A reinforcement net system and its use with spray-applied materials

Abstract

The invention relates to a reinforcement net system for use with spray-applied materials, such as gypsum or cementitious plasters, mortars, renders, or concretes. The system comprises a pre-assembled bracket-net unit designed to adapt to structures of varying lengths, such as ventilation ducts, steel beams, and columns, the unit being configured with a repeating bracket-net-bracket-net pattern to provide a stable, continuous base for spray application.

Description

[0001] A reinforcement net system and its use with spray-applied materials

[0002] Field of the Invention

[0003] The present invention relates to reinforcement systems for use with spray-applied materials, such as gypsum plasters, cementitious plasters, or other sprayable coatings, for application to building structures including ventilation ducts, beams, columns, and other surfaces.

[0004] Background of the Invention

[0005] In the domain of building safety, the fire protection of ventilation systems is a pivotal element. This encompasses the utilization of fire-resistant materials in the construction of ventilation ducts, designed to endure elevated temperatures and impede the propagation of fire and smoke. Metal ducts are prevalently employed owing to their inherent fire resistance. Integral to this system are fire dampers, strategically installed within the ductwork. These dampers autonomously close during fire incidents, facilitated by the melting of a fusible link or activation by smoke detectors, thereby obstructing the fire and smoke spread through the ducts.

[0006] Additionally, smoke dampers are employed, functioning analogously to fire dampers but specifically aimed at controlling smoke movement. The incorporation of fire and smoke seals around the ductwork, particularly where they traverse through different building compartments, is critical. These seals, composed of fire-resistant materials, ensure that any gaps do not permit the passage of fire and smoke.

[0007] The concept of compartmentalization in ductwork design plays a crucial role. It involves segregating the ductwork into distinct sections with fire-rated barriers, effectively limiting fire and smoke spread to other building areas. Ensuring the functionality of these systems necessitates regular inspection and maintenance, particularly of fire and smoke dampers. Moreover, the application of fire-rated coatings on ductwork provides an additional protective layer. These coatings, which expand when exposed to high temperatures, form an additional barrier against fire and heat. The integration of ventilation systems with the building's fire alarm and suppression systems is also a key aspect. This integration may involve the HVAC system shutting down or modifying its operation during a fire, aiding in firefighting and evacuation efforts.

[0008] The environmental ramifications of fire-resistant coatings, particularly those applied in ventilation systems, present a multifaceted issue warranting comprehensive examination. The production phase of these coatings is characterized by the utilization of various chemicals and materials, each bearing its own ecological footprint. This phase encompasses the extraction of raw materials, the energy expended during manufacturing, and the resultant waste and emissions. Notably, the use of volatile organic compounds (VOCs) and other potentially hazardous materials in some coatings is a pertinent concern, given their implications for air quality and ecological well-being.

[0009] During the application process of these coatings, the emission of VOCs emerges as a significant environmental and health consideration. The shift towards low-VOC and water-based alternatives in recent years represents a concerted effort to mitigate these issues. The durability of fire-resistant coatings, while beneficial in reducing the frequency of reapplications and thereby conserving resources, also raises questions regarding their long-term environmental impact, including potential off-gassing and interactions with other building materials.

[0010] The end-of-life treatment of materials coated with fire-resistant substances is another critical environmental aspect. Particularly concerning are coatings that contain hazardous components, as these materials may not be recyclable and could necessitate specialized handling to avert environmental degradation. A comprehensive Life Cycle Analysis (LCA) of these coatings is essential to fully understand their environmental footprint. Such an analysis would encompass all stages from raw material extraction through to disposal or recycling, offering a holistic view of the environmental impact.

[0011] Regulatory frameworks increasingly scrutinize the ecological aspects of building materials, including fire-resistant coatings. This regulatory landscape has spurred the development of environmentally friendlier alternatives, encompassing coatings derived from natural, non-toxic, or recycled materials.

[0012] In summary, while the primary function of fire-resistant coatings is to enhance building safety, their environmental impact is a nuanced and complex subject that encompasses their entire lifecycle. The progression towards more environmentally sustainable building practices is influencing the development and use of these coatings, balancing safety with ecological responsibility.

[0013] Protecting steel beams and columns from fire is critical due to the material’s susceptibility to weakening at elevated temperatures. Steel, while robust and versatile, absorbs heat quickly during a fire, causing significant temperature increases that can lead to a substantial loss of strength and stiffness. This rapid heat absorption can compromise the structural integrity of a building, as steel can lose about half of its strength at around 600°C (1112°F). Consequently, protecting these elements is essential to prevent structural failures and ensure the safety of occupants.

[0014] Several fire protection methods can be employed to safeguard steel beams and columns. Intumescent coatings are widely used due to their ability to expand when exposed to high temperatures. This expansion forms a thick, insulating char layer that slows the rate of heat transfer to the steel, helping to maintain its structural integrity for a longer period during a fire. Spray-applied fire-resistive materials (SFRMs) involve spraying a fire-resistant material onto the steel surface. These materials, which can include mineral fibers, cementitious compounds, or lightweight aggregates, provide thermal insulation to the steel, delaying its temperature rise during a fire.

[0015] Board encasement is another effective method, involving the attachment of fire-resistant boards, such as gypsum or calcium silicate boards, to steel elements. These boards create a protective barrier that insulates the steel from heat. Board encasement is often used in combination with other fire protection measures to enhance overall effectiveness.

[0016] Another method is fire-resistant insulation, which involves applying materials such as ceramic fiber blankets or rigid insulation panels directly to steel beams and columns. These materials are designed to withstand extreme heat and provide effective thermal protection.

[0017] Improved structural design can also enhance the fire performance of steel structures. This includes using thicker steel sections, incorporating additional bracing, and designing connections that can accommodate thermal expansion without failing.

[0018] Protecting steel beams and columns from fire is essential due to their critical role in maintaining structural stability. Methods such as intumescent coatings, spray-applied fire-resistive materials, board encasement, fire-resistant insulation, and improved structural design can significantly enhance the fire resistance of steel structures. Implementing these measures helps ensure that steel beams and columns can maintain their integrity and perform their load-bearing functions during a fire, thereby safeguarding the overall safety and stability of buildings.

[0019] However, although these various methods to protect steel beams and columns from fire are effective in enhancing structural safety, they often come with significant environmental costs. Understanding these environmental impacts is crucial for developing more sustainable fire protection strategies.

[0020] Firstly, intumescent coatings, which are popular for their ability to expand and form an insulating char layer under high temperatures, involve the use of various chemical compounds. The production of these coatings typically requires significant energy and raw materials, leading to a considerable carbon footprint. Moreover, some of the chemicals used in intumescent paints can be hazardous to both human health and the environment if not managed properly. Disposal of these coatings at the end of their life cycle can also pose environmental challenges, as they may release toxic substances into the soil and water.

[0021] Spray-applied fire-resistive materials (SFRMs), commonly used for their ability to provide thermal insulation, also have environmental implications. The production and application processes of SFRMs often require substantial amounts of energy and generate dust and other particulate emissions. The materials used, such as mineral fibers and cementitious compounds, involve intensive mining and processing activities that contribute to habitat destruction, resource depletion, and pollution. Additionally, the waste generated during application and the eventual disposal of these materials can add to the environmental burden.

[0022] Board encasement using fire-resistant materials like gypsum or calcium silicate boards presents another set of environmental concerns, primarily due to their carbon footprint during production and transportation. Furthermore, much cutoff waste is generated during the construction of the encasement that may even be difficult to mount at inaccessible places in a building.

[0023] Fire-resistant insulation materials, such as ceramic fiber blankets or rigid insulation panels, also pose environmental issues. The production of ceramic fibers is energy-intensive and involves the use of raw materials that need to be mined and processed, contributing to environmental degradation and pollution. The disposal of these insulation materials, which are often non-biodegradable, adds to the growing problem of construction waste.

[0024] Improved structural design, while beneficial in enhancing fire resistance, often necessitates the use of more steel or other materials. This increase in material usage results in higher environmental costs due to the additional mining, processing, and transportation required. The embodied energy and emissions associated with producing more substantial steel sections or additional bracing elements can significantly contribute to the overall environmental impact of a construction project.

[0025] DE3028046A1 discloses a protective material that is mechanically or manually made into a sheath, applied with the aid of a rendering support, as fire insulation for statically vital steel structures, esp. steel girders of H-section. The girders are fitted with substructures at prescribed axial intervals. These serve as mounting for sheathing, which comprises both rendering support and fireproof material, and for the fixture of the rendering support and of insulating material filling the space between sheath and girder profile stem and flanges.

[0026] Object of the Invention

[0027] The objective of the present invention is to provide a reinforcement system for spray-applied materials that ensures reliable adhesion, thickness control, and stability on building structures such as ventilation ducts, steel beams, and columns, while enabling applications including fire protection, impact resistance, structural encasement, insulation, corrosion protection, and surface repair.

[0028] This has been accomplished according to this invention by utilizing a reinforcement net system together with a spray-applied material. Summary of the Invention

[0029] The reinforcement net system is designed to provide a stable base for spray-applied material application on structural surfaces, particularly around ventilation ducts, steel beams, and columns. The system consists of a series of support brackets with a mesh net installed between them. This setup ensures that the spray-applied material adheres uniformly, adding both strength and stability to the overall structure, while allowing for flexibility during installation.

[0030] In the present context, the term “spray-applied material” is to be understood as any composition that is capable of being applied to a surface by spraying, pumping, or projecting in a fluid or semi-fluid state, and that subsequently hardens or sets to form a solid coating or layer.

[0031] The spray-applied material may comprise, for example, gypsum plasters, cementitious plasters, mortars, renders, spray-applied concretes, intumescent coatings, or other mineral- or polymer-based compositions suitable for forming a protective or structural layer on a substrate.

[0032] Such materials may be aqueous or non-aqueous, may contain hydraulic or non-hydraulic binders, and may include fillers, aggregates, fibers, polymers, plasticizers, setting agents, retarders, or other additives known in the art to modify workability, adhesion, or setting properties.

[0033] The term “spray-applied material” is intended to encompass both fire- protective coatings and structural or decorative coatings, provided they are applied in a sprayable form and capable of adhering to and hardening on a surface supported by the reinforcement net system.

[0034] This reinforcement net system for spray-applied material consists of modular preassembled bracket-net units, engineered to adapt seamlessly to structures of varying lengths, such as ventilation ducts, steel beams, and columns. The design of each unit allows for easy installation with a repeating bracket-net-bracket-net pattern, providing a uniform and structurally sound base for spray-applied material.

[0035] A first aspect relates to a reinforcement net system for use with spray-applied material, the reinforcement net system comprising a pre-assembled bracket-net unit, designed to adapt to structures of varying lengths, such as ventilation ducts, steel beams, and columns; wherein the pre-assembled bracket-net unit is designed with a repeating bracket-net-bracket-net pattern.

[0036] A second aspect relates to the use of the reinforcement net system according to the first aspect for fire protecting building structures; wherein the reinforcement net system is used as reinforcement in a layer of spray-applied material.

[0037] A third aspect relates to a method for fire protecting a building structure, the method comprising:

[0038] a) providing or constructing a building structure;

[0039] b) mounting a reinforcement net system according to the first aspect on the outer surface of said building structure;

[0040] c) optionally, applying, preferably spraying, a coating layer of adhesive onto said reinforcement net system and / or building structure; and

[0041] d) applying, preferably spraying, a layer of a spray-applied material composition onto said building structure or onto said optionally adhesive coated building structure.

[0042] The invention is described in more detail in the following detailed description. Brief description of the figures

[0043] Figures 1-3 show a reinforcement net system according to the present invention being mounted to a ventilation tube.

[0044] Figure 4 shows a reinforcement net system according to the present invention being mounted to an I-beam.

[0045] Figure 5 shows a schematic side view of a reinforcement net system according to the present invention.

[0046] Figure 6 shows a schematic front view of a reinforcement net system according to the present invention.

[0047] Detailed Description of the Invention

[0048] In the present context, the term “in general” when used when mentioning a feature relating to the present invention, it must be understood that the feature may be used with all embodiments of the invention, even if the mentioning is made in the detailed part of the document.

[0049] Testing conventions: Unless stated otherwise, reported property values (e.g., strength, adhesion, impact, abrasion, thermal or acoustic properties) are obtained using generally accepted laboratory methods; values are approximate and method-independent, and equivalent procedures are contemplated.

[0050] In general, the reinforcement net system for spray-applied material is composed of modular pre-assembled bracket-net units, designed to adapt to structures of varying lengths, such as ventilation ducts, steel beams, and columns. The preassembled bracket-net unit’s design follows a repeated bracket-net-bracket-net pattern, creating a uniform and structurally sound base for spray-applied material, such as sprayable gypsum plaster. In one or more embodiments, each unit begins with a first bracket, which is adapted for being securely anchored to the structure to establish a stable foundation. Between this first bracket and a second bracket, a section of folded net is pre-attached. This net section is folded during production, allowing it to be easily unfolded during installation, extending along the structure as needed. Following the first net section, the second bracket is secured, providing another anchor point and creating a transition to the next folded net section, which is preattached between the second and third brackets. This pattern of alternating brackets and net sections continues as required, allowing the unit to extend seamlessly along the structure’s length or height.

[0051] To accommodate different project dimensions, the units may be manufactured in multiple lengths, enabling installers to select the appropriate size without having to cut or modify the pre-assembled units on-site. This modularity provides flexibility in covering various surface lengths while maintaining the integrity and stability of the bracket-net structure.

[0052] During installation, the first bracket is preferably mounted to the structure to establish the starting point. Each pre-folded net section is then progressively unfolded, with each successive bracket secured to the structure to maintain uniform tension across the net. This creates a continuous, reinforced net along the surface, with each bracket stabilizing the net and providing support for the plaster application. When these units are available in different lengths, installers can simply select the unit size that best fits their project, eliminating the need for additional cutting or adjustments.

[0053] The sequential bracket-net structure offers several advantages. First, it simplifies installation by removing the need for complex on-site assembly; installers only need to secure the brackets and unfold the net sections to create an efficient, repeatable process. The consistent spacing of brackets and the pre-attached net sections ensure uniform tension across the net, preventing sagging or uneven plaster coverage. The modular length options allow for flexible project planning, particularly on irregularly shaped or extended surfaces, while providing robust support for spray-applied material. This design ensures a durable, stable, and continuous base for plaster application, suitable for covering complex shapes and extended lengths without compromising stability.

[0054] This modular bracketed net system is an ideal solution for structural applications requiring a precise, adaptable, and strong reinforcement base for spray-applied material, allowing it to provide effective support for various shapes and extended surfaces in demanding environments.

[0055] To connect one modular unit to the next, the end bracket of one unit may be designed to align with the starting bracket of the subsequent unit. This allows each unit to join smoothly without leaving gaps or creating overlaps in the netting, maintaining a continuous surface for the plaster. When positioned side-by-side, the final bracket of one unit, and the first bracket of the next unit create a seamless joint, which helps to evenly distribute the tension of the net along the entire length of the connected units.

[0056] In one or more embodiments, the pre-assembled bracket-net unit begins with a bracket and ends with a bracket.

[0057] The connection between pre-assembled bracket-net units may include pre-drilled holes or interlocking bracket designs to facilitate alignment and secure attachment.

[0058] In some designs, the brackets at the ends of each unit may come with pre-drilled holes or slots. Installers can then use bolts, screws, or specialized clips to secure the final bracket of one unit to the initial bracket of the next. This approach is common in situations where high structural integrity is required, as bolted connections provide strong, stable joints that are easy to adjust during installation if needed.

[0059] In other designs, the brackets may be engineered with an interlocking system, such as male-female or hook-and-loop configurations. The end of one bracket slides or clicks into the start of the next bracket, providing a quick and secure way to connect units without additional tools. This method is particularly useful for long, continuous surfaces, as it allows for rapid alignment while still ensuring a stable connection.

[0060] Once the brackets are aligned and connected, the net sections between them remain in tension, creating a continuous mesh surface across units. This continuity is essential for providing an uninterrupted surface for the spray-applied material, which relies on a consistent reinforcement base to adhere effectively and maintain durability. The alignment of each net section is maintained throughout the connected units, preventing sagging or misalignment that could interfere with the plaster’s stability.

[0061] The modular design offers flexibility in covering different lengths or surface areas without requiring on-site customization. Units can be manufactured in varying lengths to accommodate different installation needs. For example, shorter units may be used for compact or intricate sections, while longer units can span extended surfaces. This minimizes waste and reduces installation time, as installers can select the appropriate length of pre-assembled units for each specific area, simply connecting them in sequence along the surface to be covered.

[0062] In one or more embodiments, at least some of the brackets are made from a flexible or malleable material that allows them to be shaped or adjusted to conform to the surface shape of the structure to which they are mounted. In general, the brackets may be made from a flexible or malleable material that allows them to be shaped or adjusted to conform to the surface shape of the structure to which they are mounted. This adaptability may be essential for ensuring a secure and stable attachment to surfaces with varying contours, such as round ducts, angled steel beams, or irregular columns.

[0063] By using a material with a certain degree of flexibility or ductility, the brackets can be manually or mechanically bent, shaped, or contoured to fit tightly against curved, angled, or uneven surfaces. This property of the bracket material ensures that the entire unit, once mounted, maintains full contact with the structure, improving stability and adhesion of the spray-applied material.

[0064] The material might be a bendable metal alloy, such as aluminum or certain grades of steel, or a specially engineered composite that allows for both rigidity and controlled flexibility. This ensures that while the brackets can be adjusted to the structure’s shape, they remain strong enough to support the netting and spray-applied material without warping or losing shape overtime.

[0065] With this material flexibility, installers can quickly customize each bracket to follow the unique surface contours of complex structures, achieving a snug fit that ensures consistent plaster support across the entire reinforced surface. This feature allows the reinforcement system to perform effectively on a wide range of structural shapes and sizes, providing a versatile and reliable solution for spray-applied material application.

[0066] In one or more embodiments, at least some of the brackets are made of metal.

[0067] In one or more embodiments, at least some of the brackets are shaped to conform to a ventilation duct, a steel beam, an I-beam, ora column.

[0068] In one or more embodiments, at least some of the brackets are U-shaped. In one or more embodiments, each bracket comprises a first face adapted for facing the structure onto which it is to be mounted, and an opposite second face; wherein each net is mounted to the second face of each corresponding bracket.

[0069] In general, the reinforcement net is typically made from a durable, flexible metal mesh, such as galvanized or stainless steel, or aluminum, combining strength with just enough pliability to be stretched securely between the brackets. Metal is chosen for its resistance to corrosion and its ability to retain tension once stretched, ensuring that the net remains taut and supportive over time, even in challenging environments where moisture or temperature fluctuations might occur.

[0070] The net is preferably designed with holes, typically in the range of 3 to 5 mm in diameter, large enough to allow spray-applied material particles to penetrate and form a strong interlocking bond. This hole size also makes the net light and manageable, allowing it to be stretched smoothly between the brackets without sagging. The spacing of these holes, often about 5 to 10 mm apart, ensures that the net maintains an even distribution of tension across its surface, providing consistent support for the plaster. In this context, spacing between holes refers to the distance from the center of one hole to the center of the next in the mesh grid pattern of the net.

[0071] In addition to metal, other materials may also be suitable for the net, provided they offer the necessary strength, flexibility, and compatibility with the spray-applied material. Fiberglass mesh is a lightweight and corrosion-resistant material. Fiberglass is easy to handle and doesn’t react with e.g., gypsum, even in moist environments. Plastic mesh, e.g., made from materials like HDPE or polypropylene, is durable, moisture-resistant, and easy to install. It’s flexible and lightweight, making it ideal for conforming to irregular or curved surfaces. Basalt fiber mesh is durable, corrosion-resistant, and highly compatible with plaster and concrete applications. Like fiberglass, it is alkali-resistant and can withstand moisture and high temperatures.

[0072] In one or more embodiments, each net is folded in a pre-use state and adapted for being unfolded in a use state.

[0073] In one or more embodiments, each net is folded as a zigzag fold.

[0074] In one or more embodiments, the net is made from a flexible or malleable material that allows it to be shaped or adjusted to conform to the surface shape of the structure to which the brackets are mounted.

[0075] In one or more embodiments, the net is designed with holes that enable a spray-applied material to penetrate through, thereby creating a strong bond between the spray-applied material layers on either side of the net.

[0076] Preferably, the holes are of a diameter of at least 3 mm, preferably within the range of 5-50 mm.

[0077] In one or more embodiments, the brackets are designed to keep the net 2-30 mm away from the structure to which the brackets are mounted.

[0078] In one or more embodiments, the reinforcement net system comprises a plurality of pre-assembled bracket-net units, and wherein each pre-assembled bracket-net unit is adapted for modular connection to one another.

[0079] In the present context, the term “gypsum plaster” is to be understood as normally understood in the art, i.e., to cover compositions predominately made from calcium sulfate, preferably predominately comprising calcium sulfate hemihydrate but may also comprise calcium sulfate anhydrate, calcium sulfate dihydrate, as well as calcined gypsum. The plaster composition may also be added adhesive.

[0080] The ventilation system duct is preferably of steel, more preferably of galvanized steel.

[0081] When using adhesives for a better bonding of the spray-applied material to the building structure and reinforcement net system, the adhesive should be suitable for such use. However, the adhesive should also be able to act as an adhesive for the uncured and cured spray-applied material composition.

[0082] In one or more embodiments, the adhesive is selected from the group consisting of: adhesives comprising an anionic copolymer dispersion of acrylic acid ester and styrene, polyvinyl acetate adhesives, polyvinyl alcohol adhesives, polyurethane adhesives, phenolic resin adhesives, cyanoacrylate adhesives, adhesives comprising an ethylene / vinyl acetate copolymer, adhesives comprising an ethylene-vinyl acetate-vinyl chloride emulsion, and mixtures thereof.

[0083] In one or more embodiments, the adhesive is selected from the group consisting of: adhesives comprising an anionic copolymer dispersion of acrylic acid ester and styrene, polyvinyl acetate adhesives, polyvinyl alcohol adhesives, polyurethane adhesives, phenolic resin adhesives, cyanoacrylate adhesives, adhesives comprising an ethylene / vinyl acetate copolymer, adhesives comprising an ethylene-vinyl acetate-vinyl chloride emulsion, a natural rubber latex, a synthetic rubber latex, and mixtures thereof.

[0084] Examples of a synthetic rubber latex include butadiene rubber latex, styrenebutadiene rubber latex, nitrile rubber latex, polyurethane rubber latex, polychloroprene rubber latex, ethylene-vinyl acetate copolymer resin, acrylate-based latex, or combinations thereof. The term “natural rubber latex” refers to any rubber latex available from any natural source.

[0085] The rubber materials, but also the other adhesives, are preferably provided in the form of an aqueous latex emulsion, which can be sprayed onto the surface and / or net.

[0086] In one or more embodiments, the adhesive is in the form of a (water) redispersible polymer powder. Redispersible polymer powders are polymer emulsions, which have been converted by a series of process, such as high temperatures and pressures, spray drying and surface treatment, to powdered thermoplastic resin materials. When mixed with water, these powdered organic binders can redisperse in water back into new emulsions with essentially identical properties to the original copolymer emulsions.

[0087] The invention also contemplates several optional embodiments that further adapt the reinforcement net system for use with different spray-applied materials and structural conditions, as described below.

[0088] Spray-Applied Material Variants

[0089] In one or more embodiments, the spray-applied material is a cementitious composition, such as a cement-based plaster, mortar, render, or concrete slurry. Such compositions may comprise hydraulic binders including Portland cement, calcium aluminate cement, or other mineral binders, optionally combined with fine or coarse aggregates, fibers, or polymers. The reinforcement net system according to the invention provides structural support and adhesion control for these heavier or higher-density materials during and after spraying.

[0090] In one or more embodiments, the spray-applied material is a spray-applied concrete, also known as shotcrete or liquid concrete. In such embodiments, the brackets and net may be dimensioned and fabricated from materials capable of withstanding higher compressive and impact loads during application. The net may, for instance, be formed from high-tensile steel mesh, stainless steel, or fiber-reinforced composite materials to ensure sufficient mechanical strength and stability.

[0091] In one or more embodiments, the spray-applied material is a polymer-modified plaster or mortar, wherein the presence of polymer additives (e.g., styrenebutadiene, acrylic, or vinyl acetate copolymers) improves flexibility, adhesion, or water resistance. The reinforcement net system provides a stable and continuous base that accommodates such formulations and ensures uniform layer thickness during spraying.

[0092] In one or more embodiments, the spray-applied material is a fire-protective or intumescent coating applied in a sprayable form. In such embodiments, the net system maintains coating uniformity and prevents sagging orcracking during curing, particularly on complex or overhead structures.

[0093] Structural Adaptations

[0094] In one or more embodiments, the brackets are fabricated from high-strength materials, such as reinforced steel, stainless steel, or structural composite alloys, to accommodate the increased load of cementitious or concrete materials. The bracket design may include reinforced ribs, cross-bracing, or increased gauge thickness to prevent deformation during application.

[0095] In one or more embodiments, the spacing between brackets is adjusted according to the density and viscosity of the spray-applied material. For example, for cementitious or concrete compositions, the spacing may be reduced to 100-250 mm to provide additional support, whereas for lighter plasters or coatings, spacing of up to 400 mm may be sufficient. In one or more embodiments, the net mesh size is selected to match the particle size of the spray-applied material. For coarse aggregates, mesh openings may be 10-50 mm, whereas for fine plasters or intumescent coatings, openings of 3-10 mm are preferred. The mesh may be formed by weaving, welding, or perforating a metal sheet, depending on the required mechanical and bonding properties.

[0096] Corrosion and Environmental Protection

[0097] In one or more embodiments, the brackets and / or net are provided with a protective surface coating, such as galvanization, epoxy resin coating, powder coating, ora corrosion-resistant alloy layer, particularly when the system is used with alkaline cementitious or outdoor materials.

[0098] In one or more embodiments, the reinforcement net system includes surface treatments or coatings designed to improve adhesion with specific spray-applied materials. For example, the net and bracket surfaces may be roughened, primed, or treated with bonding agents to enhance mechanical interlocking or chemical bonding with cementitious or polymeric compositions.

[0099] Functional and Application Variations

[0100] In one or more embodiments, the reinforcement net system is used to reinforce structural or protective coatings beyond fireproofing, such as impact-resistant layers, acoustic or thermal insulation coatings, or surface protection layers for concrete, steel, or masonry structures.

[0101] In one or more embodiments, the reinforcement net system may be integrated into prefabricated or modular building elements, where the net system is premounted and subsequently coated with a spray-applied material during manufacturing or on-site assembly. In one or more embodiments, the reinforcement net system is used in combination with automated or robotic spraying equipment, where the consistent bracket spacing and net alignment facilitate precise, uniform application of the spray material.

[0102] Figures 1-3 show a schematic step-by-step representation of how to mount a reinforcement system to a ventilation system duct 10. The reinforcement net system comprises a pre-assembled bracket-net unit 100 designed with a repeating bracket-net-bracket-net pattern. For simplification, the net 120 is not shown in its folded state for a better view of the brackets 110. In the shown configuration, the folded netting is mounted to the outer face(s) of the brackets 110, thereby allowing the inner face of the brackets 110 to come into direct contact with the ventilation system duct 10.

[0103] Figure 4 shows an embodiment, where the brackets 110 are malleable and now shaped for fitting onto an I-beam 20.

[0104] Figures 5-6 show schematic views of a reinforcement net system according to the present invention, where the net 120 is hanging folded from a bracket 110 (the other bracket is not shown).

[0105] Spray layer thickness and density

[0106] The spray-applied material may be applied in layers of 5-60 mm for plasters / renders, 10-80 mm for repair mortars, and 25-120 mm for spray-applied concretes. Typical fresh densities: 700-1,400 kg / m3(lightweight insulating plasters) and 1,700-2,400 kg / m3(cementitious mortars / concretes).

[0107] Bracket spacing vs. load.

[0108] The spacing between brackets is selected in proportion to the mass per unit area of the fresh spray-applied material so that heavier and / or thicker layers are supported by closer spacing. Illustrative spacings include about 250-400 mm for gypsum plasters at 15-25 mm thickness, about 120-250 mm for cementitious mortars at 15-40 mm, and about 80-160 mm for spray-applied concretes at 30-80 mm. A safety margin is applied so that the load per bracket remains below the bracket’s yield capacity.

[0109] Stand-off distance. The net is held 2-30 mm, preferably 5-20 mm, off the substrate to promote keying and through-mesh interlock.

[0110] Illustrative surface preparation and adhesion

[0111] Substrates can be cleaned mechanically (e.g., wire-brushing, grinding, blasting) for steel, or dampened to a saturated surface-dry condition for concrete / masonry. Optional primers / adhesives may be applied at 100-400 g / m2(solids) to the substrate and / or net.

[0112] Illustrative Application methods

[0113] Suitable methods include air-assisted spray, airless spray, wet-mix or dry-mix projection. Typical nozzle diameters / heights (wide nozzle pistols have been developed by the applicant): 6-14 mm (plasters) and 10-22 mm (mortars / shotcrete). For mortars / shotcrete, a projection velocity sufficient to compact material through the mesh (e.g., >15 m / s) is preferred.

[0114] Curing

[0115] Cementitious systems may be moist-cured 24-72 h or sealed; polymer-modified systems may be cured at 5-35 °C and 40-95 % RH.

[0116] Illustrative use-specific embodiments

[0117] Impact-resistant layers

[0118] A fiber-reinforced cementitious render (e.g., 0.3-2.0 wt % alkali-resistant glass fibers or 0.2-1.5 wt % polymer fibers, length 6-24 mm) at 10-40 mm thickness may withstand >10 J hard-body impact without perforation and achieve adhesion >2.0 MPa to steel or concrete measured by a dollie pull-off method. Structural encasement / strengthening with shotcrete

[0119] Spray-applied concrete with fine aggregates (maximum size 4-8 mm), water-to-binder ratio 0.38-0.50, and optional silica fume (3-10 wt %) can be projected through 15-40 mm mesh openings to form encasements of 25-60 mm cover around beams / columns. Representative 28-day compressive strength >25-40 MPa; rebound controlled by nozzle angle and mesh opening.

[0120] Thermal / acoustic insulation

[0121] Lightweight plaster with perlite / vermiculite / aerogel (fresh density 700-1,000 kg / m3) at 15-50 mm thickness may exhibit thermal conductivity A <0.08-0.12 W / m K measured by a steady-state or transient method, and noise reduction coefficient (NRC) >0.3-0.6 measured by an accepted laboratory method. Surface texture can be tuned by nozzle standoff (e.g., 300-500 mm).

[0122] Corrosion-protection coats

[0123] A polymer-modified or calcium-aluminate cement coating containing corrosion inhibitors (e.g., 0.2-2 wt % zinc phosphate, nitrite, or amino-alcohol) applied 8-20 mm thick over galvanized, epoxy-coated, stainless, or bare-steel substrates can deliver adhesion >1.5-2.0 MPa (dollie pull-off). After 720 h neutral salt-fog exposure, typical rust creep from an intentional scribe may be <1 mm.

[0124] Surface repair / levelling

[0125] Spray-applied repair mortar with shrinkage compensation (e.g., CSA / aluminate) and 0.3-1.0 wt % fibers at 10-40 mm thickness provides a levelled plane defined by the stand-off; typical adhesion >2.0-2.5 MPa and controlled surface crack width <0.2 mm at 28 days.

[0126] Prefabricated / modular manufacture

[0127] The system may be pre-mounted on a factory module (panel, duct section, beam wrap), sprayed to a target thickness with ±2 mm tolerance using simple gauges or optical thickness checks; modules are joined on site with a wet joint and a 30-80 mm mesh overlap.

[0128] Automated / robotic spraying

[0129] Bracket spacing and / or simple visual fiducials on brackets can act as position references for automated spray heads. Temporary depth gauges clipped to brackets may be used to verify wet-film thickness and left embedded or removed.

[0130] Weather / abrasion protection shells

[0131] A polymer-modified mineral coating or ultra-fine mortar (maximum particle size <2 mm) may achieve low abrasion loss (<150 mm3in a rotary abrasion test) and low capillary water uptake (<0.5 kg m-2h-0-5); optional hydrophobic sealers can be applied after curing.

[0132] It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.

[0133] EXAMPLE 1 - TEST OF ADHESIVES

[0134] This example tests six different adhesives’ effect on a ventilation system duct. The adhesives were coated or applied onto the outer surface of the ventilation system duct. The six selected adhesives were Selvol™ Polyvinyl Alcohol 205S (polyvinyl alcohol) from Sekisui Specialty Chemicals America, LLC, Wood Adhesive 730 Outdoor (Polyvinyl acetate) from Bostik A / S, Acronal® S 430 P (redispersible polymer powder based on an aqueous, plasticizer-free, anionic copolymer dispersion of acrylic acid ester and styrene) from BASF SE, and Acronal® 5018 (aqueous dispersion of acrylic acid ester and styrene copolymer, 50% w / w solid in water), Dermulsene 222 from DRT (a solvent-free water-based dispersion formulated with terpene resin and stabilized rosin ester, 50% w / w solid in water), and Dermulsene TR 602 (a solvent-free formulated with terpene phenolic resin, 50% w / w solid in water). All six types of adhesives showed good adhesion to the ventilation system duct.

[0135] EXAMPLE 2 - TEST OF SPRAY PLASTER TO ADHESIVE COATINGS This example tests the adhesive effect of a spray plaster composition onto different types of adhesive coatings, and the durability of the cured constructs. Four tubular ventilation system ducts (galvanized steel, 40 cm long) were coated with one of the four selected adhesives. The coated ventilation system ducts were then sprayed with 20 mm of a spray plaster composition. MP75 L from Knauf was used. The samples were then allowed to cure and harden to form a plaster layer. Then the samples were then placed in a climate cabinet for 120 hours. The temperature cycles were 5 degrees Celsius for 24 hours, 40 degrees Celsius for 24 hours, 5 degrees Celsius for 24 hours, 40 degrees Celsius for 24 hours, and finally 5 degrees Celsius for 24 hours. At 5 degrees Celsius, the humidity was kept at 50-80%, and at 40 degrees Celsius, the humidity was kept at about 90%. No cracks were observed in the plaster layer of any of the samples.

[0136] References

[0137] 10 Ventilation tube

[0138] 20 I-beam

[0139] 100 Bracket-net unit

[0140] 110 Bracket

[0141] 120 Net

Claims

25Claims1. A reinforcement net system for use with spray-applied materials, the reinforcement net system being designed to adapt to structures of varying lengths, such as ventilation ducts (10), steel beams (20), and columns;characterized in that the reinforcement net system comprises a pre-assembled bracket-net unit (100) designed with a repeating bracket-net-bracket-net pattern.

2. The reinforcement net system according to claim 1, wherein the preassembled bracket-net unit (100) begins with a bracket (110) and ends with a bracket.

3. The reinforcement net system according to any one of the claims 1-2, wherein at least some of the brackets (110) are made from a flexible or malleable material that allows them to be shaped or adjusted to conform to the surface shape of the structure to which they are mounted.

4. The reinforcement net system according to any one of the claims 1-3, wherein at least some of the brackets (110) are made of metal.

5. The reinforcement net system according to any one of the claims 1-4, wherein at least some of the brackets (110) can be shaped to conform to a ventilation duct, a steel beam, an I-beam, or a column.

6. The reinforcement net system according to any one of the claims 1-5, wherein at least some of the brackets (110) are U-shaped.

7. The reinforcement net system according to any one of the claims 1-6, wherein each bracket (110) comprises a first face adapted for facing the structure onto which it is to be mounted, and an opposite second face; wherein each net (120) is mounted to the second face of each corresponding bracket (110).

8. The reinforcement net system according to any one of the claims 1-7, wherein each net (120) is folded in a pre-use state, and adapted for being unfolded in a use state.

9. The reinforcement net system according to claim 8, wherein each net (120) is folded as a zigzag fold.

10. The reinforcement net system according to any one of the claims 1-9, wherein the net (120) is made from a flexible or malleable material that allows it to be shaped or adjusted to conform to the surface shape of the structure to which the brackets (110) are mounted.

11. The reinforcement net system according to any one of the claims 1-10, wherein the net (120) is designed with holes that enable a spray-applied material to penetrate through, thereby creating a strong bond between the spray-applied material layers on either side of the net (120).

12. The reinforcement net system according to claim 11 , wherein the holes are of a diameter of at least 3 mm, preferably within the range of 5-50 mm.

13. The reinforcement net system according to any one of the claims 1-12, wherein the brackets (110) are designed to keep the net 2-30 mm away from the structure to which the brackets (110) are mounted.

14. The reinforcement net system according to any one of the claims 1-13, comprising a plurality of pre-assembled bracket-net units (100) according to any one of the claims 1-13, and wherein each pre-assembled bracket-net unit (100) is adapted for modular connection to one another.

15. The reinforcement net system according to any one of claims 1-14, wherein the spray-applied material is selected from gypsum plaster, cementitious plaster, mortar, render, or spray-applied concrete.

16. Use of the reinforcement net system according to any one of the claims 1-15 for fire protecting building structures; wherein the reinforcement net system is used as reinforcement in a layer of spray-applied material.

17. Use of the reinforcement net system according to any one of claims 1-15 for forming an impact-resistant layer on a building structure, wherein the spray-applied material is a cementitious plaster, mortar, or render.

18. Use of the reinforcement net system according to any one of claims 1-15 for structural encasement or strengthening, wherein the spray-applied material is a spray-applied concrete, e.g., shotcrete or liquid concrete.

19. Use of the reinforcement net system according to any one of claims 1-15 for providing thermal and / or acoustic insulation, wherein the spray-applied material comprises lightweight aggregates and / or polymer modifiers configured to reduce density and improve damping / insulating properties.

20. Use of the reinforcement net system according to any one of claims 1-15 for corrosion protection of metallic substrates, wherein the spray-applied material is a polymer-modified cementitious coating, mineral coating, or other corrosioninhibiting sprayable composition.

21. Use of the reinforcement net system according to any one of claims 1-15 for surface repair or levelling of uneven substrates, wherein the spray-applied material is a repair mortar or render.2822. Use of the reinforcement net system according to any one of claims 1-15 in the manufacture of prefabricated or modular elements, wherein the spray-applied material is applied to the net system pre-mounted on a prefabricated component.

23. Use of the reinforcement net system according to any one of claims 1 -15 with automated or robotic spraying equipment, the bracket spacing and net alignment providing a thickness control guide for the sprayed layer.

24. Use of the reinforcement net system according to any one of claims 1-15 for abrasion or weather protection of ducts or exposed steelwork, wherein the spray-applied material forms a protective outer shell.

25. A method of applying a spray-applied material to a substrate, comprising mounting the reinforcement net system according to any one of claims 1-15 to the substrate, and spraying the material while controlling thickness using bracket spacing and / or bracket-mounted gauges as positional references.

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