WO2024119215A1

WO2024119215A1 - Improved polymer concrete material

Info

Publication number: WO2024119215A1
Application number: PCT/AU2022/051457
Authority: WO
Inventors: Kenneth Richard Williams; Alan Frank Travers
Original assignee: Kenneth Richard Williams; Alan Frank Travers
Priority date: 2022-12-06
Filing date: 2022-12-06
Publication date: 2024-06-13

Abstract

The present invention provides a polymer concrete material comprising an aggregate and a polymer, wherein said aggregate comprises a ground glass. The present invention further relates to methods for preparing the polymer concrete material, and manufactured concrete articles prepared from the concrete material.

Description

Improved Polymer Concrete Material

Field of the Invention

The present invention relates to a polymer concrete material comprising aggregate and a polymer, and in particular wherein said aggregate comprises at least about 10 wt% ground glass, and also to associated methods.

Background of the Invention

Manufactured concrete articles are produced and used every day, especially in the building and constructions industries. Most are made of traditional concrete which is a mixture of natural soils: natural sand aggregate (quartz), optionally fine natural gravel, and hydrated Portland cement as a binder.

There are many different types of traditional concrete that differ by minor variations in the proportions of the ingredients used. The altered ingredient proportions may produce concrete materials with different properties; compressive strengths, workability, durability etc., for use in different applications. For example, normal concrete which is typically used to manufacture footpaths and driveways and the like, uses a water/cement weight ratio of 0.6 to 0.7. In comparison, high strength concrete which is typically used in high weight-bearing structural applications has a reduced water/cement weight ratio, for example 0.35. As a result high strength concrete has poorer workability than normal concrete, but a higher compressive strength. Other examples include lightweight concrete which contains light aggregates and is typically used in non- or low-weight bearing structural applications, and high-density concrete which contains heavy aggregates and is used in, for example, heat shielding applications. There is also limecrete in which Portland cement is replaced with lime (Portland cement itself contains some lime) and typically used in polished floor slabs, and polymer concrete (also called resin concrete), in which a portion of the hydrated cementitious phase is replaced with a polymer as binder. Polymer concrete finds use in, for example, repair of traditional concrete articles.

As a result of the prolific use of concrete, the demand for natural aggregates, especially water-eroded sand, is immense. Sand is amongst the world’s most-consumed natural resources. Production of water-eroded sand materials focusses on river, lake and seashore sands. This adds an element of complexity and cost to production, which is not in itself inexpensive; it is usually a process of bulk extraction, sorting, washing, crushing, and transportation. More and more water-eroded sand deposits are becoming depleted. As the more-accessible deposits are spent, attention has turned to more remote and less-accessible sites, often at increased production costs. Producing these materials also has a significant environmental impact, not least of all the destruction of natural landscapes. The production of Portland cement which includes a firing step also has a significant environmental impact.

The different types of concrete find use in different applications. While there are many options available, it is not always straight-forward to select a concrete material for a given application, considering the desired properties, cost and environmental impact. Alternative concrete materials that find use in new and existing applications, that may reduce cost or environmental impact, are desirable.

There exists a need to overcome, or at least alleviate, one or more of the difficulties or deficiencies associated with the prior art.

Summary of the Invention

In one aspect, the present invention provides a polymer concrete material comprising aggregate and a polymer, wherein said aggregate comprises at least about 50 wt% ground glass.

By a “polymer concrete material” is meant a material which comprises aggregate and a polymer and in which, once set, the aggregate is bound by the polymer. That is, generally speaking, a polymer concrete material may be thought of as a traditional concrete in which a polymer replaces at least a portion of natural lime-type cements (Portland cement) as a binder. In preferred embodiments, the polymer concrete material is a pure polymer concrete material. By “pure” is meant a polymer concrete material in which a polymer essentially wholly replaces lime-type cements, in which case the polymer concrete material consists essentially of aggregate and a polymer. That is, pure polymer concrete material essentially does not contain a hydrated cement phase. By a “polymer” is meant a chemical substance comprising monomeric units which bond together in chemical reactions to form one or more polymeric units, and is taken to include the polymer unit(s), and taken to include a catalyst, accelerator, low-profile additive and/or other functional additive, when required. In polymer concrete material, the polymer may be any one or more of a polyester resin, furan resins, acrylics, styrene-acrylics, vinyl acetateethylene, polyvinyl acetates, styrene-butadiene resins, styrenes, polyester styrenes, epoxy resins, polyurethane resins and urea formaldehyde resins. Preferably, the polymer is a resin and preferably a thermosetting resin, catalytically-curable such that an external heat source is not required. In preferred embodiments, the polymer is an unsaturated polyester and/or vinylester resin which may include a cobalt accelerator, polystyrene as an anti-shrink additive low profile additive, and a peroxide catalyst. Examples include polymers available under the NORSODYNE trade mark such as polymer “C 16191 A” being orthophthalic unsaturated polyester containing methyl ethyl ketone peroxide and cobalt catalyst, and polymers available under the CDR trade name such as “CDR Polyester and/or Vinyl Ester Resin in Styrene Monomer” being unsaturated polyester resin solution in styrene monomer and I or unsaturated vinyl ester resin solution in styrene monomer, and equivalents or similar.

The use of polymer concrete is advantageous as it reduces the use of natural cement materials and the associated environmental impact. Polymer concrete is also generally stronger than many types of traditional concrete, especially being less prone to chipping and fracture.

The polymer may be present in the polymer concrete material in an amount of between about 5 wt% to about 20 wt%, though is preferably present in an amount of about 8 wt% to about 17 wt%, and more preferably present in amount of about 10 wt% to about 15 wt%, including any of about 10, 11 , 12, 13, 14 or 15 wt%.

In addition to a polymer, the principal components of polymer concrete may be aggregates, or inert granular materials, such as natural sand, gravel or crushed stone and calcium carbonate or fly ash. Suitable aggregates include silica, quartz, granite and limestone, and mixtures thereof. Thus, polymer concrete typically does not contain a hydrated cement phase. The aggregate may be of any suitable grade, for example coarse, medium or fine, or a mixture thereof. In one preferred embodiment, the aggregate may include a mixture of coarse quartz sand, medium quartz sand, fine quartz sand and micron-sized calcium carbonate. In preferred embodiments where the polymer concrete material is a pure polymer concrete material, the aggregate may thus be present in the polymer concrete material in an amount of between about 80 wt% to about 95 wt%, though is preferably present in an amount of about 83 wt% to about 92 wt%, and more preferably present in amount of about 85 wt% to about 90 wt%, including any of about 85, 86, 87, 88, 89 or 90 wt%.

In an embodiment, the aggregate of the polymer concrete material comprises at least about 50 wt% ground glass (also called crushed, crunched, rolled or granulated glass, or glass cullet). In preferred embodiments, the ground glass is present in the aggregate in an amount of about 75 wt% to about 98 wt%, more preferably present in amount of about 80 wt% to about 95 wt%, and most preferably present in an amount of about 86 wt% to about 92 wt%, including any of about 86, 87, 88, 89, 90, 91 or 92 wt%.

Accordingly, in preferred embodiments, the ground glass may thus be present in the polymer concrete material in an amount of between about 60 wt% to about 93 wt%, though is preferably present in an amount of about 66 wt% to about 87 wt%, and more preferably present in amount of about 73 wt% to about 83 wt%, including any of about 73, 74, 75, 76, 77, 78, 79, 80, 81 , 82 or 83 wt%.

In alternate embodiment, the polymer concrete may include at least approximately 10 wt%, more preferably at least approximately 15 wt%, more preferably at least approximately 20 wt% of the aggregate as ground glass. In preferred embodiments, the polymer concrete may include ground glass as aggregate in lieu of natural sands, of approximately 10 wt% to 50 wt%, more preferably approximately 20 wt% to 40 wt%, more preferably approximately 25 wt% to 35 wt%, and even more preferably approximately 30 wt% aggregate as ground glass. When a mixture of aggregates or grades of aggregates is used, the ground glass may replace any one or more. In a preferred embodiment, such as the embodiment described above containing coarse quartz sand, medium quartz sand, fine quartz sand and micron-sized calcium carbonate, the ground glass may replace any one or more of the quartz sands, preferably primarily the medium quartz sand. Thus, in a preferred embodiment, the aggregate may primarily include a mixture of coarse quartz sand, ground glass, fine quartz sand and micron-sized calcium carbonate.

It is most preferred that the ground glass includes, or is wholly (i.e. consists essentially of), recycled ground glass. In a preferred embodiment the aggregate may further comprises an inert granular material selected from natural sand, gravel, crushed stone, calcium carbonate, fly ash and/or a mixture thereof.

The other aggregate elements may be any suitable inert granular material, natural sand, gravel, crushed stone, calcium carbonate, fly ash, silica, granite, limestone, marble and mixtures thereof, often a combination of natural sand, gravel or silt. Sand, gravel and silt are defined into grades by particle size according to ISO 14688-1 :2002: fine gravel has a particle size range of 2.0 mm to 6.3 mm, coarse sand has a particle size distribution of between 0.62 mm and 2.0 mm, medium sand has a particle size distribution of between 0.2 mm and 0.63 mm, and fine sand has a particle size distribution of between 0.063 mm and 0.2 mm. Similarly, coarse silt has a particle size distribution of between 0.02 mm and 0.063 mm, medium silt has a particle size distribution of between 0.0063 mm and 0.02 mm and fine silt has a particle size distribution of between 0.002 mm and 0.0063 mm. In traditional concrete, the aggregate is often included in a mixture of grades. Natural gravel, sand and silt aggregates are produced in the grades specified above, and must be mixed together in the process of producing traditional concrete. In the polymer concrete material, the other aggregate may similarly be present in a mixture of grades, including for example coarse, medium and fine sands and silt in suitable proportions.

In preferred embodiments, the silt is present in the aggregate in an amount of about 2 wt% to about 25 wt%, more preferably present in amount of about 5 wt% to about 20 wt%, and most preferably present in an amount of about 8 wt% to about 14 wt%, including any of about 8, 9, 10, 11 , 12, 13 or 14 wt%.

In preferred embodiments, the silt may thus be present in the polymer concrete material in an amount of between about 2 wt% to about 24 wt%, though is preferably present in an amount of about 4 wt% to about 18 wt%, and more preferably present in amount of about 7 wt% to about 13 wt%, including any of about 7, 8, 9, 10, 11 , 12 or 13 wt%.

In preferred embodiments, the silt is a medium silt. Preferably, the silt includes, or is wholly (i.e. consists essentially of), micronised calcium carbonate and/or fly ash (i.e. particle size approximately 10-20 microns).

Accordingly, the aggregate of the polymer concrete material may consist essentially of a mixture of ground glass (preferably recycled) and medium silt in the proportions specified above, and optionally a sand element. In preferred embodiments where the polymer concrete material is a pure polymer concrete material, the polymer concrete material may consist essentially of polymer, ground glass (preferably recycled) and medium silt, in the proportions specified above.

The proportions as specified above may be altered within the specified ranges as required. For example, workability may be increased by using an amount of aggregate that is less than the highest amount in the range, and an amount of polymer that is higher than the lowest amount in the range. Similarly, for a thermosetting resin for example, the proportion of catalyst in the polymer may be increased when working at low ambient temperatures (optionally along with pre-warming the polymer) to facilitate full thermosetting potential.

In one aspect, the present invention provides a polymer concrete material comprising: about 10 wt% to about 15 wt% polymer, and most preferably about 14 wt%; about 7 wt% to about 13 wt% medium silt, and most preferably about 9 wt% (equating to about 10.5 wt% of the aggregate); and about 73 wt% to about 83 wt% ground glass, and most preferably about 77 wt% (equating to about 89.5 wt% of the aggregate).

In another aspect the present invention provides a polymer concrete material comprising: about 10 wt% to about 15 wt% polymer, most preferably about 12 wt%; about 8 wt% to about 18 wt% medium silt, most preferably about 15 wt% medium silt; and about 10 wt% to about 35 wt% ground glass, most preferably about 30 wt% ground glass.

In another aspect the present invention provides a polymer concrete material comprising: about 5 wt% to about 25 wt% polymer, most preferably about 8 wt% to 15 wt%; about 15 wt% to about 35 wt% medium silt, most preferably about 20 wt% to 25% wt medium silt; and about 10 wt% to about 75 wt% ground glass, most preferably about 65 wt% ground glass

In another aspect the present invention provides a brick, tile or paver formed from a polymer concrete material comprising: about 10 wt% to 25 wt% polymer, most preferably about 12 wt% to 15wt%; about 15 wt% to 30 wt% medium silt, most preferably about 20 wt% to 25 wt%; and about 50 wt% to 75 wt% ground glass, most preferably about 65 wt% to 75 wt%.

In another aspect the present invention provides a pipe formed from a polymer concrete material comprising: about 5 wt% to 25 wt% polymer, most preferably about 12 wt% to 15 wt%; about 15 wt% to 30 wt% medium silt, most preferably about 20 wt% to 25 wt%; and about 10 wt% to 60 wt% ground glass, most preferably about 15 wt% to 50 wt%.

In preferred embodiments the pipe formed from a polymer concrete material comprises quartz sand at about 15 wt% to 35 wt%; most preferably about 20 wt% to 25 wt%. In an alternatively preferred embodiment, the pipe formed from a polymer concrete material is absent a quartz sand component.

By the term pipe as used herein is meant a tube or hollow body for carrying a substance. In preferred embodiments the pipe may be an open pipe or a closed pipe. For example, the pipe may be a drainage channel for carrying a liquid or semi-solid substance.

In another aspect the present invention provides a traffic management device formed from a polymer concrete material comprising: about 10 wt% to 25 wt% polymer, most preferably about 12 wt% to 20 wt%; about 15 wt% to 30 wt% medium silt, most preferably about 20 wt% and 25 wt%; and about 10 wt% to 75 wt% ground glass, most preferably about 50 wt% to 75 wt%.

As compared to traditional concrete, just like the polymer replaces Portland cement, in the present invention the ground glass is included in lieu of natural aggregates. Ground glass, including recycled ground glass, is producible with a wider particle size distribution. As such, the present inventors have found that the ground glass can replace two or more grades of natural aggregate in polymer concrete material, such as replacing both fine gravel and medium sand. The use of additional medium silt has also been found to be to advantage in applications where the ground glass is not producible with a particle size distribution which overlaps with that of medium silt. Moreover, the present inventors have surprisingly found that polymer concrete materials which comprise a high proportion of ground glass aggregate (i.e. at least 50 wt% of the aggregate) do not sacrifice compressive strength of the material, but rather that polymer concrete material with a high proportion of ground glass aggregate complies with the compressive strength requirements for resin concrete as set down in the European Standards EN 1433:2002 Part 6.3.4 (> 90 N/mm²) relating to Drainage Channels for Vehicular and Pedestrian Areas.

Further, the present inventors have surprisingly found that polymer concrete materials which comprise a low proportion of ground glass aggregate (i.e. between at least 10 wt% to 50 wt% of the aggregate) do not sacrifice compressive strength of the material, being observed to have a compressive strength of between about 90 to 115 Mpa.

Also to advantage is the use of recycled ground glass in reducing the demand on, cost, and environmental impact of producing, natural sand and gravel materials, and also in providing an alternative use for used glass which would otherwise be waste and likely disposed in landfill.

In another aspect, the present invention provides a method for producing a polymer concrete material as herein described, said method including: providing aggregate and a polymer; mixing the aggregate and polymer to form a polymer concrete material; and optionally allowing the polymer concrete material to set.

For example, when preparing the composition as described herein, the desired percentage of each aggregate component may be programmed into an automated mixing and dosing machine. The machine mixes the dry aggregate components to form an aggregate mixture and then the polymer resin is injected into the mixture. The resin and dry components are mixed to form a polymer concrete material and discharged into a desired mould.

Further, the polymer concrete material may be further modified by adding colours. The colours, when required, are added to the mixture either by pre-mixing with the polymer resin or by independently injecting a pigment in the mixing process.

In the alternative, on a small scale the polymer concrete material as described herein may also be prepared by using manual combining and mixing steps.

The polymer concrete material of the present invention find particular use in the building and construction industries, in the manufacture of articles to which concrete materials may be applied, including for example, one or more of a building element and/or a traffic management device, which may include a brick, block, tile, paver, panel, post, beam, slab, sleeper, girder, wall, column, channel, pipe, pit, sump, road hump, roundabout, entry statement, refuge island, isolation island, wheel stop and a planter box. In preferred embodiments, the manufactured concrete article consists essentially of polymer concrete material, in that it is composed entirely of polymer concrete material (additional non-concrete features notwithstanding).

Accordingly, in another aspect, the present invention provides a manufactured concrete article including a polymer concrete material as herein described. In preferred embodiments, the manufactured concrete article consists essentially of a polymer concrete material as herein described (additional non-concrete features notwithstanding).

The manufactured concrete article may be made by any suitable method, though is preferably made using a mould. In another aspect, the present invention provides a method for producing a manufactured concrete article, said method including: providing a polymer concrete material as herein described, and a mould; transferring said polymer concrete material to the mould; allowing the polymer concrete material to set; and removing the set polymer concrete material from the mould to provide the manufactured concrete article.

In this specification, the term ‘comprises’ and its variants are not intended to exclude the presence of other integers, components or steps.

In this specification, references to prior art are not intended to acknowledge or suggest that such prior art is part of the common general knowledge in Australia or that a person skilled in the relevant art could be reasonably expected to have ascertained, understood and regarded it as relevant.

The present invention will now be more fully described with reference to the accompanying Examples and drawings. It should be understood, however, that the description following is illustrative only and should not be taken in any way as a restriction on the generality of the invention described above. Detailed Description of the Embodiments

Example 1 - Manufacture concrete article comprising > 50% glass

A manufactured concrete article was manufactured using a polymer concrete material, according to the specifications as set down in European Standard EN 1433:2002 Part 6.3.4 for a maximum aggregate particle size of < 8 mm, being 40 mm by 40 mm by 200 mm, ± 1 mm (the test block).

The test block was manufactured as follows: recycled glass aggregate with a particle size distribution of about 150 microns to 4.75 mm, calcium carbonate silt, and a polymer being an unsaturated polyester resin were provided. The recycled glass aggregate, calcium carbonate and polymer were mixed to form a polymer concrete material, in a mould corresponding to the test block dimensions. The polymer concrete material was allowed to set and the test black was removed from the mould.

The composition of the polymer concrete material was as follows: about 14 wt% polymer; about 9 wt% calcium carbonate (equating to 10.5 wt% of the aggregate); and about 77 wt% ground glass (equating to 89.5 wt% of the aggregate).

The test block was aged for seven days. The test block was tested for compression strength according to the test method as set down in European Standard EN 1433:2002 Part 6.3.4, by applying a load to the test block using test plates having dimensions of 40 mm by 62.5 mm.

The determined load achieved on the test black was 228.4 kN, corresponding to a compression strength of 91.36 N/mm², which passes the strength requirement of EN 1433:2002 Part 6.3.4 being > 90 N/mm².

Finally, it is to be understood that various alterations, modifications and/or additions may be made without departing from the spirit of the present invention as outlined herein.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A polymer concrete material comprising aggregate and a polymer, wherein said aggregate comprises at least about 50 wt% ground glass.

2. A polymer concrete material according to claim 1 , consisting essentially of aggregate and a polymer.

3. A polymer concrete material according to claim 1 or 2, comprising about 5 wt% to about 20 wt% polymer.

4. A polymer concrete material according to any one of claims 1 to 3, wherein said aggregate comprises about 75 wt% to about 98 wt% ground glass.

5. A polymer concrete material according to any one of claims 1 to 4, wherein said polymer concrete material comprises about 60 wt% to about 93 wt% ground glass.

6. A polymer concrete material according to any one of claims 1 to 5, wherein said aggregate comprises about 2 wt% to about 25 wt% medium silt.

7. A polymer concrete material according to any one of claims 1 to 6, wherein said aggregate consists essentially of ground glass and medium silt.

8. A polymer concrete material according to any one of claims 1 to 7, wherein said aggregate comprises about 90 wt% ground glass and about 10 wt% medium silt.

9. A polymer concrete material, comprising: about 10 wt% to about 15 wt% polymer; about 7 wt% to about 13 wt% medium silt; and about 73 wt% to about 83 wt% ground glass.

10. A polymer concrete material according to claim 9, comprising: about 14 wt% polymer; about 9 wt% medium silt; and about 77 wt% ground glass.

11. A polymer concrete material according to any one of claims 1 to 10, wherein said ground glass includes recycled ground glass.

12. A polymer concrete material according to any one of claims 1 to 11 , wherein said ground glass consists essentially of recycled ground glass.

13. A manufactured concrete article, including a polymer concrete material according to any one of claims 1 to 12.

14. A polymer concrete material comprising aggregate and a polymer, wherein said aggregate comprises less than 50 wt% ground glass.

15. A polymer concrete material according to claim 14, comprising about 5 wt% to about 20 wt% polymer.

16. A polymer concrete material according to claims 14 and 15, wherein said aggregate comprises about 10 wt% to about 50 wt% ground glass.

17. A polymer concrete material according to any one of claims 14 to 16, wherein said polymer concrete material comprises about 8 wt% to about 18 wt% polymer.

18. A polymer concrete material according to any one of claims 14 to 17, wherein said aggregate comprises about 2 wt% to about 25 wt% medium silt.

19. A polymer concrete material according to any one of claims 14 to 18, wherein said aggregate comprises about 30 wt% ground glass and about 10 wt% medium silt.

20. A polymer concrete material according to any one of claims 14 to 19, wherein said aggregate further comprises an inert granular material selected from natural sand, gravel, crushed stone, calcium carbonate, fly ash and/or a mixture thereof.

21. A polymer concrete material, comprising: about 10 wt% to about 15 wt% polymer; about 8 wt% to about 18 wt% medium silt; and about 10 wt% to about 35 wt% ground glass.

22. A polymer concrete material according to claim 10, comprising: about 12 wt% polymer; about 15 wt% medium silt; and about 30 wt% ground glass.

23. A polymer concrete material according to any one of claims 14 to 22, wherein said ground glass includes recycled ground glass.

24. A polymer concrete material according to any one of claims 14 to 23, wherein said ground glass consists essentially of recycled ground glass.

25. A manufactured concrete article, including a polymer concrete material according to any one of claims 1 to 24.

26. A brick or tile formed from a polymer concrete material comprising: about 10 wt% to 25 wt% polymer; about 15 wt% to 30 wt% medium silt; and about 50 wt% to 75 wt% ground glass.

27. A brick or tile according to claim 26, formed from a polymer concrete material comprising: about 12 wt% to 15 wt% polymer; about 20 wt% to 25 wt% medium silt; and about 65 wt% to 75 wt% ground glass.

28. A pipe formed from a polymer concrete material comprising: about 5 wt% to 25 wt% polymer; about 15 wt% to 35 wt% medium silt; and about 10 wt% to 60 wt% ground glass.

29. A pipe according to claim 28, formed from a polymer concrete material comprising: about 10 wt% to 15 wt% polymer; about 20 wt% to 25 wt% medium silt; and about 15 wt% to 50 wt % ground glass.

30. A traffic management device formed from a polymer concrete material comprising: about 10 wt% to 25 wt% polymer; about 15 wt% to 30 wt% medium silt; and about 10 wt% to 75 wt% ground glass.

31. A traffic management device according to claim 30, formed from a polymer concrete material comprising: about 12 wt% to 20 wt% polymer; about 20 wt% to 25 wt% medium silt; and about 50 wt% to 75 wt% ground glass.

32. A method for producing a polymer concrete material according to any one of claims 1 to 31, said method including: providing aggregate and a polymer; mixing the aggregate and polymer to form a polymer concrete material; and optionally allowing the polymer concrete material to set.