SYSTEMS AND METHODS FOR CURING A PREFABRICATED CONCRETE PRODUCT

Abstract

A method for curing a concrete product with a cavity is described, which includes placing the concrete product on a base, sealing an opening to the cavity using a cover plate, introducing carbon dioxide (CO2) gas into the cavity to carbonate the concrete product, and, as a result, the concrete product achieves a target specification, and then opening the opening. A system for curing a precast concrete product is also described.

Description

SYSTEMS AND METHODS FOR CURING A PREFABRICATED CONCRETE PRODUCT Cross-reference This application claims priority over United States Patent Application No. 62 / 945,936, filed on December 10, 2019, the contents of which are incorporated herein by reference in their entirety. Technical field of the invention The application refers, in general terms, to precast concrete products, and more particularly to systems and methods for curing such precast concrete products. Background of the invention Concrete products are ubiquitous in construction structures worldwide. Therefore, improvements in curing systems and methods for precast concrete products are always desirable, and even small improvements can provide significant advantages to today's construction industry. Brief description of the invention Precast concrete products, such as pipes, manholes, and sewers, are conventionally cured with heat and steam or carbon dioxide in sealed chambers, spaces, rooms, or containers. Calcium-rich materials, such as hydraulic cement, slag, and non-hydraulic cement, containing calcium silicate phases, react with carbon dioxide in the presence of water and transform into strength-contributing phases, including calcium carbonates. This description relates to a method for producing a precast concrete product where fresh concrete is cured with carbon dioxide to achieve its strength. The walls of the demolded and optionally preconditioned concrete product act as pressure-retaining vessels. In certain embodiments, neither an external pressurized vessel nor a curing chamber is used to activate the concrete. Instead, the internal or external partition of the hollow concrete products is used as a chamber, and the carbon dioxide penetrates unidirectionally into the concrete walls. An external airtight enclosure is not required. This innovation relates to the production of precast concrete products, such as precast hollow concrete products, including, but not limited to, concrete pipes, manholes, catch basins, box girders, and hollow-core slabs. Accordingly, in one aspect, a method is provided for curing a concrete product having a cavity within the concrete product and an opening in the cavity. The method comprises: placing the concrete product on a base, sealing the opening using a p / n / cn / zznz / q / uli covered plate, introducing carbon dioxide (CO2) into the cavity to effect carbonation of the concrete product, and in response to the concrete product achieving a target strength (and / or other specified requirements), opening the opening. The method as described above and herein may also include, in whole or in part, and in any combination, one or more of the following additional features and / or steps. In some modalities, the introduction of CO2 into the cavity involves pressurizing the cavity to a first pressure for a first period of time, followed by increasing the pressure in the cavity to a second pressure for a second period of time. In some models, the introduction of CO2 is carried out through the cover plate and / or the concrete product. In some embodiments, the opening is one of an open upper end of the concrete product and one open lower end of the concrete product, and positioning includes placing the other of the open upper end and the open lower end on the base to seal the other of the open upper end and the open lower end. In some embodiments, the method involves balancing the first and second pressures with the cover plate so that the cover plate continues to seal the opening during the presence of the first and second pressures. In some variations, the method involves pouring and demolding the concrete product before placing the concrete product, and where the steps of positioning the concrete product and introducing CO2 are carried out after and close in time to the demolding step. In some modalities, the steps of positioning the concrete product and introducing the CO2 are carried out immediately after the demolding step. In some modalities, the method involves performing at least one of the setting, hydration and preconditioning steps with respect to the concrete product before the CO2 introduction step. In some forms, the method involves hydrating the concrete product after completing the CO2 introduction step. In some forms, the method involves pressurizing the cavity to a predetermined CO2 pressure. In some forms, the method involves varying the predetermined CO2 pressure. In some modes, the default pressure is at least atmospheric pressure. In some forms, the sealing of the opening is such that at least some CO2 is allowed to escape from the cavity during the carbonation of the concrete product. In some modalities, the pouring is carried out using one or a combination of zero-flake concrete, wet concrete, and self-compacting concrete. In some forms, fresh concrete is made using one or a combination of hydraulic cement, non-hydraulic cement, slag, pozzolanic materials, fly ash, silica fume, and calcium hydroxide as a binder. In some methods, the casting is carried out as both dry and wet casting. In some forms, the introduction of CO2 is carried out by introducing a gas containing CO2 at a concentration of between 5% and 99.5% CO2 by mass. In another aspect, a system is provided for curing a precast concrete product having a cavity therein, the cavity having an open lower end and an open upper end, comprising: a base dimensioned to receive the precast concrete product therein and to cover the lower end of the cavity, a cover plate dimensioned to be received on top of the precast concrete product and to cover the upper end of the cavity, a carbon dioxide (CO2) gas source, and a CO2 conduit fluidly connected to the CO2 source and configured to fluidly connect to the cavity. The system, as described above and herein, may also include, in whole or in part, and in any combination, one or more of the following additional features and / or stages. In some embodiments, the system comprises a height control system connected between the base and the cover plate and which can be operated to move the cover plate between a closed position in which the cover plate covers the upper end of the cavity and an open position. In some embodiments, the system comprises a frame connected between the base and the cover plate; the cover plate is hinged to the frame to move between a closed position in which the cover plate covers the top end of the cavity and an open position. In some embodiments, the CO2 conduit is seamlessly connected to the cavity through one or more of the cover plate, a wall of the precast concrete product, and the base; and the CO2 source is configured to pressurize the cavity to at least two different pressures that are equal to or greater than atmospheric pressure. In some models, a flow control valve is arranged in fluid flow communication with the CO2 source; the flow control valve is configured to control a rate and / or pressure of the CO2 gas supplied into the cavity. In another aspect, a method is provided for curing a concrete product that has a cavity therein, the method comprising: sealing the cavity; performing carbonation of the concrete product by introducing carbon dioxide (CO2) gas into the cavity, and in response to the concrete product achieving a target specification (such as strength and / or other specified characteristics), opening the cavity. The method as described above and herein may also include, in whole or in part, and in any combination, one or more of the following additional features and / or steps. In some embodiments, the method includes placing at least one container in the cavity before sealing the cavity, the at least one container that contains the CO2 gas pressurized in it, and where introducing the CO2 gas into the cavity includes releasing the CO2 gas into the cavity from the at least one container. In some modalities, the introduction of CO2 into the cavity involves pressurizing the cavity to a first pressure for a first period of time, followed by increasing the pressure in the cavity to a second pressure for a second period of time. In some forms, the at least one container includes at least one inner tube and one tire. In some models, the introduction of CO2 into the cavity involves operating at least one valve fluidly connected to at least one of the air chamber and the tire. In some embodiments, the sealing of the cavity is carried out using a cover plate and further comprises balancing the first and second pressures with the cover plate so that the cover plate continues to seal the opening during the presence of the first and second pressures. In some variations, the method includes pouring and demolding the concrete product before sealing the cavity, and where the CO2 introduction step takes place after and close in time to the demolding step. In some models, the CO2 introduction step is carried out immediately after the demolding step. In some modalities, the method includes performing at least one of the setting, hydration, and preconditioning steps with respect to the concrete product before the CO2 introduction step. In some forms, the method includes hydrating the concrete product after completing the CO2 introduction step. In some forms, the method includes pressurizing the cavity to a predetermined CO2 pressure. In some modalities, the method includes varying the predetermined CO2 pressure. In some modes, the default pressure is at least atmospheric pressure. In some forms, the method includes sizing at least one container to occupy between 10% and 98% of the cavity volume. In some modalities, at least one of the inner tube and the tire is used. In some methods, the casting is carried out as both dry and wet casting. In some forms, the introduction of CO2 is carried out by introducing a gas containing CO2 at a concentration of between 5% and 99.5% CO2 by mass. In another aspect, a method for curing a concrete product is provided, the method comprising: enclosing an outer surface of the concrete product in a sleeve having a shape that conforms at least in part to the outer surface of the concrete product, such that the sleeve is disposed close to, but separate from, the outer surface, to define a space between the outer surface and the sleeve; sealing the space between the outer surface and the sleeve; introducing carbon dioxide (CO2) gas into the space between the outer surface and the sleeve to effect carbonation of the concrete product, wherein at least part of the CO2 gas passes through the outer surface of the product in an inward direction; and in response to the concrete product achieving a target specification (such as strength and / or other specified characteristics), opening the space between the outer surface and the sleeve. The method as described above and herein may also include, in whole or in part, and in any combination, one or more of the following additional features and / or steps. In some forms, the concrete product includes a cavity therein and an opening in the cavity, and the outer surface of the concrete product is enclosed, excluding the sealing of the opening. In some forms, enclosing the outer surface of the concrete product leaves the opening open. In some models, introducing CO2 gas into the space is done through the jacket. In some embodiments, sealing the space between the outer surface of the concrete product and the sleeve includes placing a cover plate over the concrete product. The cover plate is functionally connected to the sleeve at least during the CO2 gas introduction step by being one or more of the following: weighted to balance a CO2 pressure; hinged to the sleeve; and guided with respect to the sleeve. In some embodiments, the cover plate includes an opening therein; the opening aligns at least in part with the opening in the cavity of the concrete product when the cover plate is placed over the concrete product. In another aspect, a system is provided for curing a precast concrete product having a cavity therein, the cavity having an open lower end and an open upper end, comprising: a base dimensioned to receive the precast concrete product therein and thereby cover the lower end of the cavity, a sleeve dimensioned to encompass the concrete product therein, the sleeve having a lower end that is disposed and sealed with respect to the base, a cover plate dimensioned to be received on top of the precast concrete product and thereby cover the upper end of the cavity, the cover plate being functionally connected to the sleeve to seal a gap between the sleeve and an outer surface of the concrete product when the cover plate is in place and thereby seal the gap, and a carbon dioxide (CO2) gas source configured to be fluidly connected to the gap. The system, as described above and herein, may also include, in whole or in part, and in any combination, one or more of the following additional features and / or stages. In some models, the CO2 source is seamlessly connected to the separator through at least one of the jacket and cover plate. In some embodiments, the cover plate is hinged to the sleeve to be rotatable between an open position in which the concrete product can be moved in and out of the sleeve and a closed position in which the cover plate seals the space between the concrete product and the sleeve. o 1 n / cn / 77n7 / q / υιλι In some configurations, the CO2 source is set to pressurize the cavity to at least two different pressures that are equal to or greater than atmospheric pressure. pjnj cn / zznz / q / uιλι Brief description of the figures Reference is now made to the attached figures in which: Figure 1 is a schematic diagram of a system for curing a concrete product; Figure 2A is a schematic diagram of a system for curing a concrete product, according to another modality; Figure 2B is a schematic diagram of a sealing mechanism for one or more concrete products, according to another modality; Figure 3 is a schematic diagram of a system for curing a concrete product, according to another modality; Figure 4 is a schematic cross-section of a part of the system in Figure 3; Figure 5 is a schematic diagram of non-limiting modalities of example alternatives of a cover plate, and a schematic diagram of a base, of the system in Figure 1; Figure 6 is a schematic diagram of a system for curing a concrete product, according to another modality; Figure 7 is a schematic diagram of a system for curing a concrete product, according to another modality; Figure 8 is a schematic diagram of a system for curing a concrete product, according to another modality; Figure 9 is a schematic diagram of a system for curing a concrete product, according to another modality; Figure 10 is a schematic diagram of a system for curing a concrete product, according to another modality; Figure 11 is a schematic diagram of a system for curing a concrete product, according to another modality; Figure 12 is a schematic diagram of various sealing parts of the systems according to some modalities described herein; Figure 13 shows a method for curing a concrete product; Figure 14 shows another method for curing a concrete product; and Figure 15 shows another method for curing a concrete product. Detailed description of the invention Precast concrete products, such as pipes, manholes, and culverts, are conventionally cured with heat and steam. They can also be cured with carbon dioxide when placed in sealed chambers, spaces, rooms, or containers. Calcium-rich materials, such as hydraulic cement, slag, and non-hydraulic cement, which contain calcium silicate phases, react with carbon dioxide in the presence of water and transform into strength-contributing phases, including calcium carbonates. This description relates to systems and methods for producing a precast concrete product (P) where fresh concrete is cured with carbon dioxide (CO2) to achieve its strength. In some embodiments, the walls of the demolded concrete product (P), and in some preconditioned embodiments, act to contain and maintain the CO2 pressure, thereby helping to reduce curing time and cost. With this technology, at least some aspects of the production of hollow-core concrete products (P), such as precast concrete products including concrete pipes, manholes, catch basins, box girders, and hollow-core slabs, can be improved. With the above in mind, the present description first describes non-limiting modalities of a system for curing a precast concrete product (P), then describes non-limiting examples of various possible materials and casting methods that may be associated with the system, and then describes non-limiting examples of various possible methods for curing concrete that may, for example, be put into practice using one or more of the illustrated modalities of the system. System 100 With reference to Figure 1, a system 100 for curing a precast concrete product (P) is shown. System 100 includes a base 102, such as a floor, for example, a bottom seal 104 disposed on the base 102, and a top seal 106 coupled with a cover plate 108. The seals 104 and 106 can be rubber gaskets, seams, epoxy, O-rings, or any other suitable seal. The seals 104 and 106 can enclose the concrete product (P) like a sleeve, as shown by number 306 in Figure 5, for example. Such a sleeve-like concrete product (P) can cover up to approximately 20% of the height of the concrete product (P) in some configurations. Although such configurations can provide sealing advantages, other height percentages are also considered. In some forms, the lower seal 104 and / or the upper seal 106 may be omitted. In this embodiment, seals 104, 106, and cover plate 108 are annular to match and seal the corresponding portions of the concrete product (P), although other shapes and seals may be used, for example, when the concrete product (P) is of a different shape. In some embodiments, cover plate 108 is sized and / or its material is selected to provide a cover plate weight that balances the gas pressures that may be present within the concrete product (P) as described in this document.As will be described and shown in more detail below, in its various forms and applications / systems, the cover plate 108 may be weighted (e.g., to support the sealed concrete product (P) as described without requiring additional mechanical forces to be applied to the cover plate 108), and / or may be hinged and / or guided on one or more rods / supports, and / or may be automatically movable (e.g., by means of a suitable conventional electric drive mechanism). The base 102, seals 104, 106, and cover plate 108 are dimensioned to cover a cavity (C) in a precast concrete product (P) of at least one size.In some embodiments, seals 104, 106 and cover plate 108 are made large enough to enclose and cure, as described in detail below, any of a number of different sizes of precast concrete products (P) and / or cavities (C). System 100 further includes a carbon dioxide (CO2) source 110 that supplies CO2 into the cavity (C) of the precast concrete product (P), and a pressure gauge 112 mounted through the cover plate 108 to monitor the gas pressure in the cavity (C). As shown, in some embodiments, one or more suitable CO2 conduits 110P, such as pipes or ducts, are seamlessly connected to the carbon dioxide (CO2) source 110 to receive CO2 from it. The CO2 conduits 110P pass through the cover plate 108 to supply the CO2 into the cavity (C) of the precast concrete product (P) for curing. In other embodiments, the concrete product (P) may have a different shape. In some embodiments, the interface(s) between the CO2 110P conduits and the cover plate 108 may be sealed to be at least substantially gas-tight. In some embodiments, to facilitate movement of the cover plate 108 over a given concrete product (P), the CO2 110P conduits may be partially or fully flexible. In other embodiments, the CO2 110P conduits may be rigid and / or removable from the cover plate 108, such as by means of clamping connectors, to provide movement of the cover plate 108 at one outlet of each given concrete product (P). The carbon dioxide (CO2) source 110 can be any suitable carbon dioxide (CO2) source, such as a conventional carbon dioxide (CO2) source, and is therefore not described in detail herein. In some embodiments, the carbon dioxide (CO2) source 110 is configured to control the rate and pressure of the CO2 supplied into the cavity (C) in the precast concrete product (P). To this end, and as shown in Figure 1, the carbon dioxide (CO2) source 110 and / or one or more of the CO2 ducts 110P may include manually and / or actively controlled flow control valves 114. The flow control valves 114, and their associated controls, may be conventional and are therefore not described in detail herein. The cover plate 108 in this embodiment is made of a suitable metal and is sized to have sufficient weight to keep the cavity (C) in the precast concrete product (P) at least substantially sealed during the curing process. It is understood that the cover plate 108 may have different weights, depending on the pressure(s) at which the carbon dioxide (CO2) source 110 can be set to pressurize the cavity (C) in the precast concrete product (P) with CO2. That is, the weight of the cover plate 108 may be selected to sufficiently compress the seals 104 and 108 to keep the cavity (C) in the precast concrete product (P) at least substantially sealed during the curing process.In other modalities, seals 104, 108 and cover plate 108 may have a different shape, depending on the shape of the cavity (C) and the shape of the precast concrete product (P) to be sealed. System 200 Referring now to Figure 2A, a System 200 for curing a precast concrete product (P) is shown. System 200 is similar to System 100, and therefore the corresponding parts of System 200 are labelled with the same reference numbers used with respect to System 100. One difference between system 100 and system 200 is that system 200 includes a cover plate 108 that is mounted on a height control system 204. In this embodiment, the height control system 204 includes a vertically oriented support member 206, such as a steel rod, for example. The support member 206 is connected at its lower end 206A to the base 102 by a suitable connection, such as a sealed connection to prevent CO2 from escaping the cavity (C) through an interface between the support member 206 and the base 102. At its upper end 206B, once the cover plate 108 reaches the appropriate position, the support member 206 is connected to a center of the cover plate 108 by a translational assembly 208 received on the upper end 206B of the support member 206.In other embodiments, such as when the concrete product is molded to fit around the support member 206 by moving the product horizontally near and, in some embodiments, over the support member 206, the cover plate 108 may remain connected to the translation assembly 208 while the concrete product (P) is being positioned. In other embodiments, different configurations of the sealing mechanism may be used. For example, as shown in Figure 2B, the sealing mechanism may have a support member such as a frame that includes one or more rods 206' arranged at one or more distances from each other, selected to allow one or more concrete products (P) to move under the cover plate 108' while the cover plate 108' is movably / translationally connected to the one or more rods 206'.Once in position, the translation assembly 208', whether manual and / or automatic, can be operated to move the cover plate 108' into position to seal the interior(s) of the concrete product(s) (P). For this purpose, and as shown by a double-ended arrow in Figure 2B, the translation assembly 208' can be configured to move / translate up and down. In one embodiment, once the cover plate 108' seals the concrete product(s) (P), it can be secured in place by one or more suitable mechanisms, which may be automatic or manual (e.g., bolts / nuts). Figure 2B thus shows a different embodiment of a sealing mechanism, which can be connected to a CO2 source, such as the CO2 source in Figure 2A, and can therefore be part of system 200.Any number of sealing mechanisms can be used to cure multiple concrete products (P) in parallel. Any number of CO2 sources can be used for each concrete product (P) and / or sealing mechanism. The transfer assembly 208 can be screwed into a corresponding thread at the upper end 206B of the support member 206 and can be manually operated by rotating it about the support member 206 in one of two directions to transfer the cover plate 108 r / n / cn / 77n7 / q / uili upwards or downwards relative to the support member 206. It is envisaged that any other suitable construction of the transfer assembly 208 may be used, including, inter alia, an actively driven transfer assembly 208 that can be controlled by one or more suitable actuators, such as electric motors, which can be functionally connected to a suitable controller, such as a computer, for example. Since these details may be conventional, they are not described herein in detail.In other embodiments, the transfer assembly 208 may be a different type of transfer assembly, such as a hydraulic and / or electric transfer assembly that functions to provide the functionality of system 200 as described herein. System 300 Referring now to Figures 3 and 4, a System 300 for curing a precast concrete product (P) is shown. System 300 is similar to System 100, and therefore the corresponding parts of System 300 are labeled with the same reference numbers used with respect to System 100. One difference between System 100 and System 300 is that System 300 includes one or more frame members 302 that form a structure supporting the cover plate 306. The one or more frame members 302 can be arranged vertically and can optionally be connected to the base 102. Alternatively, the frame can be attached to or placed on the ground. In some embodiments, a single frame member 302 can form the frame 302F. The frame 302F in this embodiment is open on opposite sides of the precast concrete product (P), as shown in Figure 4, and therefore does not form a chamber above the precast concrete product (P). In other embodiments, the frame 302F may be different. The frame / support 302F may be larger than the concrete product (P) to accommodate it.The 302F frame / support can be made of steel, iron, stainless steel, FRP, plastic, or aluminum, although these are not exhaustive examples. It may not be necessary to cover the 302F frame / support and / or it may be manufactured using one or more layers of mesh. Another difference between system 100 and system 300 is that in system 300, the cover plate 306 is hinged, by means of one or more hinges 304, for example, to a top portion of the frame 302F so that it can move between a closed position 306C and an open position 3060 (shown by the dotted line in Figure 3). In this embodiment, and although this may not be the case in other embodiments, the cover plate 306 is rotatable about the hinge(s) 304 between the closed position 306C and the open position 3060. In the closed position 306C, the cover plate 306 encloses the cavity (C) in the precast concrete product (P) to allow a CO2 curing process to take place as described later herein. In the open position 3060, the cover plate 306 does not obstruct the top of the frame 302F sufficiently to allow the precast concrete product (P) to be inserted into the frame 302F for curing, and to allow the precast concrete product (P) to be removed from the frame 302F after curing. It is contemplated that any other movable connection, such as a translation joint, may be used in place of or in addition to the hinge 304. As shown in Figure 3, in this embodiment, one of the frame members (302) is threaded into an upper end of the frame and passes through a groove or opening in the cover plate (306) when the cover plate (306) is in the closed position (306C). A bolt and / or nut, and / or other fastener locks the cover plate 306 in the closed position 306C by being attached to the upper end of that frame member 302 and / or may be tightened to increase the compression of the upper seal(s) 106 by the cover plate 306. Any suitable fastener may be used. In some embodiments, the fastening may be omitted. With reference to Figure 4, as shown in this embodiment, the top seal 106 is annular and thinner than a wall of the precast concrete product (P). In at least some embodiments and applications, this helps improve the cavity casing (C) and the placement of the precast concrete product (P) in the 300 system. In some embodiments, the top seal 106 may have a different thickness and / or shape. Referring to Figure 5, in some embodiments, the cover plate 306 may have a different shape. An alternative example of the cover plate 306 is shown in the center drawing of Figure 5 and is labelled 306'. Still referring to Figure 5, in some embodiments, the base 102 may be separate from the floor on which at least part of the 300 system may be positioned, and may have different suitable shapes. An alternative example of the base 102 is shown in the right drawing of Figure 5 and is labelled 102'. In some embodiments, such as in the non-limiting alternative embodiment 102', for example, the lower seal(s) 104 may be part of the base 102' and / or may be omitted. System 400 Referring now to Figure 6, a System 400 for curing a precast concrete product (P) is shown. System 400 is similar to System 100, and therefore the corresponding parts of System 300 are labeled with the same reference numbers used with respect to System 100. One difference between System 100 and System 400 is that System 400 has a 402 base that includes a 402B base portion, which may be, for example, cast from concrete or otherwise made part of a floor (or, as another example, separate from the floor), and a 402P base plate disposed on the 402B base portion. In some embodiments, the 402P base plate may be an integral part of the 402B base portion and / or may be omitted. As shown, in these embodiments, the 104 bottom seal is an integral part of the 402P base plate, although this may not be the case in other embodiments. As shown, the CO2 110P conduits from the CO2110 source pass through the base portion 402B of the base 402 and are positioned to open into the cavity (C) of the precast concrete product (P) when the precast concrete product (P) is placed in the system 400, over the outlets of the CO2 110P conduits. In some embodiments, the system 400 can be configured to cure precast concrete products (P) that may have more than one cavity (C). In some of these embodiments, the system 400 may have one or more CO2110P conduits for each cavity (C) of the precast concrete products (P), such as, for example, more than two CO2110P conduits in total. Description of the deck plate: can be weighted, hinged, or rod-guided (top deck systems similar to 100, 200, and 300). System 500 Referring now to Figure 7, a System 500 for curing a precast concrete product (P) is shown. System 500 is similar to System 100, and therefore the corresponding parts of System 500 are labeled with the same reference numbers used with respect to System 100. One difference between System 100 and System 500 is that System 500 has one or more CO2110P conduits that pass through a wall of the precast concrete products (P), as shown. While in this configuration, System 500 has two CO2110P conduits, in other configurations, System 500 may have one or more CO2110P conduits with corresponding CO2110P conduits that pass through the wall(s) of the precast concrete products (P) to inject CO2 into the cavity (C) of these products during the curing process. In some embodiments, the 500 system may include an injection assembly 502 for each of the 110P CO2 conduits, which can help limit or prevent CO2 leakage from the cavity (C) during the curing process. Referring to Figure 7, three non-limiting examples of the 502 injection assembly are shown, labeled 502A, 502B, and 502C, respectively. The 502A injection assembly may include an epoxy or other suitable sealant 504 at the interface between the 110P CO2 conduit and the defined opening through the wall of the precast concrete product (P) that receives the 110P CO2 conduit. In some embodiments, the epoxy and / or other suitable sealant 504 may be injected at the interface, for example, although other installation methods may also be used. The injection assembly 502B may include a rubber plug 506 with one or more suitable openings defined therethrough, which may be attached to or inserted into the outer end of the CO2110P conduit and / or the interface between the CO2110P conduit and the opening defined through the wall of the precast concrete product (P) that receives the CO2110P conduit, as shown. The rubber plug 506 is an example of a sealing member 506 that may be used. Other sealing member(s) are also contemplated. For example, injection assembly 502C may include an expansion plug 508 with one or more suitable openings defined through it, which may be joined or inserted into the outside end of the CO2110P conduit and / or the interface between the CO2110P conduit and the opening defined through the wall of the precast concrete product (P) that receives the CO2110P conduit, as shown. Expansion plug 506 is another example of the sealing member 506 that may be used. Other sealing member(s) are also contemplated. System 600 etn 1 cn / zznz / q / υιλι Referring now to Figure 8, a System 600 for curing a precast concrete product (P) is shown. System 600 may use a base 102 and one or more seals 104 as previously described. However, in this embodiment, System 600 may have a cover plate 602 that is sized and / or made of selected material(s) to provide a cover plate 602 weight that balances the CO2-containing gas pressures that may be present within the concrete product (P). In other embodiments of System 600, the cover plate 602 may be, for example, hinged or guided on rods similar to the other embodiments described herein (e.g., similar to the top cover systems 100, 200, and / or 300). The CO2-containing gas in this embodiment may be supplied by one or more vessels 604 containing pressurized CO2-containing gas.In some embodiments, the container(s) 604 may be vehicle tires and / or inner tubes, as shown schematically in Figure 8. In some embodiments, to reduce waste, the container(s) 604 may utilize vehicle tires and / or inner tubes. The container(s) 604 may be retrofitted with one or more valves 606, such as conventional valves, which may be passive or actuated, configured to release gas to provide pressurization of the concrete product (P) as described herein. In some embodiments, one or more of the containers may be interconnected by one or more conduits 608 in order to reduce the number of valves 606 to less than one per container 608. In some embodiments, and although this may differ in other embodiments, the valve(s) 606 may be configured to provide an overall gas flow rate of less than 50.97 m³ / h (30 standard cubic feet per minute). This allows for a single 606 valve to serve multiple 604 vessels. In some configurations, the CO2-containing gas in the 604 vessel(s) can have a CO2 concentration between 5% and 99.5% by mass. In some configurations, the 604 vessels can be sized to occupy between 10% and 98% of the cavity (C) volume and can be positioned to avoid contact with the internal walls of the concrete product (P) that define the cavity (C). This can reduce the volume / content of CO2 required to fill the cavity (C) and allow it to fill with CO2 more quickly, as a smaller free volume of the cavity (C) is available. Furthermore, at the end of the carbonation process, less CO2 remains within the cavity (C). This results in a faster depletion process and less CO2 usage.The pressure built up between the concrete walls of the product (P) and the 604 vessel(s) allows the gas / CO2 to penetrate the concrete walls and react with the binder in the concrete walls in the presence of water, carbonating and thus increasing the strength of the product (P). In some applications, and depending on the use, the 604 vessel(s) can be refilled and reused for each new concrete product (P) to be carbonated using the 600 system, or they can be sized and / or pressurized to carbonate two or more concrete products (P) before requiring refilling. System 700 With reference now to Figure 9, yet another embodiment of a 700 system is shown. Similar to the 600 system, the 700 system includes the step of reducing the CO2-fillable volume of the cavity (C) with one or more objects 702. As shown, in some embodiments, the object(s) 702 may be a gas-containing balloon, i.e., an inflatable bag, inflatable plastic, or inflatable rubber placed inside the cavity (C) and may be inflated to occupy between 10% and 98% of the volume of the cavity (C), with objectives and results similar to those described with respect to the 600 system above. The filling gas can be air, nitrogen, carbon dioxide, oxygen, or any other gas. The gas-holding component 702 can be made of flexible materials such as plastic. The gas pressure inside component 702 can be greater than the CO2 pressure introduced into cavity (C). Furthermore, component 702 can be made of steel, iron, aluminum, or FRP. Components 702 can be reused for each new product (P) to be carbonated using system 700. System 800 With reference now to Figure 10, yet another embodiment of a system 800 is shown. Similar to system 700, system 800 includes the step of reducing the CO2-fillable volume of the cavity (C) with one or more objects 802. As shown, in some embodiments, the object(s) 802 may be a hollow collector, a chamber, a tube, and the like. System 900 With reference to Figure 11, yet another embodiment of a 900 system is shown. The 900 system includes an external jacket 902 arranged near the outer walls of the concrete product (P) and receiving CO2 from one or more CO2 sources 110. The jacket 902 must be made of steel, iron, aluminum, FRP, plastic, or any other suitable material. The jacket 902 may be made of impermeable materials that prevent the gas from escaping. Consequently, when introduced into the jacket 902, the CO2 is pressurized on the outer surfaces of the product walls (P) and thus penetrates the walls inward into the cavity (C), as shown by the arrows in Figure 11.The jacket 902 may be shaped to match the shape of the product (P) and at one end (e.g., the bottom) may be enclosed by the base 102 and the seal(s) 104, and at the top end may be enclosed / sealed by a cover plate 904. This cover plate may be implemented similarly to any of the embodiments described above, except that it may include an opening 906 positioned to be in fluid communication with the cavity (C). The opening 906 may allow CO2 to escape from the cavity (C) after passing through the walls of the product (P). In some embodiments, the opening 906 may be used to depressurize the cavity (C) to create a larger pressure differential across the walls of the product (P) and thus increase CO2 infiltration through the walls. In some cases, this may help accelerate the carbonation process.To depressurize the cavity (C) any suitable means may be used, such as one or more conventional fans, pumps, vacuum cleaners and the like. As an example, the 900 system can be used to perform a carbonation process whereby, after optional preconditioning of the product (P) as described in the present document, the product (P) is enclosed within the liner 902. The space between the product and the liner 902 can be more than 1 mm from all sides / edges. Carbon dioxide gas is introduced into the space between the product (P) and the liner 902. The concentration of injected carbon dioxide can be greater than 5%. In this way, the gas penetration into the concrete walls occurs unidirectionally inward into the cavity (C). The gas can be injected at a constant flow rate during the carbonation process or at a variable flow rate. In the case of a variable injection flow rate, the flow rate can be less than 50.97 m³ / h (30 standard cubic feet per minute) initially, and this can be gradually increased over time. The initial low flow rate can help reduce the porosity of the concrete product (P) without causing significant leakage. When calcium carbonates and other carbonation reaction products are generated and partially fill the pores in the concrete product (P), a higher carbon dioxide flow rate can be applied. This approach can help develop rapid early strength and can reduce significant leakage. The rate of accumulated CO2 pressure may depend on the gas injection rate, the volume of space between the 902 jacket and the product, the concrete mix ratio, the concrete permeability, porosity, concrete type, and product geometry. The carbonation reaction may be exothermic. Additional external heat / temperature may not be required for the carbonation curing process. The activation process may occur at ambient temperature and humidity. The pressure accumulated between the concrete walls and the 902 outer jacket may allow the gas to penetrate the concrete walls and enable the carbon dioxide to react with the binder in the presence of water. In this configuration, the reaction begins at the outer surface of the product (P). In some embodiments, the gas injection and carbonation curing process may continue for at least 5 minutes. Some of the gas within the space between the product (P) and the jacket (902) can travel through the concrete wall and escape from the inner layer of the product (P). At the end of the carbonation curing process, any remaining carbon dioxide within the space may be released before the product (P) is removed from system 900. In another configuration, the jacket 902 can be sized to fit within the cavity (C) to encompass the inner concrete walls of the product (P), allowing CO2 gas to penetrate from the inner to the outer layer of the product (P). Materials The concrete products (P) referred to in the descriptions of the various embodiments of systems 100 to 900 above may be manufactured from prior art concrete using any conventional method known in the prior art. In some embodiments, the concrete may include Portland cement or other hydraulic cements as the principal cementing material. The fresh concrete may be zero-flake concrete, wet concrete, or self-compacting concrete (SCC), for example. The concrete products may be dry-cast or wet-cast. In some applications, concrete can be produced with a slag-based binder. The primary binder in slag-based concrete production can be slag from steel mills and stainless steel plants. Other byproduct materials such as zinc, iron, copper, and sludge can also be used as binders. Various steel slags can be collected from steel mills that employ different steelmaking methods. Types of slag that can be incorporated as the primary binder in slag-based concrete production include: stainless steel slag, reducing steel slag, oxidizing steel slag, converter steel slag, electric arc furnace slag (EAF slag), basic oxygen furnace slag (BOF slag), ladle slag, rapid-cooling steel slag, and slow-cooling steel slag. The calcium oxide content of the slag may be greater than 10%, greater than 15%, and in some forms, greater than 20%. The silica oxide content may be greater than 6%, greater than 8%, and in some forms, greater than 12%. The total iron oxide content of the slag may be less than 40%, and in some forms, less than 30%. Steel slag may have a cumulative calcium silicate content of at least 20% and a free lime concentration of less than 10%. All the above values ​​are based on the mass / weight of the slag. In some forms, the apparent density of the slag may be within the range of 1.0 g / cm³ to 2.0 g / cm³, and its bulk density may vary from 2.0 g / cm³ to 6.0 g / cm³. Slag can be ground to a smaller size in some methods before being incorporated into the concrete mix. Slag grinding can be performed using any mechanical machine, such as a ball mill, rod mill, autogenous mill, SAG mill, pebble mill, high-pressure grinding roll, VSI, or tower mill. The grinding process can be carried out wet or dry. If a wet process is chosen for grinding the slag, the ground slag can be completely or semi-dried at the end of the grinding process. Passing the slag through sieves is an alternative option for obtaining smaller grain size slag. Slag passing through #10 mesh (2000 microns), #50 mesh (297 microns), #200 mesh (74 microns), and #400 mesh (37 microns) can be used as a binder. Sieves can be used to filter slag either before or after grinding.Therefore, one of, or a combination of, grinding and screening methods can be performed to obtain slag with a suitable particle size. In some embodiments, the slag may be pulverized and / or filtered to a Blaine fineness of at least 150 m² / kg and at least 200 m² / kg. In some embodiments, for the use of slag in slag-based concrete, fifty percent slag may be less than 200 mire (D50=200), less than 150 mire (D50=150), less than 100 mire (D50=100), less than 50 mire (D50=50), less than 25 mire (D50=25), and in some embodiments less than 10 mire (D50=10). In some embodiments, the free lime content of the slag may be reduced by any standard method known in the prior art before it is incorporated into the mix. In other methods, the slag may first be aged to reduce its calcium hydroxide content and then incorporated into the mix. The slag content may be no less than 5% of the concrete weight, and in some methods no less than 20% of the concrete weight. r ¡ n / cn / zznz / q / υιλι Various types of aggregates, including normal-weight and lightweight natural or artificial aggregates, can be incorporated into concrete as filler in the production of slag-based concrete. Examples of potential lightweight aggregates include natural lightweight aggregates (e.g., pumice), expanded clay aggregates, expanded shale aggregates, recycled plastic aggregates, and expanded iron slag aggregates. Other usable aggregates include crushed stone, manufactured sand, gravel, sand, recycled aggregate, granite, limestone, quartz, chalk dust, marble dust, quartz sand, and artificial aggregate. These aggregates can be incorporated into the mix as fine and / or coarse aggregates. The aggregate content can be as high as 90% of the concrete's weight. In some applications, mineral and chemical admixtures can be incorporated into the mix. Mineral admixtures may include fillers, supplemental cementitious materials, and pozzolanic materials. Possible mineral admixtures include one or a combination of fly ash, calcined shale, silica fume, zeolite, GGBF, limestone powder, hydraulic cement, and non-hydraulic cement. Chemical admixtures, meanwhile, can be incorporated into the mix to achieve specific properties. Possible chemical admixtures include, but are not limited to, accelerators, retarders, viscosity modifiers, air depositors, foaming agents, ASR inhibitors, antiwashers, corrosion inhibitors, shrinkage reducers, crack reducers, plasticizers, superplasticizers, water reducers, water repellents, efflorescence controls, and workability retainers.In some applications, fibers can be added to slag-based concrete. One or a combination of cellulose fiber, fiberglass, micro-synthetic fibers, natural fibers, PP fibers, PVA fibers, and steel fibers can be incorporated into the mix. Slag-based concrete products can be dry-cast or wet-cast concrete. Fresh slag-based concrete can be made as zero-flake concrete, wet-cast concrete, or self-compacting concrete (SCC). For example, in some forms, the water-to-slag ratio, by mass, of self-compacting concrete (SCC) can be greater than 0.2. In some forms, the water-to-slag ratio, by mass, of wet-cast concrete can be greater than 0.1. In some forms, the water-to-slag ratio, by mass, of dry-cast concrete can be less than 0.5. Mixing and production The concrete products (P) referred to in the descriptions of the various embodiments of systems 100 to 900 above can be produced using prior art mixing methods. In some embodiments, the concrete products (P) can be produced by uniformly mixing all the batch ingredients, which may include binders, aggregates, chemical admixtures, mineral admixtures, fibers, and water. For example, in one approach, the dry ingredients are mixed for at least 1 minute, then water and other liquid ingredients are added after mixing. In another approach, water can be added gradually during the mixing of the dry ingredients. The water content of wet-cast concrete and self-compacting concrete can be higher than that of dry-cast or zero-flake concrete if no water-reducing admixture is incorporated.Any existing method, technique, and equipment used in the state of the art to produce concrete products (P) can be implemented for the production of zero-flake concrete, wet concrete, conventional self-compacting / consolidating concrete, and slag-based concrete. Booster As shown in Figure 2A, for example, the concrete products (P) referred to in the description of the various embodiments of the 100-900 systems above can have a wall thickness of between approximately 1 mm and 350 mm, for example (although any other thickness can also be used) and can be optionally reinforced with reinforcing material (PR) such as carbon steel, stainless steel, and / or FRP reinforcing bars. In one embodiment, before casting a concrete product (P), the mold is prepared, and the reinforcing material, in some embodiments, is placed inside the mold before casting. In some embodiments, the diameter of the bars (PR) can vary from 1 mm to 100 mm, with a yield strength between 100 MPa and 2100 MPa, for example.In some applications, the reinforcement (PR) of a precast concrete product (P) may be designed in accordance with codes and standards applicable to a jurisdiction for which the precast concrete product (P) may be designed. These quantifications and specific characteristics are merely non-limiting examples. Casting and placement Fresh concrete can be molded into a suitable conventional mold using any method described in the preceding techniques. The fresh concrete may be zero-flake concrete (dry concrete), wet concrete, or self-compacting concrete. The mold, made of steel, iron, aluminum, plastic, or FRP, should be lubricated before pouring to facilitate demolding. Wet-cast concrete may be vibrated within the mold using internal or external vibrators, in some applications, for no more than 120 seconds. Dry-cast concrete may be formed by a combination of pressing / compacting and vibration. No internal or external vibration may be required for self-compacting concrete. The resulting concrete product may be either dry-cast or wet-cast concrete. Steel, FRP, or other types of concrete reinforcement may be installed within the mold before pouring to strengthen the concrete, for example. Preconditioning Before a given carbonation activation process, a concrete product (P) may undergo preconditioning. Preconditioning is optional and depends on the type of concrete (conventional or slag-based), the type of concrete product (dry-cast or wet-cast), and the mix proportions. Under certain conditions, preconditioning is not necessary. The preconditioning process reduces the water content of the concrete to a second water-to-binder ratio by weight before CO2 curing. In some applications, the preconditioning step can be performed before or after demolding. In the preconditioning of some demolded (DMP) concrete products, and depending on the methods and / or materials used to produce a given concrete product (DMP): after demolding, the concrete product (DMP) may begin to reduce its water content to generate additional voids within the concrete. The rate of evaporation of the demolded concrete depends on the temperature, relative humidity, initial water content, product surface area, and airflow if the mold is exposed to wind. In addition to natural evaporation, in a preferred embodiment, one or a combination of the following evaporation and / or heating equipment may be used to accelerate the rate of evaporation: heating elements, drum heaters, floor heating mats, fans, heaters, blowers, or fan heaters. Heating devices (e.g., heating elements / wires or floor heating mats or drum heaters) can be installed to cover the exterior or interior surfaces of the demolded concrete product (P). The elements heat the walls of the demolded concrete and can accelerate the evaporation process to reduce the moisture content of the concrete. Fans, heaters, fan heaters, and blowers can be placed inside the hollow demolded concrete product (P) (to reduce moisture content from the inside) or can be placed in front of the exterior surfaces (to reduce moisture content from the outside). These preconditioning steps may continue until the initial water-to-binder content, based on mass, is reduced to 95%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or 1%. The increase in porosity, defined in terms of volume, created within the demolded concrete by any of the above preconditioning methods is 90%, 60%, 50%, 40%, 30%, 20%, 10%, 5%, or 0.1% of the concrete volume. The water-to-binder ratio of the preconditioned concrete may be less than the initial water-to-binder ratio by weight. Preconditioning of concrete within the mold can occur before a given concrete product (P) is demolded. In this case, the concrete product (P) can be preconditioned and / or cured within the mold before demolding. For example, for wet-cast concrete and self-compacting concrete, it may be preferable for the concrete to be preconditioned and / or cured within the mold if preconditioning is required. The mold can be kept at room temperature and humidity, allowing free water to evaporate gradually. This can permit partial or complete hydration and setting of the binder. The rate of hydration and setting may depend on the type of binder, its chemical composition, and the concrete mix proportions. Fans, heaters, fan heaters, blowers, heating elements / wires, floor heating mats, or drum heaters can be used to accelerate the preconditioning and setting of the concrete while it remains in the mold. Alternatively, the concrete product (P) can remain in the mold to set completely or partially without implementing any of the preconditioning methods mentioned above. Another example is that part of the preconditioning step can occur inside the mold, and the remainder outside the mold. Demolding Concrete products (P) can be demolded immediately after casting or can be placed / preconditioned / hydrated within the mold, for example, up to 7 days before demolding. In another example, the concrete can be demolded immediately and subjected to carbonation curing right after casting. Demolding can be carried out in a given manner where the compressive strength of the concrete is at least 0.01 MPa. These quantifications and particular characteristics are only non-limiting examples. Curing / Carbonation Methods Taking into account the 100 to 900 systems described in this document, the methods for curing concrete products (P) are described below. A non-limiting example of the methods of the present technology, method 1000, is shown in Figure 13. In one particular embodiment of a method for curing a precast concrete product, the demolded concrete product is sealed from the bottom and top, or sides, such as by using the base(s) 102, cover plate(s) 108, seal(s) 104, 106, and / or injection assemblies 502 described above. As described above, in some embodiments, the sealing can be achieved by means of a rubber gasket 106, sealants 504, epoxy 504, an O-ring 106, or any other sealing method known in the prior art. This can limit or at least substantially prevent CO2 from escaping from the cavity (C) of the concrete product (P). In another example, the lower seal / sealer 104 can be placed inside the mold before pouring the concrete product (P) and the concrete product (P) can be cured according to one or more methods described herein while at least partially in the mold.In examples where only the weight of the cover plate 108 is used to seal the top of the concrete product (P), the cover plate 108 can apply pressure to the top seals 106 to ensure minimal CO2 leakage from the top end of the concrete product (P). The weight of the cover plate(s) 108 can be selected to avoid cracking or damaging the concrete product (P). The weight and thickness of the cover plate(s) 108 can be chosen to be greater than the force applied to hold the cover plate(s) 108 in place. In some embodiments, the thickness of the cover plate(s) 108 can be greater than 1 mm. In some embodiments, the cover plate(s) 108 can be made of steel, iron, stainless steel, FRP, plastic, or aluminum. Depending on which of the systems 100 to 900 described above is used, the cover plate(s) 108 may or may not be connected anywhere to the base 102 and can therefore simply rest on the concrete product (P) to cover the cavity (C).As seen previously, in some of these embodiments, the cover plate(s) 108 include at least one opening that connects to one or more CO2 sources 110 via one or more CO2 ducts 110P. In some embodiments, the diameter of each of these openings may range from approximately 1 mm to 500 mm. These quantifications and particular characteristics are merely non-limiting examples. CO2 can be introduced in pure form, or as part of a suitable gas, such as an inert gas, through openings in the cover plates 108 and / or via the CO2 ducts 110P. A non-limiting example is a CO2-containing gas that can be introduced into the cavity (C) to cure the optionally pre-conditioned concrete product (P), which can be introduced at room temperature at a concentration of, for example, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90% or 99.5% CO2 by mass. CO2 can be injected to fill the cavity (C) within the concrete product (P). In some embodiments, the CO2 can be injected to fill the cavity (C) at atmospheric pressure or at one or more pressures above atmospheric pressure. In some embodiments, the internal pressure can be monitored with the pressure gauge 112 installed on the cover plate(s) 108. As described above, in some embodiments, the internal pressure can be monitored and controlled by a controller and one or more flow control valves 114, using the pressure sensors 112 installed on the cover plate(s) 108. In some formulations, the concrete product (P) can be carbonated under CO2 gas for a period of between 5 and 15 minutes, depending on the CO2 concentration. In some formulations, the CO2 curing process can continue for up to 72 hours. These quantifications and specific characteristics are merely non-limiting examples. In some forms of concrete product (P), external energy or heat may not be required during the carbonation curing process. The CO2 activation process can be an exothermic reaction that increases the temperature of the concrete product (P). In some embodiments, the carbonation curing process can be carried out at atmospheric pressure, or under a constant carbon dioxide pressure, above atmospheric pressure, or under varying gas pressures during the activation process. In some embodiments, the carbonation curing process can be carried out at variable CO2 pressure. For example, in some embodiments, an initial CO2 pressure in the cavity (C) can be brought to between 0 kPa and 68,948 kPa (0 psig and 10 psig) for, for example, between 5 and 15 minutes, depending on the particular composition of the concrete product (P). The CO2 pressure in the cavity (C) can then be gradually increased over time to one or more higher pressures. Such initial low-pressure approaches can help reduce concrete porosity without causing significant leakage. In some cases, when calcium carbonates and other carbonation reaction products are generated and partially fill the pores in the concrete, a higher carbon dioxide pressure can be applied. This approach can help develop rapid early strength in the concrete product (P) and can help reduce leakage. In some embodiments, at each pressure increment, carbonation curing can continue for at least 5 minutes. This interval approach can help prevent carbon dioxide from escaping through the outer layer of the product and can also help protect the integrity of the concrete product (P) at early ages. In some embodiments, the CO2 / gas pressure in the cavity (C) can be reduced at the end of the carbonation activation process to minimize the amount of carbon dioxide remaining within the cavity (C) before the cavity (C) is opened. In some embodiments, the remaining gas can be vented to the atmosphere or recycled at the end of the curing process. In some embodiments, the recycling step(s) can be performed without reducing the gas pressure. The recycled gas can be used for the next batch production. The applied gas pressure in the cavity (C) can vary from atmospheric pressure to, for example, 689.48 kPa (100 psig), depending on the wall thickness, porosity, concrete maturity, concrete mix proportions, shape and ingredients of the concrete product (P), and / or the sealing methods used to seal the cavity (C). In some configurations, the cavity (C) may not be completely airtight. Some of the injected gas may leak from the ends of the product or may penetrate completely through the wall thickness and eventually escape from the outer layer of the concrete product (P). In some embodiments, once a target strength (and / or other target specifications, such as, for example, specified in the cured concrete product (P), the minimum standard requirement described in ASTM / ACI / CSA / NBC as applicable for one or more intended uses) of the concrete product (P) is achieved, the CO2 gas supply to the cavity (C) may be shut off, such as by means of the flow control valves 114 described above; the remaining gas in the cavity (C) may be recycled or simply vented to the atmosphere; the cavity (C) may be opened, such as by moving the cover plate(s) 108 to the open position 3060 as described above; the CO2 conduits 110P may be removed from the walls of the concrete product (P) (if any were inserted there as described above); and the cured concrete product (P) may then be removed from any system 100, 200, 300, 400, 500 that was used. In some embodiments where a system with a hinged and / or secured cover plate 108 is used, the hinge and / or securing mechanism may help reduce the effort required to operate the system and / or may help reduce the required weight of the cover plate 108, respectively. In embodiments where an automated lifting / moving / jacking system is not used to move the cover plate(s) 108 between the closed and open positions 306C, 3060, as described above with respect to system 200, the cover plate(s) 108 may be lifted or otherwise moved between the closed and open positions 306C, 3060 by means of a crane, forklift, or other suitable equipment. The same or similar suitable equipment may be used to remove the cured concrete product (P) from system 100, 200, 300, 400, 500. After removing the cured concrete product (P), the 100, 200, 300, 400, or 500 system can then be ready to receive a new precast concrete product (P) for curing using one or more of the methods described above. In methods where one or more CO2 110P conduits are inserted through the walls of the precast concrete product (P), after the precast concrete product (P) has cured / carbonated and the CO2 110P conduits are removed from the walls, the remaining openings in the concrete product (P) after curing can be filled with a suitable material, such as cement paste, grout, concrete, mortar, polymer, or epoxy. With reference now to Figure 14, yet another Method 1100 is shown for curing a concrete product (P) having a cavity (C) therein. Method 1100 may include placing at least one container (e.g., 604) containing pressurized carbon dioxide (CO2) gas in the cavity (C), sealing the cavity (C), introducing the CO2 into the cavity (C) from the at least one container to effect carbonation of the concrete product, and in response to the concrete product achieving a target strength (and / or other target specifications), opening the cavity (C). In some embodiments of Method 1100, the step of introducing CO2 into cavity (C) may include pressurizing cavity (C) to a first pressure for a first period of time, followed by increasing the pressure in cavity (C) to a second pressure for a second period of time. In some embodiments of Method 1100, the at least one container may include at least one inner tube and one tire. In some embodiments of Method 1100, the introduction of CO2 into cavity (C) may include operating at least one valve fluidly connected to at least one inner tube and one tire.In some embodiments of Method 1100, cavity sealing may be accomplished using a cover plate, such as a suitable cover plate described above, and may further comprise balancing the first and second pressures with the cover plate so that the cover plate continues to seal the opening during the presence of the first and second pressures. In some embodiments of Method 1100, Method 1100 may include casting and demolding the concrete product before cavity sealing, and the CO2 introduction step may be performed after and close to the demolding step. In some embodiments of Method 1100, the CO2 introduction step may be performed immediately after the demolding step. In some embodiments of Method 1100, Method 1100 may also comprise performing at least one of the setting, hydration, and preconditioning steps with respect to the concrete product before the CO2 introduction step. In some embodiments of Method 1100, Method 1100 may also comprise hydrating the concrete product after completing the CO2 introduction step. In some embodiments of Method 1100, Method 1100 may also comprise pressurizing the cavity to a predetermined CO2 pressure. In some embodiments of Method 1100, Method 1100 may also comprise varying the predetermined CO2 pressure. In some embodiments of Method 1100, the predetermined pressure may be at least atmospheric pressure. In some embodiments of Method 1100, Method 1100 may also comprise sizing at least one vessel to occupy between 10% and 98% of the cavity volume.In some variations of Method 1100, at least one of the inner tube and tire components can be reused (i.e., previously used products, thus reducing the environmental footprint of Method 1100). In some variations of Method 1100, the casting of the product (P) can be carried out as either dry or wet casting. In some variations of Method 1100, the introduction of CO2 can be achieved by introducing a CO2-containing gas at a concentration of between 5% and 99.5% CO2 by mass. With reference to Figure 11, a method 1200 is also provided for curing a concrete product (P), which may include enclosing an outer surface (OS) of the concrete product (P) in a sleeve 902 having a shape that fits at least in part, as shown in Figure 11, for example, to the outer surface (OS) of the concrete product (P), such that the sleeve 902 is disposed close, also as shown in Figure 11, to the outer surface (OS) to define a separation 908 between the outer surface (OS) and the sleeve 902, sealing the space 908 between the outer surface (OS) and the sleeve 902, and introducing CO2 into the space 908 between the outer surface (OS) and the sleeve 902 to carry out carbonation of the concrete product (P).As shown, in some embodiments, the CO2 introduction step may include at least some of the CO2 passing through the outer surface (OS) of the product in an inward direction (i.e., in a direction from the liner 902 into the concrete product (P)). In some embodiments of Method 1200, the method may also include, in response to the concrete product (P) achieving a target strength (and / or other target specifications), opening the space 908 between the outer surface (OS) and the liner 902, and, for example, removing the liner 902 from the concrete product (P) or removing the concrete product (P) from the liner 902, depending on the particular embodiment of System 900 used to carry out Method 1200. As shown in Figure 11, in some of these embodiments, the concrete product (P) includes a cavity (C) and an opening within that cavity (C), and the outer surface covering (OS) of the concrete product (P) excludes sealing the opening (O) in the cavity (C). Furthermore, as shown in Figure 11, in some of these embodiments, the outer surface covering (OS) of the concrete product (P) may leave the opening (O) open, for example, to facilitate the passage of CO2 through the walls of the concrete product (P). Moreover, in some of these embodiments, the introduction of CO2 into the space may be carried out through the sleeve 902.Furthermore, as shown in Figure 11, in some of these embodiments, sealing the gap 908 between the outer surface (OS) and the sleeve 902 includes placing a cover plate 904 over the concrete product (P). The cover plate 904 is functionally connected to the sleeve 902 at least during the CO2 introduction step, such as by being rotatably connected to it, for example, or as described in any of the preceding embodiments by way of further example. As shown in Figure 11, in some of these embodiments, the cover plate 904 may include an opening 904' therein, and the opening 904' may be at least partially aligned with the opening (O) in the cavity (C) of the concrete product (P) when the cover plate 904 is placed over the concrete product (P). The systems and methods described herein may be used to produce concrete products (P) that meet at least the minimum standard requirements described in ASTM / ACI / CSA / NBC. These systems and methods may also be used to produce concrete products (P) manufactured using one or a combination of hydraulic cement, non-hydraulic cement, slag, pozzolanic materials, fly ash, silica fume, and calcium hydroxide as a binder. The foregoing description is intended to be merely illustrative, and a person skilled in the art will recognize that changes may be made to the described methods without departing from the scope of this technology. For example, a particular system for curing a precast concrete product (P) may have a combination of at least some of the features of one or more of the methods mentioned above.Still other modifications that lie within the scope of the present technology will be evident to experts in the field, in light of a review of this description.

Claims

CLAIMS 1. A method for curing a concrete product having a cavity within the concrete product and an opening in the cavity, wherein the method comprises: placing the concrete product on a base; sealing the opening using a cover plate; introducing carbon dioxide (CO2) gas into the cavity to effect carbonation of the concrete product; and in response to the concrete product achieving a target specification, opening the opening.

2. The method according to claim 1, wherein the introduction of CO2 gas into the cavity includes pressurizing the cavity to a first pressure for a first period of time, followed by increasing the pressure in the cavity to a second pressure for a second period of time.

3. The method according to claim 1 or 2, wherein it further comprises introducing the CO2 gas through the cover plate and / or the concrete product.

4. The method according to any one of claims 1 to 3, wherein the opening is one of an open upper end of the concrete product and one open lower end of the concrete product, and the positioning further comprises placing the other open upper end and the open lower end on the base to seal the other open upper end and the open lower end.

5. The method according to claim 2, wherein it further comprises balancing the first and second pressures with the cover plate so that the cover plate continues to seal the opening during the presence of the first and second pressures.

6. The method according to any of claims 1 to 5, wherein it further comprises pouring and demolding the concrete product before placing the concrete product, and wherein the steps of positioning the concrete product and introducing the CO2 gas are carried out after and close in time to the demolding step.

7. The method according to any of claims 1 to 5, wherein the steps of positioning the concrete product and introducing the CO2 are carried out immediately after the demolding step.

8. The method according to any of claims 1 to 7, wherein it further comprises performing at least one of the setting, hydration and preconditioning steps with respect to the specific product before the CO2 introduction step.

9. The method according to any of claims 1 to 8, wherein it further comprises hydrating the concrete product after completing the CO2 gas introduction step.

10. The method according to any of claims 1 to 9, wherein it further comprises pressurizing the cavity to a predetermined CO2 gas pressure.

11. The method according to claim 10, wherein it further comprises varying the predetermined pressure of the CO2 gas.

12. The method according to any of claims 1 to 11, wherein it further comprises sealing the opening so as to allow at least some of the CO2 gas to escape from the cavity during carbonation of the concrete product.

13. The method according to claim 6, wherein the casting is carried out using one or a combination of zero-flake concrete, wet concrete, self-compacting concrete, Portland cement, and slag.

14. The method according to claim 6, wherein the casting is carried out as a dry casting and a wet casting.

15. The method according to any of claims 1 to 14, wherein the introduction of the CO2 gas is carried out by introducing a gas containing CO2 at a concentration of between 5% and 99.5% CO2 by mass.

16. A system for curing a precast concrete product having a cavity therein, the cavity having a lower end and an upper end that are open, the system comprising: a base dimensioned to receive the precast concrete product therein and to cover the lower end of the cavity; a cover plate dimensioned to be received on top of the precast concrete product and to cover the upper end of the cavity; a carbon dioxide (CO2) gas source; and a CO2 conduit fluidly connected to the CO2 source and configured to fluidly connect to the cavity.

17. The system according to claim 16, wherein it further comprises a height control system connected between the base and the cover plate and capable of moving the cover plate between a closed position in which the cover plate covers the upper end of the cavity and an open position.

18. The system according to claim 16 or 17, wherein it further comprises a structure connected between the base and the cover plate, the cover plate being hinged to the structure to move between a closed position in which the cover plate covers the upper end of the cavity, and an open position.

19. The system according to any of claims 16 to 18, wherein the CO2 conduit is fluidly connected to the cavity through one or more of the cover plate, a wall of the precast concrete product and the base; and the CO2 gas source is configured to pressurize the cavity to at least two different pressures that are at least equal to atmospheric pressure.

20. The system according to any of claims 16 to 19, wherein a flow control valve is arranged in fluid flow communication with the CO2 source, the flow control valve being configured to control a velocity and / or a pressure of the CO2 gas q 1 n / cn / 77n7 / q / uili 28 supplied in the cavity.

21. A method for curing a concrete product having a cavity therein, wherein the method comprises: sealing the cavity; carrying out carbonation of the concrete product by introducing carbon dioxide (CO2) gas into the sealed cavity; and in response to the concrete product achieving a target specification, opening the cavity.

22. The method according to claim 21, wherein further comprising placing at least one container in the cavity before sealing the cavity, the at least one container containing the CO2 gas pressurized therein, and wherein introducing the CO2 gas into the cavity includes releasing the CO2 gas into the cavity from the at least one container.

23. The method according to claim 21 or 22, wherein the introduction of CO2 gas into the cavity includes pressurizing the cavity to a first pressure for a first period of time, followed by increasing the pressure in the cavity to a second pressure for a second period of time.

24. The method according to claim 22 or 23, wherein the at least one container includes at least one air chamber and one tire, and introducing CO2 gas into the cavity includes operating at least one valve fluidly connected to at least one of the air chamber and the tire.

25. The method according to any of claims 21 to 24, wherein sealing the cavity further comprises using a cover plate that is one or more of: weighted to balance a CO2 gas pressure, hinged to a member disposed near the concrete product, and guided with respect to the member.

26. The method according to any of claims 21 to 25, wherein it further comprises pouring and demolding the concrete product before sealing the cavity, and wherein the step of introducing the CO2 gas is carried out after and close in time to the demolding step.

27. The method according to claim 26, wherein the CO2 gas introduction step is carried out immediately after the demolding step.

28. The method according to any of claims 21 to 27, wherein it further comprises performing at least one of the setting, hydration and preconditioning steps with respect to the concrete product before introducing the CO2 gas.

29. The method according to any of claims 21 to 28, wherein it further comprises hydrating the concrete product after completing the CO2 gas introduction step.

30. The method according to any of claims 21 to 29, wherein it further comprises dimensioning at least one container to occupy between 10% and 98% of a cavity volume.

31. A method for curing a concrete product, wherein the method comprises: enclosing an outer surface of the concrete product in a sleeve having a shape that conforms at least partially to the outer surface of the concrete product, such that the sleeve is disposed near, but separate from, the outer surface to define a space between the outer surface and the sleeve; sealing the space between the outer surface and the sleeve; introducing carbon dioxide (CO2) gas into the space between the outer surface and the sleeve to effect carbonation of the concrete product, wherein at least some of the CO2 gas passes through the outer surface of the product in an inward direction; and in response to the concrete product achieving a target specification, opening the space between the outer surface and the sleeve.

32. The method according to claim 31, wherein the concrete product includes a cavity therein and an opening in the cavity, and enclosing the outer surface of the concrete product excludes sealing the opening.

33. The method according to claim 32, wherein enclosing the outer surface of the concrete product leaves the opening open.

34. The method according to any of claims 31 to 33, wherein the introduction of CO2 gas into the space is carried out through the jacket.

35. The method according to any of claims 31 to 34, wherein sealing the gap between the outer surface of the concrete product and the sleeve includes placing a cover plate over the concrete product, the cover plate being functionally connected to the sleeve at least during the CO2 gas introduction step by being one or more of: weighted to balance a CO2 pressure; hinged to the sleeve; and guided with respect to the sleeve.

36. The method according to claim 35, wherein the cover plate includes an opening therein, the opening being at least partially aligned with the opening in the cavity of the concrete product when the cover plate is disposed over the concrete product.

37. A system for curing a precast concrete product having a cavity therein, the cavity having a lower end and an upper end that are open, the system comprising: a base dimensioned to receive the precast concrete product therein and to cover the lower end of the cavity; a sleeve dimensioned to encompass the concrete product therein, the sleeve having a lower end that is disposed and sealed with respect to the base; a cover plate dimensioned to be received on top of the precast concrete product and to cover the upper end of the cavity, the cover plate being functionally connected to the sleeve to seal a gap between the sleeve and an outer surface of the concrete product and thereby seal the gap; and a carbon dioxide (CO2) gas source fluidly connected to the separation.

38. The system according to claim 37, wherein the CO2 gas source is fluidly connected to the separation by means of at least one of the jacket and cover plate.

39. The system according to claim 37 or 38, wherein the cover plate is hinged to the sleeve to be rotatable between an open position in which the concrete product can be moved in and out of the sleeve and a closed position in which the cover plate seals the space between the concrete product and the sleeve.

40. The system according to any of claims 37 to 39, wherein the COa gas source is configured to pressurize the cavity to at least two different pressures that are at least equal to atmospheric pressure.

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