WO2010055497A2 - Panneau de béton précoulé et procédé de fabrication de panneau de béton précoulé - Google Patents

Panneau de béton précoulé et procédé de fabrication de panneau de béton précoulé Download PDF

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Publication number
WO2010055497A2
WO2010055497A2 PCT/IB2009/055109 IB2009055109W WO2010055497A2 WO 2010055497 A2 WO2010055497 A2 WO 2010055497A2 IB 2009055109 W IB2009055109 W IB 2009055109W WO 2010055497 A2 WO2010055497 A2 WO 2010055497A2
Authority
WO
WIPO (PCT)
Prior art keywords
concrete mixture
concrete
lightweight
mixture
bed
Prior art date
Application number
PCT/IB2009/055109
Other languages
English (en)
Other versions
WO2010055497A3 (fr
Inventor
Peter Hermann Schmalfuss
Original Assignee
Peter Hermann Schmalfuss
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from SG200906474-2A external-priority patent/SG169912A1/en
Application filed by Peter Hermann Schmalfuss filed Critical Peter Hermann Schmalfuss
Publication of WO2010055497A2 publication Critical patent/WO2010055497A2/fr
Publication of WO2010055497A3 publication Critical patent/WO2010055497A3/fr
Priority to SG2012004214A priority Critical patent/SG177712A1/en
Priority to PCT/IB2010/053530 priority patent/WO2011015997A2/fr

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
    • E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
    • E04C2/26—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials composed of materials covered by two or more of groups E04C2/04, E04C2/08, E04C2/10 or of materials covered by one of these groups with a material not specified in one of the groups
    • E04C2/284—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials composed of materials covered by two or more of groups E04C2/04, E04C2/08, E04C2/10 or of materials covered by one of these groups with a material not specified in one of the groups at least one of the materials being insulating
    • E04C2/296—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials composed of materials covered by two or more of groups E04C2/04, E04C2/08, E04C2/10 or of materials covered by one of these groups with a material not specified in one of the groups at least one of the materials being insulating composed of insulating material and non-metallic or unspecified sheet-material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B1/00—Producing shaped prefabricated articles from the material
    • B28B1/08—Producing shaped prefabricated articles from the material by vibrating or jolting
    • B28B1/084—Producing shaped prefabricated articles from the material by vibrating or jolting the vibrating moulds or cores being moved horizontally for making strands of moulded articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B1/00—Producing shaped prefabricated articles from the material
    • B28B1/52—Producing shaped prefabricated articles from the material specially adapted for producing articles from mixtures containing fibres, e.g. asbestos cement
    • B28B1/523—Producing shaped prefabricated articles from the material specially adapted for producing articles from mixtures containing fibres, e.g. asbestos cement containing metal fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B19/00—Machines or methods for applying the material to surfaces to form a permanent layer thereon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B23/00—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects
    • B28B23/0075—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects for decorative purposes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B23/00—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects
    • B28B23/0081—Embedding aggregates to obtain particular properties
    • B28B23/0087—Lightweight aggregates for making lightweight articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B23/00—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects
    • B28B23/02—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects wherein the elements are reinforcing members
    • B28B23/022—Means for inserting reinforcing members into the mould or for supporting them in the mould
    • B28B23/024—Supporting means
    • B28B23/026—Mould partitionning elements acting as supporting means in moulds, e.g. for elongated articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B3/00—Producing shaped articles from the material by using presses; Presses specially adapted therefor
    • B28B3/20—Producing shaped articles from the material by using presses; Presses specially adapted therefor wherein the material is extruded
    • B28B3/22—Producing shaped articles from the material by using presses; Presses specially adapted therefor wherein the material is extruded by screw or worm
    • B28B3/228—Slipform casting extruder, e.g. self-propelled extruder
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B7/00—Moulds; Cores; Mandrels
    • B28B7/0064—Moulds characterised by special surfaces for producing a desired surface of a moulded article, e.g. profiled or polished moulding surfaces
    • B28B7/0079—Moulds characterised by special surfaces for producing a desired surface of a moulded article, e.g. profiled or polished moulding surfaces with surfaces for moulding interlocking means, e.g. grooves and ribs
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
    • E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
    • E04C2/04—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of concrete or other stone-like material; of asbestos cement; of cement and other mineral fibres
    • E04C2/049—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of concrete or other stone-like material; of asbestos cement; of cement and other mineral fibres completely or partially of insulating material, e.g. cellular concrete or foamed plaster

Definitions

  • the present application relates to a precast concrete panel and to a method for making the precast concrete panel.
  • Modern construction methods can use wall panels. These precast wall panels can have lightweight and can have desirable physical properties of high strength, water resistance, rigidity, heat insulation, and flame retardant. For wide adoption of the precast wall panels, the wall panels should have a low cost.
  • precast wall panel which comprises a lightweight concrete mixture be produced with low cost and still provide satisfactory strength.
  • the lightweight concrete mixture can have several implementa- tions.
  • the lightweight concrete mixture weighs at least about 20% lighter than normal concrete mixture.
  • the lightweight concrete mixture weights less than about 1.2 kg/1 (kilogram per litre) .
  • the lightweight concrete mixture weights less than about 1.0 kg/1.
  • the lightweight concrete mixture weights less than about 0.8 kg/1.
  • the light- weight concrete mixture includes significantly amount of lightweight material, such as polystyrene beads, perlite, or foam material.
  • the application provides a slip-forming extruder assembly for casting or making a precast concrete product with an extruder .
  • the slip-forming extruder assembly is also called an extruder assembly.
  • the extruder is used for moulding or for casting a wet lightweight concrete mixture.
  • the precast concrete product can be provided as a precast concrete slab or block.
  • the term "slip-forming" is also known as continuous pouring or continuously forming.
  • the extruder comprises one or more concrete hoppers that contain a lightweight concrete mixture.
  • the concrete hoppers may receive a lightweight concrete mixture from a concrete mixer.
  • the lightweight concrete mixture is usually in a semi-dry or wet form.
  • the lightweight concrete mixture is also known as lightweight concrete slurry.
  • the lightweight concrete mixture is for release by the concrete hopper.
  • the concrete hopper can have discharge openings for releasing or supplying the lightweight concrete mixture.
  • One or more augers are disposed or located below the concrete hoppers for receiving the lightweight concrete mixture.
  • the augers also compact and then release the lightweight concrete mixture.
  • the augers are also called tubes.
  • the augers can also be provided as called screw feeders and they have an Archimedean type of blades for compacting.
  • the compacting can leave hollow cores or channels with spiral grooves within the lightweight concrete mixture. This is one of the possible features of a concrete panel, which is made with an extruder.
  • the augers also feed or transport the compacted lightweight concrete mixture onto an elongated bed.
  • the bed receives the lightweight concrete mixture from the augers.
  • One or both of the bed and the augers are movable relative to each other along a path of travel for casting the lightweight concrete mixture.
  • the bed is also known as a casting bed or a mould.
  • the extruder assembly can include and one or more claddings.
  • the claddings are attached to an external surface of the cured concrete mixture for providing coverings for the cured concrete mixture.
  • a conveyer can transport the bed whilst the augers remain stationary.
  • tracks and corresponding wheels enable the augers to move above the bed that remains stationary.
  • the bed can comprise one or more sidewalls and one or more side shakers that are attached to the sidewalls.
  • the shakers are also called vibrators.
  • the sidewalls are intended for casting or moulding the lightweight concrete mixture into a panel whilst the side shakers provide a vibrating action for compacting the lightweight concrete mixture.
  • One sidewall can include an elongated protrusion at a side of the sidewall that faces or contacts the lightweight concrete mixture.
  • the protrusion is positioned in a longitudinal direction of the bed.
  • the protrusion is also known as a tongue.
  • another sidewall can comprise an elongated groove at a side of the sidewall that faces or contacts the lightweight concrete mixture.
  • the groove is positioned in a longitudinal direction of the bed.
  • the tongue and the groove are means for forming the moulded lightweight concrete mixture into panels that to interconnect to other panels.
  • the bed can comprise a top plate for casting the lightweight concrete mixture.
  • a top shaker can be attached to the top plate for compacting the lightweight con- crete mixture.
  • the application also provides a slip-former assembly for casting a precast concrete product.
  • the slip-former assembly includes a slip-former.
  • the slip- former is forming a wet lightweight concrete mixture.
  • the slip-former is a type of a slide casting apparatus.
  • the slip-former comprises an elongated stationary bed and a frame that is movable relative to the bed along a path of travel.
  • the frame can be moved by a driving mechanism in the path of travel.
  • One or more concrete hoppers are mounted on the frame and they are disposed above the bed.
  • the concrete hoppers contain or hold a lightweight concrete mixture.
  • the lightweight concrete mixture is usually in a semi-dry or wet form.
  • the lightweight concrete mixture is also known as lightweight concrete slurry.
  • the concrete hopper controls a release of the lightweight concrete mixture.
  • the concrete hoppers comprise discharge openings for depositing or releasing or supplying a lightweight concrete mixture onto the bed for casting the deposited lightweight concrete mixture.
  • the lightweight concrete mixture is in a semi-dry or wet form.
  • the slip-former assembly can include one or more claddings that act as coverings for the cured lightweight concrete mixture.
  • the cladding is attached to the casted and cured lightweight concrete mixture.
  • One or more divider plates can be provided on the bed for separating longitudinally the casted lightweight concrete mixture in the longitudinal direction of the bed.
  • the divider plates move together with the frame.
  • the divider plates allow two or more separated concrete slab to be produced with each production run.
  • the slip-former can include one or more barriers for preventing the layer of lightweight concrete mixture from reaching a predetermined height. The also prepares the lightweight concrete mixture for moulding or casting.
  • the slip-former can also comprise one or more tubes.
  • the tubes are use for shaping or forming hollow volume areas or cores within the concrete mixture.
  • the tubes can develop or form elongated channels or traces on a surface of the lightweight concrete mixture. These hollow cores then do not comprise spiral grooves.
  • the bed can comprise one or more sidewalls and one or more side shakers being attached to the sidewalls for compacting or casting the lightweight concrete mixture. The shakers are also called vibrators.
  • One sidewall can include an elongated protrusion at a side of the sidewall that faces or contacts the lightweight concrete mixture.
  • another sidewall can comprise an elongated groove at a side of the sidewall that faces or contacts the lightweight concrete mixture.
  • one sidewall can include a tongue whilst another sidewall can include a groove .
  • the bed can comprise a top plate for casting a top surface of the lightweight concrete mixture.
  • the bed can also comprise a top shaker being attached to the top plate for compacting the lightweight concrete mixture.
  • the slip-former can include a smoothener for providing a top surface of the lightweight concrete mixture.
  • the smoothener treats the top surface to make it smoother.
  • the application also provides a further slip former assembly for casting a concrete product.
  • the further slip former assembly includes a slip-former.
  • the further slip-former is for forming a wet lightweight concrete mixture .
  • the further slip-former includes a casting bed, a frame, a driving mechanism, one or more concrete hoppers, and one or more divider plates.
  • the frame is movable relative to the bed along a path of travel.
  • the driving mechanism is intended moving the frame in the path of travel.
  • the concrete hoppers are mounted on the frame and being disposed or positioned above the bed.
  • the concrete hopper includes discharge opening for depositing a lightweight concrete mixture onto the bed for casting the deposited lightweight concrete mixture. The said arrangement allows a continuous or continual pouring of the concrete mix- ture onto the bed.
  • the divider plates are provided on the bed for separating the casted lightweight concrete mixture. These divider plates move together with the concrete hoppers.
  • the further slip former assembly can include one or more claddings for covering one or more external surfaces of the cured concrete mixture.
  • the slip-former assembly can include one or more tubes for forming one or more hollow volume areas or cores within the lightweight concrete mixture.
  • the hollow cores do not have spiral areas of compression. Channels corresponding to the hollow cores may be formed on a top surface of concrete mix- ture.
  • One or more barriers for preventing the layer of lightweight concrete mixture from reaching a predetermined height may also included in the slip-forming assembly.
  • the application provides a concrete product in the form of a panel.
  • the concrete product comprises a lightweight concrete mixture that is provided by an extruding process and one or more claddings on one or more surfaces of the concrete product.
  • the extruding process also forms the lightweight concrete mixture.
  • the concrete product can also be referred to as a precast concrete slab.
  • the extruding process uses one or more augers that leave one or more spiral areas of compression within the lightweight concrete mixture.
  • the augers scratch or compact the lightweight concrete mixture to produce the areas of compression.
  • the application also provides a further concrete product.
  • the further concrete product includes a lightweight concrete mixture and one or more claddings.
  • the lightweight concrete mixture is provided by a slip forming process whilst the one or more claddings are attached to one or more surfaces of the concrete product.
  • the slip forming process also forms the lightweight concrete mixture.
  • the cladding is placed or is attached on a top or bottom surface of the concrete product.
  • the cladding can comprise a board.
  • the board can have fibre for reinforcement or other types for providing different protection or charac- teristics.
  • the concrete product can be provided with a surface area that comprises a layer that has significantly less lightweight material than other volume areas.
  • the layer can be without or be free of lightweight material.
  • the lightweight concrete mixture comprises lightweight material in the form of polystyrene beads. Polystyrene material is also referred to as Styrofoam. The polystyrene beads in the concrete mixture tend to float or swim upwards. Hence, a thin bottom layer of the concrete mixture is mostly free of the polystyrene beads or the lightweight material.
  • the concrete product can also include one or more wires for reinforcing purpose.
  • the wires are placed in a longitudinal direction of the concrete product.
  • the wires are placed in the casting bed before the lightweight concrete mixture is casted onto the bed.
  • the wires allow the concrete product to withstand or bear a greater load.
  • the concrete product can incorporate pre-stressed wires or non pre-stressed wires for reinforcement.
  • the concrete product can also include one or more hollow volume areas or cores.
  • the augers can have tapered ends such that the augers do not produce any hollow core within the concrete product.
  • the augers can also have ends that produce hollow cores within the concrete prod- uct.
  • the slip-former can have tubes for producing hollow cores within the concrete product, wherein the hollow cores do not have spiral grooves.
  • the slip- former can have tubes that have ends, which are adapted to a point such that the tubes do not produce hollow cores within the concrete product.
  • the concrete product is provided as a solid panel with a solid core.
  • the slip-former does not have tubes for producing any hollow cores.
  • the application also provides a precast concrete panel.
  • the concrete panel includes a separated portion of the above- mentioned concrete product.
  • the precast concrete panel can be used as a wall, roof, or floor panel. After the concrete product is cured or dried, a sawing mechanism can separate the precast concrete product into several precast concrete panel.
  • the application provides a method of producing a concrete product.
  • the method includes the steps of depositing a lightweight concrete mixture on a casting bed for casting the lightweight concrete mixture.
  • One or more claddings are then attached onto the deposited lightweight concrete mixture.
  • the claddings can be provided on the bed before the lightweight concrete mixture is deposited on the bed.
  • the deposited lightweight concrete mixture is deposited directly onto the claddings. This has the advantage of easier removal of the concrete mixture from the casting bed.
  • the claddings can be provided on the bed after the lightweight concrete mixture is deposited on the bed.
  • the claddings are attached to a top surface of the concrete mixture.
  • the top surface is often rough and this attachment covers the rough surface.
  • the deposited concrete mixture is deposited directly onto the bed. This has the advantage of producing a smooth surface for a bottom surface of the concrete mixture that contacts the bed.
  • a layer of oil is usually provided on the bed before the deposition for easier removal of the concrete mixture from the bed.
  • the step of depositing of the lightweight concrete mixture can include the step of using one or more augers of an extruder to cast or to extrude the lightweight concrete mixture.
  • the extruded concrete mixture is then released onto the bed.
  • the extruding step leaves one or more spiral areas of compaction that correspond to the respective augers.
  • the step of depositing of the lightweight con- crete mixture can comprise the step of using one or more tubes of a slip-former to cast or to form the lightweight concrete mixture.
  • the tubes do not leave any area of compaction within the concrete mixture.
  • the depositing step can form one or more hollow areas or cores within the lightweight concrete mixture.
  • the hollow cores are formed by the augers of the extruder or by the tubes of the slip-former.
  • the application provides a concrete product that is produced according to the above-mentioned method steps.
  • the produced concrete product is also cured partially or fully.
  • the application also provides a method of selecting elements of a lightweight concrete mixture to reduce production cost of the lightweight concrete mixture.
  • the concrete mixture can have high strength but is too costly or have low cost but with insufficient strength.
  • the method comprises the step of selecting a predetermined or desired strength of the finished concrete mixture. Respectively amounts of cement, sand, water, and lightweight material to produce the concrete mixture are then selected whilst keeping a range of a predetermined ratio of cement to water. After this, the strength of the ready made concrete mixture is measured. If the measured strength is too high, the amount of cement, sand, and water is reduced by a predetermined percentage whilst keeping a predetermined ratio of cement to wa- ter. On the other hand, if the measured strength is too low, the amount of cement, sand, and water is increased by a predetermined percentage whilst keeping a predetermined ratio of cement to water. The above steps are then repeated until the desired strength is achieved.
  • the application provides a method of selecting elements of a lightweight concrete mixture to achieve a predetermined density.
  • the presented method can achieve desired density at lower cost.
  • the method comprises the step of selecting a desired or target density of a finished or cured concrete mixture. After this, a ratio or portion between lightweight material and a group of the cement, sand, and water for producing the concrete mixture is selected. The selected ratio allows the concrete mixture to have a density that is less or the same as the desired density.
  • the lightweight material can comprise polystyrene material. A use of more lightweight material would cause the concrete mixture to have less density.
  • a ratio between cement and sand is also selected.
  • the density of cement and sand is about the same. Use of more cement would usually cause the concrete mixture to be harder and would usually increase the costs of the concrete mixture.
  • the concrete mixture is later produced using the selected ratio.
  • the strength of the produced concrete mixture is then measured.
  • the produced concrete mixture is already cured partially or fully.
  • the ratio of cement to sand is later ad- justed using the measured strength.
  • the producing step can be repeated with the adjusted ratio of cement to sand and the measuring step repeated for obtaining the strength value of the adjusted concrete mixture. In this way, the density of the concrete mixture is improved.
  • the application provides a method of producing a concrete product .
  • the method comprises the step of depositing a lightweight concrete mixture on a casting bed for casting the lightweight concrete mixture. Elements of the lightweight concrete mix- ture are already selected using one of the two above- mentioned selection methods depending on desired goals. One or more claddings are then attached onto the deposited lightweight concrete mixture.
  • the claddings can be provided on the bed either before the lightweight concrete mixture is deposited on the bed or after the lightweight concrete mixture is deposited on the bed.
  • the step of depositing of the lightweight concrete mixture can include the step of using an extruder to provide the lightweight concrete mixture.
  • the extruder also compacts the lightweight concrete mixture.
  • the step of depositing of the lightweight concrete mixture can comprise the step of using a slip-former to provide the lightweight con- crete mixture.
  • the slip-former also forms or moulds the lightweight concrete mixture.
  • the method can include the step of forming one or more hollow areas or cores within the lightweight concrete mixture by ei- ther augers or tubes.
  • the application also provides a concrete product that is produced using the above steps. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
  • Figure 1 illustrates a side view of a first embodiment of a casting machine for producing precast wall panels, the casting machine including an extruder,
  • Figure 2 illustrates a top view of the extruder of Figure 1
  • Figure 3 illustrates a top view of a first side plate of the extruder of Figure 1
  • Figure 4 illustrates a front view of the first side plate of Figure 3
  • Figure 5 illustrates a top view of a second side plate of the extruder of Figure 1
  • Figure 6 illustrates a front view of the second side plate of Figure 5
  • Figure 7 illustrates a side view of a top plate of the extruder of Figure 1
  • Figure 8 illustrates a side view of a first precast wall panel that is produced by the extruder of Figure 1, the first precast wall panel including a fibre- reinforced board,
  • Figure 9 illustrates a front view of the precast wall panel of Figure 8.
  • Figure 10 illustrates a side view of a second precast wall panel that is produced by the extruder of Figure 1, the second precast wall panel including two fibre- reinforced boards,
  • Figure 11 illustrates a front view of the second precast wall panel of Figure 10
  • Figure 12 illustrates a side view of a step of applying a top layer to a wet precast slab
  • Figure 13 illustrates a side view of applying another type of top layer to a wet precast slab
  • Figure 14 illustrates a side view of applying still another type of top layer to a wet precast slab
  • Figure 15 illustrates a top view of supporting rollers of the extruder of Figure 1
  • Figure 16 illustrates a top view of another embodiment of possible supporting rollers of the extruder of Figure 1
  • Figure 17 illustrates side cross-sectional view of a tumbler for treating polystyrene beads that are used in a precast wall panel of the extruder of Figure 1 as well as for providing a concrete mixture comprising lightweight particles,
  • Figure 18 illustrates a cross-sectional view of a longitudinally symmetric component of the tumbler of Figure 17,
  • Figure 19 illustrates a side view of a polystyrene bead that has been treated with the tumbler of Figure 17,
  • Figure 20 illustrates a side view of a second embodiment of a casting machine for making precast wall panels, the casting machine including an extruder,
  • Figure 21 illustrates a cross-sectional view of a precast wall panel that is produced by the extruder of Figure 20,
  • Figure 22 illustrates an expanded view of a portion of the precast wall panel of Figure 21,
  • Figure 23 illustrates an expanded view of another portion of the precast wall panel of Figure 21,
  • Figure 24 illustrates a front view of a precast wall panel that is produced by the extruder of Figure 20
  • Figure 25 illustrates a front view of another precast wall panel that is produced by the extruder of Figure 20
  • the second precast wall panel including multiple reinforcement wires
  • Figure 26 illustrates mounting of the wires of Figure 25 onto a steel casting bed of the extruder of Figure 20
  • Figure 27 illustrates a front view of two adjacent precast wall panels in an installed state
  • Figure 28 illustrates an embodiment of a steel casting bed for producing the precast wall panel of Figure 27
  • Figure 29 illustrates an embodiment of a fibre-reinforced board for producing the precast wall panel of Figure 27
  • Figure 30 illustrates a stack of several precast wall panels of Figure 27
  • Figure 31 illustrates a side view of a third embodiment of the casting machine for producing precast wall panels, the casting machine includes a slip-former
  • Figure 32 illustrates a side view of a frame of the slip- former of Figure 31
  • Figure 33 illustrates a top view of the frame of Figure 32
  • Figure 34 illustrates front view of a plurality of shoes of the slip-former of Figure 31
  • Figure 35 illustrates a top view of the shoes of Figure 34
  • Figure 36 illustrates a top view of a plurality of cores of the slip-former of Figure 31,
  • Figure 37 illustrates a side view of frames for supporting the cores of Figure 36
  • Figure 38 illustrates a top view of a vibrator of the slip- former of Figure 31
  • Figure 39 illustrates a smoothener of the slip-former of Figure 31
  • Figure 40 illustrates a front view of a further embodiment of the casting area of slip-former with a separation wall
  • Figure 41 illustrates a microstructure in the precast wall panel of Figure 31.
  • Figure 42 illustrates a side view of a further embodiment of a slip-former,
  • Figure 43 illustrates a top view of the slip-former of Figure
  • Figure 44 illustrates a side view of a vibrator of the slip- former of Figure 42
  • Figure 45 illustrates a front view of a concrete hopper of the slip-former of Figure 42
  • Figure 46 illustrates a front view of an embodiment of a hol- low wall panel that is produced by the slip-former of Figure 31,
  • Figure 47 illustrates a second embodiment of the hollow wall panel of Figure 46
  • Figure 48 illustrates a side view of a further embodiment of the hollow wall panel of Figure 46
  • Figure 49 illustrates a front view of the embodiment of Figure 48
  • Figure 50 illustrates a side view of a further embodiment of the hollow wall panel of Figure 46
  • Figure 51 illustrates a front view of the embodiment of Figure 46
  • Figure 52 illustrates a flow chart of a method for optimizing the production costs of a concrete mixture for use by a casting machine
  • Figure 53 illustrates a flow chart of a method of optimizing the density of a concrete mixture or use by a casting machine.
  • Figure 1 shows a first embodiment of a casting machine for producing precast wall panels.
  • the casting machine includes a slip-forming extruder that is also called an extruder.
  • slip-forming is also known as continuous pouring or continuously forming.
  • Figures 1 and 2 illustrate an extruder 10 and a grabber 20 for making precast wall panels 12.
  • the precast wall panels 12 are also called precast concrete wall panels.
  • the extruder 10 comprises a pair of rollers 40 for feeding or for introducing fibre-reinforced boards 16 onto a conveyer 18.
  • the fibre-reinforced boards 16 are also called fibre- boards.
  • a group 50 of auger screw feeders is positioned above the conveyer 18 whilst a concrete hopper or concrete-mixing tank 14 is located above the group 50 of screw feeders.
  • the group 50 of screw feeders is located between the rollers 40 and a group 70 of guiding plates.
  • the guiding plates are also called vibrating plates.
  • the feeding rollers 40 are located at one end of the conveyer 18 and they are driven by motors to rotate in opposite directions for feeding the fibre- reinforced boards 16 to the conveyer 18.
  • the conveyer 18 includes an array of supporting rollers 30.
  • the supporting rollers 30 are arranged usually in one or more columns with essentially a same distance between adjacent rollers 30 of the same column.
  • the concrete-mixing tank 14 is positioned above the group 50 of screw feeders. It has a general shape of a funnel that includes a larger upper receiving end 36 and a smaller lower releasing end 38. Both the receiving end 36 and the releasing end 38 have a rectangular shape. Each lateral side of the receiving end 36 is connected to a corresponding lateral side of the releasing end 38. The releasing end 38 is located directly above the group 50 of screw feeders.
  • the group 50 of screw feeders are provided above the conveyer 18 and it is inclined with respect to the conveyer 18.
  • the group 50 comprises a first screw feeder 104, a second screw feeder 106, and a third screw feeder 22 that have simi- lar parts with similar construction.
  • a fourth and a fifth screw feeder are provided but are not shown in full detail.
  • the similar parts have the same names.
  • the first screw feeder 104 is placed adjacent to the second screw feeder 106 that is placed adjacent to the third screw feeder 22.
  • Each of the screw feeders 104, 106, and 22 are arranged with equal spaces between them and they are arranged essentially in parallel to a longitudinal axis of the conveyer 18.
  • the first screw feeder 104 has a first Archimedean screw 116 that is integrally connected with a first mandrel 119.
  • a first driving motor 127 drives the first Archimedean screw 116 via a first cardanic joint 122.
  • the first Archimedean screw 116 and the first mandrel 119 essentially share a common longitudinal axis 108 as seen in Figure 2.
  • the first man- drel 119 includes a cylinder that has the same diameter as the diameter of the centre tube of the first Archimedean screw 116, but without a tapered portion.
  • the second screw feeder 106 has a second Archi- medean screw 126 that is integrally connected with a second mandrel 128.
  • a second driving motor 128 drives the second Archimedean screw 126 via a second cardanic joint 127.
  • the second Archimedean screw 126 and the second mandrel 128 essentially share a common longitudinal axis 112 as seen in Figure 2.
  • the third screw feeder 22 has a third Archimedean screw 26 that is integrally connected with a third mandrel 28.
  • a third driving motor 24 drives the third Archimedean screw 26 via a third cardanic joint 34.
  • the third Archimedean screw 126 and the third mandrel 28 essentially share a common longitudinal axis 32 as seen in Figure 2.
  • the second mandrel 128 has a cone shaped front end whilst the first mandrel 119 and the third mandrel 28 have a cylindrical shaped front end.
  • the fourth and the fifth mandrels have partial cone shaped portions, the end piece having a smaller di- ameter that the end piece of the first and the third mandrels 119 and 28.
  • the group 70 of guiding plates are placed in the area around the Archimedean screws 26, 116, and 126.
  • the group 70 includes a top side guiding plate 46, a first side guiding plate 52, and a second side guiding plate 48, as illustrated in Figures 1 and 2. These guiding plates 46, 52, and 48 also enclose a portion of the conveyer 18.
  • the group 70 generally surrounds a portion of the conveyer 18 to form a rectangular tunnel 56 with an entrance 58 and an exit 62.
  • the first side guiding plate 52 comprises a first side fixed steel plate 53 and a first side vibrating plate 55 that is connected to the fixed steel plate 53 via a first side flexible joint 86, as shown in Figure 2.
  • the steel plate 53 has a longitudinal axis that is essentially parallel to the axis of the conveyer 18.
  • a first side shaker 66 is attached to an ex- ternal surface of the first side vibrating plate 55, as illustrated in Figures 3 and 4.
  • An elongated tongue 142 with a semi-circular profile is provided on an internal side of the first side vibrating plate 55. The elongated tongue 142 protrudes from a middle portion of first side vibrating plate 55 at a predetermined height.
  • the second side guiding plate 48 includes a second side fixed steel plate 57 and a second side vibration plate 59 that is connected the fixed steel plate 57 via a second side flexible joint 88, as shown in Figure 2.
  • the steel plate 57 has a longitudinal axis that is parallel to the axis of the conveyer 18.
  • a second side shaker 68 is attached to an external side of the second side vibrating plate 59, as illustrated in Figures 5 and 6.
  • An elongated groove 145 with a semi-circular profile is provided on an internal side of the second side vibrating plate 59 at a predetermined height.
  • the top side guiding plate 46 includes a top side fixed top steel plate 63 and a top side vibrating plate 65 that is connected to the fixed top steel plate 63 via a top side flexible joint 146, as depicted in Figure 1.
  • a top side shaker 64 is positioned at a centre of an external top surface of the top side vibrating plate 65, as illustrated in Figure 7.
  • the grabber 20 comprises a hoisting frame 82 is attached to an underside of a lifting frame 76.
  • Two grabbing forks 78 are mounted pivotally to outer edges of the lifting frame 76.
  • a driving mechanism 84 is mounted onto the lifting frame 76 for propelling the two grabbing forks 78 and the hoisting frame
  • the lifting frame 76 resembles a rectangular board, which has a broad rectangular surface that is parallel to the conveyer 18. Opposite edges of a bottom side of the lifting frame 76 are attached to the two grabbing forks 78.
  • the driving mechanism 84 rotates the two forks 78 for grabbing or releasing the formed precast wall panel 12.
  • the hoisting frame 82 is mounted on the underside of the lifting frame 76 and it is moved by the driving mechanism 84 to lift or lower down the precast wall panel 12 to desired positions.
  • the two forks 78 have an identical shape. Each of the two forks 78 has three fingers 96 that extend downwards.
  • the two forks 78 can be brought closer to or apart from each other by the driving mechanism 84 to grab or release the formed precast wall panel 12.
  • a mobile crane - not shown here - can lift the grabber 20 that is connected to the mobile cane by steel cables 94, which are connected to four corners of a top of the lifting frame 76 by mounting rings 92.
  • Figure 2 illustrates a front portion 132 and a front portion 134 of mandrels that have a shape of a truncated cone. Furthermore, a total number of screw feeders can vary. Manual grabbing can replace the grabber 20.
  • the fibre-reinforced boards 16 include fibres and cement to provide an external cladding against rain and provide heat insulation.
  • the fibre-reinforced boards 16 have a width of about 600 millimetres.
  • the feeding rollers 40 are intended for receiving the fibre- reinforced boards 16 and for pushing these fibre-reinforced boards 16 to the conveyer 18.
  • the fibre- reinforced boards 16 cover the conveyer 18, as illustrated in the Figure 1. Every fibre-reinforced board 16 is placed generally next to another fibre-reinforced board 16.
  • the conveyer 18 is used for supporting and for transporting the fibre-reinforced boards 16 in the direction 44, as illustrated in Figure 1.
  • the supporting rollers 30 of the conveyer 18 act as cylindrical idlers.
  • the supporting rollers 30 are arranged to allow the rollers 30 to transport the fibre- reinforced boards 16 in a horizontal direction 44.
  • the concrete-mixing tank can be provided as a rotatable hopper to mix evenly contents of the lightweight concrete mix- ture 42.
  • the concrete-mixing tank 14 can also incorporate an agitator to prevent an early setting of the concrete mixture 42.
  • the concrete mixture 42 is pre- mixed and is then transferred to the concrete-mixing tank 14.
  • the concrete mixture 42 is also called concrete slurry.
  • a shutter of the releasing end 38 of the concrete-mixing tank 14 is controlled by an electro-magnetic or hydraulic means to regulate a gravitational flow or release of the concrete mixture 42.
  • the shutter is also called a discharge gate.
  • Figure 2 shows projection lines 114 of the releasing end 38 for indicating a contact area of the concrete mixture 42 onto the Archimedean screws 26, 116, and 126.
  • the concrete mixture 42 within the concrete-mixing tank 14 has a watery or semi-dry form that allows it to be moulded. After moulding, the concrete mixture 42 solidifies after a period of curing and drying.
  • the concrete mixture 42 comprises concrete material and a substantial amount of lightweight compound, such as polystyrene beads.
  • the lightweight compound is produced from expanded polystyrene (EPS) foam or from material, which has flame retardant ability, good thermal insulation, lightweight, and a high strength-to-weight ratio .
  • EPS expanded polystyrene
  • the expanded polystyrene material is not easily broken down by microorganism and is also able to withstand frost.
  • the group 50 of screw feeders rotate in a synchronized manner to extrude a monolithic concrete slab.
  • the group 50 of screw feeders rotates by means of a motor.
  • the Archimedean-screws 132, 134, 116, 126, and 26 of the group 50 of screw feeders receives the wet concrete mixture 42 from the concrete-mixing tank 14.
  • the Archimedean-screws 132, 134, 116, 126, and 26 then transfer the concrete mixture 42 to the group 70 of three guiding plates via the respective mandrels 119, 128, and 28.
  • the Archimedean-screws can create or leave elongated holes or hollow cores in the transferred concrete mixture 42.
  • the first, second, fourth, and fifth mandrels leave hollow cores within the said concrete mixture 42.
  • the cylindrical shaped front end of the third mandrel 28 is adapted such that the third mandrel 28 does not leave any hollow core within the transferred concrete mixture 42.
  • the hollow cores have longitudinal axes, which are generally parallel to each other.
  • the hollow cores have internal spiral grooves around its surfaces, which correspond to blades of the Archimedean screws.
  • the guiding plates 46, 48, and 52 together with the vibrating plates 55, 59, and 65 compact and mould the wet concrete mixture 42 for producing a lightweight precast concrete slab 72, as illustrated in Figure 1.
  • the precast concrete slab 72 is also called a precast slab.
  • the vibrating plates 55, 59, and 65 are activated by the shakers 66, 68, and 64.
  • the shakers are also called vibrators.
  • the precast concrete slab 72 is intended for separating into several precast wall panels 12 by means of a concrete sawing mechanism. The sawing mechanism is not shown in Figure 1.
  • the precast wall panels 12 are lightweight and produced with lower cost due to the presence of the polystyrene beads within the concrete mixture 42.
  • the lightweight also allows the precast wall panels 12 to be transported easily around construction sites without use of heavy lifting machinery, which saves a lot of energy. Further, the precast wall panels 12 can also be cut to any desired shape and size for meeting geometrical profile requirements at the construction site.
  • the extruder or other types of casting machines can produce precast concrete slabs using the lightweight concrete mixture 42.
  • the concrete mixture 42 can have different compositions.
  • the precast wall panels 12 are a type of a precast concrete panel or of a precast panel.
  • the precast concrete panel can act as a wall panel, a floor slab, or a ceiling board.
  • the floor slab acts as a board that is used in a beam and block building method.
  • the precast wall panels 12 can have two fibre-reinforced boards instead of one.
  • the fibre-reinforced boards are placed on opposite sides of the precast wall pan- els 12.
  • a wall panel with this configuration is also called a sandwich panel.
  • the fibre-reinforced boards 16 comprise fibre cement material.
  • the fibre cement material may include a bonding agent, additives, reinforcing fibres, process fibre, water, and also air.
  • the bonding agent can com- prise Swiss Portland cement, wherein raw material is sintered from limestone and clay marl.
  • the additives can include powdered lime.
  • the reinforcing fibres can include synthetic organic fibres that are made of poly-vinyl-alcohol material.
  • the process fibres can include cellulose fibres, such as those used in paper industry and they can include recycled waste paper.
  • the water may remain the fibre cement material after the hardening process.
  • the air can be present in the form of microscopically small pores.
  • the first implementation has similarity to boards that are produced by Eternit. Modifications and alternatives of these boards are possible and can also be applied to the said im- plementation .
  • the fibre-reinforced boards 16 include a rigid board that is made of layers of fibreboard or of paper bonded to a gypsum plaster core.
  • the fibre-reinforced boards 16 include gypsum and paper fibres, which may be obtained through a recycling process.
  • the gypsum and paper fibres can be mixed in a homogeneous manner with water and later be pressed under high pressure to form the fibre-reinforced boards 16.
  • the third implementation has similarity to boards that are produced by Fermacell. Modifications and alternatives of these boards are possible and can also be applied to the said implementation.
  • gypsum boards, calcium silicate fibreboards, as well as metal or plastic sheets replace or enhance the fibre-reinforced boards 16 to provide other physical properties.
  • the calcium silicate material can be produced from silicon oxide, calcium oxide, alkali silicate, and cellulose or cellulosis.
  • the calcium silicate boards In addition to thermal insulation and environmentally friend- liness, the calcium silicate boards have the advantages of a low moisture content, little hydric movement, and good fire resistance properties.
  • the calcium silicate boards have good water management in that it has high capillary capability and water is quickly distributed over the whole board. The absorbed water can later be released. It also has good resistance against fungus, virus, and bacteria because of relatively high pH value as well as inherent anti-molding proper- ties.
  • the calcium silicate boards can save energy in cold and warm climates. Surfaces of the boards can rapidly warm up or cold down while it has certain insulation that prevents transfer- ence of heat. This is often excellent for rooms, which are used only temporarily. These calcium silicate boards are not so useful, if relatively high temperature resistance requirements in places, such as front of an oven or similar, are present. For these requirements, cement fiberboards or con- crete fiberboards may be a better choice.
  • the metal sheet can include aluminum, steel, or copper material .
  • the boards 16 can be adapted to provide other functions, such as a decorative cover.
  • the board 16 can have a combination of other materials, such as rubber that provides a waterproofing ability or also a exfoliated graphite top layer that provides fireproof ability.
  • the board 16 has a fabric layer for providing an aesthetic outlook or a stainless steel layer for providing corrosion resistance ability.
  • the board 16 includes a metal or plastic netting, such as a rabbit fence.
  • Other materials can replace the polystyrene beads or can be included into the con- crete mixture 42 as an additive to provide certain desired physical properties.
  • fibre material can be mixed into the concrete mixture 42 for increasing mechanical strength and flexibility of the concrete mixture 42.
  • recycled materials such as waste plastic beads and concrete particles made from discarded debris, can also be mixed into the concrete mixture 42 for reducing the costs of the concrete mixture 42 and for protecting the environment.
  • lightweight mineral particles can also be added to the concrete mixture 42 for strengthening and for reducing the weight of the final concrete mixture 42.
  • One possible method of producing the precast wall panel 12 includes the step of a user or of a machine using the pair of feeding rollers 40 to introduce the fibre-reinforced boards 16 into the extruder 10.
  • the feeding rollers 40 rotate continuously and push the fibre-reinforced boards 16 onto the conveyer 18 whilst the sup- porting rollers 30 of the conveyer 18 move the fibre- reinforced boards 16 in the feeding direction 44. Once one fibre-reinforced board 16 is pushed completely onto the supporting rollers 30, another fibre-reinforced board is immediately fed through the feeding roller 40 such that each fibre- reinforced board 16 is positioned adjacent to another fibre- reinforced board 16 on the conveyer 18.
  • the concrete-mixing tank 14 discharges the concrete mixture 42 onto the group 50 of screw feeders.
  • the discharge gate of the concrete-mixing tank 14 regulates the said discharge.
  • the screw feeders 22, 104, and 106 rotate at a speed that is between zero and 60 rounds per minute.
  • the Archimedean screws 26, 116, 126 of the respective screw feeders 22, 104, and 106 receive the discharge of concrete mixture 42 and then force the concrete mixture 42 in the direction of feeding 44 towards the mandrels 119, 128, and 28 and towards the group 70 of guiding plates.
  • the Archimedean screws 26 and 116 create hollow cores within the concrete mixture 42 whilst blades of the Archimedean screws 26 and 116 also form spiral grooves within these hol- low cores. This action also causes concrete material at surfaces of the hollow cores to be denser than inner parts of the concrete mixture 42.
  • the screws 132 and 134 also create hollow cores but of a smaller diameter than those of the screws 28 and 119. A solid slab with no hollow cores is pro- vided if all screws are pointed, such as the screw 126.
  • the group 70 of guiding plates later compact and mould the concrete mixture 42.
  • the fixed steel plates 53, 57, and 63 mould or shape the concrete mixture 42 to form the wet pre- cast slab 72 with a rectangular profile.
  • the vibrating plates 55, 59, and 65 vibrate at amplitude of about two to five millimetres for providing or moulding the said profile of the wet precast slab 72 with a tongue and a groove.
  • the compacted surface of the precast slab 72 is denser than inner parts of the precast slab 72.
  • the precast slab 72 is later allowed to cure or dry.
  • a sawing mechanism afterward cut the cured precast slab 72 into several precast wall panels 12.
  • the grabber 20 later transfers the precast wall panel 12 a storage place for stacking. Alternatively, the precast wall panel 12 is transferred manually to the storage place. At the storage place, the precast wall panel 12 undergoes further hardening.
  • the width, height, and length of the precast wall panels 12 can be easily adjusted by regulating a speed of the supporting rollers 30, flow rate of the concrete-mixing tank 14 and cutting parameters of the sawing mechanism.
  • steel sheets are placed on the conveyer 18 to provide rigid support for the fibre-reinforced boards 16.
  • This also allows the precast concrete slab 72 to be straight and flat.
  • the method can omit the use of the fibre-reinforced boards 16.
  • the steel sheets are coated with a layer of oil.
  • the concrete mixture 42 is placed directly onto the said steel sheets to form the precast concrete slab 72.
  • a surface of the precast concrete slab 72, which is next to in contact with the steel sheets would be smooth. Users usually desire the smooth surface.
  • Figures 8 and 9 depict a first embodiment of the precast wall panel 12 that is produced by the extruder 10 of Figure 1.
  • Figures 8 and 9 show a first precast wall panel 152 that has an upper portion 156 and a lower 154 or fibre-reinforced board that is placed below the upper portion 156.
  • the fibre- reinforced board 154 covers an entire bottom surface of the upper portion 156.
  • the upper portion 156 has a first hollow core 162, a second hollow core 164, a third hollow core 166, and a fourth hollow core 168.
  • the upper portion 156 comprises a cured concrete mixture 42.
  • the upper portion 156 has an elongated protruding tongue 158 along a longitudinal direction of the precast wall panel 152.
  • Figures 10 and 11 depict a second embodiment of the precast wall panel 12 that is produced by the extruder 10 of Figure 1.
  • Figures 10 and 11 show the precast wall panel 152 of Figure 8.
  • the precast wall panel 152 is attached to a fibre- reinforced board 174 to form a second precast wall panel 172.
  • the fibre-reinforced board 174 is attached to one side of the upper portion 156 whilst the fibre-reinforced board 154 is attached to an opposite side of the portion 156.
  • the two fibre-reinforced boards 154 and 174 cover opposite surfaces of the upper portion 156 for providing protection layers for the two opposite surfaces.
  • One method for processing the second embodiment of the precast wall panel 12 includes the additional step of applying an adhesive agent on a top surface of the precast slab 72 of Figure 1. An additional fibre-reinforced board 174 is then placed on the said adhesive agent.
  • the adhesive agent can comprise glue, such as Methocel as well as also cement, sand, and water. Applying different layers
  • Figures 12 to 14 show step of applying different layers onto the precast slab 72 of Figure 8.
  • the pre-cast wall panel 152 is not yet fully cured or is not yet hardened.
  • Figure 12 depicts a side view of an additional step of applying a hooked first layer 176 to the precast wall panel 152 of Figure 8.
  • the hooked layer 176 has a base sheet 184 that has an array of closely packed blocks 178, which is attached to the base sheet 184.
  • the blocks 178 include a plurality of hooks 182 that is attached to external surfaces of the blocks 178.
  • the application of the hooked layer 176 comprises the step of placing the hooked layer 176 between the pre-cast wall panel 152 and a vibrating roller 186. Then, the vibrating roller 186 compacts or presses the hooked layer 176 onto the upper portion 156 of the pre-cast wall panel 176.
  • the blocks 178 can comprise a hard or decorative surface for enhancing the precast wall panel 152.
  • the blocks 178 can com- prise ceramic material, wood, plastic, and also metal.
  • the blocks 178 can be connected through a layer of woven fabric, which form a base sheet.
  • FIG 13 shows a side view of a step of applying a staggered second top layer 188 to the precast wall panel 152.
  • the stagger top layer 188 comprises an array of slanted strips 192 or blocks that are positioned closely to each other.
  • the slanted strips 192 comprise hooks 182 at their base surfaces.
  • a vibrating roller 186 is positioned above the precast wall panel 152 for compacting the staggered top layer 188 onto the precast wall panel 152.
  • the hooks 182 of the staggered top layer 188 pierce into the upper portion 156 of the precast wall panel 152 under the pressure of the vibrating roller 186.
  • the slanted strips 192 can provide a decorative and protective surface for the precast wall panel 152.
  • Figure 14 shows a side view of a step of applying a third top layer of a thin plastic sheet 192 to the precast wall panel 152.
  • a thin plastic sheet 192 is glued and is pressed onto the upper portion 156 of the precast wall panel 152 by a vibrating roller 186 such that the plastic sheet 192 adheres onto the upper portion 156.
  • the plastic sheet 192 can provide a surface of the precast wall panel 152 to prevent absorbing of water.
  • Figure 15 shows a first embodiment of the supporting rollers 30 of the extruder 10 of Figure 1.
  • Figure 15 shows a top view of the fibre-reinforced board 16 that is placed on the supporting rollers 30.
  • Guide plates 200 are placed next to a side edge 201 of the fibre-reinforced board 16.
  • the supporting rollers 30 are arranged in an array and they are inclined at an angle ⁇ to the direction of feeding 44, as shown in Figure 15. This inclination of causes the supporting rollers 30 to exert a shifting force on the wall panels 152.
  • the guide plates 200 act to keep this shifting force from diverting the wall panel 152.
  • this arrangement advantageously provides a continual support for a leading edge 203 of the fibre-reinforced board 16 to keep the leading 203 from drooping or sinking downwards.
  • Figure 16 shows a second embodiment of the supporting rollers 30 of the extruder 10 of Figure 1.
  • Figure 16 illustrates a top view of the fibre-reinforced board 16 that is placed on the supporting rollers 30.
  • the supporting rollers 30 are arranged in four rows.
  • a first row 206 is placed next to a second row 208, which is placed next to a third row 210.
  • a fourth row 212 is placed next to the third row 210.
  • the supporting rollers 30 of the first row 206 and of the third row 210 are inclined slightly one way or direction whilst the supporting rollers 30 of the second row 208 and of the fourth row 212 are inclined slightly another way.
  • This arrangement keeps the leading edge 203 of the fibre-reinforced board 16 in continual contact with the sup- porting rollers 30 as the fibre-reinforced board 16 moves in the direction of feeding 44. Because of the continual contact, the leading edge 203 or leading portion of the fibre- reinforced board 16 is keep from drooling. Further, this arrangement does not exert a shifting force on the fibre- reinforced board 16.
  • FIG 17 shows a side cross-sectional view of a tumbler 216 for treating polystyrene beads that are used in a production of the precast wall panel 12 of Figure 1.
  • the treatment provides an exterior surface 242 of polystyrene beads 240 with multiple dents 244.
  • the treated polystyrene beads may have several advantages.
  • the dents 244 can provide the polystyrene beads 240 with a better adhesion with concrete material. The better adhesion would possibly keep the polystyrene beads 240 in a concrete mixture from floating up as well as from gathering.
  • the re- sultant concrete mix hence has a more even or a more homogenous mix.
  • the tumbler 216 comprises a motor 218 that is fixed to a cage 220 or container and to a body 222.
  • the body 222 includes a central hub 224 that is connected via spokes 226, 228, and 230, which are connected to longitudinally symmetric blades 232, 234, and 236.
  • Each of longitudinally symmetric blades 232, 234, and 236 has a longitudinally unvarying cross- section, as shown in Figure 18 and as viewed in the direction A of Figure 17.
  • the tumbler 216 can have bottom hub 237 that is connected to the central hub 224.
  • the bottom hub 224 is positioned at a bottom part of the tumbler 216 and extends over the bottom of the tumbler 216.
  • the motor 218 rotates the hub 224 of the body 222 about an axis.
  • the rotation moves each of the blades 232, 234, and 236 horizontally for stirring contents of the tumbler 216.
  • the blades 232, 234, 236 are properly spaced apart such that its rotation exerts no or little lat- eral force on the hub 224.
  • the rotation also turns the additional hub 237 for moving contents of the tumbler 216 away from the bottom of the tumbler 216.
  • One possible method of treating the polystyrene beads 240 comprises the step of rotating the blades 232, 234, and 236 at about 300 rounds per minute for about 3 to 5 minutes. About one 100 litres of sand and polystyrene beads 240 are then poured into the cage 220.
  • the sand can have a diameter of less than about 2 millimetres and it is thus smaller than a diameter of the polystyrene beads 240.
  • the rotation of the additional hub 237 brings the polystyrene beads 240 and sand away from a bottom of the tumbler 216 and toward the blades 232, 234, and 236.
  • the rotation of the blades 232, 234s and 236 then causes the polystyrene beads 240 and sand to mix and to stir.
  • the stirring causes the sand to hit or to strike the polystyrene beads 240 and to leave marks or dents on the exterior surface 242 of the polystyrene beads 240, as illustrated in Figure 19.
  • the tumbler 216 can also be used to mix parts of a concrete slurry or mixture.
  • Figure 20 shows a side view of a second embodiment of the casting machine for making precast wall panels.
  • the casting machine includes an extruder.
  • Figure 20 depicts a mobile extruder 320.
  • the mobile extruder 320 has wheels 264 that are run on tracks 266.
  • the tracks 266 are also called rails.
  • a stationary steel casting bed 262 is placed between the tracks 266.
  • the casting bed 262 includes a steel plate, which is welded to the tracks 266 and is anchored to the floor.
  • the mobile extruder 320 is motor driven for propelling the mobile extruder 320 along the tracks 266 in a direction as indicated by an arrow 322. The engine and transmission is not shown the Figure 20.
  • the mobile extruder 320 comprises parts that are available in the extruder 10 of Figure 1, except that the mobile extruder 320 can move along the tracks 266.
  • the mobile ex- truder 320 has a group 50 of screw feeders that is placed under a concrete hopper or concrete-mixing tank 14.
  • a group 70 of guiding plates is placed next to the group 50 of screw feeders .
  • the steel-bed 262 acts as a type of a casting bed or a forming bed.
  • the steel-bed 262 can have heating elements that are installed below for heating wet precast slabs to expedite curing. In one example of the heating elements comprises a hot water heating system that is integrates with the steel- bed 262.
  • One possible method of using the mobile extruder 320 com- prises the step of laying multiple fibre-reinforced boards 154 on the stationary steel-bed 262.
  • the fibre-reinforced boards 154 are positioned such that one fibre-reinforced board 154 is placed next to the neighbouring fibre-reinforced board 154, if possible without a gap between them.
  • the mobile extruder 320 moves along the tracks 266 and over the casting bed 262.
  • the concrete-mixing tank 14 discharges the lightweight concrete mixture 42 onto the group 50 of screw feeders.
  • the group 50 of screw feeders then forces and feeds the received concrete mixture 42 onto the fibre-reinforced boards 154 that are placed on the casting bed 262. This action also creates hollow cores within the wet concrete mixture 42.
  • FIG. 21 shows a cross-sectional view of a precast wall panel 340 that is produced by the mobile extruder of Figure 20.
  • the precast wall panel 340 is placed on the stationary casting bed 262.
  • the casting bed 262 has an upper longitudinal surface that is smooth and flat. This allows concrete mixture that is deposited on the said surface to be smooth and flat.
  • a layer 350 of oil is released between the precast wall panel 340 and the casting bed 262.
  • the oil layer 350 enables easy removal or release of the precast wall panel 340 from the casting bed 262 after curing.
  • a pair of rails 352 is placed adjacent to longitudinal sides of the casting bed 262.
  • the precast wall panel 340 has multiple hollow cores 355.
  • the oil layer 350 is not needed if the concrete mixture 42 is separated from the casting bed 262 by a fibre-reinforced board or a similar board.
  • the precast wall panel 340 comprises concrete material, such as sand 365, and polystyrene beads 360, as better seen in Figure 22.
  • Figure 22 shows an expanded view of a bottom part of the precast wall panel 340.
  • the polystyrene beads 360 distributes evenly throughout the precast wall panel 340 except for a thin layer 363 that is positioned at a bottom of the precast wall panel 340.
  • the thin layer 363 does include any portion of the polystyrene beads 360.
  • polystyrene beads 360 float or swim upwards when the precast wall panel 340 is a wet or a semi-dry state during a production of precast wall panel 340. Vibrations of the shakers may also cause the polystyrene beads 360 to move upwards. For the same reason, some portions of the polystyrene beads 360 protrude outside a top surface of the precast wall panel 340 as the polystyrene beads 360 floats up, as illustrated in Figure 23.
  • Figure 23 shows an expanded view of a top part of the precast wall panel 340.
  • the polystyrene beads 360 have rough or uneven surfaces.
  • Figures 24 to 30 show different embodiments of the precast wall panel 340.
  • Figure 24 depicts a first embodiment of the precast wall panel 340.
  • Figure 24 shows a front view of a first precast wall panel 366, which is produced by the extruder 320 of Figure 20.
  • the first precast wall panel 366 has several hollow cores 368.
  • a bottom surface 371 of the precast wall panel 366 is flat and smooth. This is because the bottom surface 371 is extruded on a flat and smooth upper surface of a casting bed of the extruder 320 during the making of the first precast wall panel 366.
  • a top surface 372 of the precast wall panel 366 is rough and it can be even be uneven with longitudinal traces 374.
  • the traces 374 comprise channels with generally flat bottoms. Each trace 374 is positioned roughly above each hollow core 368.
  • the hollow cores 368 also have generally cylindrical surfaces and they may have substantially flat top portions 373 that correspond to the traces 374, as illustrated in Figure 24. The said traces 374 and the said flat top portions 373 are produced during the manufacturing process of the precast wall panel 366 when the hollow cores 368 are formed, if the concrete mixture is too wet.
  • the upper surface of the wall panel 366 can later be covered with a fibreboard.
  • a layer of adhesive material is provided between the fibreboard and the top surface. This would also equalise or cover the traces 374.
  • Figure 25 depicts a second embodiment of the precast wall panel 340.
  • Figure 25 shows a front view of a second precast wall panel 380 that is produced by the extruder 320 of Figure 20.
  • the second precast wall panel 380 includes multiple longitudinal steel wires 382.
  • the steel wires 382 allow the precast wall panel 380 to bear additional loads or tension.
  • the steel wires 382 are placed over the casting bed 262, as illustrated in Figure 26.
  • the steel wires 382 are positioned at approximately at an equal distance d above the casting bed 262.
  • the steel wires 382 are pulled from both ends of the casting bed 262. Ends of the steel wires 382 are connected to stress stands 384 for loosely stretching the steel wires 382. The stretching is just sufficient to keep the steel wires 382 substantially straight and parallel to a longitudinal upper surface of the casting bed 262.
  • the casting bed 262 is placed over a concrete floor 385 of a factory.
  • the steel wires 382 can also be over-stretched but the wall panel 380 may then bend when it is cut.
  • Figure 27 depicts a third embodiment of the precast wall panel 340.
  • Figure 27 shows a front view of two precast wall panels 390 in an installed state.
  • the extruder 320 of Figure 20 can produce the precast wall panels 390.
  • Each precast wall panel 390 includes a concrete panel 392 and a fibre-reinforced board 393 that is placed next to the concrete panels 392.
  • a surface of the concrete panel 392 is connected with a surface of the fibre-reinforced board 393 by a layer 406 of filler.
  • a bottom side 395 of the concrete panel 392 has two longitudinal recesses 397 that are provided at outer edges of the bottom side 395.
  • Two longitudinal metal strips 400 on the casting bed 262 of the extruder 320 create the recesses 397, as illustrated in Figure 28.
  • the metal strips 400 are provided on the casting bed 262 before the concrete mixture 42 is deposited on the casting bed 262.
  • the metal strips 400 provide a protruding profile for creating the recesses 397 on the concrete mixture 42 when the concrete mixture 42 is deposited on the casting bed 262.
  • a top side 402 of the fibre-reinforced board 393 includes two longitudinal recesses 404 that are provided at longitudinal outer edges of the top side 402, as illustrated in Figure 29. The recesses 404 are cut out before the fibre- reinforced board 393 are attached to the concrete panel 392.
  • the concrete wall panel 392 is provided with the fibre- reinforced board 393 by a layer 406 of filler to form the precast wall panel 390.
  • the precast wall panel 390 has two fibre-reinforced boards 393.
  • One fibre-reinforced board 393 is attached next to the bottom surface of the concrete panel 393 whilst the other fibre-reinforced board 393 is attached next to a top surface of the concrete panel 393.
  • the layer 406 of filler can attach each fibre-reinforced board 393 to the concrete panel 393.
  • the filler layer 406 can comprise cement glue or other forms of adhesive.
  • precast wall panels 390 are stored usually by stacking the precast wall panels 390, as illustrated in Figure 30.
  • One precast wall panel 390 is placed on top of another precast wall panel 390.
  • the stacked wall panels 390 are placed on a concrete floor 407.
  • the recesses 404 are filled with pieces of wood 409. This stacking arrangement allows for better adhesion between each fibre-reinforced board 393 and the respective concrete panel 392.
  • one precast wall panel 390 can be connected to another precast wall panel 390 by cement glue 408, as shown in Figure 27.
  • the recess 397 of one precast wall panel 390 also joins with the recess 397 of the adjacent precast wall panel 390 to form a wider recess.
  • This wider recess can be filled with a fibre band 410, as illustrated in Figure 27.
  • the recess 404 of one precast wall panel 390 also joins with the recess 404 of another precast wall panel 390 to form a wider recess.
  • This said wider recess can be filled with a fibre band 411, as illustrated in Figure 27.
  • This manner of joining precast wall panels provides a flat and smooth connection. Any cracks in the joint can be easier avoided or be at least covered.
  • Figure 31 shows a side view of a third embodiment of the casting machine for producing precast wall panels.
  • Figure 31 depicts a slip-former 450 that comprises a frame 452.
  • the frame 452 is placed over an elongated steel casting bed 453.
  • the frame 452 has a set of guide wheels 455 that is mounted on a pair of rails 456. This is better seen in Figures 32 and 33.
  • a drive motor 458 is provided for moving the frame 452 along the rails 456 in a longitudinal direction of the rails 456.
  • the frame 452 receives delivers power supply from a cable reel 461.
  • the frame 452 supports a foremost concrete hop- per 462 and a rearmost concrete hopper 464.
  • the concrete hoppers 462 and 464 are also called feed hoppers.
  • the foremost concrete hopper 462 On a first side of the rearmost concrete hopper 464 are provided the foremost concrete hopper 462 as well as a first barrier 465, a first vibrator 467 for shoes 469, and a step motor 471 for tubes 473.
  • the barrier is also called a discharge gate.
  • the discharge gate can be adjusted.
  • the tubes 473 are also called hollow-core forming mandrels.
  • the first barrier 465 is placed next to the foremost concrete hopper 462 whilst the first vibrator 467 is placed between the first barrier 465 and the rearmost concrete hopper 464.
  • the step motor 471 is placed between the first vibrator 467 and the rearmost concrete hopper 464.
  • a first tube frame 475 supports a first set of the tubes 473 and a second tube frame 477 supports a second set of the tubes 477.
  • the multiple tubes 473 are arranged such that each tube 473 of the first set is provided next to one tube 473 of the second set.
  • a second barrier 481 On a second side of the rearmost concrete hopper 464 are provided a second barrier 481, a second vibrator 483 for compacting, and a smoothener 485.
  • the first side is opposite to the second side.
  • the second barrier 481 is placed next to the rearmost concrete hopper 464.
  • the second vibrator 483 is placed next to the second barrier 481 whilst the smoothener 485 is placed next to the second vibrator 483.
  • the slip-former 450 acts to cast or to mould a lightweight concrete mixture 488 on the casting bed 453 to form a precast concrete slab whilst its frame 452 is transported over the casting bed 453.
  • the concrete mixture 488 includes lightweight material.
  • the foremost concrete hopper 462 places a concrete mixture 488 on a lower part of a casting mould to form a lower concrete layer.
  • the concrete mixture 488 is in wet or semi-dry form.
  • Side plates 490 that are illustrated in Figure 34 and the casting bed 453 define the casting mould. The side plates are called side compactors.
  • a shutter 486 controls the release of the concrete mixture 488, as illustrated in Figure 31.
  • the rearmost concrete hopper 464 guides a con- crete mixture 488 to an upper part of the casting mould to form an upper concrete layer.
  • a shutter 487 controls the release of the concrete mixture 488, as illustrated in Figure 31.
  • the upper layer of concrete mixture 488 is positioned over and is adjacent to the lower layer of concrete mixture 488.
  • the first barrier 465 and the second barrier 481 prevent the concrete mixture 488 from maintaining or from reaching a cer- tain pre-determined height of a concrete slab.
  • the vibrating shoes 469 form traces 492 or channels on the lower layer of concrete mixture 488. This is illustrated in Figure 35.
  • the tubes 473 are aligned generally with the traces 492 such that the traces 492 together with the tubes 473 and the upper layer of concrete mixture 488 form into hollow cores within the combined upper and the lower layer, as illustrated in Figures 38 and 39. These hollow cores do not have spiral grooves since the tubes 473 do not have a feature, such as a rotating blade, for forming the said spiral grooves.
  • the step motor 471 moves the first tube frame 475 and the second tube frame 477 by back-and-fore steps of about one centimetre (cm) in a longitudinal direction of the casting bed 453. Further, the step motor 471 is arranged such that the first set of the tubes 473 and the second set of the tubes 473 moves in opposite directions, as illustrated in Figure 37. Put differently, the first and the second set of tubes 473 moves in reciprocal direction to each other.
  • microstructures 496 may include steps 498 along circular portions of surfaces of the hollow cores 492.
  • the second vibrator 483 is intended for compacting the con- crete mixture 488, which are deposited on the casting bed
  • the smooth- ener 485 is intended for treating the compacted upper surface to make it smooth and flat.
  • One possible method of using the slip-former 450 to form a precast concrete slab includes the step of a feeding tank dispensing a concrete mixture 488 to the foremost concrete hopper 462 and to the rearmost concrete hopper 464 via conveyors .
  • the drive motor 458 moves the slip-former 450 along the rails 456 over the stationary casting bed 453
  • the foremost concrete hopper 462 guides the concrete mixture 488 to the lower part of the casting mould to form a lower layer of the precast concrete slab.
  • the first barrier 465 also prevents the deposited concrete mixture 488 of the lower layer from maintaining a certain pre-determined concrete height. This step prepares the lower layer for the next step of forming the traces 492 on the lower layer.
  • the vibrating shoes 469 later compact on the lower layer to form the traces 492.
  • the tubes 473 also form and change the traces 492 into the hollow cores within the precast concrete slab.
  • the second barrier 481 also prevents the upper layer from maintaining a certain pre-determined concrete height to prepare the upper surface of the upper layer for the second vibrator 483.
  • the second vibrator 483 then defines an upper surface of the upper layer by a compacting action.
  • the smoothener 485 later treats the compacted upper surface of the upper layer to make it smooth and flat.
  • the precast concrete slab is separated later into several precast wall panels by a sawing mechanism that is not shown in the Figure 31 after hardening of the precast concrete slab.
  • the slip-former 450 can produce the precast concrete slab without the side plates 490 or the smoothener 485.
  • the slip-former 450 can also produce a solid precast concrete slab without using the tubes 473 and the shoes 469.
  • the pre-cast concrete slab may have no hollow cores.
  • Figure 40 shows a special embodiment of the shoes of Figures 34 and 35 and of the tubes of Figures 36.
  • Figure 40 depicts an elongated divider plate 493, which is part of the moving slip-former 450.
  • the divider plate 493 is positioned over the casting bed 453 of Figure 34 in a longitudinal direction of the casting bed 453.
  • the divider plate 493 is also provided in the middle of the casting bed 453.
  • the side-elongated plates 490 enclose outer edges of the casting bed 453.
  • Each of the side plates 490 is placed next to one rail 452.
  • Vibrators 494 are attached to the side plates 490 and to the divider plate 493.
  • the divider plate 492 replaces a middle shoe 469 of Figure 34.
  • the divider plate 492 also replaces a middle tube 473 of Figure 36. This allows the slip-former to produce two pre-cast slabs of half width with each production run.
  • the precast concrete slab or the precast wall panel can include one or more hollow cores or no hollow cores, which relates to a solid panel or slab.
  • the precast concrete slab or the precast wall panel can in- elude one fibre-reinforced board on one side of the precast concrete slab or of the precast wall panel. It can also include two fibre-reinforced boards, one on each side of the precast concrete slab or the precast wall panel.
  • the precast concrete slab or the precast wall panel can also be produced without the fibre-reinforced board.
  • the fibre-reinforced board may comprise a cement-fibreboard.
  • the precast wall panel can have a width of up to about 1,200 millimetres.
  • Figures 42 and 43 show different views of an embodiment of a slip-former that is depicted in Figure 31.
  • Figure 42 depicts a slip-former 502.
  • the slip-former 502 and the slip-former 450 of Figure 31 have similar parts with similar construc- tion.
  • the similar parts have same name or same part reference numbers. The description of the similar parts is incorporated hereby by reference, where appropriate.
  • the slip-former 502 comprise the foremost concrete hopper 462 and the rearmost concrete hopper 464.
  • the slip-former 502 also includes the guide wheels 455 for moving over the stationary casting bed 453.
  • the foremost concrete hopper 462 includes an inspection hole 504 and the shutter 486 whilst the rearmost concrete hopper 464 includes an inspection hole 506 and the shutter 487.
  • An adhesive applicator 507 is installed on a first side of the foremost concrete hopper 462.
  • the first vibrator 467, the steel springs 479, as well as the rearmost concrete hopper 464 are provided on a second side of the foremost concrete hopper 462 that is opposite to the first side.
  • the first vibrator 467 is placed next to the foremost concrete hopper 462 whilst the steel springs 479 are placed between the first vibrator 467 and the rearmost concrete hopper 464.
  • the first set of the tubes 473 is fixed or is mounted to the first tube frames 475 via the steel springs 479 whilst the second set of the tubes 473 is fixed to the second tube frames 477 via the steel springs 479.
  • the multiple tubes 473 are arranged such that each tube 473 of the first set is provided next to one tube 473 of the second set.
  • the steel springs 479 are provided on a first side of the rearmost concrete hopper 464 whilst the second vibrator 483 is provided on a second side of the rearmost concrete hopper 464 that is opposite to the first side.
  • the slip-former 502 is intended for moving over the stationary casting bed 453 by means of the guide wheels 455.
  • the casting bed 453, as provided here, is intended for holding or carrying multiple fibre-reinforced boards 510.
  • the adhesive applicator 507 is used for applying a layer of adhe- sive on the fibre-reinforced boards 510.
  • the foremost concrete hopper 462 is used for releasing the concrete mixture 488 via the shutter 486 onto the casting bed 453 to form a bottom concrete layer 512.
  • the concrete mixture 488 at this stage, is in a semi-dry or wet form.
  • the adhesive layer acts to bond the lightweight concrete mixture 488 onto the fibre-reinforced boards 510.
  • the rearmost concrete hopper 464 is used for releasing the concrete mixture 488 via the shutter 487 to form a top concrete layer 514 on the bottom concrete layer 512.
  • the top concrete layer 514 is positioned above and adjacent to the bottom concrete layer 512.
  • the top concrete layer 514 and the bottom concrete layer 512 are intended to form a monolithic concrete precast slab.
  • the inspection holes 504 and 506 are intended for taking samples of contents of the respective concrete hoppers 462 and 464.
  • the sample is used for monitoring and for controlling quality of the content of the concrete hoppers 462 and 464.
  • the first vibrator 467 is used for compacting the bottom concrete layer 512 by means of a flat plate.
  • the said compacting prepares the bottom layer 512 for forming of the traces 492 on an upper surface of the bottom layer 512 by the tubes 473.
  • the traces 492 are illustrated in Figure 42.
  • the second vibrator 483 is intended for compacting the upper concrete layer 514 by means of a flat plate. This said compacting provides the upper concrete layer 514 with a smooth and flat upper surface.
  • slip-former 502 One possible method of using the slip-former 502 to produce several precast wall panels or one precast concrete slab is described below.
  • the method includes the step of laying several fibre- reinforced boards 510 onto an upper surface of the casting bed 453.
  • the fibre-reinforced boards 510 are positioned in such a manner that one fibre-reinforced board 510 is placed adjacent to another fibre-reinforced board 510.
  • the slip- former 502 then moves over the fibre-reinforced boards 510 from one end to another end of the casting bed 453 whilst the adhesive applicator 507 sprays a layer of adhesive on the fibre-reinforced boards 510.
  • the foremost concrete hopper 462 releases the concrete mixture 488 onto the fibre-reinforced boards 510 to form the bottom concrete layer 512 on the fibre-reinforced boards 510.
  • the concrete mixture 488 is in a semi-dry or wet form.
  • the first vibrator 467 later compacts the deposited bottom concrete layer 512.
  • the tubes 473 later form multiple traces 492 on the upper surface of the bottom concrete layer 512.
  • the rearmost concrete hopper 464 releases the concrete mixture 488 onto the bottom concrete layer 512 to form the upper concrete layer 514 above and adjacent to the bottom concrete layer 412.
  • the tubes 473 then convert the traces 492 into hollow cores within the combined concrete layers 512 and 514.
  • the said hollow cores do not have spiral grooves.
  • the second vibrator 483 later compresses the upper surface of the upper concrete layer 514.
  • a precast concrete slab is thus formed from a combination of the upper concrete layer 514 and the bottom concrete layer 512.
  • a sawing mechanism separates the precast concrete slab into several precast wall panels of desired length.
  • Figure 44 shows a side view of an embodiment of the vibrator 457 of the slip-former 502 of Figure 42.
  • the vibrator 457 provides a better compaction of the fresh wet concrete mixture.
  • the vibrator 457 has a body 520 that has a heavy ele- ment 521 and a generally flat plate 523.
  • the heavy element 521 also acts as a weight.
  • One end of the body 520 is attached to the flat plate 523 by a hinge 525 whilst another end of the body 520 has a rubber element 527 that can be abutted to the flat plate 523 when the vibrator 457 the vi- brator 457 is in a rest state.
  • the flat plate 523 is intended for been fixed to a machine bed 528.
  • the machine bed 528 can be in the form of a plate.
  • the vibrator 457 When the vibrator 457 is in an operating state, the vibrator 457 provides a vibrating or shaking action for the machine bed 528.
  • the weight 521 rotates about an axis 529 of the body 520 at about 2000 rounds per minute. This rotation causes the rubber element 527 to alternate quickly between moving away and towards the flat plate 523 with a maxi- mum separation between the rubber element 527 and the flat plate 523 of about 10 millimetres.
  • An inclination between the body 520 and the flat plate 523 also varies with a maximum angle of about 5 degrees. In other words, the rotation of the weight 521 causes the rubber element 527 to hit continually the flat plate 523. These movements also translate into the vibrating or shaking action for the machine bed 528.
  • the vibrator 483 of Figure 42 can also have the above implementation.
  • Figure 45 shows a front view of the concrete hopper 462 of the slip-former 502 of Figure 42 for illustrating a step of using the slip-former 502 that is described above.
  • Figures 46 to 51 show different embodiments of the wall panel that are produced by the slip-former 502 of Figure 31. The different embodiments have similar parts.
  • Figure 46 shows a front view of first embodiment of a hollow wall panel 532 that is produced by the slip-former 502 of
  • the hollow wall panel 532 has a lightweight concrete mixture 534.
  • the concrete mixture 534 has several longitudinal hollow cores 536.
  • a top fibre-reinforced board 538 is attached to a top surface and another bottom fibre- reinforced board 538 is attached to a bottom surface of the hollow wall panel 532.
  • the hollow wall panel 532 has a longitudinal groove 540 on one side and a longitudinal tongue 542 on another side of the hollow wall panel 532.
  • the method of producing the hollow wall panel 532 includes an additional step of applying an adhesive agent on the top surface of the concrete mixture 534.
  • the top fibre-reinforced board 538 is placed on the adhesive agent.
  • Figure 47 shows a second embodiment of the hollow wall panel 532 of Figure 46.
  • Figure 47 shows a wall panel 545.
  • the wall panel 545 has hollow cores 536 with different profiles.
  • the profiles include circular, square, triangular, semi-circular, oval, and rectangular shapes as depicted in Figure 47. Dif- ferent shapes of tubes of the slip-former 502 form or determine the different profiles.
  • Figures 48 and 49 show a third embodiment of the hollow wall panel 502 of Figure 46.
  • Figure 46 shows a wall panel 547.
  • the wall panel 547 has one fibre-reinforced board 538 and not two fibre-reinforced boards 538.
  • the said fibre-reinforce board 538 is attached a flat surface of the wall panel 547.
  • Figures 50 and 51 show a fourth embodiment of the hollow wall panel 502 of Figure 46.
  • Figure 50 shows a solid wall panel 549.
  • the wall panel 549 has the lightweight concrete mixture 534 and it does not include any hollow core.
  • the wall panel 549 has a fibre-reinforced board 538 that is placed on a top surface of the wall panel 549 and another fibre-reinforced board 538 that is placed on a bottom surface of the wall panel 549.
  • a slip-former, which produces the wall panel 549, does not comprise the tubes.
  • the lightweight concrete mixture 42 can be used for an extruder or a slip-former to produce a precast concrete slab.
  • the concrete mixture 42 can be pro-losed using about 150 to 400 kg (kilogram) of cement, about 150 to 500 kg of dry sand, about 550 to 900 litres of polystyrene, about water 40 to 160 litres of water, and about one kg of adhesive, such as Methocel adhesive, may be included in the production.
  • the adhesive can comprise concrete glue, ce- ment glue, or glue and colouring.
  • the concrete mixture 42 is produced using about 250 kg of cement, about 300 kg of dry sand, about water 75 litres of water, and about 700 litres of polystyrene. About one kg of adhesive may also be included in the concrete mixture 42.
  • the rule of thumb is to have a preferred water to cement weight ratio (w/c) of about 0.3. This can also be between 0.2 and 0.4 or between 0.25 and 0.35. With this water to cement ratio, the concrete slump is not too liquid and maintains its shape after being formed and vibrated.
  • the concrete mixture 42 can be produced using about 150 to 400 kg of cement, about 100 to 400 kg of dry sand, about 500 to 900 litres of expanded clay, and about 40 to 160 litres of water.
  • the expanded clay can be produced by expanding clay using heat.
  • the expanded clay may include a lightweight granular material that has insulation property and that has a cellular structure formed by expanding clay minerals by heat.
  • the concrete mixture 42 is produced using about 220 kg of cement, about 180 kg of dry sand, about 66 litres of water, and about 700 litres of expanded clay.
  • the concrete mixture 42 can be produced using about 200 to 350 kg of cement, about 100 to 300 kg of dry sand, about 550 to 900 litres of pumice, and about 60 to 105 litre of wafer.
  • the pumice refers to a grey light stone.
  • the concrete mixture 42 is produced using about 250 kg of cement, about 75 kg of water, and about 700 litres of pumice.
  • the concrete mixture 42 can be produced using about 150 to 400 kg of cement, about 100 to 350 kg of dry sand, about 600 to 900 litres of slag, and about 45 to 120 litre of water.
  • the slag refers to furnace slag that refers to waste material that is generated, for example, from iron or copper smelting.
  • the concrete mixture 42 is produced using about 300 kg of cement, about 90 kg of water, and about 650 litres of slag.
  • the concrete mixture 42 can be produced using about 150 to 350 kg of cement, about 100 to 400 kg of water, and about 900 litres of the perlite.
  • the perlite can refer to volcanic glass. More water here is required if the perlite is not treated against taking up or absorbing water.
  • the concrete mixture 42 is produced using, about 300 kg of cement, about 120 kg of water, about 900 litres of perlite, and about 150 litres of water .
  • up to 20 percents by weight of the cement can be replaced by fly ash.
  • the fly ash can relate to fine solid particles of ashes, dust, and soot that are produced from burning fuel, such as coal or oil.
  • the entire amount of dry sand of the concrete mixture 42 is replaced by the fly ash.
  • the above mixtures or compositions are for standard or normal grain size of EPS (expanded polystyrene) and sand. If optimised or improved grain sizes are used, the amount of sand and cement as well as consecutively water can be reduced without loss of compressive strength.
  • a first concrete mixture is produced with 300 kg of cement, 400 kg of fine sand, 95 kg of water, 600 litres of EPS, and 1 litre of additive or adhesive.
  • the water to cement ratio amounts to 0.317.
  • a second concrete mixture is produced with 300 kg of cement, 400 kg of fine sand, 90 kg of water, 620 litres of EPS, and 1 litre of additive or adhesive.
  • the water to cement ratio amounts to 0.3. Both mixtures worked but weight per square meter comes to 160 kg for a panel of 1.2 by 1.2 meter, which amount to 111 kg per square meter.
  • the specific weight comes to 1150 kg per cubic meter, which may be too heavy for some applications.
  • a first concrete mixture is produced with 300 kg of cement, 400 kg of fine sand, 100 kg of water, 500 litres of EPS, and 1 litre of additive or adhesive.
  • the water to cement ratio amounts to 0.33.
  • a second concrete mixture is produced with 300 kg of cement, 400 kg of fine sand, 100 kg of water, 500 litres of EPS, and 1 litre of additive or adhesive.
  • the water to cement ratio amounts to 0.33. Both mix- tures worked.
  • a first concrete mixture is produced with 300 kg of cement, 300 kg of fine sand, 120 kg of water, 500 litres of EPS, and no additive or adhesive.
  • the water to cement ratio amounts to 0.4.
  • the vibrator and finisher or smoothener is adjusted for better and smoother surface. The mixture worked.
  • a first concrete mixture is produced with 300 kg of cement, 300 kg of fine sand, 90 kg of water, 800 litres of EPS, and no additive or adhesive.
  • the water to cement ratio amounts to about 0.3.
  • 800 litres of EPS and 10 litres of water are provided and the mixture is mixed for 10 seconds.
  • 300 kg of sand is poured into the mixture and the mixture is mixed for 15 seconds.
  • 300 kg of cement is added into the mixture and the mixture is mixed for 10 seconds.
  • 80 kg of water is added into the mixture and the mixture is mixed for 20 seconds. This causes the sand and cement to settle on the mixer bottom with a bottom gap of about 15 millimetres. Additional 100 kg of sand and cement is added to fill the bottom.
  • the wet mixing time for this could also be shortened for getting a better result.
  • 300 kg of cement one could also use 350 kg of cement.
  • a first concrete mixture is produced with 300 kg of cement, 300 kg of fine sand, 120 kg of water, 700 litres of EPS, and no additive or adhesive.
  • the water to cement ratio amounts to 0.4.
  • the wet mixing time is reduced to improve mixing.
  • the concrete mixture has a plastic insulating property by using inorganic binders and ball shaped expanded polystyrene particles.
  • the mixture also includes hydraulic lime and a further binder.
  • the hydraulic lime refers to a variety of slaked lime that is used to make lime mortar whilst the "hydraulic" expression refers to ability of lime to set under water.
  • insulating materials are not pressure resistant and must therefore be covered with a second layer. This alternative avoids the second layer.
  • insulating particles are not deformed when pressing the material into gaps. In other words, the insulating effect is not impaired.
  • the concrete mixture can be producing using about 75 litres of expanded polystyrene (EPS) with a grading curve of about 1 to 5 millimetres, about 20 litres of slaked lime, also known as calcium hydroxyde, Ca(OH) 2 , and about 3 litres of bitumen dispersion. These ingredients are mixed in the dry state and water is added until it becomes like dough with the required consistency.
  • EPS expanded polystyrene
  • perlite particles can be used, especially if the perlite particles have a size distribution according to a predefined grading curve.
  • the first alternative is similar to the concrete mixture as shown in DE 1 471 400, column 2, last paragraph.
  • the modifications and alternatives of the concrete ingredients as shown in the DE 1 471 400 can also be applied to the above- mentioned concrete mixture, if the consistency and strength are adapted to the production process with an extruder or slip-former .
  • the lightweight concrete mixture in- eludes about 800 parts porous, that is expanded, polystyrene beads with diameter between about 2 and 6 millimetres and a specific weight of about 0.05, about 800 parts gypsum, and about 100 parts water.
  • the polystyrene beads are mixed with the gypsum while water is added. The mixture is dry after about 8 hours.
  • the second alternative is similar to the concrete mixture as shown in DE 964 217, column 4, second paragraph.
  • the modifications and alternatives of the concrete ingredients as shown in the DE 964 217 can also be applied to the above-mentioned concrete mixture, if the consistency and strength are adapted to the production process with an extruder or slip-former.
  • a lightweight concrete mixture in- eludes about 100 litres of foamed material with specific weight about 0.01, about 0.1 litre of one adhesive with about 4 litres of water, about 30 litres cement, such as Portland cement PZ 275, and about 8 to 10 litres of water.
  • the about 0.1 litre of one adhesive with about 4 litres of water is op- tional.
  • One possible method of producing the concrete mixture includes a first step of soaking the adhesive in the water and mixing the foamed material with the adhesive. The cement is mixed then thoroughly with the water until cement-glue is obtained. The cement glue is later added from above to the mixture of foamed material and adhesive and the ingredients are mixed thoroughly. The sand is then added. Approximately 40 1 of water can be added until the mixture becomes suitable dough. The amount of water depends on the moisture content of the sand.
  • the shrinkage behaviour is improved when the components are not mixed all at once but separately according to the description above.
  • the cement and water forms a better scaffold in between the foamed material.
  • the adhesive can even be omitted.
  • the third alternative is similar to the concrete mixture as shown in page 6 of DE 181 5053.
  • the modifications and alternatives of the concrete ingredients as shown in the DE 181 5053 can also be applied to the above-mentioned concrete mix- ture, if the consistency and strength are adapted to the production process with an extruder or slip-former.
  • polyurethane beads used in a lightweight concrete mixture is shown.
  • the beads are sprayed into a cavity and are covered by a layer of cement. Thereby it is avoided that the beads glue together.
  • remaining cement and water are added to produce a slurry mixture.
  • Sand and water - if necessary - are added to produce a dough or mixture of a desired consistency.
  • remaining cement and water are added and the ingredients are mixed. Water is added until the mixture is like the dough or the mixture has a desired consistency.
  • the fourth alternative uses beads which is known from DE 1 901 675.
  • the modifications and alternatives of the polyurethane beads as shown in the DE 1 901 675 can also be applied to the above-mentioned concrete mixture, if the consistency and strength are adapted to the production process with an extruder or slip-former.
  • a lightweight concrete mixture uses polystyrene concrete, also known as "Styroporbeton" .
  • the mixture contains a mixture of expanded polystyrene (EPS) granulate and cement and, optionally, a small amount of fine sand.
  • EPS expanded polystyrene
  • a typical composition has about 1085 litre per cubic meter of polystyrene, about 380 kilogram per cubic meter of cement, about 90 kilogram per cubic meter of sand, and about 140 kilogram per cubic meter of water.
  • the material has a high rigidity and stiffness. Therefore, it is able to hold the span wires in place but it is on the other hand still suitable for sawing and nailing.
  • the material is preferably used for the inner plate of a three layer concrete. In the inner plate, span wires are embedded which are arranged perpendicular to the inner plate.
  • the fifth alternative is similar to the concrete mixture as shown in DE 2 644 738, page 18, first paragraph.
  • the modifications and alternatives of the concrete ingredients as shown in the DE 2 644 738 can also be applied to the above- mentioned concrete mixture, if the consistency and strength are adapted to the production process with an extruder or slip-former .
  • a lightweight concrete mixture includes about 500 litres of expanded polystyrene beads, about 550 kg of cement, about 800 litres fly ash, about 700 g/m 3
  • polypropylene fibres about 5.5 litre per cubic meter of a additive liquifier, also known as super-plasticizer, are added.
  • This composition or mixture is mixed with 230 litres of water.
  • the super-plasticizers or high range water reducers or dispersants refer to chemical admixtures that can be added to concrete mixtures to improve workability
  • the polystyrene beads are present as a dry and loose fill in a size spectrum with a maximum diameter of approximately 4.5 millimetres.
  • Polypropylene waste material can also be used, but beads are preferably used.
  • the polypropylene fibres have a fibre-strength of between about 20 to 40 micrometers and a width of between about 100 to 300 micrometers. Therefore, the fibres have a low lateral contraction while at the same time providing high tensile strength and a large surface. This type of concrete is hardened after pouring into the mould without any additional heating.
  • the sixth alternative is similar to the concrete mixture as shown in DE 3 933 615, column 4, third paragraph.
  • the modifications and alternatives of the concrete ingredients as shown in the DE 3 933 615 can also be applied to the above- mentioned concrete mixture, if the consistency and strength are adapted to the production process with an extruder or slip-former .
  • a lightweight concrete mixture refers to polystyrene concrete that includes about 200 kg (kilogram) of sand, about 800 litres of EPS or granulated old polystyrene, about 600 g of staple fibres, about 350 kg of cement, such as Portland cement.
  • the old polystyrene relates to recycled material but EPS will do even better.
  • the concrete mixture contains includes a foam that is produced from a foaming agent, such as Tricosal PL. About 200 litres of this foam are added to the mixture in a proportion of about 1:40. About 145 litres of water are added to the mixture.
  • the resulting polystyrene concrete has a density of about 700 kilogram per cubic meter and can thus be used as a structural concrete.
  • a size of the staple fibres can be from about 20 to 40 micrometer by about 100 to 300 micrometer.
  • the seventh alternative is similar to the concrete mixture as shown in DE 4 135 243, column 4, second paragraph.
  • the modifications and alternatives of the concrete ingredients as shown in the DE 4 135 243 can also be applied to the above- mentioned concrete mixture, if the consistency and strength are adapted to the production process with an extruder or slip-former.
  • a very lightweight concrete has a specific mass of only 0.8 gram per cubic meter. It comprises foam glass with a size distribution of about 1 to 2 mi1lime- tres. Perlite can be a kind of foam glass.
  • the concrete mixture can be used as structural concrete or as screed. The mixture includes about 24.5 percent weight of foam glass, about 42.0 percent weight of cement, about 3.5 percent weight of basalt dust, about 7.0 percent weight of alumina, about 2.0 percent weight of vinyl acetate copolymers, such PAV 333, and about 21.0 percent weight of water.
  • the alumina can be of a special type, which is also known as "Schmelztonerde” .
  • the PAV 333 refers to Rhoximat PAV series from Rhodia.
  • the size distribution of the stone dust is about 0 to 0.1 millimetres with a maximum size of about 0.1 millimetres.
  • Other types of stone dust may be used which have similar chemical characteristics. Measurements were conducted on this type of concrete mixture. After a hardening time of about 7 days, a bending - tensile strength of about 2.5 N/mm2 (Newton per millimetre square) and a compressive strength of about 11.0 N/ mm2 (Newton per millimetre square) is obtained. The resulting specific mass has a value of approximately 1.25 g/cm3 (gram per cubic centimetre) .
  • the concrete mixture includes about 200 kg of perlite, about 350 kg of cement, about 25 kg of basalt dust that has about 0 to 0.1 mil- limetres diameter, about 55 kg of alumina or alum earth, about 16 kg of Vinyl Acetate, and about 165 kg of water.
  • the eighth alternative is similar to the concrete mixture as shown in DE 10 111 016, paragraph 24.
  • the modifications and alternatives of the concrete ingredients as shown in the DE 10 111 016 can also be applied to the above-mentioned concrete mixture, if the consistency and strength are adapted to the production process with an extruder or slip-former.
  • the concrete mixture includes a mortar that comprises within one cubic meter dry mortar, about 6 kg, which refers to about 0.85 percentage by weight, of coarse polystyrene with maximum diameter of 6 mm, - about 54 kg, which refers to about 7.7 percentage by weight, of perlite with maximum diameter of 1.5 mm, about 350 kg, which refers to about 49.8 percentage by weight, of cement, such as PZ 45, about 180 kg, which refers to about 25.6 percentage by weight, of lime, such as slaked lime, about 110 kg, which refers to about 15.6 percentage by weight, of filling material, such as coal fly ash, - about 2 kg, which refers to about 0.28 percentage by weight, of air entraining agent, and about 1 kg, which refers to about 0.14 percentage by weight, of retarder, also known as retarding agent, for the lime.
  • cement such as PZ 45
  • about 180 kg which refers to about 25.6 percentage by weight
  • lime such as slaked lime
  • filling material such as coal fly ash
  • the values in weight percent are stated relative to the dry mortar.
  • the mortar in this example does not contain lique- fier.
  • the density values of the concrete mixture are usually whereas its compressive strength can be improved when liquefier is left out.
  • the retarding agent By using the retarding agent, one can work for about 1 day with the mortar without having to add water.
  • the polystyrene recycled polystyrene is used. It is ground, blown into silos and weighed to determine the desired amount.
  • a lightweight mortar is provided which is economic to produce and which has very good heat insulation properties and sufficient strength.
  • the ninth alternative is similar to the concrete mixture as shown in DE 195 48 952, page 6, lines 30 ff, and example F.
  • the modifications and alternatives of the concrete ingredients as shown in the DE 195 48 952 can also be applied to the above-mentioned concrete mixture, if the consistency and strength are adapted to the production process with an extruder or slip-former.
  • the concrete mixture is composed of - about 200 kg (about 180 to 220 kg) of cement
  • This kind of concrete hardens rapidly. It quickly becomes re- silient for walking and screed can be applied to it, for example. It also has a high compressive strength.
  • the tenth alternative is similar to the concrete mixture as shown in DE 202 09 620 U, page 2, second paragraph.
  • the modi- fications and alternatives of the concrete ingredients as shown in the DE 202 09 620 U can also be applied to the above-mentioned concrete mixture, if the consistency and strength are adapted to the production process with an extruder or slip-former.
  • the mixture becomes very hard and one needs to be cautious because the mixture needs to be processed within about 15 minute of time. Otherwise, the hardened concrete may damage the extruder.
  • This mixture is preferably used with the slip- former because this equipment is easier to clean after use.
  • the ingredients of the lightweight concrete are natural materials and their properties depend largely on the origin of the respective material and the way it is prepared.
  • Sea sand has properties which are different from sand that is produced by crushing rock material, just to name one example.
  • the humidity of the sand can have an influence on the amount of water which needs to be added.
  • the above examples, embodiments and alternatives start from dry ingredients.
  • a systematic approach to find an appropriate lightweight concrete mixture is of advantage for achieving a quick result.
  • Possible methods of producing the lightweight concrete mixture 42 are provided in the following.
  • One way to optimize the strength of the cured lightweight concrete mixture would comprise two steps, which are repeated iteratively until the desired result is found.
  • a first step one would like to find a lightweight concrete mixture with a desired consistency for production with the extruder or slip-former by using the materials, which are available on site.
  • a second step the ratio of the ingredients is altered such that the strength of the final concrete panel af- ter curing is just as big as necessary in order to reduce costs .
  • the adding or including of sand is done before the adding of cement.
  • a desired moisture level for the lightweight concrete mixture is about the same as a common moisture level of soil, such as live or arable soil.
  • Flowerpot soil which is used for cactus is definitely too dry for a comparison with a lightweight concrete mixture with a desired moisture level, and fresh peat is too wet.
  • water to cement ratio should be about 0.3, at least between 0.2 and 0.4 or between 0.25 and 0.35.
  • a ratio of water to cement is kept usually to about 0.3 or between roughly 0.25 to 0.35 for providing a plasticity characteristic.
  • Fillers or aggregates such as sand, fly ash, alumina, perlite, or EPS are used for increasing volume and strength.
  • the fillers can also act to reduce to cost of the final mixture, because a given volume of water/cement/sand mixture is usually more expensive than the same volume of filler material.
  • the strength of the cured mixture is of less importance if the finished product is to be used as load bearing elements in low-rise buildings or as non-load bearing wall elements. A higher strength is desired if the if the finished product is to be used as load bearing elements in high-rise buildings.
  • Figure 52 shows a flow chart 560 of one possible method of optimizing or of improving cost of the concrete mixture for use by the casting machine of Figure 1, 20, or 31.
  • the flow chart 560 includes steps 562, 563, 565, and 566.
  • the method comprises the step 562 of deciding or selecting the desired strength class of the finished concrete mixture.
  • Strength classes are defined in the DIN 1053-1 standard. If one produces panels for the strength class 2 (green) , the amount of cement per volume can be smaller than for panels for the strength class 6 (red) , which reduces the costs of the panels.
  • an amount of cement, an amount of lightweight material, an amount of water, and an amount of sand is each selected, as shown in the step 563.
  • the ratio of cement to water such as 1 to 3, is also selected.
  • Combining water with cement based material forms a cement paste.
  • the cement paste glues the aggregate together, fills voids within it, and allows it to flow more easily.
  • Cement needs to be mixed with a certain amount of water to initiate hydration.
  • Cement needs a minimum amount of water because it solidifies and hardens after mixing with water due to a chemical process known as hydration.
  • the water reacts with the cement, which bonds the other components together after curing, eventually creating a stone-like material.
  • Hydration involves different reactions, often occurring at the same time. As the reactions proceed, the products of the cement hydration process gradually bond together the individual sand and gravel particles, and other components of the concrete, to form a solid mass. Fine and coarse aggregates or fillers make up the bulk of the concrete mixture. Sand, natural gravel and crushed stone are mainly used for this purpose. Recycled aggregates (from construction, demolition and excavation waste) are increasingly used as partial replacements of natural aggregates, while a number of manufactured aggregates, including air-cooled blast furnace slag and bottom ash are also permitted.
  • a mixture of lightweight concrete mixture is produced from 300 kg of cement, 800 litres of EPS for lightweight material, 105 kg of water, and 250 kg of sand.
  • the ratio of cement to water remains at about 0.3. This provides a net weight of 655 kg.
  • the concrete mixture After 28 days of drying, the concrete mixture has a net weight of 500 kg.
  • the concrete mixture is moulded immediately after mixing for forming a wall or roof panel before the concrete mixture is dried.
  • strength of the concrete mixture is measured, as shown in the step 565.
  • the amount of the cement, sand, and water is adjusted using the measured strength, as shown in the step 566. If the measured strength is too high, the amounts of cement, water, and sand are reduced each by 10 percent, with the ratio of cement to water remaining unchanged. If the measured strength is too low, the amount of cement, water, and sand are increased by 10 percent. As before, the strength of the concrete mixture is measured again later after drying of the concrete mixture. These steps are repeated until the measured strength meets the earlier selected strength. For fine-tuning purposes, the iterative steps are made smaller from 10% to 5% in later iterative steps.
  • the content or amount of filler and the ratio of cement to water are kept constant whilst the content of cement to sand is adapted accordingly.
  • Gypsum is generally not used in the concrete mixture as it may hamper production due to its characteristic of hardening very quickly. It can be used, however, if further ingredients such as a retarder are provided which slow down the curing speed of the concrete mixture.
  • One important goal is to adapt the humidity of the respective concrete mixture such that it can be used for producing concrete panels with an extruder or a slip-former as described above.
  • a good mixture is achieved if the groove and the tongue remain stable without collapsing after being formed. After formation of the channels it is wanted that the channels in the panel do not collapse. It is acceptable if the upper part of the panel in the areas above the channels becomes sunken by a small distance.
  • One possible method of optimizing or improving a density of the concrete mixture comprises the step of deciding or selecting a desired density of a finished concrete mixture.
  • the finished concrete mixture is also known as cured concrete.
  • a start weight of 700 kg of cement, sand, and water is for selecting a ratio between lightweight material and the group of the cement, sand, and water for producing the cured concrete mixture of the desired density.
  • the weight of water would be 21 kg, assuming the finished set concrete comprises 3 percent weight of water.
  • the value of 3 percent weight moisture or water is a typical value of cured concrete.
  • This amount of water is adapted such that one would like to find a lightweight concrete mixture with a desired consistency for production with the extruder or the slip-former by using the materials, which are available on site, for example Styrofoam, cement, and sand.
  • the excess water above the 21 kg, that is 3% value, would evaporate while curing the con- crete. After about 28 days, the strength of the concrete has increased.
  • the final density of the lightweight concrete mixture is somewhat below the desired value of 0.75 kg per liter.
  • Consistency or density of the mixture is often measured before using the lightweight concrete mixture for production.
  • the consistency is chosen such that a good and easy manufacturing is possible as described above.
  • the outcome would often be a concrete which falls into class Kl of the DIN 1045 standard, which means that the consistency is about 1.26 to 1.45, also depending on the compaction in the slip-former or extruder which is used for producing the lightweight concrete panel .
  • the flow chart 570 includes a step 572 of selecting a desired density of a finished concrete mixture. This is followed by a step 574 of selecting a ratio between lightweight material and a group of the cement, sand, and water for producing the concrete mixture of the desired density. After this is a step 575 of selecting a ratio between cement and sand. Measuring strength of the cured concrete mixture is then done, as shown in a step 578. After the ratio of cement to sand is adjusted to improve strength the cured concrete mixture, as shown in a step 579.
  • the thickness of the wall panels mentioned herein can be anything between 30 millimetres and 300 millimetres or even more or also less.

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  • Chemical & Material Sciences (AREA)
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  • Mechanical Engineering (AREA)
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  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
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Abstract

La demande concerne un produit de béton comprenant un mélange de béton de poids léger et un ou plusieurs parements, au moins un, de même qu’un procédé d'extrusion pour constituer le mélange de béton de poids léger. Le ou les parements sont fixés à une ou plusieurs surfaces du produit de béton.
PCT/IB2009/055109 2008-11-17 2009-11-17 Panneau de béton précoulé et procédé de fabrication de panneau de béton précoulé WO2010055497A2 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
SG2012004214A SG177712A1 (en) 2009-08-04 2010-08-04 Precast concrete panel with a plastic cladding, method for making the precast concrete panel, precast concrete panel with lateral hollows and method for making it
PCT/IB2010/053530 WO2011015997A2 (fr) 2009-08-04 2010-08-04 Panneau de béton préfabriqué avec bardage en plastique, procédé de fabrication du panneau de béton préfabriqué, panneau de béton préfabriqué à renfoncements latéraux et procédé de réalisation

Applications Claiming Priority (12)

Application Number Priority Date Filing Date Title
SG200808522-7 2008-11-17
SG200808522 2008-11-17
SG200905206 2009-08-04
SG200905206-9 2009-08-04
SG200905452 2009-08-14
SG200905452-9 2009-08-14
SG200905652 2009-08-24
SG200905652-4 2009-08-24
SG200906138-3 2009-09-15
SG200906138 2009-09-15
SG200906474-2 2009-09-28
SG200906474-2A SG169912A1 (en) 2009-09-28 2009-09-28 Precast concrete panel, slipformer and method for making the precast concrete panel

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111923435A (zh) * 2020-08-10 2020-11-13 四川苏邦建筑节能科技有限公司 一种全自动聚苯保温板设备全自动化生产工艺流程
CN112374808A (zh) * 2020-10-29 2021-02-19 安徽扬子地板股份有限公司 一种便于安装的预制墙板的生产方法
CN114477924A (zh) * 2021-12-28 2022-05-13 重庆重通成飞新材料有限公司 风电叶片回用纤维增强纤维硫铝酸盐水泥墙板配方

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1134554A (en) * 1965-11-20 1968-11-27 Klaue Hermann Improvements relating to the production of lightweight constructional plates
GB1225518A (fr) * 1967-06-29 1971-03-17
EP0175930A2 (fr) * 1984-08-24 1986-04-02 Lohja Parma Engineering Lpe Oy Procédé et dispositif pour la fabrication de plaques creuses et d'éléments de construction semblables de préférence en béton

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1134554A (en) * 1965-11-20 1968-11-27 Klaue Hermann Improvements relating to the production of lightweight constructional plates
GB1225518A (fr) * 1967-06-29 1971-03-17
EP0175930A2 (fr) * 1984-08-24 1986-04-02 Lohja Parma Engineering Lpe Oy Procédé et dispositif pour la fabrication de plaques creuses et d'éléments de construction semblables de préférence en béton

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111923435A (zh) * 2020-08-10 2020-11-13 四川苏邦建筑节能科技有限公司 一种全自动聚苯保温板设备全自动化生产工艺流程
CN112374808A (zh) * 2020-10-29 2021-02-19 安徽扬子地板股份有限公司 一种便于安装的预制墙板的生产方法
CN114477924A (zh) * 2021-12-28 2022-05-13 重庆重通成飞新材料有限公司 风电叶片回用纤维增强纤维硫铝酸盐水泥墙板配方

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