depending on the variant embodiments, is suitable for being used both to laterally cover the base of a pre-formed concrete structure 5, before burying this base, as shown for example in FIG. 11, and as a base on which to cast the concrete which will constitute, once solidified, the base of a structure 5, as shown for example in FIG. 10.

[0103] Advantageously, the membrane 100 comprises a first layer 1 of thermoplastic polymeric material, impermeable or substantially impermeable to water, and a second layer 2 of thermoplastic polymeric material, impermeable or substantially impermeable to methane gas and/or radon gas and/or volatile organic compounds (VOC), fixed to the first layer 1 and adapted to be positioned, when installed, between the first layer 1 and a concrete structure 5.

[0104] Preferably, the second layer 2 has a thickness comprised between 0.05 mm and 0.3 mm.

[0105] Preferably, the first layer 1 and the second layer 2 are made, at least at their contact surfaces, of the same material, or of materials whose chemical composition allows its union by fusion.

[0106] Advantageously, the second layer 2 can be fixed to the first layer 1 before it has completely cooled down, so that there is at least a partial fusion of the contact surfaces between the two.

[0107] Advantageously, the first layer 1 and the second layer are made, at least at their contact surfaces, of materials having substantially the same fusion temperature, so as to facilitate their union by fusion.

[0108] Preferably, the first layer 1 is made of polyethylene (PE) or polyolefin mixtures.

[0109] Preferably, the first layer 1 has a thickness comprised between 0.5 mm and 2 mm.

[0110] Advantageously, the second layer 2 has a permeability to methane gas lower than 40 cm.sup.3/(24 h*m.sup.2*atm) and/or a permeability to radon gas lower than 10 cm.sup.3/(24 h*m.sup.2*atm).

[0111] In a preferred embodiment, the second layer 2 has a multilayer structure, and comprises: [0112] a third layer 2.sup.III of thermoplastic polymeric material impermeable or substantially impermeable to water; [0113] a fourth layer 2.sup.IV of thermoplastic polymeric material impermeable or substantially impermeable to methane gas and/or to radon gas and/or volatile organic compounds (VOC), positioned between the third layer 2.sup.III and the first layer 1; [0114] a fifth layer 2.sup.V of thermoplastic polymeric material impermeable or substantially impermeable to water, positioned between the fourth layer 2.sup.IV and the first layer 1.

[0115] Advantageously, the fifth layer 2.sup.V is fixed directly to the first layer 1.

[0116] Preferably, the fifth layer 2.sup.V is made of the same material as the first layer 1 or of a material whose composition allows its union by fusion with the first layer 1.

[0117] Advantageously, the fifth layer 2.sup.V is made of a material having substantially the same fusion temperature as the first layer 1.

[0118] Preferably, the fifth layer 2.sup.V is fixed to the first layer 1 by, at least partial, fusion of the fifth layer 2.sup.V and the first layer 1.

[0119] Preferably, the third layer 2.sup.III is made of polyethylene (PE).

[0120] Preferably, the fourth layer 2.sup.IV is made of polyamide

[0121] (PA), or polyethylene terephthalate (PET), or polyvinyl ethylene-alcohol (EVOH).

[0122] Preferably, the fifth layer 2.sup.V is made of low density polyethylene (LDPE), or linear low density polyethylene (LLDPE), or high density polyethylene (HDPE).

[0123] Preferably, the third layer 2.sup.III has a thickness comprised between 0.020 and 0.145 mm.

[0124] Advantageously, the fourth layer 2.sup.IV has a fusion temperature higher than that of the fifth layer 2.sup.V.

[0125] Advantageously, the fourth layer 2.sup.IV has a fusion temperature higher than 135° C., and preferably comprised between 160° C. and 200° C., more preferably comprised between 165° C. and 191° C.

[0126] Preferably, the fifth layer 2.sup.V has a thickness comprised between 0.020 and 0.145 mm.

[0127] Advantageously, the fifth layer 2.sup.V has a fusion temperature from 100° C. to 135° C.

[0128] Advantageously, as shown for example in FIG. 6, the second layer 2 can comprise a sixth layer 2.sup.VI of thermoplastic polymeric material impermeable or substantially impermeable to methane gas and/or radon gas and/or volatile organic compounds (VOC), interposed between the fourth layer 2.sup.IV and the fifth layer 2.sup.V.

[0129] Advantageously, the sixth layer 2.sup.VI is made of polyvinyl ethylene-alcohol (EVOH).

[0130] Preferably, the sixth layer 2.sup.VI has a thickness comprised between 0.003 mm and 0.006 mm.

[0131] Preferably, as shown for example in FIG. 6, the second layer 2 can comprise a seventh layer 2.sup.VII of thermoplastic polymeric material impermeable or substantially impermeable to methane gas and/or radon gas and/or volatile organic compounds (VOC), interposed between the sixth layer 2.sup.VI and the fifth layer 2.sup.V.

[0132] Advantageously, the seventh layer 2.sup.VII has a fusion temperature higher than that of the fifth layer 2.sup.V.

[0133] Preferably the seventh layer 2.sup.VII has the same composition as the fourth layer 2.sup.IV.

[0134] Preferably, the seventh layer 2.sup.VII is made of polyamide (PA), or polyethylene terephthalate (PET).

[0135] In a further advantageous embodiment, not shown, the membrane 100 can comprise, between the seventh layer 2VII and the fifth layer 2.sup.V, one or more series of three layers similar (i.e. having the same composition and possibly the same thickness) to the fourth layer sixth layer 2VI and seventh layer 2.sup.VII, arranged in this order.

[0136] In an advantageous embodiment, the third layer 2.sup.III and the fourth layer 2.sup.IV are fixed together by a first bonding layer 2.sup.inc1 arranged between the two.

[0137] Said first bonding layer is preferably made of a thermoplastic material, and/or of a material and in a concentration such that its presence with respect to the total mass of the membrane keeps it recyclable, at least 99%.

[0138] Advantageously, the weight percentage of this first bonding layer 2.sup.inc1 with respect to the weight of the membrane does not exceed 5%, more preferably does not exceed one percent.

[0139] Preferably the first bonding layer 2.sup.inc1 is made of polyethylene (PE) grafted maleic anhydride.

[0140] In a preferred embodiment, the fifth layer 2.sup.V is fixed to the layer immediately superimposed on it (for example the layer 2.sup.VII in the example of FIG. 6) on the side opposite to the first layer 1, by means of a second bonding layer 2.sup.inc2.

[0141] Said second bonding layer 2.sup.inc2 is preferably made of a thermoplastic material, and/or of a material and in a concentration such that its presence with respect to the total mass of the membrane keeps it recyclable, at least 99%.

[0142] Advantageously, the weight percentage of this second bonding layer 2.sup.inc2 with respect to the weight of the membrane does not exceed 5%, more preferably does not exceed one percent.

[0143] Preferably the second bonding layer 2.sup.inc2 is made of polyethylene (PE) grafted maleic anhydride.

[0144] In an advantageous embodiment, such as for example the embodiments shown in FIGS. 7 to 10, the membrane 100 comprises an adherence layer 4 associated with the second layer 2 and adapted to be positioned, when installed, between the second layer 2 and a concrete structure 5 to increase the adhesion of the membrane 100 to the concrete structure 5. As shown for example in FIG. 10, in this embodiment the membrane 100 lends itself to being positioned, for example, on a bottom wall 8a and possibly also on the side wall(s) of a seat dug into the ground 9, before pouring a concrete casting on it which will constitute, once solidified, the base of a structure 5.

[0145] The adherence layer 4 binds or is constrained with the concrete and, once the latter has solidified, the membrane 100 remains fixed externally to the same, isolating the base of the structure 5 from the ground 9.

[0146] Advantageously, the adherence layer 4 comprises an adhesive and/or granules and/or a mesh and/or a non-woven fabric, adapted to promote the adhesion of the concrete, during its solidification, to the adherence layer 4.

[0147] Preferably, the adherence layer 4 has a thickness comprised between 0.3 mm to 5.5 mm, more preferably between 0.5 and 5 mm.

[0148] In an advantageous embodiment, the adherence layer 4 is fixed directly to the second layer 2.

[0149] In a further advantageous embodiment, the membrane 100 can comprise, between the adherence layer 4 and the second layer 2, a further layer, not shown, made of thermoplastic polymeric material, impermeable or substantially impermeable to water, with the function of additional thermal and/or mechanical protection for the second layer 2.

[0150] Preferably, this further layer has a composition similar to the first layer 1.

[0151] In an advantageous embodiment, such as for example those shown in FIGS. 3 and 8, the membrane 100 comprises a drainage layer 6 fixed to the first layer 1 on the opposite side of the second layer 2, and adapted to be positioned, when installed, in contact with the wall 8a of a seat 8 obtained in the ground 9, to drain possible liquids present in the seat 8.

[0152] The drainage layer 6 contributes to distribute possible water present in the ground in a direction parallel to the lying plane of the membrane 100, thus avoiding localized water concentrations which could cause high pressures in some points of the membrane 100, with the risk of damaging it.

[0153] Preferably, the drainage layer 6 comprises a membrane 6a, preferably bulged, advantageously of high density polyethylene (HDPE), more preferably coupled to a layer 6b of non-woven fabric (tnt) of polypropylene.

[0154] Advantageously, the drainage layer has a thickness comprised between 0.2 mm and 0.8 mm, preferably 0.5 mm.

[0155] Preferably, the drainage layer comprises bulges; more preferably, the bulges have a height comprised between 1 mm and 5 mm, preferably 3 mm.

[0156] In an advantageous embodiment, such as for example those shown in FIGS. 4 and 9, the first layer 1 can comprise or be an anti-pressure layer adapted to be positioned, when installed, in contact with a wall 8a of a seat 8 obtained in the ground 9, to reduce the pressure on the membrane 100 of possible liquid escaping from said wall 8a, and which could damage the membrane 100.

[0157] Advantageously, the first layer, in the event that it comprises or is an anti-pressure layer, comprises bulges 7a; preferably these bulges have a height comprised between 5 mm and 20 mm, preferably between 5 mm and 8 mm.

[0158] Advantageously, said bulges have a concentration comprised between 1200 and 24000 bulges per square meter.

[0159] Among the bulges 7a, channels 7b are defined which allow possible water, which impacts the anti-pressure layer perpendicularly to the lying plane of the membrane 100, to flow in a direction parallel to the lying plane of the membrane 100, thus reducing the pressure of water on the membrane 100 itself.

[0160] Advantageously, in this case, the first layer 1 can be associated with a protective layer, not shown, preferably made of non-woven fabric (tnt), fixed to the free end of the bulges 7a, and having the function of filtering the water, and preventing the ground from entering in the channels 7b defined between the bulges 7a, occluding them.

[0161] Preferably the first layer 1, in the event that it comprises or is an anti-pressure layer, has a thickness comprised between 0.4 mm and 1 mm.

[0162] Advantageously, the first layer 1, in the event that it comprises or is an anti-pressure layer, is made of polyethylene (PE).

[0163] In an advantageous embodiment, as for example in the embodiments of FIGS. 4 and 9, in the event that the first layer 1 comprises or is an anti-pressure layer, and comprises aforementioned bulges 7a, the second layer 2 fixed to said first layer 1, adapting to the bulged conformation of the latter, can assume a bulged or substantially bulged configuration.

[0164] The use of the membrane 100 according to the invention is as follows.

[0165] With reference to FIG. 11, the membrane 100 can be positioned around the base of a concrete structure 5 already formed and positioned in a seat 8 obtained in the ground 9, before burying this base.

[0166] The membrane 100 is therefore interposed between the wall 8a of the seat 8 and the concrete structure 5, thus preventing water, methane and/or radon and/or volatile organic compounds present in the ground from reaching the side surface of the base of the structure 5.

[0167] In a further advantageous embodiment, not shown in the appended figures, the membrane 100 can also be positioned on a bottom wall of a seat 8 formed in the ground before positioning an already formed concrete structure 5 on this membrane; in this case, a membrane 100 can optionally be advantageously positioned also around the base of this already formed concrete structure 5, so as to be interposed between the side wall of the seat 8 and the concrete structure 5.

[0168] In the variant embodiments in which the membrane 100 is provided with the adherence layer 4, the same can also be used as shown for example in FIG. 10, i.e. it can be positioned on the bottom wall 8a, and possibly also on the side wall(s) 8a of a seat 8 dug in the ground 9, before pouring a concrete casting on it which will constitute, once solidified, the base of a structure 5. The adherence layer 4 binds or is constrained with the concrete and, once the latter has solidified, the membrane 100 remains fixed externally to the same, isolating the base of the structure 5 from the ground 9.

[0169] It should be noted that in this case the membrane 100 can be positioned, before the concrete casting, also in a position such as to laterally cover also the base of the concrete structure 5 when it has solidified.

[0170] From the above description the features of the membrane of the present invention, as well as the advantages thereof, are evident.

[0171] Finally, it is to be understood that the multilayer membrane for construction as conceived herein is susceptible to many modifications and variations, all falling within the invention; furthermore, all the details are replaceable by technically equivalent elements. In practice, the materials used, as well as the dimensions, can be of any type according to the technical requirements.