METHOD FOR MANUFACTURING SUBGRADE UTILITY VAULTS, LIDS AND TRENCHES USING RECYCLED POLYSTYRENE

Abstract

Methods, compositions, and apparatuses are provided herein that utilize polystyrene from recycled products to make a high strength composite concrete that can be used for subgrade utility vaults, utility trenches, etc. Polystyrene is a widely-used plastic that can be collected and then densified at particular parameters including temperature to transform the polystyrene to a usable form. Then, the densified polystyrene is combined with other resin materials and dry materials to form a high-strength concrete material. The amount of densified polystyrene that is combined with the other materials is critical to control shrinkage and expansion of the concrete material during manufacturing.

Claims

1. A method of manufacturing high-strength concrete with recycled polystyrene, comprising: collecting polystyrene from recycled products; densifying said polystyrene at an elevated temperature between approximately 140° C. to 160° C. to melt said polystyrene and to increase a density of said polystyrene; mixing said densified polystyrene with a monomer material and at least one other resin material to form a resin component, wherein said densified polystyrene comprises between approximately 3% to 7% of a weight of said resin component; and mixing said resin component with a dry component to form a high-strength concrete.

2. The method of claim 1, wherein said elevated temperature is approximately 150° C.

3. The method of claim 1, wherein said densified polystyrene comprises approximately 5% of said weight of said resin component.

4. The method of claim 1, wherein said dry component comprises an aggregate material and a sand material, and said aggregate material is between approximately 60% to 80% of a weight of said dry component.

5. The method of claim 1, wherein said dry component comprises an aggregate material and a sand material, and said sand material is between approximately 20% to 40% of a weight of said dry component.

6. The method of claim 1, further comprising shredding said recycled polystyrene from a first average particle size to a smaller second average particle size.

7. The method of claim 1, further comprising grinding said densified polystyrene into flour with an average particle size of between approximately 0.15 mm to 1.0 mm.

8. A method of manufacturing a high-strength concrete product with recycled polystyrene, comprising: densifying recycled polystyrene at an elevated temperature to melt said polystyrene and to increase a density of said polystyrene; mixing said densified polystyrene, a monomer material, and at least one other resin material in a hopper to form a resin component; mixing an aggregate material and a sand material to form a dry component; mixing said resin component and said dry component in a turbine mixer to form a concrete material; and pressing said concrete material in a mold to produce a high-strength concrete product.

9. The method of claim 8, further comprising mixing said densified polystyrene, said monomer material, and said at least one other resin material in said hopper for approximately 45 seconds.

10. The method of claim 8, further comprising mixing a polymerization catalyst and a coupling agent into said resin component in said hopper for at least 60 seconds.

11. The method of claim 10, wherein said polymerization catalyst is a peroxide material, and said coupling agent is a silane material.

12. The method of claim 8, further comprising transferring said concrete material from said turbine mixer to said mold in a container.

13. The method of claim 8, further comprising inducing a vibration in said mold as said concrete material is pressed in said mold.

14. The method of claim 8, wherein said elevated temperature is approximately 150° C., said densified polystyrene comprises between approximately 5% of a weight of said resin component, and said aggregate material is between approximately 60% to 80% of a weight of said dry component.

15. A high-strength concrete structure made in part from recycled products, comprising: a resin component having a densified polystyrene, a monomer material, and at least one other resin material, wherein said densified polystyrene comprises between approximately 3% to 7% of a weight of said resin component, and wherein said monomer material comprises between approximately 40% to 50% of said weight of said resin component; and a dry component having an aggregate material and a sand material, wherein a weight of said aggregate material is between approximately 60% to 80% of a weight of said dry component, wherein said resin component and said dry component are combined to form a concrete material used to product said high-strength concrete structure.

16. The concrete structure of claim 15, wherein at least one sidewall and a bottom portion of said concrete structure form at least one of a subgrade utility vault or a utility trench.

17. The concrete structure of claim 16, further comprising a lid made from a material that is distinct from said high-strength concrete material, wherein said lid at least partially defines a partially enclosed space with said at least one sidewall and said bottom portion.

18. The concrete structure of claim 15, wherein said at least one other resin material is a silane material that is between approximately 40% to 55% of said weight of said resin component.

19. The concrete structure of claim 15, wherein said monomer material is a styrene monomer that is between approximately 40% to 50% of said weight of said resin component.

20. The concrete structure of claim 15, further comprising a pigment material that is mixed with said resin component and said dry component to change a color of said concrete material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosure and together with the Summary given above and the Detailed Description of the drawings given below, serve to explain the principles of these embodiments. In certain instances, details that are not necessary for an understanding of the disclosure or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the disclosure is not necessarily limited to the particular embodiments illustrated herein. Additionally, it should be understood that the drawings are not necessarily to scale.

[0035] FIG. 1 is a flowchart showing the collection and densification of recycled polystyrene in accordance with an embodiment of the present disclosure;

[0036] FIG. 2 is a graph showing the contraction characteristics of a concrete material based on the relative amount of polystyrene in a resin component of the concrete material in accordance with an embodiment of the present disclosure;

[0037] FIG. 3 is a side elevation view of components of a batching system in accordance with an embodiment of the present disclosure;

[0038] FIG. 4 is a flowchart showing an exemplary batching process in accordance with an embodiment of the present disclosure;

[0039] FIG. 5A is a perspective view of a mold in an initial state in accordance with an embodiment of the present disclosure; and

[0040] FIG. 5B is a perspective view of the mold in FIG. 5B in a final state in accordance with an embodiment of the present disclosure.

[0041] Similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a letter that distinguishes among the similar components. If only the first reference label is used, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

[0042] A list of the various components shown in the drawings and associated numbering is provided herein:

[0043] Component No. Component

[0044] 10 Collecting Polystyrene

[0045] 12 Densifying Polystyrene

[0046] 14 Grinding Polystyrene

[0047] 16 Mixing Polystyrene

[0048] 18 Batching System

[0049] 20 Resin Mixer

[0050] 22 Resin Hopper

[0051] 24 Dry Scale

[0052] 26 Turbine Mixer

[0053] 28 Releasing Dry Component

[0054] 30 Mixing Resin Component

[0055] 32 Releasing Pigment Material

[0056] 34 Mixing Components

[0057] 36 Transferring to Mold

[0058] 38 Pressing Concrete Material

[0059] 40 Mold

[0060] 42 Upper Portion

[0061] 44 Concrete Material

[0062] 46 Final Concrete Product

DETAILED DESCRIPTION

[0063] The present disclosure has significant benefits across a broad spectrum of endeavors. It is the Applicant's intent that this specification and the claims appended hereto be accorded a breadth in keeping with the scope and spirit of the disclosure being disclosed despite what might appear to be limiting language imposed by the requirements of referring to the specific examples disclosed. To acquaint persons skilled in the pertinent arts most closely related to the present disclosure, a preferred embodiment that illustrates the best mode now contemplated for putting the disclosure into practice is described herein by, and with reference to, the annexed drawings that form a part of the specification. The exemplary embodiment is described in detail without attempting to describe all of the various forms and modifications in which the disclosure might be embodied. As such, the embodiments described herein are illustrative, and as will become apparent to those skilled in the arts, may be modified in numerous ways within the scope and spirit of the disclosure.

[0064] Although the following text sets forth a detailed description of numerous different embodiments, it should be understood that the detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims. To the extent that any term recited in the claims at the end of this patent is referred to in this patent in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term by limited, by implication or otherwise, to that single meaning.

[0065] Various embodiments of the present disclosure are described herein and as depicted in the drawings. It is expressly understood that although the figures depict the inclusion of recycled polystyrene in a high-strength concrete and related methods and systems, the present disclosure is not limited to these embodiments. Now referring to FIG. 1, a flowchart showing the collection and densification of recycled polystyrene is provided. As noted above, polystyrene is widely used, and can be collected 10 from a variety of sources. Polystyrene can be recovered from protective packaging, containers, lids, bottles, trays, tumblers, disposable cutlery, models, etc. These polystyrene products can be processed 11 in a number of ways. The polystyrene products can be sterilized if the products were used for food or in other ways that could potentially contaminate the polystyrene. The polystyrene products can be segregated based on characteristics such as density, color, etc. Further still, the polystyrene products can have different sizes, and therefore the polystyrene products can be shredded to standardize the sizes of individual pieces of the polystyrene.

[0066] Next, the recycled polystyrene is densified 12 at an elevated temperature to increase the density of the recycled polystyrene for use in a structural application like high-strength concrete. In addition, the densification process can remove undesirable impurities such as butane and pentane. However, if the densification process is conducted at too high of a temperature, the molecular chains of the polystyrene can break and reduce the strength of the polystyrene. Thus, there is a critical temperature or range of temperatures at which to conduct the densification process in the present disclosure. In some embodiments, the recycled polystyrene is densified at a temperature between approximately 140° C. to 160° C. In various embodiments, the recycled polystyrene is densified at a temperature of approximately 150° C. The recycled polystyrene is densified for an amount of time that is sufficient to melt all or substantially all of the recycled polystyrene. Stirring, agitating, or shaking can assist in evenly melting and heating the recycled polystyrene.

[0067] Once the recycled polystyrene is densified, the densified polystyrene is ground 14 into smaller pieces for further processing. In some embodiments, the densified polystyrene is completely ground into flour for use in a batching process, which is described in further detail below. However, it will be appreciated that the present disclosure encompasses embodiments where the densified polystyrene is simply cut or shredded into smaller pieces or not further ground or sized at all. In one embodiment, the average particle or piece size of the ground, densified polystyrene is approximately 0.25 mm, and the density of the densified polystyrene is approximately 400 kg/m.sup.3. It will be appreciated that in some embodiments, the average particle or piece size is between approximately 0.15 mm to 1.0 mm, in some embodiments 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, and 1.0 mm, or a range or value between two of these values, and the density of the densified polystyrene is between approximately 350 kg/m.sup.3 and 450 kg/m.sup.3, in some embodiments 350 kg/m.sup.3, 375 kg/m.sup.3, 400 kg/m.sup.3, 425 kg/m.sup.3, and 450 kg/m.sup.3, or a range or value between two of these values.

[0068] Next, the densified polystyrene is mixed 16 with a monomer material and at least one other resin material to form a resin component. The monomer material promotes the polymerization of the densified polystyrene and adds flexibility to the resin component. The monomer material can be, for example, a styrene monomer or a methyl methacrylate monomer. The styrene monomer has a chemical formula of C.sub.8H.sub.8 and molecular weight of 104.1 g/mol. The methyl methacrylate monomer has a chemical formula of C.sub.5H.sub.8O.sub.2 and a molecular weight of 100.12 g/mol. The additional resin material can be, for example, a silane coupling agent that adds flexural and tensile strength to the resin component and concrete. The silane material can be the reaction product of vinylbenzyl chloride and ethylene diaminopropyltri-methoxysilane. Once the resin component is prepared, the resin component is mixed with a dry component to form a high-strength concrete.

[0069] Now referring to FIG. 2, a graph showing the contraction characteristics of a concrete material based on the relative amount of densified polystyrene in the resin component is provided. The relative amounts and composition of the resin component is critical to producing the desired characteristics of the resulting concrete material as well as the contraction during a molding process. As described above, a small amount of contraction is desirable to help remove the concrete from a mold, but too much contraction will warp the outer surface of the concrete and expansion will lodge the concrete in the mold and potentially damage the mold. In some embodiments, the densified polystyrene comprises between approximately 3% to 7% of a weight of the resin component. In various embodiments, the densified polystyrene comprises approximately 5% of a weight of the resin component. In further embodiments, the polystyrene comprises greater than approximately 0% and less than approximately 9% of a weight of the resin component to achieve the desired contraction in the concrete material, in some embodiments 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, and 9%, or a range or value between two of these values.

[0070] Next, relative amounts of the monomer material and the additional resin component in the resin component are also critical to ensure the proper polymerization of the densified polystyrene as well as the proper material properties and characteristics of the resulting concrete. In some embodiments, the monomer material can be between approximately 40% to 50% of a weight of the resin component, in some embodiments 40%, 42%, 45%, 47%, and 50%, or a range or value between two of these values. In various embodiments, the monomer material can be between approximately 43.6% and 49.1% of a weight of the resin component, in some embodiments 43%, 43.6%, 44%, 45%, 46%, 46%, 48%, 49.1%, and 50% or a range or value between two of these values. Similarly, in some embodiments, the additional resin material is between approximately 40% to 55% of a weight of the resin component, in some embodiments 40%, 45%, 50%, and 55%, or a range or value between two of these values. In various embodiments, the additional resin material is between approximately 45.2% to 51.0% of a weight of the resin component, in some embodiments 45%, 45.2%, 46%, 47%, 48%, 49%, 50%, and 51.0%, or a range or value between two of these values.

[0071] Various embodiments of the resin component can have differing amounts of the constituent materials within the above ranges. Table I shows the relative amounts, by weight, of densified polystyrene versus the contraction of the resulting concrete for the different embodiments, and this comparison is presented in FIG. 2. The more densified polystyrene percentage by weight, the less contraction, and after a certain point, the resulting concrete begins to expand when pressed in a mold. It will be appreciated that the present disclosure is not limited to these embodiments.

TABLE-US-00001 TABLE I Relative amounts of materials of the resin component, by weight, and contraction of the resulting concrete material. Note that all embodiments have more resin material than monomer material. First Second Third Fourth Fifth Sixth Seventh Eighth Material Emb. Emb. Emb. Emb. Emb. Emb. Emb. Emb. Resin 48.41% 50.93% 49.98% 49.04% 48.10% 47.15% 46.21% 45.27% Material Monomer 46.65% 49.07% 48.16% 47.26% 46.35% 45.44% 44.53% 43.62% Material Densified 4.94% 0.00% 1.85% 3.70% 5.56% 7.41% 9.26% 11.11% Polystyrene Contraction −0.097% −2.02% −1.60% −0.36% −0.09% −0.008% 0.005% 0.080%

[0072] As described elsewhere herein, the resin component is mixed with a dry component to form the high-strength concrete, and the dry component can be made from constituent materials in specific proportions that ensure proper mixing with the resin component and resulting material properties of the high-strength concrete. In some embodiments, an aggregate material is between approximately 60% to 80% of a weight of the dry component. In various embodiments, a sand material is between approximately 20% to 40% of a weight of the dry component. Table II is presented below to show the different amounts of the materials used to make the high-strength concrete where the amounts are within the above ranges. The embodiments in Table II correspond to the embodiments in Table I and, again, the present disclosure is not limited to these embodiments. Moreover, while absolute values are presented in Table II, the relative amounts between the various materials can be established to produce more or less concrete in a batch or to product concrete in a continuous manner. The catalyst can be Norox® (Di(4-tert.butylcyclohexyl)peroxydicarbonate) in some embodiments, and the BPO or benzoyl peroxide ((BzO).sub.2) can be used to aerate the concrete material.

TABLE-US-00002 TABLE II Amounts of materials of the resin component and dry component. First Second Third Fourth Fifth Sixth Seventh Eighth Material Emb. Emb. Emb. Emb. Emb. Emb. Emb. Emb. Resin 130.71 g 137.50 g 134.96 g 132.41 g 129.86 g 127.32 g 124.77 g 122.22 g Material Monomer 125.95 g 132.50 g 130.04 g 127.59 g 125.14 g 122.68 g 120.23 g 117.78 g Material Densified 13.34 g 0.00 g 5.00 g 10.00 g 15.00 g 20.00 g 25.00 g 30.00 g Polystyrene Aggregate 450 g 450 g 450 g 450 g 450 g 450 g 450 g 450 g Material Sand 200 g 200 g 200 g 200 g 200 g 200 g 200 g 200 g Material Catalyst 0.48 g 0.50 g 0.49 g 0.49 g 0.48 g 0.47 g 0.46 g 0.45 g Benzoyl 1.14 g 1.20 g 1.18 g 1.17 g 1.14 g 1.12 g 1.09 g 1.08 g Peroxide

[0073] Now referring to FIG. 3, a side elevation view of components of a batching system 18 is provided. The batching system 18 has a resin hopper 22 with a resin mixer 20 that can include one or more blades to physically mix or churn different constituent materials of the resin component, and the resin hopper 22 holds the resin component prior to combination with a dry component. A dry scale 24 can collect the constituent materials of the dry component, and in some embodiments, the dry scale 24 can simply weigh the materials prior to release into a turbine mixer 26. The turbine mixer 26 is positioned below the resin hopper 22 and the dry scale 24, and the turbine mixer 26 can have at least one blade to mix the resin and dry components together. However, it will be appreciated that the present disclosure encompasses other systems to mix resin and dry components as well as other processes than the batching process described below.

[0074] Now referring to FIG. 4, a flowchart of an exemplary batching process 28 is provided. Each action can be performed automatically or manually, and the actions can be performed in any order, in series, or in parallel. First, the constituent materials of the dry component are weighed in the dry scale and released 28 into the turbine mixer. An aggregate material is released into the turbine mixer, which turns three rotations. This action can take approximately 2 minutes. Next, a sand material is moved into the dry scale via a conveyor and released into the turbine mixer, which turns three rotations. This action can take approximately 2 minutes. Finally, a silica granular or powder material is moved into the dry scale via one or more augers and released into the turbine mixer, which turns in multiple rotations to advance the material from one position to another. This action can take approximately 1.5 minutes.

[0075] The constituent materials of the resin component are mixed 30 in the resin hopper. To begin, the monomer material is poured into the resin hopper and the resin mixer begins to turn. This action can take approximately 1 minute. Next, the densified polystyrene is moved via a venturi tube into the resin hopper. The resin mixer is turned off for the last pound of the densified polystyrene, and then the resin mixer is restarted. This action can take approximately 7 minutes. Then, the resin material is moved into the resin hopper with the resin mixer still turning its one or more blades to mix the different materials together. This action can take approximately 1 minute. Various other materials are added to the resin hopper while the resin mixer is still turning. A silane coupling agent such as XIAMETER™ OFS-6032 Silane, a catalyst (e.g., Perkadox LW75 or dibenzoyl peroxide), another catalyst (e.g., Norox 600 CL2 or di(4-tert.butylcyclohexyl)peroxydicarbonate), and/or hydroquinone can be added to the resin hopper. This action can take approximately 2 minutes.

[0076] A pigment material or materials can be released 32 into the turbine mixer to add color to the final concrete product. Next, the resin component is released 34 into the turbine mixer to mix with the pigment material and the dry component for approximately 45 seconds. Then, the concrete material is released from the turbine mixer into a hopper or other container where the concrete material is transferred 36 to a mold.

[0077] The concrete material is poured into a mold, and a motor can vibrate the mold and remove air from the concrete material. Then, an upper portion of the mold presses 38 on the concrete material in the mold with a force that can be constant, varying, etc. The motor can still induce a vibration while the upper portion presses with the force. Then, the motor stops vibrating, and the upper portion continues to apply the force for approximately 8 minutes. The upper portion moves away, and the concrete product is removed from the mold. The concrete product, such as a subgrade utility vault, utility trench, etc., is inspected and the mold is cleaned for the next batch of concrete material.

[0078] Now referring to FIGS. 5A and 5B, a mold 40 is provided in an initial state and a final state, respectively. In FIG. 5A, the concrete material 44 is poured into the mold 40, and an upper portion 42 of the mold 40 descends and imposes a force on the concrete material 44. Then, as shown in FIG. 5B, the result is a concrete product 46 that is lightweight and incorporates recycled polystyrene.

[0079] The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limiting of the disclosure to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments described and shown in the figures were chosen and described in order to best explain the principles of the disclosure, the practical application, and to enable those of ordinary skill in the art to understand the disclosure.

[0080] While various embodiments of the present disclosure have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. Moreover, references made herein to “the present disclosure” or aspects thereof should be understood to mean certain embodiments of the present disclosure and should not necessarily be construed as limiting all embodiments to a particular description. It is to be expressly understood that such modifications and alterations are within the scope and spirit of the present disclosure, as set forth in the following claims.

[0081] Any one or more aspects described herein can be combined with any other one or more aspects described herein. Any one or more features described herein can be combined with any other one or more features described herein. Any one or more embodiments described herein can be combined with any other one or more embodiments described herein.