A METHOD FOR PRODUCING A WATERPROOFING DETAIL PART

Technical field

The invention relates to sealing elements for use in waterproofing of below ground structures and to production of such sealing elements using additive manufacturing techniques. Particularly, the invention relates to waterproofing detail parts that are suitable for use in below grade waterproofing.

Background art

In the field of construction, polymeric sheets that are often referred to as membranes, panels, sheets, or liners, are used to protect below and above ground constructions, such as base slabs, walls, floors, basements, decks, plazas, tunnels, wet rooms, building facades, flat and low-sloped roofs, landfills, water-retaining structures, ponds, and dikes against penetration of water. Waterproofing membranes are applied, for example, to prevent ingress of water through cracks that develop in the concrete structure due to building settlement, load deflection or concrete shrinkage.

Waterproofing membranes can be “post-applied” to an existing concrete structure, for example, by using adhesive bonding means. On the other hand, fully bonded membrane systems that have been designed to form a permanent adhesive bond to freshly poured concrete after curing are gaining increasing importance in the construction industry. Such systems can prevent ingress of groundwater into basements of buildings and due to the adhesive bond, they can also effectively prevent lateral water migration in case of a locally damaged waterproofing membrane. Since the membrane is placed on an underlying concrete structure or formwork before the concrete structure to be waterproofed has been formed, these types of fully bonded membrane systems are also known as “pre-applied” waterproofing membranes”.

A fully bonded membrane system typically comprises a waterproofing barrier layer providing the membrane with required barrier properties against the penetration of water and at least one further layer that is operative to form a permanent bond to a fresh cementitious composition, particularly a fresh concrete composition. In addition to waterproofing membranes, various detailing parts, such as corner and penetration cover elements, are needed for waterproofing of below grade (ground) structures. The detailing parts have to be connected to other parts of the waterproofing system, particularly to the waterproofing membranes, to create a continuous waterproofing shield. It is generally preferred to bond the detailing parts to waterproofing membranes by heat-welding, but another bonding technique might be also used, for example, adhesive bonding and/or clamping. Since joining of the parts by heatwelding is preferred, the detail parts are typically prepared from material of the waterproofing membranes.

One example of a pre-applied waterproofing membrane is disclosed in a published patent application WO 2010043661 A1. The disclosed membrane includes a barrier layer and a composite layer, for example, a layer of non-woven fabric, which is affixed to the barrier layer via a sealant layer, such as a layer of hot-melt adhesive. EP2533974 B1 discloses another type of pre-applied waterproofing membrane comprising a barrier layer, a layer of pressure sensitive adhesive, and a strewed particle-based layer to the reduce the tackiness and protect the adhesive layer from impact of UV-radiation. The above-mentioned pre-applied waterproofing membranes art are not monolithic systems. Consequently, the detail parts used in combination with these types of membranes cannot be produced by using injection molding or extrusion techniques, but they have to be assembled at the construction site from pieces cut from waterproofing membranes. Such manual preparation of detail parts is very prone to errors. Furthermore, the use of adhesive tapes for fixation of shapes of the assembled detail parts increases the risk of providing a non-watertight part.

It would therefore be highly desirable to have a method for producing pre-fabricated waterproofing detailing parts, which form a full and permanent bond to fresh cementitious compositions to prevent lateral water migration, and which parts can be connected to other waterproofing elements, particularly to polymeric waterproofing membranes, by heat-welding.

Furthermore, although most waterproofing detailing parts are standardized, it would also be desirable to be able to produce detailing parts having an arbitrary shape providing compatibility with individual geometries of the below grade structures to be waterproofed.

Brief description of figures

Fig. 1 shows a schematic representation of a 3D printing process whereby a waterproofing detail part (12) is printed with a 3D printer (7) based on the digital model (10) of the waterproofing detail part (12).

Fig. 2 shows a schematic representation of a below ground structure with a corner element (1) whereby the corner element (1) is scanned with a 3D scanner (3) for obtaining a digital model (6) of the corner element (1).

Fig. 3 shows a schematic representation of a basement structure after the waterproofing detail part (12) has been installed on the corner element (1) and bonded to the waterproofing membrane (2) in order to produce a watertight connection between the waterproofing detail part (12) and the waterproofing membrane (2).

In the figures, the same components are given the same reference symbols.

Disclosure of the invention

It is an object of the present invention to provide a method for producing waterproofing detail parts for below grade waterproofing.

Surprisingly, it has been found out that the object can be achieved by the features of claim 1.

Especially, it has been found out that customized waterproofing detailing parts, such as corners and penetration cover elements, can be produced by means of additive manufacturing technology. Since the produced detail parts do not comprise any weld lines or adhesively bonded sections, the risks of material failure are significantly lower than in using detailing parts assembled from pieces of waterproofing membranes.

Furthermore, production of the waterproofing detailing parts by an additive manufacturing process allows producing a single individualized items at very low costs. Specifically, the costs per part are essentially independent on the lot size. Also, it can be ensured that the waterproofing detailing parts provide the same quality as that of the waterproofing membranes, which are used for waterproofing of below grade structures.

Further subjects of the present invention are defined in further independent claims. Preferred embodiments are outlined throughout the description and the dependent claims.

Detailed description

The subject of the present invention is a method for producing a waterproofing detail part for below grade waterproofing comprising steps of: i) Providing and/or obtaining a digital model of the waterproofing detail part (1) and ii) Based on the digital model, producing the waterproofing detail part (1) by additive manufacturing.

The abbreviation 3D is used throughout the present disclosure for the term “three- dimensional.

The term “polymer” refers to a collective of chemically uniform macromolecules produced by a polyreaction (polymerization, polyaddition, polycondensation) of monomers of same of different type where the macromolecules differ with respect to their degree of polymerization, molecular weight, and chain length. The term also encompasses derivatives of said collective of macromolecules resulting from polyreactions, that is, compounds which are obtained by reactions such as, for example, additions or substitutions, of functional groups in predetermined macromolecules and which may be chemically uniform or chemically non-uniform.

The term “softening point” refers to a temperature at which compound softens in a rubber-like state, or a temperature at which the crystalline portion within the compound melts. The softening point is preferably determined by Ring and Ball measurement conducted according to DIN EN 1238:2011 standard.

The term “melting temperature” refers to a temperature at which a material undergoes transition from the solid to the liquid state. The melting temperature (Tm) is preferably determined by differential scanning calorimetry (DSC) according to ISO 11357-3 standard using a heating rate of 2 °C/min. The measurements can be performed with a Mettler Toledo DSC 3+ device and the Tm values can be determined from the measured DSC-curve with the help of the DSC-software. In case the measured DSC-curve shows several peak temperatures, the first peak temperature coming from the lower temperature side in the thermogram is taken as the melting temperature (Tm).

The term “glass transition temperature” (T _g ) refers to the temperature above which temperature a polymer component becomes soft and pliable, and below which it becomes hard and glassy. The glass transition temperature (T _g ) is preferably determined by dynamical mechanical analysis (DMA) as the peak of the measured loss modulus (G”) curve using an applied frequency of 1 Hz and a strain level of 0.1 %.

The “amount or content of at least one component X” in a composition, for example “the amount of the at least one polymer P” refers to the sum of the individual amounts of all polymers P contained in the composition. Furthermore, in case the composition comprises 20 wt.-% of at least one polymer P, the sum of the amounts of all polymers P contained in the composition equals 20 wt.-%.

The term “normal room temperature” designates a temperature of 23 °C. According to ISO 52900-2015 standard, the term “additive manufacturing (AM)” refers to technologies that use successive layers of material to create a 3D objects. In an AM process, the material is deposited, applied, or solidified under computer control based on a digital model of the 3D object to be produced, to create the 3D article.

Additive manufacturing processes are also referred to using terms such as "generative manufacturing methods" or "3D printing". The term “3D printing” was originally used for an ink jet printing based AM process created by Massachusetts Institute of Technology (MIT) during the 1990s. Compared to conventional technologies, which are based on object creation through either molding/casting or subtracting/machining material from a raw object, additive manufacturing technologies follow a fundamentally different approach for manufacturing. Particularly, it is possible to change the design for each object, without increasing the manufacturing costs, offering tailor made solutions for a broad range of products.

Generally, in an AM process a 3D article is manufactured using a shapeless material (e.g. liquids, powders, granules, pastes, etc.) and/or a shape-neutral material (e.g. bands, wires, filaments) that in particular is subjected to chemical and/or physical processes (e.g. melting, polymerization, sintering, curing or hardening). The main categories of AM technologies include VAT photopolymerization, material extrusion, material jetting, binder jetting, powder bed fusion, direct energy deposition, and sheet lamination techniques.

According to one or more preferred embodiments, the additive manufacturing step ii) is effected by 3D printing, preferably by fused filament fabrication (FFF) or fused particle fabrication (FPF).

In a fused filament fabrication, also known as fused deposition modeling (FDM), a 3D article is produced based on a digital model of the 3D article using a polymer material in form of a filament. A "digital model" refers to a digital representation of a real world object, for example of a waterproofing detail part, that exactly replicates the shape of the object. A digital model can be created, for example, by using a CAD software or a 3D object scanner. Typically, the digital model is stored in a computer readable data storage, especially in a data file. The data file format can, for example, be a computer-aided design (CAD) file format or a G-code (also called RS-274) file format.

In a fused filament fabrication process, a polymer filament is fed into a moving printer extrusion head, heated past its glass transition, or melting temperature, and then deposited through a heated nozzle of the printer extrusion head as series of layers in a continuous manner. After the deposition, the layer of polymer material solidifies and fuses with the already deposited layers.

The printer extrusion head is moved under computer control to define the printed shape based on control data calculated from the digital model of the 3D article. Typically, the digital model of the 3D article is first converted to a STL file to tessellate the 3D shape and slice it into digital layers. The STL file is then transferred to the 3D printer using custom machine software. A control system, such as a computer-aided manufacturing (CAM) software package, is used to transform the STL file into control data, which is used for controlling the printing process. Usually, the printer extrusion head moves in two dimensions to deposit one horizontal plane, or layer, at a time. The formed object and/or the printer extrusion head is then moved vertically by a small amount to start deposition of a new layer.

A fused particle fabrication, also known as fused granular fabrication (FGF), differs from a fused filament fabrication only in that the polymer material is provided in form of particles, such as granules or pellets, instead of a filament.

The waterproofing detail part produced with the inventive method is preferably an inner corner, outer corner, or a penetration cover element, such as a collar element. These types of detail parts are known to a skilled person in the field of construction industry.

Typically, such elements comprise a base plate and at least one portion extending from the base plate. The corner elements typically comprise two wall portions extending from the base plate and forming an angle between 0 and 180°, particularly between 85 and 95 °, with the base plate and with each other. A collar element typically comprises a base plate and a hollow tubular portion extending from the base plate.

Particularly, a wall thickness of the produced waterproofing detail part is 0.1 - 10 mm, preferably 0.5 - 5 mm. Such parts tuned out to be physically stable and watertight while still being flexible enough for installation. However, for specific applications, waterproofing detail parts with other wall thicknesses may be suitable as well. It is also possible that the thickness of the base plate differs from the thickness of the portions extending from the base plate.

Preferably, the waterproofing detail part is monolithic. With monolithic parts, there is no risk of leakage caused by weld lines or the like. Thus, a monolithic part is much more reliable than a part consisting of several interconnected sections.

The detail parts obtained by using the method of the present invention have the advantage that they are compatible with the materials that are typically used for waterproofing of below grade structures, particularly with polymeric waterproofing membranes. Therefore, the waterproofing detail parts can be easily joined by heatwelding with waterproofing membranes to create a continuous waterproofing shield.

According to one or more embodiments, step i) of the method comprises:

- providing and/or obtaining a digital model of a below grade element and

- generating a digital model of the waterproofing detail part to be produced based on the digital model of the below grade element.

In these embodiments, the digital model of the waterproofing detail part to be produced is calculated based on a digital model of the below grade element.

The term “below grade element” refers in the present disclosure to a portion of any type of below grade structure to be waterproofed, for example base slab, foundation wall, deck, plaza, tunnel, or basement. The digital model of the waterproofing detail part can, for example, be obtained by taking the outer surface of the digital model of the below grade element and generating a surface with negative shape as the inner surface in the digital model of the waterproofing detail part. An outer surface of the digital model of the waterproofing detail part can, for example, be generated by adding a certain wall thickness to the regions behind the inner surface of the digital model of the waterproofing detail part.

According to one or more embodiments, the digital model of the below grade element is obtained by 3D scanning of the below grade element.

3D scanning is a process of analyzing a real-world object, for example, a portion of a below grade structure, such as a corner between two vertical walls of a foundation, to collect data on its shape. The collected data can then be used to construct the digital model of the object. Thereby, a control system can be used to generate the digital model out of the collected data. The control system can be part of the 3D scanner, or it can be part of a separate data processing unit, for example, a computer system.

With 3D scanning, the real below grade element can directly be scanned on the construction site. This ensures that the digital model is an exact representation of the real below grade element to be sealed with the waterproofing detail part. Overall, the combination of 3D scanning and additive manufacturing, especially with a 3D printer, offers an efficient way for producing individualized waterproofing detail parts with high precision.

However, it is also possible to obtain the digital model by measuring all of the lengths and angles of the below grade element by hand and generating the digital model manually in a modelling software. Nevertheless, this is time consuming and more error-prone.

There are many different 3D scanners available on the market, which can be used for 3D scanning. Preferably, the scanning of the basement element is performed with a handheld and/or portable 3D scanner. Handheld and/or portable 3D scanners do not need a complicated installation and allow for a quick and easy scanning of the below grade element to be sealed.

Preferably, the 3D scanner is designed for capturing objects from 1 cm to 20 m, especially 20 cm to 10 m, in length.

Especially, the 3D scanner is a non-contact 3D scanner. Such kind of scanners emit some kind of radiation, e.g., light, ultrasound, or x-rays, and detect its reflection or radiation passing through the object to be scanned in order to probe the object.

According to one or more embodiments, the waterproofing detail part is produced from a material comprising at least one polymer P and at least one solid filler F.

The expression “produced from a material” is understood to mean that the waterproofing detail part is produced by additive manufacturing using the material, for example, by feeding the material into a 3D printer.

Preferably, the at least one polymer P is selected from ethylene vinyl acetate copolymers, polyolefins, halogenated polyolefins, polyvinylchloride, thermoplastic rubbers, and ketone ethyl esters.

Term "polyolefin" refers in the present disclosure to homopolymers and copolymers obtained by polymerization of olefin monomers and “thermoplastic rubber” refers to a class of copolymers or a physical mix of polymers, typically a plastic and a rubber, that have both thermoplastic and elastomeric properties. Thermoplastic rubbers are also known as “thermoplastic elastomers (TPE)”.

According to one or more preferred embodiments, the at least one polymer P is selected from ethylene vinyl acetate copolymers, polyethylene, ethylene copolymers, polypropylene, propylene copolymers, and polyvinylchloride, more preferably from ethylene vinyl acetate copolymers, polyethylene, ethylene copolymers, polypropylene, and propylene copolymers. The term “copolymer” refers in the present disclosure to a polymer derived from more than one species of monomer (“structural unit”). The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained by copolymerization of two monomer species are known as bipolymers and those obtained from three and four monomer species are called terpolymers and quaterpolymers, respectively.

Suitable ethylene vinyl acetate copolymers for use as the at least one polymer P include ethylene vinyl acetate bipolymers and terpolymers, such as ethylene vinyl acetate carbon monoxide terpolymers.

Suitable ethylene vinyl acetate bipolymers and terpolymers are commercially available, for example, under the trade name of Escorene® (from Exxon Mobil), under the trade name of Primeva® (from Repsol Quimica S.A.), under the trade name of Evatane® (from Arkema Functional Polyolefins), under the trade name of Greenflex® (from Eni versalis S.p.A.), under the trade name of Levapren® (from Arlanxeo GmbH), and under the trade name of Elvaloy® (from Dupont).

Suitable polyethylenes for use as the at least one polymer P include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE), preferably having a melting temperature (T _m ) determined by differential scanning calorimetry (DSC) according to ISO 11357-3:2018 standard using a heating rate of 2 °C/min of at or above 85 °C, preferably at or above 95 °C, more preferably at or above 105 °C.

Suitable ethylene copolymers for use as the at least one polymer P include random and block copolymers of ethylene and one or more C3-C20 a-olefin monomers, in particular one or more of propylene, 1 -butene, 1 -pentene, 1 -hexene, 1 -heptene, 1- octene, 1 -decene, 1 -dodecene, and 1 -hexadodecene, preferably comprising at least 60 wt.-%, more preferably at least 65 wt.-% of ethylene-derived units, based on the weight of the copolymer.

Suitable ethylene random copolymers include, for example, ethylene-based plastomers, which are commercially available, for example, under the trade name of Affinity®, such as Affinity® EG 8100G, Affinity® EG 8200G, Affinity® SL 8110G, Affinity® KC 8852G, Affinity® VP 8770G, and Affinity® PF 1 OG (all from Dow Chemical Company); under the trade name of Exact®, such as Exact® 3024, Exact® 3027, Exact® 3128, Exact® 3131 , Exact® 4049, Exact® 4053, Exact® 5371 , and Exact® 8203 (all from Exxon Mobil); and under the trade name of Queo® (from Borealis AG) as well as ethylene-based polyolefin elastomers (POE), which are commercially available, for example, under the trade name of Engage®, such as Engage® 7256, Engage® 7467, Engage® 7447, Engage® 8003, Engage® 8100, Engage® 8480, Engage® 8540, Engage® 8440, Engage® 8450, Engage® 8452, Engage® 8200, and Engage® 8414 (all from Dow Chemical Company).

Suitable ethylene-a-olefin block copolymers include ethylene-based olefin block copolymers (OBC), which are commercially available, for example, under the trade name of Infuse®, such as Infuse® 9100, Infuse® 9107, Infuse® 9500, Infuse® 9507, and Infuse® 9530 (all from Dow Chemical Company).

Suitable polypropylenes for use as the at least one polymer P include, for example, isotactic polypropylene (iPP), syndiotactic polypropylene (sPP), and homopolymer polypropylene (hPP), preferably having a melting temperature (T _m ) determined by differential scanning calorimetry (DSC) according to ISO 11357-3:2018 standard using a heating rate of 2 °C/min of at or above 100 °C, preferably at or above 105 °C, more preferably at or above 110 °C.

Suitable propylene copolymers for use as the at least one polymer P include propylene-ethylene random and block copolymers and random and block copolymers of propylene and one or more C4-C20 a-olefin monomers, in particular one or more of 1 -butene, 1 -pentene, 1 -hexene, 1 -heptene, 1 -octene, 1 -decene, 1 -dodecene, and 1- hexadodecene, preferably comprising at least 60 wt.-%, more preferably at least 65 wt.-% of propylene-derived units, based on the weight of the copolymer.

Suitable propylene random and block copolymers are commercially available, for example, under the trade names of Intune®, and Versify (from Dow Chemical Company) and under the trade name of Vistamaxx® (from Exxon Mobil). According to one or more preferred embodiments, the at least one polymer P comprises at least one ethylene vinyl acetate copolymer P1 , preferably having a content of structural unit derived from vinyl acetate of at least 5 wt.-%, more preferably at least 10 wt.-%, based on the weight of the ethylene vinyl acetate copolymer.

Generally, the expression “the at least one compound X comprises at least one compound XN”, such as “the at least one polymer P comprises at least one ethylene vinyl acetate copolymer P1” is understood to mean in the context of the present disclosure that the material comprises one or more ethylene vinyl acetate copolymers P1 as representative(s) of the at least one polymer P.

Preferably, the at least one ethylene vinyl acetate copolymer P1 has a content of a structural unit derived from vinyl acetate of 10 - 90 wt.-%, preferably 15 - 80 wt.-%, based on the weight of the copolymer.

The polymer P can be composed of the ethylene vinyl acetate copolymer P1 , or it may comprise further polymers, for example, to improve some properties of the polymer P1. For example, if soft ethylene vinyl acetate copolymers are used, addition of other types of polymers having a higher softening point than P1 may be used, for example, to reduce the tackiness of the polymer component.

According to one or more embodiments, the at least one polymer P further comprises at least one polymer P2 different from the at least one ethylene vinyl acetate copolymer P1.

According to one or more embodiments, the at least one polymer P2 is compatible with the at least one ethylene vinyl acetate copolymer P1.

By the polymers components being “compatible” is meant in the present disclosure that the properties of a blend composed of the polymer P1 and P2 are not inferior to those of the individual polymer components.

It may also be preferable that the polymer P1 and P2 are partially miscible but not necessarily entirely miscible with each other. By the polymer components being “miscible” is meant in the present disclosure that a polymer blend composed of the polymer P1 and P2 has a negative Gibbs free energy and heat of mixing. The polymer blends composed of entirely miscible polymer components tend to have one single glass transition point, which can be measured using dynamic mechanical thermal analysis (DMTA).

Especially suitable polymers for use as the polymer P2 include, for example, polyolefins, halogenated polyolefins, thermoplastic rubbers, and polyvinylchloride.

According to one or more embodiments, the at least one polymer P2 is polyolefin, preferably polyethylene, wherein the weight ratio of the amount of the at least one ethyne vinyl acetate copolymer P1 to the amount of the at least one polymer P2 is preferably from 3:1 to 1 :3, preferably from 2:1 to 1 :2.

The material for the waterproofing detail part further comprises at least one solid filler F.

According to one or more embodiments, the at least one solid filler F has a median particle size dso of not more than 150 pm, preferably not more than 100 pm, more preferably not more than 50 pm, even more preferably not more than 35 pm.

The term “particle size” refers in the present disclosure to the area-equivalent spherical diameter of a particle (Xarea). The term “median particle size dso“ refers in the present disclosure to a particle size below which 50% of all particles by volume are smaller than the dso value. The particle size distribution can be determined by sieve analysis according to the method as described in ASTM C136/C136M -2014 standard (“Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates).

According to one or more embodiments, the at least one solid filler F has a median particle size dso in the range of 0.1 - 50 pm, preferably 0.25 - 35 pm, more preferably 0.5 - 25 pm, even more preferably 1 - 15 pm.

Suitable compounds for use as the at least one solid filler F include, for example, inorganic fillers, such as sand, granite, calcium carbonate, clay, expanded clay, diatomaceous earth, pumice, mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite, Wollastonite, barite, magnesium carbonate, calcium hydroxide, calcium aluminates, silica, fumed silica, fused silica, aerogels, glass beads, hollow glass spheres, ceramic spheres, bauxite, comminuted concrete, and zeolites.

Further suitable compounds for use as the at least one solid filler F include mineral binders, such as hydraulic binders, non-hydraulic binders, latent hydraulic binders, and pozzolanic binders.

Generally, the term “mineral binder” refers to mineral materials, which undergo a hydration reaction in the presence of water. Particularly, the term “mineral binder” refers to non-hydrated mineral binders, i.e. , to unreacted mineral binders that have not yet reacted in a hydration reaction.

Hydraulic binders react with water in a hydration reaction hydration reaction under formation of solid mineral hydrates or hydrate phases, which are not soluble in water or have a low water-solubility. Therefore, hydraulic binders, such as Portland cement, can harden and retain their strength even when exposed to water, for example underwater or under high humidity conditions. In contrast, non-hydraulic binders harden by reaction with carbon dioxide and, therefore, do not harden in wet conditions or under water.

Examples of suitable hydraulic binders to be used as the at least one hydraulic binder include hydraulic cements and hydraulic lime. The term “hydraulic cement” refers here to mixtures of silicates and oxides including alite, belite, tricalcium aluminate, and brownmillerite.

Commercially available hydraulic cements can be divided in five main cement types according to DIN EN 197-1 , namely, Portland cement (CEM I), Portland composite cements (CEM II), blast-furnace cement (CEM III), pozzolan cement (CEM IV) and composite cement (CEM V). These five main types of hydraulic cement are further subdivided into an additional 27 cement types, which are known to the person skilled in the art and listed in DIN EN 197-1. Naturally, all other hydraulic cements that are produced according to another standard, for example, according to ASTM standard or Indian standard are also suitable for use as the at least one mineral binder.

Examples of suitable non-hydraulic binders to be used as the at least one solid filler F include air-slaked lime (non-hydraulic lime) and gypsum. The term "gypsum" refers in the present disclosure to any known form of gypsum, in particular calcium sulfate dehydrate, calcium sulfate a-hemihydrate, calcium sulfate R>-hemihydrate, or calcium sulfate anhydrite or mixtures thereof.

The term "latent hydraulic binder” refers in the present disclosure to type II concrete additives with a “latent hydraulic character” as defined in DIN EN 206-1 :2000 standard. These types of mineral binders are calcium aluminosilicates that are not able to harden directly or harden too slowly when mixed with water. The hardening process is accelerated in the presence of alkaline activators, which break the chemical bonds in the binder’s amorphous (or glassy) phase and promote the dissolution of ionic species and the formation of calcium aluminosilicate hydrate phases.

Examples of suitable latent hydraulic binders to be used as the at least one solid filler F include ground granulated blast furnace slag. Ground granulated blast furnace slag is typically obtained from quenching of molten iron slag from a blast furnace in water or steam to form a glassy granular product and followed by drying and grinding the glassy into a fine powder.

The term “pozzolanic binder” refers in the present disclosure to type II concrete additives with a “pozzolanic character” as defined in DIN EN 206-1 :2000 standard. These types of mineral binders are siliceous or aluminosilicate compounds that react with water and calcium hydroxide to form calcium silicate hydrate or calcium aluminosilicate hydrate phases.

Examples of suitable pozzolanic binders to be used as the at least one solid filler F include natural pozzolans, such as trass, and artificial pozzolans, such as fly ash and silica fume. The term "fly ash” refers in the present disclosure to the finely divided ash residue produced by the combustion of pulverized coal, which is carried off with the gasses exhausted from the furnace in which the coal is burned. The term “silica fume” refers in the present disclosure to fine particulate silicon in an amorphous form. Silica fume is typically obtained as a by-product of the processing of silica ores such as the smelting of quartz in a silica smelter which results in the formation of silicon monoxide gas and which on exposure to air oxidizes further to produce small particles of amorphous silica.

According to one or more embodiments, the at least one solid filler F comprises:

- at least one inorganic filler F1 , preferably selected from sand, granite, calcium carbonate, clay, expanded clay, diatomaceous earth, pumice, mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite, Wollastonite, barite, magnesium carbonate, calcium hydroxide, calcium aluminates, silica, fumed silica, fused silica, aerogels, glass beads, hollow glass spheres, ceramic spheres, bauxite, comminuted concrete, and zeolites, more preferably from calcium carbonate, clay, expanded clay, diatomaceous earth, pumice, mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite, Wollastonite, barite, and magnesium carbonate and/or

- at least one mineral binder F2, preferably selected from hydraulic binders, non- hydraulic binders, latent hydraulic binders, and pozzolanic binders, more preferably hydraulic binders, particularly Portland cement.

According to one or more embodiments, the at least one solid filler F comprises:

- calcium carbonate, wherein the amount of the calcium carbonate preferably constitutes at least at least 15 wt.-%, preferably at least 35 wt.-%, more preferably at least 50 wt.-%, even more preferably at least 75 wt.-%, still more preferably at least 85 wt.-%, of the total weight of the at least one solid filler F, or

- a hydraulic binder, preferably Portland cement, wherein the amount of the hydraulic binder preferably constitutes at least at least 15 wt.-%, preferably at least 35 wt.-%, more preferably at least 50 wt.-%, even more preferably at least 75 wt.-%, still more preferably at least 85 wt.-%, of the total weight of the at least one solid filler F. Preferably, the at least one polymer P is present in the material in an amount of at least 25 wt.-%, preferably at least 35 wt.-%, more preferably at least 50 wt.-%, based on the total weight of the material and/or the at least one solid filler F is present in the material in an amount of not more than 75 wt.-%, preferably not more than 70 wt.-%, more preferably not more than 65 wt.-%, based on the total weight of the material.

According to one or more embodiments, the material comprises: a) 25 - 85 wt.-%, preferably 30 - 80 wt.-%, more preferably 35 - 75 wt.-%, even more preferably 40 - 70 wt.-%, of the at least one polymer P and b) 5 - 65 wt.%, preferably 10 - 60 wt.-%, more preferably 15 - 55 wt.-%, even more preferably 20 - 50 wt.-%, of the at least one solid filler F.

According to one or more embodiments, the material further comprises: c) At least one chemical blowing agent CBA.

Chemical blowing agents, also known as chemical foaming agents, are typically solids that liberate gas(es) by means of a chemical reaction, such as decomposition, when exposed to elevated temperatures. Inorganic, organic, exothermic, and endothermic chemical blowing agents are all equally suitable.

Endothermic blowing agents may be preferred over exothermic blowing agents, since the latter have been found to have potential to trigger respiratory sensitivity, are generally not safe from a toxicological point of view or have a risk of explosion. Furthermore, by-products such as ammonia, formamide, formaldehyde or nitrosamines are released during decomposition of exothermic blowing agents and these substances have been classified as hazardous substances.

A chemical blowing agent is added to the material, from which the detail part is produced, to provide a molten material containing a blowing gas, which is released, mainly after deposition with a printer extrusion head, from the molten material. The blowing may be added to the molten material to enable providing the detail part with a desired surface structure/roughness that may improve the ability of the detail part to form a bond with a fresh cementitious composition after hardening.

In case a chemical blowing agent is added to the material, the deposited layer of molten material discharged from a printer extrusion head of a 3D printer is first inflated due to volume increase of the blowing gas resulting in formation of a closed cell structure. Eventually, surface of the deposited layer is penetrated by the still expanding blowing gas, which results in formation of open or semi-open cells, pores, cavities, and other surface imperfections, which can be characterized as surface roughness.

Preferably, the at least one blowing agent CBA, if used, is present in the material in an amount of not more than 2 wt.-%, preferably not more than 1 .5 wt.-%, more preferably not more than 1 .25 wt.-%, based on the total weight of the material.

The material for the waterproofing detail part may further comprise one of more additives, particularly selected from reinforcing fibers, flame retardants, and color pigments.

According to one or more embodiments, the material further comprises at least one reinforcing fiber material, preferably selected from milled glass fibers, aramid fibers, wollastonite fibers, and carbon fibers.

Suitable reinforcing fibers have an average fiber length in the range of 100 - 500 pm, preferably 150 - 350 pm and/or an average fiber diameter in the range of 5 - 50 pm, preferably 10 - 35 pm. The term “average fiber length/diameter” refers to the arithmetic average of the individual lengths/diameters of the fibers within a sample or collection or a statistically significant and representative random sample drawn from such a sample or collection. The term “fiber diameter” refers in the present disclosure to the equivalent diameter of the fiber determined according to EN 14889-2:2006 standard.

The fiber length and diameter may be determined by using dynamic image analysis method conducted according to ISO 13322-2:2006 standard, for example, with a dry dispersion method, where the particles are dispersed in air, preferably by using air pressure dispersion method. The measurements can be conducted using any type of dynamic image analysis apparatus, such as a Camsizer XT device (trademark of Retsch Technology GmbH).

According to one or more embodiments, the material further comprises at least one flame retardant, preferably selected from the group consisting of magnesium hydroxide, aluminum trihydroxide, antimony trioxide, ammonium polyphosphate, and melamine-, melamine resin-, melamine derivative-, melamine-formaldehyde-, silane-, siloxane-, and polystyrene-coated ammonium polyphosphates.

Further suitable flame retardants for use as the at least one flame retardant include, for example, 1 ,3,5-triazine compounds, such as melamine, melam, melem, melon, ammeline, ammelide, 2-ureidomelamine, acetoguanamine, benzoguanamine, diaminophenyltriazine, melamine salts and adducts, melamine cyanurate, melamine borate, melamine orthophosphate, melamine pyrophosphate, dimelamine pyrophosphate and melamine polyphosphate, oligomeric and polymeric 1 ,3,5-triazine compounds and polyphosphates of 1 ,3,5-triazine compounds, guanine, piperazine phosphate, piperazine polyphosphate, ethylene diamine phosphate, pentaerythritol, borophosphate, 1 ,3,5-trihydroxyethylisocyanaurate, 1 ,3,5-triglycidylisocyanaurate, triallylisocyanurate and derivatives of the aforementioned compounds.

Suitable flame retardants are commercially available, for example, under the trade names of Martinal® and Magnifin® (both from Albemarle) and under the trade names of Exolit® (from Clariant), Phos-Check® (from Phos-Check) and FR CROS® (from Budenheim).

According to one or more embodiments, the material further comprises at least one color pigment, preferably selected from the group consisting of titanium dioxide, zinc oxide, zinc sulfide, barium sulphate, iron oxide, mixed metal iron oxide, aluminium powder, and graphite.

Preferably, the at least one color pigment has a has a median particle size dso of not more than 1000 nm, more preferably not more than 750 nm, even more preferably not more than 500 nm. According to one or more embodiments, the at least one color pigment has a has a median particle size dso in the range of 50 - 1000 nm, preferably 75 - 750 nm, more preferably 100 - 650 nm, even more preferably 125 - 500 pm, still more preferably 150 - 350 nm, most preferably 200 - 300 nm.

The material for the waterproofing detail part may further comprise various auxiliary compounds, such as thermal stabilizers, antioxidants, plasticizers, dyes, matting agents, antistatic agents, impact modifiers, biocides, and processing aids such as lubricants, slip agents, antiblock agents, and denest aids. The total amount of these types of further additives is preferably not more than 5 wt.-%, more preferably not more than 2.5 wt.-%, based on the total weight of the material.

According to one or more embodiments, step ii) comprises steps of:

- Feeding the material into a 3D printer,

- Heating the material to provide a melted material,

- Depositing the melted material by using a printer extrusion head of the 3D printer in a selected pattern in accordance with the digital model of the waterproofing detail part to form the waterproofing detail part.

In the heating step, the material is preferably heated to a temperature, which is above the melting temperature of the at least one polymer P to obtain the melted material. Should the material comprise multiple different polymers, the material is preferably heated to a temperature, which is above the melting temperature of the polymer P having the highest melting temperature.

The movements of the printer extrusion head in the deposition step are controlled according to control data calculated from the digital model of the waterproofing detail part. The digital model of the detail part is preferably first converted to a STL file to tessellate the 3D shape of the part and to slice it into digital layers. The STL file is transferred to the 3D printer using custom machine software. A control system, such as a computer-aided manufacturing (CAM) software package, can be used to generate the control data based on the STL file. The control system can be part of the 3D printer, or it can be part of a separate data processing unit, for example a computer system.

A further subject of the invention is a waterproofing detail part obtained by using the method to the present invention.

A still further subject of the present invention is a method for sealing a below grade element comprising the following steps:

(i) Performing the method with the steps as described above in order to obtain a waterproofing detail part fitting on the below grade element,

(ii) Installing the waterproofing detail part to a surface of the below grade element, and

(iii) Optionally, connecting the installed waterproofing detail part with a further sealing element, especially by heat welding.

In step (iii), the further sealing element can, for example, be another waterproofing detail part and/or a waterproofing material, such as a waterproofing membrane.

With this method, the whole below grade structure can be sealed with waterproofing detail parts and further sealing elements, which are connected to each other to form a continuous watertight barrier.

Preferably, the polymer basis of the further sealing element is selected such that the waterproofing detail part can be joined by heat welding with the further sealing element. Especially, the further sealing element comprises at least one layer that is heat-weldable with the waterproofing detail part.

However, other combinations might be suitable as well for special applications.

Instead of or in addition to heat welding, another method of joining might be used, for example, bonding with an adhesive and/or clamping. According to one or more embodiments, the method comprises further steps:

(iv) Casting a fresh concrete composition onto an outer surface of the waterproofing detail part facing away from the basement element, and

(v) Letting the fresh concrete composition to harden.

The term “fresh concrete composition” designates concrete compositions before hardening, particularly before setting.

According to one or more embodiments, the waterproofing detail part used in the sealing method is an inner corner, outer corner, or a penetration cover element, such as a collar element.

Exemplary embodiments

Fig. 1 shows a schematic representation of an additive manufacturing process whereby a waterproofing detail part (12) is printed with a 3D printer (7) based on the digital model (10) of the waterproofing detail part (12).

In the additive manufacturing process, a digital model (10) of the waterproofing detail part stored in a data file (9) is provided to the 3D printer (7). The control unit (8) of the 3D printer (7) converts the digital model (10) of the waterproofing detail part (12) into slices, which are then used to generate the control data for the printer extrusion head (11) of the 3D printer (7) to produce the waterproofing detail part (12). As seen on the right side of Fig. 1 , the waterproofing detail part (12) is a monolithic inner corner element comprising a base plate and two wall portions extending from the base plate and forming an angle of ca. 90° with the base plate and with each other.

Fig. 2 shows a schematic representation of a process, whereby a digital model of a below grade element, i.e. , a corner (1) formed between two walls, is obtained using a 3D scanner. As shown in Fig. 2, a portion of the corner (1) is scanned using a portable 3D scanner (3) with laser light (4) in order to collect data on the shape of the corner (1 ). The collected data is then processed within the control unit of the scanner (3) and stored in a further data file (5) as a digital model (6) of the corner (1 ). The file format of the data file (5) can, for example, be a CAD file format.

Fig. 3. shows the additive manufacturing process of Fig. 1 , whereby the digital model (10) of a waterproofing detail part (12) is generated based on a digital model (6) of a corner (1). In the process of Fig. 3, a data file (5) comprising the digital model (6) of the corner (1) is transmitted to a 3D printer (7). Within a control unit (8) of a 3D printer (7), a digital model (10) of the waterproofing detail part (12) fitting on the corner (1) is generated based on the digital model (6) of the corner (1) and stored in a data file (9). The negative shape of the outer surface of the digital model (6) of the corner (1 ) corresponds to the outer surface of the digital model (10) of the waterproofing detail part (12).

In Fig. 4, a section of a below grade structure comprising two walls forming a corner

(1) between them and a base slab (13) is shown. A waterproofing membrane (2) is arranged to cover a portion of the upper surface of the base slab (13). Once the waterproofing detail part (12) is ready, it can be installed on the corner (1). Thereby, the waterproofing detail part (12) is connected to the waterproofing membrane (2) in the region of the corner (1 ), preferably by heat welding, to provide a watertight connection between waterproofing detail part (12) and the waterproofing membrane

(2).

Examples

Manufacture of pellets for 3D printing

The pellets suitable for use in 3D printing process were produced according to the following process.

A portion of the raw materials of the material for the waterproofing detail parts were premixed in a tumbler mixer and then fed to a ZSK laboratory twin-extruder (L/D 44) via a gravimetric dosing scale. Another portion of the raw materials was fed directly via gravimetric dosing trolleys into the laboratory extruder. The raw materials were mixed, dispersed, homogenized, and discharged via the holes of perforated extrusion nozzles. The extruded strands were cooled using a water bath and cut into pellets with suitable dimensions. The pellets were then dried in an oven to remove the residual moisture. The temperature of the material during the process was kept under the decomposition temperature of the blowing agent.

The composition of the prepared pellets comprised:

- 30 wt.-% of an ethylene vinyl acetate copolymer having a vinyl acetate content of 28 wt.-% and MFR of (190 °C/2.16 kg) of 1-5 g/10 min (ISO 1133)

- 29.75 wt.-% of a linear low-density polyethylene having MFR (190 °C/2.16 kg) of 1- 5 g/10 min (ISO 1133)

- 40 wt.-% of Portland cement OEM II ZB-M (T-LL) (SN EN 197-1), and

- 0.25 wt.-% of sodium hydrogen carbonate, decomposition temperature 124 °C

Production of waterproofing detail parts with 3D printing

Exemplary waterproofing corner elements were prepared by using a Yizumi Space A fused particle fabrication (FPF) 3D printer. The pellets prepared as described above were used as a feed material for the 3D printer, which was operated using the settings shown in Table 1.

Preparation of the concrete test specimen

Two sample strips having dimensions of 200 mm (length) x 50 mm (width) were cut from the 3D printed waterproofing corner element. The sample strips were placed into formworks having dimensions of 200 mm (length) x 50 mm (width) x 30 mm (height).

One edge of each sample strip was covered with an adhesive tape having a length of 50 mm and width coinciding with the width of the strip to prevent the adhesion to the hardened concrete. The adhesive tapes were used to provide easier installation of the test specimens to the peel resistance testing apparatus.

A fresh concrete formulation was obtained by mixing 8.9900 kg of a concrete dry batch of type MC 0.45 conforming to EN 1766 standard, 0.7440 kg of water and 0.0110 kg of Viscocrete 3082 for five minutes in a tumbling mixer. The concrete dry batch of type MC 0.45 contained 1 .6811 kg of CEM I 42.5 N cement (Normo 4, Holcim), 7.3089 kg of aggregates containing 3% Nekafill-15 (from KFN) concrete additive (limestone filler), 24% sand having a particle size of 0-1 mm, 36% sand having a particle size of 1-4 mm, and 37% gravel having a particle size of 4-8 mm. Before blending with water and Viscocrete 3082 the concrete dry batch was homogenized for five minutes in a tumbling mixer.

The formworks containing the sample strips were subsequently filled with the fresh concrete formulation and vibrated for two minutes to release the entrapped air. After hardening for 7 days under standard atmosphere (air temperature 23°C, relative air humidity 50%), the test concrete specimens were stripped from the formworks and measured for concrete peel resistances.

Concrete peel resistances

The measurement of peel resistances was conducted in accordance with the procedure laid out in the standard DIN EN 1372:2015-06. A Zwick Roell AllroundLine Z010 material testing apparatus equipped with a Zwick Roell 90°-peeling device (type number 316237) was used for conducting the peel resistance measurements.

In the peel resistance measurements, a concrete specimen was clamped with the upper grip of the material testing apparatus for a length of 10 mm at the end of the concrete specimen comprising the taped section of the sample strip. Following, the strip was peeled off from the surface of the concrete specimen at a peeling angle of 90 ° and at a constant cross beam speed of 100 mm/min. During the measurements the distance of the rolls was approximately 570 mm. The peeling of the sample strip was continued until a length of approximately 140 mm of the strip was peeled off from the surface of the concrete specimen. The values for peel resistance were calculated as average peel force per width of the sample strip [N/ 50 mm] during peeling over a length of approximately 70 mm thus excluding the first and last quarter of the total peeling length from the calculation.

The average 90° peel resistance value obtained with the two samples was 56 N/50 mm.

Table 1

10