Method and Arrangement for Forming Precast Concrete Panels

The present disclosure generally relates to construction technology. In particular, the present disclosure relates to a method and an arrangement for forming and/or constructing precast concrete structures, such as, precast concrete panels for use in construction technology.

Existing construction technologies involve one-off (e.g., customized) build-on site approaches in which construction material is brought to the construction site where the actual construction is performed. This has been the traditional methodology and approach for many years but has certain inherent challenges, including non-availability of skilled workforce (e.g., manual labor), heavy and expensive on-site machinery, incorrect estimate of completion time of construction projects, delays in delivery of projects, inclement weather, poor quality and wastage of materials, noise and air pollution, and cost involved in disposal of debris. This approach is also “one-off” as it provides no repeatability or scalability leverage. Each building is constructed, and each project is performed differently, and results vary widely, which may be undesirable considering present day demand for symmetrical construction projects with enhanced look and feel. However, constructing or casting each individual component of a building on site incurs significant expenditures in time and resources. It also increases a project's vulnerability to unforeseen factors, such as poor weather, worksite accidents, improper pour, etc.

In order to address the aforesaid shortfalls of such build or cast-on site approaches, some construction projects use precast modules. Examples of the precast modules may include wall panels, that are built in factories under factory scaling, repeatability, and in-factory conditions.

Moreover, the problem of thermal insulation in buildings has been a persistent issue, leading to energy inefficiency and discomfort for occupants. The need for improved insulation arises from traditional construction materials and methods that often fail to provide adequate thermal performance and strength to the building. Addressing this problem is crucial to enhance energy efficiency, reduce heating and cooling costs, and create more comfortable living and working environments along with increasing the structural strength.

Accordingly, there is a need for technical solutions that address the needs described above, as well as other inefficiencies of the state of the art. Specifically, there is a need in the art for a precast structure that meets thermal insulation and structural strength requirements.

Embodiments for a method and arrangement for forming precast concrete panels for construction projects are disclosed that address at least some of the above challenges and issues.

The following represents a summary of some embodiments of the present disclosure to provide a basic understanding of various aspects of the disclosed herein. This summary is not an extensive overview of the present disclosure. It is not intended to identify key or critical elements of the present disclosure or to delineate the scope of the present disclosure. Its sole purpose is to present some embodiments of the present disclosure in a simplified form as a prelude to the more detailed description that is presented below.

In an aspect, the present disclosure is directed to a precast concrete panel. The precast concrete panel comprises a first layer forming a rear-side of the precast concrete panel, wherein the first layer has concrete with a reinforcement structure; a core having a thermally insulating material; and a second layer forming a front-side of the precast concrete panel, wherein the second layer has fiber reinforced concrete, wherein the first layer, the core, and the second layer are coupled to each other to form the precast concrete panel.

In some embodiments of the present disclosure, the core is sandwiched between the first layer and the second layer.

In some embodiments of the present disclosure, the precast concrete panel further includes a load bearing element traversing, at least in part, through the first layer, the core, and the second layer. In some embodiments, the load bearing element comprises a lattice girder having an upper bar and two lower bars connected through a triangulated framework of lacing members.

In some embodiments of the present disclosure, the reinforcement structure includes a single-layer metal mesh.

In some embodiments of the present disclosure, the fiber includes one or more of metal fibers, glass fibers, synthetic fibers, and natural fibers.

In some embodiments of the present disclosure, the thermally insulating material comprises one or more of polystyrene (EPS), polyurethane foam (PUR), and mineral wool.

In some embodiments of the present disclosure, the precast concrete panel further includes a connecting member for interconnecting the precast concrete panel to an adjacent precast concrete panel. In some embodiments, the connecting member is a wire loop that overlaps with another wire loop of the adjacent precast concrete panel to create a hook, wherein a metal rod passes through the hook and locks the precast concrete panel to the adjacent precast concrete panel. In some embodiments, the precast concrete panel includes a plurality of connecting members along an edge of the precast concrete panel.

In some embodiments of the present disclosure, the precast concrete panel includes a first recessed section at a bottom side of the precast concrete panel for coupling to a foundation. In some embodiments, the precast concrete panel includes a second recessed section at a top side of the precast concrete panel for coupling to another precast concrete panel.

In some embodiments of the present disclosure, the core has a variable thickness throughout the length of the precast concrete panel.

In an aspect, the present disclosure is directed to a method of forming precast concrete panels. The method includes forming a first layer of the precast concrete panel using concrete with a reinforcement structure, wherein the first layer forms a rear-side of the precast concrete panel; placing a core comprising thermally insulating material on the first layer; and forming a second layer of the precast concrete panel having fiber reinforced concrete, wherein the second layer forms a front-side of the precast concrete panel, wherein the first layer, the core, and the second layer are coupled to each other to form the precast concrete panel.

In some embodiments of the present disclosure, the method further includes adding a load bearing member along with the reinforcement structure, wherein the load bearing element comprises a lattice girder having an upper bar and two lower bars connected through a triangulated framework of lacing members.

In some embodiments of the present disclosure, the reinforcement structure comprises a single-layer metal mesh.

In some embodiments of the present disclosure, the method further includes attaching one or more connecting members to an edge of the precast concrete panel for interconnecting the precast concrete panel to an adjacent precast concrete panel during installation. In some embodiments, the one or more connecting members is a wire loop that overlaps with another wire loop of the adjacent precast concrete panel to create a hook, wherein a metal rod passes through the hook and locks the precast concrete panel to the adjacent precast concrete panel.

In some embodiments of the present disclosure, the method further includes forming a first recessed section at a bottom side of the precast concrete panel for coupling to a foundation. In some embodiments, the method further includes forming a second recessed section at a top side of the precast concrete panel for coupling to another precast concrete panel.

The above summary is provided merely for the purpose of summarizing some example embodiments to provide a basic understanding of some aspects of the disclosure. Accordingly, it will be appreciated that the above-described embodiments are merely examples and should not be construed to narrow the scope or spirit of the disclosure in any way. It will be appreciated that the scope of the disclosure encompasses many potential embodiments in addition to those here summarized, some of which will be further described below.

The following detailed description is presented to enable any person skilled in the art to make and use the disclosure. For purposes of explanation, specific details are set forth to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that these specific details are not required to practice the disclosure. Descriptions of specific applications are provided only as representative examples. Various modifications to the preferred embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the disclosure. The present disclosure is not intended to be limited to the embodiments shown but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.

With modernization in construction-related methodologies and technologies, there has been a rapid shift from normal customized build on-site construction methodologies to construction using modules or blocks that are able to be built off-site and then assembled on-site to form a construction or a building. Further, as discussed above, there is a need for improved thermal insulation in buildings and for improved structural strength of the building.

The prevailing solutions to address the problem of insulation in buildings or building components, such as, walls, while also strengthening the wall typically involve a combination of thermal insulation and structural enhancement. These solutions aim to improve energy efficiency, indoor comfort, and structural integrity, but have associated challenges. For example, one solution is to add insulation material to the exterior of the wall, however, this might alter the building's appearance. Further, proper installation is crucial to moisture retention or interstitial condensation. Another approach is to add insulation to the interior surface of the wall. However, this may reduce the room's internal space, and may require thermal bridging at junctions with other walls and elements. In conclusion, the problem of thermal insulation in buildings has been a persistent issue, leading to energy inefficiency and discomfort for occupants. The need for improved insulation, that also provides structural strength while maximizing room space, arises from traditional construction materials and methods that often fail to provide adequate thermal performance and strength to the building. Addressing this problem is crucial to enhance energy efficiency, reduce heating and cooling costs, and create more comfortable living and working environments along with increasing the structural strength.

The presently claimed invention aims to provide a solution by integrating insulation technology into precast building structures, thereby enhancing thermal performance, reducing energy consumption, providing the structural strength requirement for resisting the wind loads of hurricane zones, and maximizing available indoor living space.

Certain terms and phrases have been used throughout the disclosure and will have the following meanings in the context of the ongoing disclosure.

“Cast-in-place concrete” or “Cast-in-situ concrete” is a building-construction technology where elements of a building structure are cast at the site in formwork.

“Precast structure” refers to a construction product produced by casting concrete in a reusable mold or form which is then cured in a controlled environment at an offsite location, transported to a construction site, and maneuvered into a targeted place. Examples include precast beams, slabs, wall panels, and the like.

“Wall panel” refers to a prefabricated multi-layered wall fabricated at an offsite location and installed on-site, wherein “on-site” denotes a construction site and “offsite” denotes allocation away from the construction site. The wall panel is able to be with or without door or window opening based on the design of the building structure.

“Slab” refers to a prefabricated structure at an offsite location and installed on-site. The slab includes a concrete base and a structural topping. The structural toppings, also referred to as topping screeds, are specialized materials applied to existing concrete base of the slab to enhance performance, durability, and aesthetic.

“Beam” refers to a construction element that is made by casting concrete into a mold and then curing it in a controlled environment at the offsite location. Beams are able to be used for both load-bearing and non-load bearing applications and be made in a variety of shapes and sizes.

“Foundation” refers to a monolithic cast-in-place foundation that is poured in one piece, typically 4-6 inches thick. It is commonly used in areas with shallow soil frost depths and is known for its durability and efficiency.

“Grout” is a filling, which when poured into a receptacle will fill in the receptacle and consolidate the adjacent edges into a solid mass, such as cementitious mortar or other cement-based materials, bentonite, bentonite/sand mixtures, graphite-based materials, carbon nanotubes and nanofibers, or similar materials.

“Sealant” refers to substances used to seal, block, or close gaps between various modules of the building structure to prevent fluids, air, and pests from passing through. These materials seal joints where dissimilar materials meet and filling any irregularities that may exist between the two surfaces.

In accordance with the embodiments of the disclosure, a precast concrete panel is disclosed. The precast concrete panel includes a first layer forming a rear-side of the precast concrete panel, wherein the first layer has concrete with a reinforcement structure, a core comprising thermally insulating material, and a second layer forming a front-side of the precast concrete panel, wherein the second layer has fiber reinforced concrete, wherein the first layer, the core, and the second layer are coupled to each other to form the precast concrete panel.

The embodiments of the disclosure are described in more detail with reference to.

is a detailed view of the precast concrete panel, in accordance with some embodiments. As shown in, the precast concrete panelincludes a first layer, a core, and a second layer, such that the first layer, the core, and the second layerare coupled together to form the precast concrete panel. Specifically, the coreis sandwiched between the first layerand the second layer.

Further, as shown in, the first layerforms a rear-side of the precast concrete panel. In some embodiments, the first layeris an inner or interior layer of the precast concrete panel when it is installed in a building. The second layerforms a front side of the precast concrete panel. In some embodiments, the second layeris an outer or exterior layer of the precast concrete panel when it is installed in a building. However, it should be noted that the disclosure is not limited to the above, and the placement of the first and the second layers is able to be interchanged without departing from the scope of the current disclosure.

In accordance with some embodiments, the first layeris made of concrete reinforced with a reinforcement structure, as shown in. In some embodiments, the reinforcement structureis a single-layer metal mesh or any other similar reinforcement structure or material. The reinforcement structureprovides the structural strength to the first layerto handle subjected load or stress when installed.

In some embodiments, the reinforcement structureis made from a grid or mesh of steel bars. These bars are typically arranged in both horizontal and vertical directions, creating a network within a concrete element. This enhances the structural integrity and durability of a precast structure. The mesh design ensures a uniform distribution of reinforcing material throughout the concrete element, providing strength in multiple directions. Further, mesh rebar is often prefabricated into large sheets or rolls, making it convenient to transport and handle during the precast manufacturing process. In some embodiments, the reinforcement structureor the single-layer metal mesh is embedded within the first layerduring the casting process. This reinforcement adds tensile strength to the first layer, helping it withstand stresses and prevent cracking. The reinforcement structureis able to be available in various sizes and configurations to suit different applications and structural requirements. For example, the mesh size and bar diameter is able to be customized based on the specific needs of the precast element.

For forming the reinforcement structure, such as a single-layer steel mesh, an appropriate material is able to be selected, which is typically high-quality steel. This steel is able to be either carbon steel or a type of alloy with properties that make it suitable for reinforcement applications. The steel is then processed through a rolling mill or welding equipment. In the case of rolled mesh, the steel is fed through a series of rollers that shape and form it into the desired grid pattern. For welded mesh, individual steel bars are welded together at their intersections to create the mesh structure. In some embodiments, the mesh then undergoes surface treatment processes such as galvanization to enhance its corrosion resistance. Galvanization involves coating the mesh with a layer of zinc, protecting it from rust and corrosion over time. Once the mesh is formed, it is cut to the required size and shape. This step allows manufacturers to produce mesh rebar in various configurations and dimensions to meet specific project requirements.

The corehas a thermally insulating material and is responsible for thermal insulation of the precast concrete panel. These materials have insulating properties and help to minimize heat transfer through the precast concrete panel. Further, as shown in, the coreis able to have a variable thickness throughout the length of the precast concrete panel based on structural, thermal, and/or design requirements. For example, variable thickness in the coreis able to be designed to optimize the structural and thermal performance of the precast concrete panel. The variability in thickness allows for strategic placement of insulating materials to enhance the precast concrete panel's overall efficiency. Thicker portions provide better structural support, while thinner sections focus on insulation, resulting in a precast concrete panel that meets both structural and thermal requirements effectively.

Further, the coreis able to have different shapes, such as a L-shape, for specific structural and/or functional purposes. Variations in core shapes are able to influence the distribution of materials within the precast concrete panel, optimizing insulation and thermal performance. The choice of a specific core shape is typically based on a combination of structural requirements, architectural considerations, and the desired thermal properties of the precast concrete panel. For example, the L-shape of the coreprovides added stability and strength, making it suitable for load-bearing applications. In some embodiments, the coreis placed and/or poured over the first layerwhen forming the precast concrete panel.

In some embodiments, the coreis made of materials, such as, but not limited to, expanded polystyrene (EPS), polyurethane foam (PUR), or mineral wool. EPS is a lightweight, closed-cell insulation material. EPS cores are known for their good insulation properties and are commonly used in construction for energy-efficient buildings. Polyurethane (PUR) or Polyisocyanurate (PIR) are foam insulation materials with excellent thermal performance. They offer high insulation values, making them effective choices for the insulating core of sandwich wall panels. These materials contribute to energy efficiency and temperature regulation in buildings. Mineral wool is a fibrous insulation material made from natural or synthetic minerals. Mineral wool provides both thermal and acoustic insulation. When used as the core in sandwich wall panels, mineral wool enhances fire resistance and sound absorption properties.

The primary function of the coreis to provide thermal insulation to the precast concrete panel. This helps regulate indoor temperatures, improving energy efficiency by reducing heating or cooling requirements. By minimizing heat transfer through the wall, the insulating core enhances the overall energy efficiency of the building. This is crucial for maintaining comfortable interior temperatures and reducing reliance on mechanical heating or cooling systems. The coreis also able to offer resistance to moisture by helping prevent water infiltration, reducing the risk of mold growth and maintaining the structural integrity of the wall panel. In some embodiments, the corecontributes to the fire resistance of the precast concrete panel. This is especially important for meeting building safety standards and providing occupants with additional time for evacuation in case of a fire. Further, in some embodiments, the corecontributes to the sound insulation properties of the precast concrete panel. This is beneficial for creating acoustically comfortable indoor environments by reducing noise transmission.

In accordance with some embodiments, the second layerincludes concrete reinforced with fiber or fiber reinforced concrete (FRC). That is, concrete is mixed with suitable fibers to increase the toughness and durability of the second layer. Non-reinforced concrete is likely to break down when it fractures and cracks, concrete reinforced with fiber will maintain its structural integrity, as it is held together by the fibers when a crack develops. Fiber reinforced concrete is able to be a composite material comprising mixtures of concrete combined with continuous or discontinuous, uniformly, or non-uniformly dispersed fibers. In some embodiments, the fibers include one or more of metal fibers, glass fibers, synthetic fibers, and natural fibers. Most commonly used metal fibers are steel fibers. These fibers, typically, are in round shape. In some embodiments, the diameter of the fiber is in the range of 0.25 to 0.75 mm. The steel fibers are also able to include round crimped steel fiber, melt-extract stainless steel, hooked-end steel fiber, glued steel fiber, and flat-end fiber. Further, glass fiber is a versatile type of fiber that is widely employed in the composite industry because of its excellent strength-to-weight ratio while being less stiff than other reinforcing fibers. Glass fibers are readily available in the forms of chopped strands, direct draw roving, assembled roving, mats, and so on.

Another example of the fibers that are able to be used are synthetic fibers that are made from synthesized polymers of small molecules. The compounds that are used to make these synthetic fibers come from raw materials such as petroleum-based chemicals or petrochemicals. These materials are polymerized into a chemical that bonds two adjacent carbon atoms. Differing chemical compounds are used to produce different types of synthetic fibers. Some examples of synthetic fibers include, but are not limited to, acrylic, aramid, carbon, nylon, polyester, polyethylene and polypropylene. Typically, they are categorized as micro and macro synthetic fibers for reinforcement of concrete. Micro-fiber concrete with polypropylene fibers is mainly used to reduce plastic shrinkage in fresh concrete. The micro-fiber concrete also improves the fire resistance behavior of concrete structures at very high temperatures. Addition of micro-fibers in the concrete ensures that as these fibers melt, they create open channels in the concrete pore structure which allows the built-up vapors to escape, thereby releasing the internal pressures and preventing the spalling. Macro-fiber concrete with polypropylene fibers is mainly used in lightly loaded applications to improve the concrete in terms of their crack behavior and to improve the resistance against the thermal shrinkage process. Further, macro synthetic fibers do not corrode. Hence, no rusty spots appear at the surface.

Natural fibers are also able to be used to reinforce concrete. For example, wood fibers, jute, hast fibers including hemp, flax, and ramie are able to be used as natural fiber reinforcement to concrete. Other examples that are able to be used are leaf fibers, such as, sisal, seed and fruit fibers, such as, coconut or coir, etc. Natural fibers are also able to be derived from palm trees, bamboo plants, and sugarcane.

In some embodiments, different types of fibers are mixed to form a customized fiber reinforcement for concrete. For example, blends of both steel and polymeric fibers are able to be used in order to combine the benefits of both products. Further, the distribution, orientation, and density of these fibers impact the properties of the resulting concrete. The amount of fibers added, measured as a percentage of the total volume, termed volume fraction (Vf), is able to range depending on the required tensile strength of the precast structure and/or building design requirements. The aspect ratio (l/d) of the fiber influences the flexural strength and toughness of the matrix. For example, microfibers exhibit better impact resistance compared to longer fibers.