Polymer concrete

Abstract

A method of producing a polymer concrete is disclosed which comprises the steps of: (i-1) dispersing 2D material in a resin to form a 2D material-resin dispersion, then (ii-1) mixing the 2D material-r

Description

Field of the Invention The present invention relates to polymer concrete and methods for making it. 5 Background Concrete is a composite material that is widely used in the construction of buildings, bridges, roads, dams, pavings and more. The popularity of concrete stems from its cheap and easy means of manufacture as well as its inherent strength, durability and formability. However, the widespread use of 10 concrete has had significant environmental consequences. Traditional concrete requires combining water with cement to form a paste. As a result, vast quantities of fresh water are spent on concrete manufacture, particularly in regions already experiencing water shortages. Polymer composite concretes, which are those made from mixtures of aggregates and polymers, may be 15 manufactured using far lower quantities of water than traditional concrete whilst retaining, or even improving, its strength properties. Therefore, polymer concretes can have a lower environmental impact M than traditional concrete without compromising on product quality. C\J CO The use of polymer concrete has, to date, been limited by the relatively high cost as compared to traditional concretes. Accordingly, ways to reduce its cost have been widely sought. CM The present invention has been devised in light of the above considerations. Summary of the Invention 25 2D materials has been subject to extensive research since graphene was first isolated in 2004. One of the extraordinary properties of 2D materials is their mechanical strength, with graphene having the highest tensile strength of any material ever measured. As a result, graphene has been considered as an additive for reinforcing composites to enhance their strength and durability. 30 However, a commonly faced problem in the field of 2D material composites is in the dispersion of the 2D material within the composite matrix. For example, graphene tends to agglomerate, leading to an uneven distribution throughout the composite. This would be a particular problem for a construction material such as concrete as it is critical to its 35 application that its structural properties are even throughout the material. Evenly dispersing graphene and other 2D materials within concrete, which may contain multiple solid phases, is particularly challenging. At its broadest, the present invention relates to a method of producing a polymer concrete and a polymer concrete. An object of the invention is to provide a method of producing a polymer concrete, and a polymer 5 concrete itself, throughout which 2D material is distributed substantially uniformly. The inventors have found that polymer concrete manufactured to comprise 2D material enhances at least the strength property of the polymer concrete. It was identified that when the polymer concrete was manufactured by a method that distributed 2D material uniformly the polymer concrete at least the 10 strength property of the polymer concrete was further improved. In a first aspect, the method of producing the polymer concrete comprises the steps of: (i-1) dispersing 2D material in a resin to form a 2D material-resin dispersion, then (ii-1) mixing the 2D material-resin dispersion with the hardener to form a 2D material pre-mixture; or alternatively (i-2) dispersing 2D 15 material in a hardener to form a 2D material-hardener dispersion, then (ii-2) mixing the 2D material-hardener dispersion with the resin to form the 2D material pre-mixture. Then, having conducted either steps (i-1) and (ii-1) or steps (i-2) and (ii-2), (iii) combining the 2D material pre-mixture with a filler composition to form the polymer concrete. C\J It will be recognised that in some embodiments steps (i-1) and (i-2) are carried out and steps (ii-1) and (ii-2) are not. Similarly, in other embodiments steps (ii-1) and (ii-2) are carried out and steps (i-1) and (i-2) are not. 1— C\j The inventors have found that it is advantageous to prepare the 2D material pre-mixture before combining C—^25 it with the filler composition, for example by mixing, as it helps achieve a more homogeneous distribution of 2D material within the resultant mixture. The inventors also found that introducing the 2D material pre-mixture to the filler composition releases fewer airborne 2D material particles than when 2D material is introduced to the filler composition as a 30 solid or as a dispersion in either the resin or the hardener alone. This has advantages relating to the safety of manufacturing the polymer concrete. The filler composition comprises at least (a) an aggregate material, and (b) at least one of sand, hemp, or jute, and optionally (c) a further polymer, wherein the further polymer may optionally be a thermoset 35 polymer. In some preferred embodiments of the present invention the 2D material comprises graphene. In some embodiments the 2D material is unfunctionalized graphene. 40 In some embodiments, the aggregate material comprises fine aggregate and coarse aggregate, wherein the fine aggregate has an average particle diameter of 4 mm to 8 mm and the coarse aggregate has an average particle diameter of 16 mm to 24 mm. The inventors found that the presence of fine and coarse aggregates improved the strength property of the polymer concrete. In some embodiments the aggregate material comprises at least one of stone, rubber and carbon fibre. 5 In some embodiments, the graphene pre-mixture is combined with the filler composition by spraying the 2D material pre-mixture onto the filler composition, for example while the filler composition is stirred or subject to mixing or other agitation, or by adding the 2D material pre-mixture to the filler composition dropwise, again for example while the filler composition is stirred or subject to mixing or other agitation. 10 The inventors have found that a spray or dropwise technique is advantageous at least because it improves the homogeneity of distribution of the 2D material pre-mixture, and hence also the 2D material therein, amongst the filler composition. In some embodiments, in step (i-1) the 2D material is dispersed incrementally into the resin or 15 alternatively in step (ii-1) the 2D material is dispersed incrementally into the hardener. [Clearly, this applies only to the step (i-1) or (ii-1) that is actually carried out in the method.] The inventors have found that the gradual introduction of 2D material into either the resin in step (i-1) or alternatively into the hardener in step (ii-1) improves the evenness of distribution of the 2D material within the dispersion. In some embodiments, 2D material is present in the 2D material pre-mixture in an amount no more than 5 wt%. The inventors have found that when 2D material is present in the 2D material pre-mixture in amounts in excess of 5 wt%, 2D material particles are more prone to agglomeration which reduces the homogeneity of distribution of 2D material within the 2D material pre-mixture. In some preferred embodiments, 2D material is present in the 2D material pre-mixture in an amount 1 wt% to 5 wt%. [Herein, “wt%” is used to refer to the amount of a component present in a composition by total weight of the composition]. In some embodiments, 2D material is present in the polymer concrete in an amount no more than 0.05 wt%. The inventors have found that when 2D material is present in the polymer concrete in amounts in 30 excess of 0.05 wt%, 2D material particles are more prone to agglomeration which reduces the homogeneity of distribution of 2D material within the polymer concrete. In some preferred embodiments, 2D material is present in the polymer concrete in an amount 0.005 wt% to 0.05 wt%. In some embodiments, the resin comprises at least one of a virgin thermoset polymer and a thermoplastic 35 polymer. The skilled person would be aware of suitable hardeners, such as silica based hardeners. A second aspect of the present invention relates to a polymer concrete manufactured by the method according to the first aspect of the present invention. 40 A third aspect of the present invention relates to a polymer concrete comprising (a) a binder, wherein the binder is formed from a resin and a hardener; (b) a filler composition, wherein the filler composition comprises at least (i) an aggregate material and (ii) at least one of sand, hemp or jute, and optionally (iii) a further polymer; and (c) a 2D material. In some preferred embodiments, the 2D material comprises graphene. In some embodiments the 2D 5 material is unfunctionalized graphene. In some embodiments the resin comprises at least one of a virgin thermoset polymer and a thermoplastic polymer. 10 In some embodiments, 2D material is present in the polymer concrete in an amount no more than 0.05 wt%. The inventors have found that when 2D material is present in the polymer concrete in amounts in excess of 0.05 wt%, 2D material particles are more prone to agglomeration which reduces the homogeneity of distribution of 2D material within the polymer concrete. In some preferred embodiments, 2D material is present in the polymer concrete in an amount 0.005 wt% to 0.05 wt%. 15 In some embodiments, the aggregate material comprises fine aggregate and coarse aggregate, wherein the fine aggregate has an average particle diameter of 4 mm to 8 mm and the coarse aggregate has an average particle diameter of 16 mm to 24 mm. The inventors found that the presence of fine and coarse ■ aggregate improved the strength property of the polymer concrete. CM20 A fourth aspect of the present invention relates to a method of forming a structural element comprising conducting the present method of producing a polymer concrete and then the steps of (iv) heating and consolidating the polymer concrete to form a desired shape of the structural element, and (v) cooling the polymer concrete. C\J25 In some embodiments, the polymer concrete is consolidated by at least one of 3D printing, moulding, continuous hot pressing or extrusion. The extrusion may suitably be single screw extrusion or twin screw extrusion. 30 Another aspect of the present invention relates to a structural element manufactured by the method according to the fourth aspect of the present invention. The invention includes all combinations of the aspects and preferred / suitable features of embodiments described herein except where such a combination is clearly impermissible or expressly avoided. 35 Summary of the Figures Embodiments and experiments illustrating the principles of the invention will now be discussed with reference to the accompanying figures in which: 40 Figure 1 illustrates schematically a method of producing the polymer concrete and subsequently the structural element according to some generalised embodiments of the present invention. Detailed Description of the Invention Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All 5 documents mentioned in this text are incorporated herein by reference. 2D Materials Initially it is worth discussing the meaning of various terms of art that are used herein. “2D material” is 10 used to refer to not only solids whose monolayers consist of a single layer of atoms, such as graphene and hexagonal boron nitride, but also to solids whose monolayers are a few atoms thick, such as MXenes and transition metal dichalcogenides. “2D material” is also used to refer to not only monolayer materials but also to those that consist of a few 15 layers (for example, 10 or fewer). For example, “graphene” is used to refer not only to monolayer graphene but also to few layer graphene. 25 “2D material” is also used to refer to not only a single type of 2D material but also to a plurality of 2D materials present together. In preferred embodiments of the present invention, the 2D material comprises graphene. In certain embodiments the 2D material is >50 wt% graphene, and in some further embodiments >90 wt% graphene. Named 2D materials refer not only to their unfunctionalized state but also to their functionalized derivatives. For example, “Graphene” is used to refer not only to unfunctionalized graphene but also to functionalized graphene. 30 Unfunctionalized 2D materials are 2D materials that are substantially free of chemical functionalization. For example, unfunctionalized graphene has a close to 100% carbon composition. In an embodiment the graphene is unfunctionalized graphene. 2D materials meeting these criteria are readily commercially available, and various methods of making 2D 35 materials are well known. Method Techniques for dispersing 2D materials in a liquid phase to form a 2D material dispersion include, for 40 example, mechanical stirring techniques. These techniques can be readily applied to the present invention, wherein 2D material is dispersed in a resin to form a 2D-material resin dispersion or alternatively the 2D material is dispersed in a hardener to form a 2D material-hardener dispersion. The resin or the hardener are suitably in a liquid state at the time that 2D material is dispersed in them. Preferably, the 2D material is dispersed in the resin or alternatively in the hardener incrementally, wherein 5 fractions of the 2D material are dispersed in the resin or alternatively in the hardener periodically over an appropriate amount of time. It was found that an incremental dispersion of 2D material into the resin or alternatively the hardener overtime resulted in the 2D material being more homogeneously distributed within the 2D material-resin dispersion or alternatively the 2D material-hardener dispersion. For example, the 2D material might be dispersed in the resin or alternatively in the hardener in 10 equally sized 10 fractions at regular intervals over 30 minutes, while the resin (or hardener) undergoes continuous stirring. In this way the concentration of 2D material in the resin or hardener is gradually increased, reducing the likelihood of agglomeration. The skilled person in this technical field would certainly be aware of methods for mixing a resin and a 15 hardener together, which can be readily applied to the present invention, wherein a 2D material-resin dispersion is mixed with hardener to form a 2D material pre-mixture or alternatively a 2D-material-hardener dispersion is mixed with resin to form the 2D material pre-mixture. Suitable mixing methods include, for example, mechanical mixing and ultrasonic mixing techniques. CM20 In a preferred embodiment the 2D material-resin dispersion is mixed with hardener or alternatively the 2D material-hardener dispersion is mixed with resin using screw mixing techniques such as single screw mixing ortwin screw mixing to form the 2D material pre-mixture. Recirculating the 2D material pre-mixture back through the screw mixing apparatus has been found to improve the evenness of distribution of 2D material throughout the 2D material pre-mixture. C\J25 Methods of introducing a polymer matrix (i.e. resin and hardener) to a filler composition are very well known to a person skilled in the art and include, for example, straightforward pouring techniques. These techniques can be readily applied to the present invention, wherein the 2D material pre-mixture is introduced to a filler composition to form the polymer concrete. 30 In some embodiments the 2D material pre-mixture may suitably be held in a liquid state under stirring, such as by mechanical or ultrasonic stirring techniques that would certainly be familiar to the skilled person, before combination with the filler composition. Preferably, the 2D material pre-mixture is introduced to the filler composition while the 2D material pre-mixture is in a liquid state. 35 Of course it will be recognised that the 2D material-pre-mixture may also be solidified, as an only partially cured composition, for example by cooling and then re-liquified for combination with the filler composition for example by heating. 40 In some embodiments the filler composition is stirred whilst the 2D material pre-mixture is introduced to the filler composition. The inventors have found that this more homogeneously distributes the 2D material pre-mixture amongst the filler composition. In some preferred embodiments the 2D material pre-mixture is introduced to / mixed with the filler composition using a spraying or dropwise addition technique It was found that using spraying or dropwise addition techniques to introduce the 2D material pre-mixture to the filler composition improved 5 the evenness of distribution of the 2D material pre-mixture amongst the filler composition. The skilled person would certainly be aware of suitable spray or dropwise techniques for introducing a polymer to a filler composition. Such methods also reduce the chance of a thermal runaway reaction occurring. Methods of mixing a polymer matrix and a filler composition together are extremely well known and a 10 skilled person in this technical field would certainly be aware at least of several mechanical mixing techniques, for example. In an embodiment, a screw mixing technique such as single screw mixing or twin screw mixing is used to mix the 2D material pre-mixture and the filler composition together after the 2D material pre-mixture is introduced to the filler composition. 15 The general combination and flow of these stages of the present method, along with some exemplary but non-limiting suggestions for the various ingredients and methods at the different stages, is illustrated schematically in Figure 1. Components “Resin” is used to refer to the combination of one or more resins. The resin may comprise any suitable polyester, vinylester, epoxy or polyurethane resin or combination of resins. The skilled person would be aware of suitable resins for forming a polymer composite. In some embodiments of the present invention the resin comprises at least one of a virgin thermoset polymer and a thermoplastic polymer. A “thermoset polymer” is used to refer to a polymer that irreversibly solidifies when it is cured. Heat may initiate the curing of a thermoset polymer but is not necessarily required. In some embodiments of the present invention, the presence of a hardener alone is sufficient to initiate the cross-linking reaction, without external temperatures elevated above standard room temperature. A “thermoplastic polymer” is used to refer to a polymer that is more pliable when heated to a temperature above a threshold value, and that will reversibly solidify upon cooling. Heating a solidified thermoplastic polymer above a threshold value restores its pliability without decomposing the polymer. 35 A “virgin thermoset polymer” is used to refer to a thermoset polymer that has never previously been cured prior to being mixed with the hardener as part of the method of the present invention. In some embodiments the resin comprises a virgin thermoplastic polymer, wherein the thermoplastic polymer has never previously been cured prior to being mixed with the hardener as part of the method of 40 the present invention. In some embodiments the resin comprises a recycled thermoplastic polymer, wherein the thermoplastic polymer comprising the present invention has previously been (reversibly) cured prior to comprising the resin of the present invention. Hardener is used to refer to any species or combination of one or more species that reacts or otherwise interacts with a resin to harden the resin, for example those that catalyse the cross-linking reaction of a resin. The hardener may be one or more suitable hardeners. The “2D material-resin dispersion” is used to refer to the product of dispersing the 2D material in the resin. The “2D material-hardener dispersion” is used to refer to the product of dispersing the 2D material in the hardener. “2D material pre-mixture” is used to refer to the product of mixing the 2D material-resin dispersion with the hardener or alternatively mixing the 2D material-hardener dispersion with the resin. The 2D material pre-mixture is considered to be broadly similar whether it was formed by mixing the 2D material-resin dispersion with the hardener or alternatively by mixing the 2D material-hardener dispersion with the resin. “The filler composition” is used to refer to those constituents of the polymer concrete that do not form part of the 2D material pre-mixture. The filler composition comprises at least (a) an aggregate material, and (b) at least one of sand, hemp or jute (preferably sand), and optionally (c) a further polymer. In an embodiment, the further polymer comprises a (cured) thermoset polymer, for example the further polymer is a thermoset polymer. In particular, here, a recycled thermoset polymer may be used. This has significant environmental benefits, as uses for post-use, cured thermoset polymers are much needed. Components of the filler composition may suitably be provided in a crushed or shredded state in order to control their particle size and / or to produce particles that have a more angular shape. Techniques for crushing such components will be well known to the skilled person, including mechanical crushing methods. Likewise, techniques for shredding polymers are extremely well known, for example granulating and milling methods. In some embodiments, the sand (if used) may comprise at least one of sharp sand, river sand, sea sand and artificial sand. In some embodiments, the jute (if used) comprises at least one of white jute and tossa jute. Surprisingly, the inventors have identified that the filler composition may suitably comprise unwashed sea sand. Sea sand, and particularly unwashed sea sand, has not been widely accepted as a material for producing concrete due to its high chloride content (derived from the saltwater of the sea), which renders reinforcing members such as steel vulnerable to corrosion and hence causes long-term deterioration of reinforced concrete structures. The suitability of (unwashed) sea sand in the present polymer concrete is thought to be because the polymer concrete does not comprise an aqueous medium into which salts from sea sand can dissolve. The aggregate material comprises one or more aggregates. In some embodiments, the aggregate material comprises a fine aggregate and a coarse aggregate, wherein the fine aggregate has an average particle diameter that is smaller than the average particle diameter of the coarse aggregate. The fine aggregate may be the same type of material as the coarse aggregate. Alternatively, the fine aggregate may be a different type of material to the coarse aggregate. The skilled person in this technical field would certainly be aware of techniques for controlling aggregate particle diameter, for example sieve 5 analysis techniques adhering to European protocol BS EN 933. In an embodiment of the invention, the aggregate material comprises a fine aggregate having an average particle diameter of 4 mm to 8 mm, preferably 5 mm to 7 mm and most preferably about 6 mm. In another embodiment the aggregate material comprises a coarse aggregate having an average particle 10 diameter of 16 mm to 24 mm, preferably 18 mm to 22 mm and most preferably about 20 mm. In a preferred embodiment, the aggregate material comprises both a fine aggregate having an average particle diameter of 4 mm to 8 mm, preferably 5 mm to 7 mm and most preferably about 6 mm and a coarse aggregate having an average particle diameter of 16 mm to 24 mm, preferably 18 mm to 22 mm 15 and most preferably about 20 mm. The skilled person will be aware of suitable aggregate materials fora polymer concrete. In some embodiments the aggregate material comprises at least one of stone, rubber and carbon fibre. CM20 The term “further polymer” is used to refer to an optional additional component of the filler composition material beyond the aggregate and sand / hemp / jute. The further polymer is not necessarily the same as any polymer(s) comprising the 2D material pre-mixture, such as those comprising the resin, however in some embodiments it may be the same type of polymer(s) as those used in the resin. In some preferred embodiments, the further polymer is a thermoset polymer, preferably a recycled thermoset polymer. C\J25 In some embodiments, 2D material is present in the 2D material pre-mixture in an amount no more than 5 wt%. The inventors have found that when 2D material is present in the 2D material pre-mixture in amounts in excess of 5 wt%, 2D material particles are more prone to agglomeration which reduces the homogeneity of distribution of 2D material within the 2D material pre-mixture. In some preferred 30 embodiments, 2D material is present in the 2D material pre-mixture in an amount 1 wt% to 5 wt%, preferably 2 wt% to 4 wt% and most preferably about 3 wt%. In some embodiments, 2D material is present in the polymer concrete in an amount no more than 0.05 wt%. The inventors have found that when 2D material is present in the polymer concrete in amounts in 35 excess of 0.05 wt%, 2D material particles are more prone to agglomeration which reduces the homogeneity of distribution of 2D material within the polymer concrete. In some preferred embodiments, 2D material is present in the polymer concrete in an amount 0.01 wt% to 0.05 wt%, preferably 0.01 wt% to 0.04 wt% and most preferably 0.01 wt% to 0.02 wt%. 40 Polymer Concrete Putting into practise the presently described method produces a polymer concrete that forms another aspect of the present invention, wherein the polymer concrete comprises the components as set out above. 5 Another aspect of the present invention relates to a polymer concrete comprising (a) a binder, wherein the binder is formed from a resin, and a hardener; (b) a filler composition, wherein the filler composition comprises at least (i) an aggregate material and (ii) at least one of sand, hemp or jute, and optionally (iii) a further polymer; and (c) 2D material. 10 In some embodiments the 2D material comprises graphene, preferably unfunctionalized graphene. In some embodiments the resin comprises at least one of a virgin thermoset polymer and a thermoplastic polymer. 15 In some embodiments, 2D material is present in the polymer concrete in an amount no more than 0.05 wt%. The inventors have found that when 2D material is present in the polymer concrete in amounts in excess of 0.05 wt%, 2D material is present in the polymer concrete in amounts in excess of 0.05 wt%, 2D material particles are more prone to agglomeration which reduces the homogeneity of distribution of 2D material wWri trie polymer eoricrete. Iri some embodlmerits. 2D material Is preseat in We polymer CM20 concrete in an amount 0.005 wt% to 0.05 wt%, preferably 0.01 wt% to 0.04 wt% and most preferably 0.01 wt% to 0.02 wt%. The aggregate material comprises one or more aggregates. In some embodiments, the aggregate material comprises a fine aggregate and a coarse aggregate, wherein the fine aggregate has an average C\J25 particle diameter that is smaller than the average particle diameter of the coarse aggregate. The fine aggregate may be the same type of material as the coarse aggregate. Alternatively, the fine aggregate may be a different type of material to the coarse aggregate. In an embodiment, the aggregate material comprises a fine aggregate having an average particle 30 diameter of 4 mm to 8 mm, preferably 5 mm to 7 mm and most preferably about 6 mm. In another embodiment the aggregate material comprises a coarse aggregate having an average particle diameter of 16 mm to 24 mm, preferably 18 mm to 22 mm and most preferably about 20 mm. In a preferred embodiment, the aggregate material comprises both a fine aggregate having an average 35 particle diameter of 4 mm to 8 mm, preferably 5 mm to 7 mm and most preferably about 6 mm and a coarse aggregate having an average particle diameter of 16 mm to 24 mm, preferably 18 mm to 22 mm and most preferably about 20 mm. In some embodiments the aggregate material comprises at least one of stone, rubber and carbon fibre. 40 In some embodiments, 2D material is present in the polymer concrete in an amount no more than 0.05 wt%. The inventors have found that when 2D material is present in the polymer concrete in amounts in excess of 0.05 wt%, 2D material particles are more prone to agglomeration which reduces the homogeneity of distribution of 2D material within the polymer concrete. In some preferred embodiments, 2D material is present in the polymer concrete in an amount 0.01 wt% to 0.05 wt%, preferably 0.01 wt% to 0.04 wt% and most preferably 0.01 wt% to 0.02 wt%. 5 Uses of the polymer concrete A particular usage of the polymer concrete as according to the present invention is as a construction material. This requires the polymer concrete to be formed into a structural element suitable for use in 10 construction. Hence, another aspect of the present invention regards a method of forming a structural element, comprising the steps of producing a polymer concrete as set out above, and then the steps of heating and consolidating the polymer concrete to form the structural element, and cooling the polymer concrete. The polymer concrete may suitably be consolidated using at least one of 3D printing, moulding, continuous hot pressing or extrusion techniques. Extrusion may optionally be screw extrusion, such as single screw extrusion ortwin screw extrusion. At any stage before the polymer concrete is settled by cooling to form the structural element, reinforcement members may be introduced within the polymer concrete. The skilled person would certainly be familiar with suitable reinforcing members for concrete, which may comprise for example steel, polymer or alternate composite materials, any of which may optionally be provided in conjunction with rebar. Putting into practise the presently described method produces a structural element that forms another aspect of the present invention, wherein the structural element comprises the components as set out above.

Claims

1. A method of producing a polymer concrete comprising the steps of:(i-1) dispersing 2D material in a resin to form a 2D material-resin dispersion, then5 (ii-1) mixing the 2D material-resin dispersion with the hardener to form a 2D material pre-mixture;or alternatively(i-2) dispersing 2D material in a hardener to form a 2D material-hardener dispersion, then(ii-2) mixing the 2D material-hardener dispersion with the resin to form the 2D material pre-mixture,10 and then, having conducted either steps (i-1) and (ii-1) or steps (i-2) and (ii-2),(iii) combining the 2D material pre-mixture with a filler composition to form the polymer concrete, wherein the filler composition comprises at least (a) an aggregate material, and (b) at least one of sand, hemp or jute.15 2. The method according to claim 1, wherein the filler composition comprises (c) a further polymer,whereinthe further polymer is optionally a thermoset polymer.

3. The method according to claim 1 or 2, wherein the 2D material comprises graphene.

4. The method according to claim 2 or 3, wherein the aggregate material comprises a fineaggregate and a coarse aggregate, and whereinthe fine aggregate has an average particle diameter of 4 mm to 8 mm, preferably 5 mm to 7 mm and most preferably about 6 mm, andthe coarse aggregate has an average particle diameter of 16 mm to 24 mm, preferably 18 mm to 22 mm and most preferably about 20 mm.

5. The method according to any one of claims 2 to 4, wherein the aggregate material comprises at least one of stone, rubber and carbon fibre.

306. The method according to any one of claims 1 to 5, wherein in step (iii) the 2D material premixture is combined with the filler composition by spraying the 2D material pre-mixture onto the filler composition or by adding the 2D material pre-mixture to the filler composition dropwise.35 7. The method according to any one of claims 1 to 6, wherein in step (i-1) 2D material is dispersedincrementally into the resin or alternatively in step (i-2) 2D material is dispersed incrementally into the hardener.

8. The method according to any one of claims 1 to 7, wherein the 2D material is present in the 2D40 material pre-mixture in an amount 1 wt% to 5 wt%, preferably 2 wt% to 4 wt% and most preferably about 3 wt%.

9. The method according to any one of claims 1 to 8, wherein the 2D material is present in the polymer concrete in an amount 0.005 wt% to 0.05 wt%, preferably 0.01 wt% to 0.04 wt% and most preferably 0.01 wt% to 0.02 wt%.

10. The method according to any one of claims 1 to 9, wherein the resin comprises at least one of a virgin thermoset polymer and a thermoplastic polymer.

11. The method according to any one of claims 1 to 10, wherein the 2D material comprises10 unfunctionalized graphene.

12. A polymer concrete manufactured by the method according to any one of claims 1 to 11.

13. A method of forming a structural element, comprising conducting the method of producing a 15 polymer concrete according to any one of claims 1 to 11, and then the steps of:(iv) heating and consolidating the polymer concrete to form a desired shape of the structural element, and(v) cooling the polymer concrete.

14. The method of forming a structural element according to claim 13, wherein the polymer concrete is consolidated by at least one of 3D printing, moulding, continuous hot pressing or extrusion, wherein the extrusion is optionally screw extrusion, such as single screw extrusion ortwin screw extrusion.

15. A structural element manufactured by the method according to claim 13 or 14.

Images