Moisture vapor reduction system

Abstract

The moisture vapor reduction system of the present invention comprises of as a first component the special mineral adhesive, being a hydraulic mineral adhesive, which comprises filling materials selected from the group of mineral fillers and/or plastic fillers and further comprises a binding material composition selected from the group consisting of Portland cement clinker, calcium-sulfo-aluminate and mixtures thereof, combined with an excess of a sulfate providing agent and further comprises as a second component a cover, e.g. a sheet or foil, made out of a waterproof and/or vapor-retarding material.

Claims

1. A moisture vapor reduction system for installing on a concrete slab, the system consisting of: (a) a vapor-retarding membrane; and (b) a fast hardening hydraulic mineral adhesive comprising: 70 to 95 wt % in components (i)-(iii), wherein (i) is mineral and/or plastic fillers, (ii) is a hydraulic binding material or Portland cement, and (iii) is optional additives; and further comprising 5 to 30 wt % in component (iv), which is a soluble sulfate providing agent, wherein in use, the hydraulic mineral adhesive will be spread or poured on the concrete slab, and the vapor-retarding membrane will be placed or pressed onto the mineral adhesive on the concrete slab.

2. The moisture vapor reduction system according to claim 1 wherein the vapor-retarding membrane comprises a laminated waterproof or vapor-retarding material selected to be a sheet or foil.

3. The moisture vapor reduction system according to claim 1, wherein: (a) the vapor-retarding membrane comprises a laminated waterproof or vapor-retarding material selected to be a sheet or foil; and (b) the fast hardening hydraulic mineral adhesive comprises: 20 to 95 wt % in a hydraulic binding material selected from the group consisting of Portland cement clinker, calcium-sulfo-aluminate and mixtures thereof, 1 to 30 wt % in soluble sulfate selected from the group comprising CaSO.sub.4, 1 to 10 wt % in polymeric additives selected from the group consisting of plastic fillers, silane, homopolymers and copolymers that are, in turn, selected from the group consisting of vinyl esters, vinyl acetate, ethylene and acrylic acid esters; optionally, 0 to 70 wt % in mineral additives selected from the group of mineral fillers, sand, lime stone, quartz powder and calcite wherein the average grain size of the mineral additives is not more than 250 m; 0 to 4 wt % in at least one additive for the modulation of the mechanical properties of cement; and Portland cement as a balancing rest up to 100 wt %.

4. The moisture vapor reduction system according to claim 1, wherein the vapor-retarding membrane comprises a sheet or foil made of a waterproof and/or vapor-retarding material selected from the group consisting of metal, aluminum, plastic and polymeric materials based on polyethylene, polypropylene and/or polyvinyl chloride, polyurethanes, latex and/or rubber compositions, fluoropolymers, polytetraflouroetylen and mixtures thereof.

5. The moisture vapor reduction system according to claim 1, wherein the vapor-retarding membrane is laminated on at least one side or optionally on both sides with natural or textile fibers.

6. The moisture vapor reduction system according to claim 1, wherein the composition of the hydraulic material further comprises, between 0.1 to 8 wt %, additives selected from the group of soluble carbonates consisting of Na.sub.2CO.sub.3, K.sub.2CO.sub.3 and mixtures thereof.

7. The moisture vapor reduction system according to claim 1, wherein the composition of the hydraulic material consists of about: 20 to 60 wt % in calcium-sulfo-aluminate; 5 to 15 wt % in CaSO.sub.4; 0.1 to 4 wt % in at least one additive selected from the group consisting of Na.sub.2CO.sub.3, K.sub.2CO.sub.3 and mixtures thereof; and Portland cement as a balancing rest to 100 wt %.

8. The moisture vapor reduction system according to claim 1, the fast hardening hydraulic mineral adhesive consisting of 80 to 95 wt % in components (i)-(iii), wherein (i) is mineral and/or plastic fillers, (ii) is a hydraulic binding material, and (iii) is optional one or several additives; and which further consists of 5 to 20 wt % in component (iv), which is a soluble sulfate providing agent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The objects and features of the invention can be better understood with reference to the drawings described below, and the claims. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views. All publications and patent literature described herein are incorporated by reference in entirety to the extent permitted by applicable laws and regulations.

(2) FIG. 1 shows the arrangement of a Moister Control System on a concrete slab, wherein sheets of a vapor retarding membrane are placed with overlapping edges/regions on a thin layer of mineral adhesive according to the invention. The system is then overlaid by a self-leveling screed or alternative underlayment for initiating further flooring constructions. In an embodiment, the vapor retarding membrane has geotextile fleece on both sides.

(3) FIG. 2 shows the arrangement of the Moister Control System on a concrete slab, wherein a vapor retarding membrane is placed with overlapping edges/regions on a thin layer of mineral adhesive according to the invention. In this example, the overlapping regions are additionally tightened or otherwise bonded together through the use of a waterproof adhesive, e.g. a butyl rubber adhesive. The system is then overlaid by a self-leveling screed or alternative underlayment for initiating further flooring constructions. In an embodiment, the vapor retarding membrane has geotextile fleece on both sides.

DETAILED DESCRIPTION OF THE INVENTION

(4) According to the invention, the term hydraulic binding materials refers to a Portland cement clinker as well as the individual components thereof, such as calcium-sulfo-aluminate (CSA) or mixtures thereof. These materials are characterized by their chemical reaction, which is essentially based on a hydration reaction of calcium-sulfo-aluminate (CSA) with CaSO.sub.4 to Ettringite:
C.sub.4A.sub.3S+8CSH.sub.2+6CH+74H3C.sub.6AS.sub.3H.sub.32

(5) It is worth mentioning that the term hydraulic has in construction industry a very distinct meaning from its physical meaning. In construction industry the term hydraulic refers to water binding and water stable.

(6) The composition of the present invention may contain as impurities or fillers also CaO- or Ca(OH).sub.2-comprising materials, e.g., cement or Portland cement. However, the term hydraulic binding material as referred to in the application is to be understood as referring in general to cement, Portland cement or a composite material containing silica, aluminum oxide, calcium oxide or calcium hydroxide as well as other hydraulic calcium silicates and ferric oxide, which mainly react in a hydration process.

(7) According to the present application, the term mineral adhesive therefore refers to a composition, which comprises as main component a hydraulic binding material, and which is used to join or connect inorganic materials. Upon preparing an adhesive paste from the composition as claimed together with water, this composition starts to harden as a consequence of the hydration process of CSA with sulfate releasing materials and together with the comprised fillers or additives.

(8) It is known that typically in the chemical reaction of CSA+CaSO.sub.4.fwdarw.Ettringite+Al(OH).sub.2, as this hydration reaction is quite fast, long Ettringite needles are formed. These needles (pointed long crystals) influence the short term hardening behavior, but on the long term have a negative impact on the stability of the concrete.

(9) According to the application, the term mineral fillers stands for all materials that can be described also as mineral aggregate, or simply aggregate. It comprises a broad category of coarse particulate material, including sand, limestone, quartz powder, calcite, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates and other known additives. Additionally, the term also and in particular comprises lightweight aggregates, such as clay, pumice, perlite and vermiculite.

(10) Besides the definition of the material of the mineral fillers, according to the present invention, a size definition for the mineral fillers is also important. The mineral adhesive of the present invention is particularly suitable to treat preexisting concrete slabs, and thus, is typically prepared as a thin paste or even liquid emulsion suitable to be spread and able to plane out well into any unevenness of the surface or even to fulfill possibly existing holes, cracks or pores in the surface of the concrete. Accordingly, any mineral fillers used for the present invention should have an average grain size of about 0.06 to 0.250 mm, alternatively of about 0.120 to 0.200 mm or about 0.080 to 0.200 mm.

(11) Typically, the average grain size and distribution of a grain size is evaluated in a standardized sieve analysis. The analysis is performed in nested columns of sieves by defining the percentage of remains on a sieve with a particular mesh size. The standardized method, the resulting grain size and grain category, the properties and the terminology regarding mineral fillers for concrete production are standardized and summarized in DIN EN 12620 and EN 13139.

(12) The grain size as claimed promotes as a further advantage fast hardening. Additionally, thin paste or emulsion for treating a concrete slab prepared with the composition of the present invention shows excellent hardening and stability characteristics. They do have an excellent hardening profile and start to harden soon after they have been spread out over the concrete slab. Typically, the hardening process starts to be visible 15 min after preparing the paste or emulsion. Also important to note is that already 60 minutes after spreading out the claimed mineral adhesive over the concrete slab, the hardening is advanced in a way that it can be walked on and further work can progress. After 4 hours, the surface is fully stable and shows a compressive strength of 15 to 20 MPa.

(13) In contrast, concrete mixtures according to the state of the art need a hardening time of at least 24 hours and reach typically a compressive strength of 20 MPa only after 24 hours.

(14) According to the invention, the term plastic fillers stands for all materials that can be described also as polymers or monomers in a dispersed or powdery form. Additionally, plastic fillers could be added in a liquid form to the freshly prepared mineral adhesive. According to the application, the term plastic fillers comprises homopolymers, copolymers, polymer latexes selected from the group of silane, polyacrylic ester, vinyl esters, vinyl acetate, ethylene, acrylic acid esters, polyvinyl acetate, polyethylene vinyl acetate, styrene butadiene and mixtures thereof. Typically, the polymers interact with the hydrating cement and may retard the hydration. It is furthermore considered advantageous that a polymer-modified adhesive can improve water stability of the mixture and thereby also retards water permeation.

(15) The term soluble sulfate providing agent according to the application describes materials that contain a sulfate group, which is reactive in concrete compositions. Typically, sulfate providing agents are CaSO.sub.4, anhydrite, gypsum or mixtures thereof. The sulfate providing agents influence the setting and hardening time of the cement mixture. Any unbalanced amount of sulfate providing agent can lead to the formation of gypsum crystals and thus, hardening disorders. This is to be avoided as these gypsum crystals have a tendency to swell at the contact of water, and thereby become instable and cause an overall instability of the mineral adhesive.

(16) Preferred compositions of the present invention consist of a mixture where the ratio of CSA:CaSO.sub.4 is in the range of 2:1 to 6:1, preferably 4:1 to 6:1, further preferably is a ratio of 2.5:1, 3:1, 3.5:1, 3.75:1, 4.0:1, 4.2:1, 4.5:1, 4.7:1, 5:1, 5.2:1, 5.5:1, 5.75:1 or 6.0:1. It is believed without being bound by the theory that in this range the Ettringite as a result of the chemical reaction between CSA and CaSO.sub.4 does form cubic crystals instead of needles, and thereby leads to a more stable and more dense consistency, which leads to the advantages of the present invention.

(17) The term additives according to the present application comprises additives known by the skilled practitioner for the modulation of the mechanical properties of cement compositions or the resulting concrete. Typically, such additives are chemical admixtures for improving the anti-freezing properties, for reducing the expansion or shrinkage behavior, for improving the water-repellent characteristics, for avoiding foam, for changing or delaying the setting times of the cement mixture as well as many other properties. Preferred additives, without limiting the options, are according to the present invention selected e.g. from the group comprising potassium-sodium-tartrate, sodium tartrate, tartaric acid, potassium bitartrate, gluconic acid, gluconate, citric acid and citrate and mixtures thereof.

(18) According to a further embodiment, the term additives is also understood to comprise water-soluble carbonates, which can be added to the composition of the mineral adhesive. Water-soluble carbonates according to the invention are for example selected from the group comprising Na.sub.2CO.sub.3, K.sub.2CO.sub.3 and mixtures thereof.

(19) According to the invention, of at least one or more additives and/or one or more water-soluble carbonates are added to the composition of the mineral adhesive in an amount selected from the group of about 0.1 wt %, 0.5 wt %, 0.7 wt %, 1 wt %, 1.2 wt %, 1.5 wt %, 3 wt %, 3.5 wt %, 4.5 wt %, 5 wt %, 5.5 wt %, 6 wt %, 6.5 wt %, 7 wt %, 7.5 wt % or 8 wt %, or selected from the range of about 0.1-1.5 wt %, 0.1-4 wt %, 0.5-1.7 wt %, 0.5-4 wt %, 1-2 wt % and 1.5-3 wt %, 1.5-6 wt %, 1.5-8 wt %, of about 2.5-4.5 wt %, 3-5 wt % and 3.5-6 wt %, of about 4.5-6.5 wt %, 5-7 wt % or 5.5-8 wt %, and of about 6-7.5 wt % or 7-8.0 wt %.

(20) The moisture and/or vapor reduction system of the invention further comprises a cover, e.g., a sheet or foil made out of a waterproof and/or vapor-retarding material. In this context, the term water proof and/or vapor-retarding material is understood to refer to all materials used for flexible sheets or foils, which are known to be waterproof or vapor proof. Such materials comprise thin metal foils such as aluminum foil and also comprise plastic foils or sheets made out of polypropylene, polyethylene, PVC, polyurethanes or other known mixtures thereof. Additionally, the term waterproof and/or vapor-retarding material also comprises textiles made out of e.g. polytetrafluoroethylene or other fluoropolymers.

(21) According to a preferred embodiment, the waterproof or vapor-retarding sheet or foil is also addressed as membrane. It is laminated on at least one side, but optionally on both sides. For laminating purposes, natural or polymeric textile fibers can be used, which are applied to or integrated into the foil or sheet. One embodiment uses geotextiles, i.e. woven, needled or preferably punched fabrics made from polypropylene. By laminating the foil or sheet the surface becomes rough and less slippery. A laminated foil or sheet thereby interacts better and closer with the mineral adhesive. Thus, the adhesion is improved and very stable. Additionally, when placing a laminated foil onto still water containing material, this foil will be able to stick and will not slip away. Thus, handling improves as the foil can be installed more accurately.

(22) According to one embodiment of the invention, the composition of the mineral adhesive consists of a fast hardening hydraulic mineral adhesive comprising:

(23) 20 to 95 wt % of a hydraulic binding material selected from the group of Portland cement clinker, calcium-sulfo-aluminate and mixtures thereof.

(24) 1.0 to 30.0 wt % soluble sulfate, e.g., but not limited to, CaSO.sub.4;

(25) 1 to 10 wt % polymeric additives selected from the group of plastic fillers, silane, homopolymers and copolymers selected from the group consisting of vinyl esters, vinyl acetate, ethylene and/or acrylic acid esters;

(26) 0 to 70 wt % mineral additives selected from the group of mineral fillers, sand, lime stone, quartz powder and calcite wherein the average grain size of the mineral additives is not more than 250 m;

(27) 0 to 4 wt % of at least one or more additives for the modulation of the mechanical properties of cement; and

(28) Portland cement as the balance, bringing the total to 100 wt %.

(29) Alternatively, according to other embodiments of the invention, the compositions of the mineral adhesive contains varying ranges for one or more of the following:

(30) (i) the hydraulic binding materials, wherein the composition contains about 10 to 40 wt % of the selected hydraulic binding material; alternatively, the composition contains about 15 to 35 wt % of the selected hydraulic binding material; alternatively, the composition contains about 18 to 32 wt % of the selected hydraulic binding material; alternatively, the composition contains about 20 to 40 wt % of the selected hydraulic binding material; alternatively, the composition contains about 25 to 35 wt % of the selected hydraulic binding material;
(ii) soluble sulfate providing agent, in the following definedwithout limitingas CaSO.sub.4, wherein the composition contains about 1.0 to 30.0 wt % CaSO.sub.4; alternatively, about 3.0 to 18.0 wt % CaSO.sub.4; further alternatively, 4.0 to 22.0 wt % CaSO.sub.4; alternatively, the composition contains about 3.5 to 6.0 wt % CaSO.sub.4; alternatively, the composition contains about 4.5 to 7.0 wt % CaSO.sub.4; alternatively, the composition contains about 5.0 to 8.0 wt % CaSO.sub.4; alternatively, the composition contains about 4.0 to 9.0 wt % CaSO.sub.4; further alternatively, 14.0 to 28.0 wt % CaSO.sub.4; further alternatively, 10.0 to 25.0 wt % CaSO.sub.4; and further alternatively, 6.0 to 9.5 wt % CaSO.sub.4.

(31) The composition of the present invention can be represented by any combination of the above ranges and according to the invention additionally contains mineral and/or plastic fillers in a range of 0.0 to 8.0 wt %, alternatively a range of 1.0 to 4.5 wt %, a range of about 2.0 to 5.0 wt %. Furthermore, the ranges of optionally contained additives may vary between about 1 wt % up to a maximum of 5 wt %. The additives for the modulation of the cement properties and/or water-soluble carbonates are added in an amount of about 0.5 wt %, 1 wt %, 1.5 wt %, 3 wt %, 3.5 wt %, 4.5 wt %, 5 wt %, 5.5 wt %, 6 wt %, 6.5 wt %, 7 wt %, 7.5 wt % or 8 wt %, or are added in an range selected from the following ranges 0.5-1.5 wt %, 1-2 wt % and 1.5-3 wt %, of about 2.5-4.5 wt %, 3-5 wt % and 3.5-6 wt %, of about 4.5-6.5 wt %, 5-7 wt % or 5.5-8 wt %, and of about 6-7.5 wt % or 7-8.0 wt %.

(32) The balance to 100 wt % for any of the compositions according to the invention is provided by the addition of corresponding amount of Portland cement.

(33) Exemplary Compositions

(34) TABLE-US-00001 Comp- Comp1 Comp2 Comp3 Comp4 Comp5 StoA Components % % % % % % CSA 60 40 60 40 60 20 CaSO.sub.4 20 15 15 10 20 8 Calcite 13 20 13 20 13 13 (mineral filler) Polymer 5 5 5 5 5 Soluble 2 2 4 Carbonates Retarding 0.3 0.2 0.4 0.4 0.6 0.3 additive Defoaming 0.1 0.1 0.1 0.1 0.1 0.1 additive Add Portland cement to 100% Initial Set (min) 30 40 30 35 25 50 Walkable 1 2 1 2 1 4 after (h) Adhesive 1.5 1.1 1.4 1.2 1.7 1.0 Strength (MPa, 24 h) Water 1.5 2.5 1.2 2.0 0.8 15 permeability (kg/d)

(35) Portland cement is used for any of the above compositions to balance the composition to 100 wt %.

(36) In comparison to known compositions (Comp-StoA) the above composition (Comp1 to 5) show, probably due to the formation of Ettringite crystals due to the excessive amount of CaSO.sub.4 and CSA, a very fast initial setting time and allow fast progress in the workflow of adding additional flooring constructions as full walkability is found already after 60 to 120 min.

(37) The initial setting time was measured with an Vicat Needle according to ASTM C191.

(38) Interestingly, the compositions of the present invention show, after addition of hydrophobic and hydrophilic polymers, clearly improved results in the water permeability tests.

(39) While open concrete allows water permeation and a passing through of about 15 kg water per day, the system of the present invention, when added to a concrete structure such as a slab, reduces this passing through rate by 80% and more. With a composition such as (Comp3 or Comp4) the amount of water permeation can be reduced to 2 kg/day or less.

(40) The present application also refers to the method of installing the moisture vapor reduction system. For this, the hydraulic mineral adhesive according to the invention is prepared and mixed with water to become a thin paste or a viscous solution. This paste or solution is poured or spread to the concrete slab to be treated. The paste is typically spread until it has a thickness of (on average) 1-6 mm.

(41) Immediately after application of the adhesive, the waterproof and/or vapor-retarding foil or sheet is placed into or onto the mineral adhesive.

(42) If the foil or sheet is laminated on only one side, the laminated side is placed on the mineral adhesive. The foil or sheet is typically placed on the adhesive with an overlap of 3 to 7 cm along the edges.

(43) While the foil or sheet is pressed into or onto the mineral adhesive, some of the adhesive is pressed into the overlapping area, where it will harden and thereby join two stretches of foil or sheet quite stable. Additionally, the mineral adhesive of the present invention can, given that soluble carbonates are included, additionally improve the vapor reduction as any water/vapor trying to defuse through this overlap of covers filled with mineral adhesive composition, will be bound in a hydration reaction and form CaCO.sub.3, which strengthens the floor construction and thus the claimed vapor reduction system.

(44) Alternatively, it will also be possible to adapt the vapor reduction system to the actual moisture vapor emission rate (MVER). As mentioned above, the overlaps of the membrane are the remaining main path for water/vapor release through the herein described system.

(45) Accordingly, to improve the herein described system, the overlaps can be provided with an additional rapid curing adhesive for situations with an MVER of less than 12 lbs./24 h1000 square foot. This additional rapid curing adhesive is applied to adhere the overlapping membrane for 75-100 mm with full coverage.

(46) For higher MVER values, an alternative solution with a Butyl rubber adhesive strip on the overlaps secures a uniform vapor release all through the membrane. The system is especially suitable for applications on young concrete bodies if it is required to go earlier than the usual 28 days curing time. Other than the current state of technology, which uses an epoxy vapor barrier usually combined with sand broadcast, the solution outlined in this invention is able to compensate a significant degree of shrinkage of the underlying concrete.

(47) In the following examples, which are not intended to limit the scope of the claimed invention, but only intend to illustrate said invention, it is shown that the composition of the mineral adhesive is particularly advantageous for the vapor reduction system.

Example 1

(48) Fast Hardening Moisture Control Adhesive:

(49) Portland cement CEM I 42.5R (Milke): 10.0%

(50) CSA Clinker ALIPRE (Italcementi): 60.0%

(51) Hemihydrate, snow white filler (USG): 15.0%

(52) Elotex HD1501 (Elotex): 5.0%

(53) Citric acid: 0.1%

(54) Calcit FA14 (SH-Minerals): 9.9%

(55) The mixture was blended together in a suitable Mixer for powder products making sure all components were fully dispersed.

(56) The mixture was then mixed with 0.4-0.5 L water per kg adhesive. The product was applied with a notched trowel just before the membrane was installed.

Example 2

(57) Moisture Control System 1:

(58) For a system according to the invention, the membrane consisted of, e.g. a 1000 mm wide and 0.030 mm aluminum foil with a 50 g/sqm polyethylene geotextile adhered with a polyurethane adhesive. The geotextile on the upper side covered the right 950 mm of the aluminum foil. On the remaining 50 mm, a 0.1 mm butyl rubber with a wax paper was installed. The lower side had the right 50 mm of the aluminum foil just covered with the polyurethane adhesive, and the geotextile covered the remaining 950 mm.

(59) The concrete slab to be treated was prepared by shotblasting before installation. The surface was pre-dampened and the adhesive as described above was installed with 4 mm notched trowel in 950 mm wide sections. The membrane as described above was laid into the fresh adhesive and flattened with a smoothing trowel by pushing the adhesive from right to left. Excess adhesive being squeezed out from below the membrane can be used for the next roll of membrane. After installing the first roll, another 950 mm of adhesive bed was applied as described above.

(60) In the next step, the wax paper was removed from the butyl rubber and then the next roll was installed with by adhering the right 50 mm to the butyl strip and the geotextile again was flattened with a smoothing trowel into the adhesive bed.

(61) The system reduced a vapor emission rate according to ASTM E 96 of 26 lbs./24 h1000 sq. ft. to 1.4 lbs./24 h1000 sq. ft. measured above the overlapping area of the two membrane sections.

(62) A self-leveling underlayment or screed can be installed within 60 minutes after application of the membrane adhesive without priming directly onto the membrane. The minimum application thickness shall be at least 6 mm ( inch).

(63) The system achieved at least 1.0 MPa (145 psi) adhesive strength on the substrate with the bond failure typically in the upper geotextile layer.

Example 3

(64) Moisture Control System 2:

(65) The membrane consisted of a 1000 mm wide and 0.140 mm polyethylene (PE) membrane with a 50 g/sqm PE geotextile coextruded on both sides.

(66) The concrete slab to be treated was prepared by shotblasting before installation. The surface was pre-dampened and the adhesive as described above was installed with 4 mm notched trowel in 1000 mm wide areas. The membrane as described above was laid into the fresh adhesive and flattened with a smoothing trowel by pushing the adhesive from right to left. Excess adhesive being squeezed out from below the membrane could be used for the next roll of membrane.

(67) After installing the first roll, another 1000 mm of adhesive bed was applied as described above beginning on the overlapping area on top of the first roll.

(68) In the next step, the next roll of membrane was laid into the adhesive bed with an overlapping area/edge of 75 to 100 mm and again flattened with a smoothing trowel into the adhesive bed.

(69) The system reduced a vapor emission rate according to ASTM E 96 of 12 lbs./24 h1000 sq. ft. to 2.2 lbs./24 h1000 sq. ft. measured above the overlapping area of the two membrane sections.

(70) A self-leveling underlayment or screed could be installed with 60 minutes after application of the membrane adhesive without priming directly onto the membrane. The minimum application thickness shall be at least 6 mm ( inch).

(71) The system achieved 0.7 MPa (100 psi) adhesive strength on the substrate with the bond failure typically in the upper membrane layer.