The disclosure generally relates to the field of precast sandwich panels, particularly to a method for constructing precast sandwich panels.
Precast concrete is a form of construction, where concrete is cast in a reusable mould or form which is then cured in a controlled environment. A precast sandwich panel (may also be referred to as double wall precast) may include two wythes (panels or layers) of reinforced concrete sandwiched around an insulating layer having a high R-value (a measure of thermal resistance). The insulation layer may be continuous throughout the wall section, and the two wythes of the interior and exterior concrete layers may be held together with trusses or ties.
The present disclosure is directed to a concrete sandwich panel. The concrete sandwich panel may comprise a first reinforced concrete panel; a second reinforced concrete panel; an insulating panel sandwiched between the first reinforced concrete panel and the second reinforced concrete panel; a tie comprising a generally triangle wave-shaped pattern having a period defined by peaks spaced at a regular interval and a peak-to-peak amplitude greater than the thickness of the insulating panel; wherein the insulating panel has a plurality of generally linear slots defined at the regular interval of the tie for receiving the tie such that opposing ends of the tie terminate adjacent to the insulating panel, and the plurality of generally linear slots are filled utilizing an insulating material upon insertion of the tie to reduce thermal bridging; and wherein the peaks of the tie mechanically join the first and second reinforced concrete panels to the insulating panel.
A further embodiment of the present disclosure is directed to a method for constructing a concrete sandwich panel. The method may comprise configuring a first reinforcement installation; forming a first reinforced concrete panel having the first reinforcement installation embedded within; placing an insulating panel on top of the first reinforced concrete panel, the insulating panel comprising a tie having a generally triangle wave-shaped pattern, the generally triangle wave-shaped pattern having a period defined by peaks spaced at a regular interval and a peak-to-peak amplitude greater than the thickness of the insulating panel, the insulating panel having a plurality of generally linear slots defined at the regular interval of the tie for receiving the tie such that opposing ends of the tie terminate adjacent to the insulating panel; configuring a second reinforcement installation; forming a second reinforced concrete panel having the second reinforcement installation embedded within.
An additional embodiment of the present disclosure is directed to a tie for joining an insulating panel sandwiched between two reinforced concrete panels, the tie comprising a generally triangle wave-shaped pattern having a period defined by peaks spaced at a regular interval and a peak-to-peak amplitude greater than the thickness of the insulating panel, wherein the improvement comprises the tie having a length which is a segment of a length of the concrete panels; and the tie is positioned in the insulating panel through a plurality of generally linear slots defined at the regular interval of the tie, wherein opposing ends of the tie terminate adjacent to the insulating panel.
An additional embodiment of the present disclosure is directed to an insulating panel. The insulating panel may comprise a tie comprising a generally triangle wave-shaped pattern having a period defined by peaks spaced at a regular interval and a peak-to-peak amplitude greater than the thickness of the insulating panel; and a plurality of generally linear slots in the insulating panel defined at the regular interval of the tie for receiving the tie such that opposing ends of the tie terminate adjacent to the insulating panel.
An additional embodiment of the present disclosure is directed to a method for constructing an insulating panel. The method may comprise defining a plurality of generally linear slots in the insulating panel at a regular interval for receiving a tie, wherein the tie comprising a generally triangle wave-shaped pattern having a period defined by peaks spaced at the regular interval and a peak-to-peak amplitude greater than the thickness of the insulating panel; inserting the tie into the insulating panel at the plurality of generally linear slots such that opposing ends of the tie terminate adjacent to the insulating panel; sealing the plurality of generally linear slots utilizing an insulating material upon insertion of the tie.
An additional embodiment of the present disclosure is directed to an apparatus. The apparatus may comprise a frame for supporting for an insulating board; a track slidably connected to the frame for translating in a direction generally parallel to the frame; and a slotting element slidably connected to the track for translating in a direction generally perpendicular to the frame; wherein the slotting element comprises a heating member for plunging into the insulating board to create a plurality of at least partially generally triangle wave-shaped pattern of slots.
An additional embodiment of the present disclosure is directed to a system. The system may comprise means for holding a plurality of insulating boards; means for cutting one of the plurality of insulating boards to a specified configuration; means for creating a plurality of at least a partial generally triangle wave-shaped pattern of slots in said insulating board; means for determining a thickness of said insulating board and inserting a tie into the plurality of slots of said insulting board, wherein the tie comprising a generally triangle wave-shaped pattern having a period defined by peaks spaced at a regular interval and a peak-to-peak amplitude greater than the thickness of said insulating board; means for injecting an amount of insulating material into the plurality of slots of said insulting board upon insertion of the tie; and means for curing said amount of insulating material injected.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not necessarily restrictive of the present disclosure. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate subject matter of the disclosure. Together, the descriptions and the drawings serve to explain the principles of the disclosure.
The numerous advantages of the disclosure may be better understood by those skilled in the art by reference to the accompanying figures in which:
Reference will now be made in detail to the subject matter disclosed, which is illustrated in the accompanying drawings.
Referring generally to
The tie 108 is configured in a generally triangle wave-shaped pattern having a period defined by peaks 112 spaced at a regular interval and a peak-to-peak amplitude greater than the thickness of the insulating panel. In one embodiment, the peaks 112 of the generally triangle wave-shaped pattern may be rounded. The generally triangle wave-shaped pattern of the tie 108 may have a wavelength of approximately 19 inches or greater. The tie 108 may be configured to have a generally circular cross-section having a diameter of approximately ⅜ of an inch or greater (e.g., depending on the specific application). Alternatively, the tie 108 may be is configured to have a generally rectangular cross-section having a width of approximately one inch.
While the tie may be made of various types of materials, the tie 108 of a particular embodiment may comprise a composite material having at least approximately 65% fiber glass. The composite material may also include various types of resins (e.g., Urethane resin or Vinyl Ester thermoset resin). In addition, sand may be utilized as a coating material for the tie 108.
The generally triangle wave-shaped pattern of the tie 108 is configured to provide shear force resistance for the sandwich panel 100. Shear forces in the sandwich panel 100 are resisted by the legs (i.e., the straight segments between two adjacent peaks of the generally triangle wave-shaped pattern) of the tie 108 positioned at an angle with respect to the longitudinal direction of the sandwich panel 100.
The ties 108 of the present disclosure do not form continuous wave-shaped patterns along the longitudinal direction of the sandwich panel 100. Instead, the ties 108 are segmented with respect to the length of the sandwich panel 100. In one embodiment, the length of the ties 108 may be determined based on the dimensions of the insulating panels 106. For example, if a rectangular insulating panel 106 is four feet wide and eight feet long, the ties may be configured to be less than four feet in length and may be inserted into the insulating panel in a direction that is parallel to the four feet edges. Alternatively, the ties may be configured to be less than eight feet in length and may be inserted into the insulating panel in a direction that is parallel to the eight feet edges.
Some of the advantages of the ties 108 being configured to be segmented may include, but not limited to, cost reductions, structural improvements, and increased energy efficiencies. For instance, less materials and/or labor may be required for manufacturing, handling (e.g., shipping) and installing the segmented ties 108 comparing to a continuous tie. In addition, the segmented ties 108 may be utilized for joining sandwich panels of any given length, which is advantageous over continuous ties designed for a particular length. Furthermore, the generally triangle wave-shaped pattern of the ties 108 may stretch when the sandwich panel 100 stretches (e.g., due to heating), effectively reducing thermal bowing and/or other structural concerns.
The ties 108 may be inserted into the insulating panels 106 prior to the concrete placement. Referring generally to
A self-positioning feature of the tie 108 is provided where the opposing ends 110 of the tie 108 terminate adjacent to the insulating panel 106 when the tie 108 is fully inserted into the insulating panel 106. That is, the opposing ends 110 of the tie 108 may rest on the insulating panel 106 when the tie 108 is fully inserted, reducing and/or eliminating the need for adjusting the depth of which the tie 108 is inserted. In one example, as illustrated in
It is contemplated that the reinforced concrete panels 102 and 104 may include reinforcement installations. For example, the reinforcement installations may include twisting moment resisting means such as one or more reinforcing bars (rebars). In addition, the reinforcement installations may also include tensile strength imparting means such as one or more prestressed cables. It is understood that in the concrete sandwich panel 100 of the present disclosure, the ties 108 are not secured to the reinforcement installations of the concrete panels 102 and 104.
It is also contemplated that the thickness of the concrete panels 102 and 104 may vary depending on the specific application. Furthermore, the thickness of the insulating layer 116 (hence the insulating panels 106) may also vary depending on the applications. Therefore, the geometry of the generally triangle wave-shaped pattern of the tie 108 may vary based on the thickness of the concrete panels and/or the thickness of the insulating panels.
Referring generally to
It is understood that, in addition to the peak-to-peak amplitude, the wavelength, composition, and cross-sectional profile of the tie may also be configured differently based on the configurations and/or thicknesses of the concrete panels and/or insulating panels. It is contemplated that the ties may include identifiers/marks for identifying/indicating different peak-to-peak amplitudes, wavelengths, compositions, and/or cross-sectional profiles of the tie. In one embodiment, color-coded strings may be utilized as such identifiers.
Referring to
However, if the application requires the thickness of one concrete panel to be different from the thickness of another, the distances d1 and d2 may also differ accordingly. In an example depicted in
Referring generally to
Once the dimension of the sandwich panel is configured, a first reinforcement installation may be installed. The first reinforcement installation may include twisting moment resisting means such as one or more reinforcing bars (rebars) 308. In addition, the reinforcement installations may also include tensile strength imparting means such as one or more prestressed cables 306. In one embodiment, the prestressed cables 306 are oriented in a direction generally parallel to the side members 302, and are prestressed to at least 16,800 lbs of pressure. Rebars 308 having diameters of at least ⅜ of an inch (a.k.a. #3 rebar) may be oriented in a direction generally perpendicular to the side members 304. It is understood that handling inserts (inserts at the side of the sandwich panel utilized for lifting) and/or plate inserts (inserts for attachment of roof/floor elements) may also be configured per specification of the sandwich panel without departing from the scope of the present disclosure.
Once the first reinforcement installation is configured, concrete mix may be poured into the panel forming bed to form a first reinforced concrete panel 310 having the first reinforcement installation embedded within. Subsequently, as illustrated in
Depending on the desired dimension of the sandwich panel, the insulating panels placed on top of the first concrete panel 310 may not be uniformly sized. In an example illustrated in
Alternatively, the dimensions of the insulating panels may be pre-configured (e.g., custom made or configured) based on the desired dimension of the sandwich panel. In an example illustrated in
The number of ties 108 inserted into each insulating panel may vary. For example, depending on the locations of the insulating panels placed in the sandwich panel, certain insulating panels may include multiple ties while some insulating panels may not include any tie. In one instance, the ties may be substantially uniformly distributed with respect to both the width and the length of the sandwich panel. In another instance, the ties may be more concentrated at certain portions of the of sandwich panel (e.g., towards the ends of the sandwich panel).
Furthermore, depending on the design of the sandwich panel, certain portions of the insulating panels may be cut out to accommodate for elements that are inserted and/or attached to the sandwich panel. In an example illustrated in
Once all of the insulating panels (and necessary spacers) have been placed on top of the reinforced concrete panel 310, a second reinforcement installation may be installed above the insulating panels.
Also illustrated in
As illustrated in
The sandwich panel may remain in the panel forming system for at least a predetermined amount of time (e.g., a day) for the reinforced concrete panels 310 and 320 to harden. After the predetermined amount of time, portions of the prestressed cables 324 not embedded within the reinforced concrete panels 310 and 320 may be detached, and the sandwich panel may be removed from the panel forming system (e.g., utilizing a vacuum system) to be transported to a location where the sandwich panel may be completely cured. The panel forming system may be configured for forming the next group of sandwich panels.
It is understood that the forces released when detaching the portions of the prestressed cables 324 not embedded within the reinforced concrete panels 310 and 320 may damage the edges of the panels that are perpendicular to the prestressed cables. In one embodiment, as illustrated in
It is contemplated that the panel forming system may utilize vibrations to reduce the amount of air pockets in the concrete panels. In one embodiment, as the concrete panel is poured from one end to the opposite end along the length of the panel, one or more vibrators may be set at the starting point of the pour and vibrates (e.g., vibrates at 78 db and runs at 6000 vpm) till the halfway point of the panel is reached. The vibrators may then be relocated to the opposite end of the panel and vibrates for the remainder of the pour. It is understood that the vibrations may be applied only during pouring of one panel (e.g., only to the formed face which eventually becomes the exterior face of the wall). It is also understood that other vibration techniques and air pockets reducing techniques may be utilized as well.
It is also contemplated that self-consolidating concrete may be utilized to form the concrete panels. Self-consolidating concrete may attach itself to the panel forming system that it is being casted against, effectively reducing the number of air pockets without the need for vibration. It is further contemplated that the panel forming system may also include engravings and the like which may form design patterns to the outer surfaces of the concrete panels.
While the sandwich panels illustrated in the exemplary embodiments above are generally rectangular, it is understood that sandwich panels of different shapes and forms (e.g., triangular or circular shaped sandwich panels) may be manufactured utilizing the method of the present disclosure.
Referring generally to
The slotting apparatus 400 also comprises a track 406 slidably connected to the frame 402 for translating in a direction generally parallel to the frame 402, and a slotting element 408 slidably connected to the track 406 for translating in a direction generally perpendicular to the frame 402. The slotting element 408 may include a heating member 410 configured for plunging into the insulating board 404 to create a plurality of slots 412 to accommodate the ties previously described. An overhead bin 414 may also be utilized for providing lighting and/or ventilation during the operation of the slotting apparatus 400.
In one embodiment, the slotting element 408 may include a plurality of air powered cylinders and valves configured for providing location and time control of the heating member 410. The heating member 410 may include one or more alloy heating element (e.g., tungsten or beryllium rod/wire) supported by a plate 416. During the operation, the alloy heating element may be electrically heated to a temperature in excess of a melting temperature of Styrofoam. As illustrated in
Referring to
The ties 108 may be inserted into the insulating panels at the slots such that opposing ends of the tie terminate adjacent to the insulating panel. In addition, as depicted in
Referring generally to
The conveyer system 504 may transport the insulating board 506 to a subsequent device 508 for creating one or more slots in the insulating board 506. The slotting device 508 may be configured similarly to the slotting apparatus previously described. In addition, the slotting device 508 may be configured to receive electronic information specifying the exact locations of which the slots may be needed. Such information may be predetermined based on the specifications and/or designs of the sandwich panel and transmitted to the slotting device 508 via a control terminal (e.g., a computer system). It is understood that one or more sensors 510 may be utilized to facilitate positioning of the slotting device 508 with respect to the insulating board 506 to achieve desired precisions.
Since the dimensions of the sandwich panels may vary, certain is insulating boards may need to be readjusted (cut) to fit the specific dimension requirements. The automated system 500 may include a cutting device 512 for cutting the insulating board 506 to a specified configuration. For example, given a required dimension of a sandwich panel, the number of insulating boards needed to form the insulating layer of the sandwich panel may be determined. In addition, the insulating boards that need to be readjusted may be identified. Such information may be transmitted electronically to the cutting device 512, which may cut the insulating boards accordingly.
The cutting device 512 may comprise one or more movable cutting apparatus 520 (e.g., blades or tungsten wires) actuated by air powered cylinders and valves 522. One or more sensors 510 may also be utilized to facilitate positioning of the cutting apparatus 520 with respect to the insulating board to achieve desired precisions.
In one embodiment, the electronic information provided to the cutting device 512 may specify a particular cutting order. For example, the cutting device 512 may cut the insulating boards in accordance with the order of which these insulating boards are installed. In another example, a labeling device may be utilized to label the insulating boards based on their corresponding orders. Such labels may help workers to identify the insulating boards during the installation process. It is understood that certain insulating boards may not need cutting, in such cases, these insulating boards may pass through the cutting device 512.
The automated system 500 may further include a tie inserting device 514 configured for inserting ties into the insulating boards. The tie inserting device 514 may utilize one or more sensors 510 to align the ties with the slots in the insulating boards. It is contemplated that the tie inserting device 514 may be configured for holding ties having different peak-to-peak amplitudes. The sensors 510 may determine the thickness of the insulating board, and the tie inserting device 514 may select a tie having appropriate peak-to-peak amplitude based on the thickness of the insulating board and insert the selected tie into the insulting board.
The automated system 500 may also include an injecting device 516 configured for injecting a predetermined amount of insulating material into the slots of the insulting board upon insertion of the tie. In addition, a curing device 518 may be utilized to quickly cure the insulating material injected into the slots. For example, the curing device 518 may include a heat source and/or an ultraviolet light source for curing. The insulating boards with ties inserted may be removed from the automated system 500 (e.g., utilizing a vacuum lift) and delivered to the sandwich panel manufacturing area.
It is contemplated that the method for constructing a concrete sandwich panel in accordance with the present disclosure may be utilized at the construction sites.
It is also contemplated that the insulating panels with ties inserted in accordance with the present disclosure may be appreciated in certain cast-in-place applications. Referring to
Referring to
As illustrated in
The two-way action sandwich panel 702 may be manufactured by first defining the boundaries of the sandwich panel 702 on a panel forming bed. Reinforcement mats (e.g., rebars 704 arranged in a perpendicular configuration as depicted in
In one embodiment, once the insulating layer is formed, a second reinforcement mat is installed for the top layer of concrete in the sandwich panel and fixedly attached to the ties 108 to form a strong three-dimensional truss. The sandwich panels are transported to the work site prior to pouring the top layer. The partially completed sandwich panels may be positioned in to their corresponding positions at the work site to form the floor. Once all of the partially completed sandwich panels are positioned for the entire floor, the top layers of the sandwich panels may be poured at once at the work site. In this manner, a continuous surface may be provided for the entire floor. For this system, there is no need to provide temporary supports under the sandwich panels except at the column locations. The partially completed panel is designed to resist its own weight and the weight of the topping fresh concrete and the weight of the construction workers and equipment, while the two-way action sandwich panels illustrated in the exemplary embodiments above can be of any general shape in a plan view and is not required to be rectangular as in one-way systems.
The methods disclosed may be implemented as sets of instructions, through a single production device, and/or through multiple production devices. Further, it is understood that the specific order or hierarchy of steps in the methods disclosed are examples of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the method can be rearranged while remaining within the scope and spirit of the disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not necessarily meant to be limited to the specific order or hierarchy presented.
It is believed that the system and method of the present disclosure and many of its attendant advantages will be understood by the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the components without departing from the disclosed subject matter or without sacrificing all of its material advantages. The form described is merely explanatory.
The present application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 61/242,441, filed Sep. 15, 2009. Said U.S. Provisional Application Ser. No. 61/242,441 is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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61242441 | Sep 2009 | US |