Method of producing a modified polymer and modifier composition thereof

Abstract

A method for producing a bitumen modified polymer (BMP) for use in preparing a polymer modified bitumen, the BMP having an amount of polymer ranging between 25%w / w and 60%w / w, the method comprising blending a select polymer and bitumen at a temperature within the range of about 160 to 200 degrees C in a high-shear force mixer in the presence of fine particles; subjecting the blended composition to a process of shredding or pelletising to obtain a desired size; wherein the density of the pelletised BMP is equal to or higher than that of hot bitumen allowing the particles to sink and disperse effectively and quickly into a binder; and wherein the pelletised BMP is storage stable.

Description

[001] Field of the Invention

[002] The present invention relates to a method of producing a stable and readily dispersible bitumen modified polymer and modifier composition thereof, and in particular to a method of producing a modified polymer having a high polymer / bitumen content for modifying bitumen in bituminous materials needing polymeric modification including polymer modified bitumen for asphalt modification, straight to the plant asphalt modifier, bituminous crack sealing, bituminous adhesives and bituminous waterproofing.

[003] The invention has been developed primarily for use in production of bitumen modified polymer (BMP) that can be used to produce polymer-modified bitumen (PMB) and polymer modified asphalt and will be described hereinafter with reference to this application.

[004] It will, however, be appreciated that the invention is not limited to this particular field of use.

[005] Background of the Invention

[006] Bitumen is commonly used in road construction as a binder for road construction. Asphalt is a composition of at least aggregate materials and bituminous binder.

[007] Road surfaces using bitumen usually deteriorate by oxidation of the bitumen causing hardening, leading to loss of aggregate from the surface and / or minor cracking that leads to ingress of moisture.

[008] Since bitumen alone cannot fully meet the standards of a high-grade roadway, modified bitumen materials are being used in the construction of roads. The rationale for bitumen modification is to improve physical, mechanical and rheological properties compared to virgin bitumen.

[009] Although it has been proven that adding polymeric modifiers improve bitumen's properties, the effectiveness of the modifiers is constrained by the current challenges in the process of polymeric modification of bitumen.

[0010] In traditional methods of producing polymer-modified bitumen (“PMB”), bitumen is initially preheated and then a polymer is gradually added into the bitumen until the required polymer content is achieved. To blend the polymer into bitumen and produce a homogenous mixture, mixing is usually conducted by a shear mill under high temperatures for a specific amount of time or other types of sophisticated equipment.

[0011] Mixing a polymer and bitumen generally takes a large amount of time at high temperatures. For example, a PMB with only 5% polymer content could take about 3 hours and increases proportionally with polymer content hence the highest practical polymer concentration in PMBs is usually around 10%w / w.

[0012] Currently produced PMBs also need to be i) stored under high heat and agitation until use and ii) transported at high temperatures in agitation tanks, to prevent phase separation in which case the polymer degrades being exposed to high heat for long time.

[0013] One of the foremost problems confronting producers and suppliers of PMB is the property losses during storage and transportation which result in poor quality of roads built using such products.

[0014] Use of PMB faces several issues including the following: • Limited accessibility to regional and rural areas, small cities, and islands due to costly and complex transportation. • Susceptibility to expiration, polymer segregation, and contamination. • High energy consumption during manufacturing, storage, and transport. • The need for specialized heated and agitated tanks at both PMB production and asphalt plants. • A limited shelf life, with polymers degrading under prolonged heat exposure. • Classification as dangerous goods due to high-temperature transportation requirements.

[0015] The present invention seeks to provide a method of producing a bitumen modified polymer (BMP) and a composition thereof, which will overcome or substantially ameliorate at least some of the deficiencies of the prior art, or to at least provide an alternative.

[0016] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.

[0017] Summary of the Invention

[0018] The invention in one aspect comprises a method of producing a modified binder including a percentage of bitumen or asphalt, wherein the modified binder is formed by: • Selection of component parts of bitumen, polymer and additives • Use of particular mixing equipment providing high shear mixing of the selection of component parts • Provision of mixing conditions of the mixed selection of component parts to provide a modified binder.

[0019] The method also includes size reduction of components.

[0020] Preferably the modified binder provides a modifier in the form of a bitumen modified polymer (BMP) to provide a transportable modifier at ambient temperature in order to be mixed for short period to form the modified binder. BMP can also be diluted by adding more bitumen to the BMP to convert to PMB as an sustainable alternative to conventional method of producing PMB by the shear mill.

[0021] The BMP can have a ratio of polymer to bitumen in the range of 25 to 70 and is usable to be added to bitumen or asphalt to form the modified binder with a polymer to bitumen ratio of less than about 10%.

[0022] The BMP compositions can be formed to be readily mixable with bitumen in a bitumen tank and with asphalt mixture in asphalt mixing plants and disperse efficiently.

[0023] The BMP compositions in preferred forms achieve complete dissolution in bitumen tanks under agitation in less than 15 minutes at 180 degrees C and fully disperse in the asphalt plant mixer in under 55 seconds mixing at 180 degrees C.

[0024] The present invention can also be considered to be directed to a bitumen modified polymer (BMP) composition for use in preparing a polymer modified bitumen (PMB), the composition comprising: bitumen in an amount ranging from about 75wt% to 30wt%; and a polymer in an amount ranging from about 25wt% to 70wt%; wherein the BMP composition is stable, transportable at ambient temperature and disperses effectively in bitumen to produce the PMB.

[0025] Applicant has surprisingly found that the BMP composition of the invention, which contains a majority amount of a polymer in bitumen, is stable at ambient temperature, i.e. it does not agglomerate, and is easily dispersible in molten bitumen. This BMP composition enables onsite production of PMBs limiting exposure of the polymer component of the PMB to prolonged high temperatures, and high energy consumption usually required during storage and transport of PMBs. Losses that would be expected to occur for conventional PMBs is substantially avoided.

[0026] The polymer used to form the BMP is preferably styrene-butadiene-styrene (SBS) block copolymer. The BMP composition of the invention can be provided in the form of pellets. The BMP composition can further include a coating of fine particles. The surface coating of fine particles can assist in substantially minimising or avoiding agglomeration. The BMP composition can further have a density equal to or greater than the density of molten bitumen by the addition of the fine particles.

[0027] In another related aspect there is provided a method of producing a polymer modified bitumen (PMB) comprising up to about 10%w / w polymer, the method including blending a bitumen modified polymer (BMP) having an amount of polymer ranging between 25%w / w and 60%w / w with a predetermined amount of bitumen, wherein the BMP is stable, transportable at ambient temperature and disperses effectively in the bitumen to produce the PMB.

[0028] In another related aspect there is provided a method for producing a bitumen modified polymer (BMP) for use in preparing a polymer modified bitumen, the BMP having an amount of polymer ranging between 25%w / w and 60%w / w, the method comprising blending a select polymer and bitumen at a temperature within the range of about 160 to 200 degrees C in a high-shear force mixer in the presence of fine particles; subjecting the blended composition to a process of shredding or pelletising to obtain a desired size; wherein the density of the pelletised BMP is equal to or higher than that of hot bitumen allowing the particles to sink and disperse effectively and quickly into a binder; and wherein the pelletised BMP is storage stable.

[0029] The high shear mixer can be one extruder with distributive mixing and dispersive mixing. The high shear mixer also can be at least two extruders where a first extruder feeds into the second extruder, wherein the first extruder initially prepares the polymer and bitumen material and feeds it to the second extruder.

[0030] Bitumen is preferably fed into the feed throat simultaneously with or immediately after the polymeric material. The fine particles are introduced following initial feed of bitumen and polymer.

[0031] The temperature range of 160 to 200 degrees C is used to ensure polymers like SBS (Styrene-Butadiene-Styrene) and others used in PMB can soften adequately, allowing for effective dispersion and mixing into the bitumen matrix, and staying within this temperature range prevents the degradation of bitumen and polymers, which can occur at higher temperatures.

[0032] The fine particles used in the BMP blend can include hydrated lime (calcium hydroxide), sulfur, hydrogen sulfide scavengers, calcium carbonate, and other fine particles. Fine particles serve two primary purposes: reducing the blend's stickiness and increasing its density. This ensures that when BMP is added to the bitumen tank, its density is slightly higher than that of hot bitumen, allowing the particles to sink and integrate effectively into the binder. The fine particles are introduced into the pellets in a concentration effective to increase the density of the pellets while remaining low enough to avoid impacting the performance of the modified PMB.

[0033] The process of pelletising to obtain a desired size is preferably performed underwater. Pelletising underwater is found to achieve good resistance to stickiness and agglomeration. Fine particles such as hydrated lime (calcium hydroxide), sulfur, hydrogen sulfide scavengers, calcium carbonate, talc, and other fine particles can be added to the water to enhance the anti-stick properties of the resultant pellets.

[0034] Pelletising of the BPM improves product storage capability and improved transportability. Smaller particles help to allow mixability of the BMP with bitumen and asphalt, allowing for quicker dispersion during application.

[0035] BMP compositions formed by the present invention can be readily mixed with bitumen in a bitumen tank and with asphalt mixture in asphalt mixing plants and disperse efficiently. The BMP compositions can achieve complete dissolution in bitumen tanks under agitation in less than 15 minutes and fully disperse in the asphalt plant mixer in under 55 seconds. The rapid dispersion enables asphalt companies to be able to produce their own desired PMBs either by adding the BMPs to their bitumen tank or adding the BMPs in their asphalt mixers, at any time, at any location, and at any quantity needed. This represents a significant development and improvement in this field.

[0036] In one embodiment, once BMP begins to cool down, it can be subjected to fine particles. Due to the stickiness of the surface of BMP pellets, fine particles can penetrate the outer layer of BMP pellet. The concentration of fine particles on the outer layer of the pellets are effective for the viscosity of the outer layer of the liquid to sit in a frictional regime substantially preventing agglomeration.

[0037] Preferably Sulfur or a combination of Sulfur and hydrogen sulfide (H2S) scavengers can be added to the BMP to provide crosslinking effects when the BMP is mixed with bitumen in a bitumen tank. The amount of these additives can vary between 0% to 2% or preferably 0.1% to 2% of total BMP by weight. The presence of Sulfur helps to prevent phase separation when forming PMB. Sulfur acts as a crosslinking agent in polymer-modified bitumen (PMB) by forming sulfur bridges between polymer chains, particularly in elastomers like SBS. This enhances elasticity, thermal stability, and resistance to rutting and fatigue while preventing polymer separation.

[0038] The most preferred concentration of sulfur and hydrogen sulfide (H2S) scavengers are 0.6% of the total weight of BMP (70% sulfur with 30% hydrogen sulfide (H2S) scavengers).

[0039] Sulfur and hydrogen sulfide (H2S) scavengers are added at the last step of producing BMP to minimize time and exposure of polymers in the BPM to avoid crosslinking in the BMP. If crosslinking occurs in BMP, it prevents the dispersion of BMP later in bitumen. Therefore, the Crosslinking is to occur in PMB.

[0040] In another related aspect there is provided a method for producing a bitumen modified polymer (BMP) for use in preparing a polymer modified bitumen (PMB), the BMP having an amount of polymer ranging between 20%w / w to 90%w / w, preferably 25%w / w to 70%w / w, the method comprising: a. heating at least one binder to a first temperature and heating a catalyst to a second temperature; b. adding at least one polymer to the at least one binder to form a mixture when the at least one binder has reached the first temperature, such that the at least one polymer is at least 20% of the total weight of the mixture; c. adding the catalyst to the mixture; d. heating the mixture and the catalyst to a third temperature and maintaining the third temperature for a first period of time; and e. either at the time of heating the mixture and the catalyst to a third temperature or after the first period of time, mixing the mixture and the catalyst at the third temperature for a second period of time until the mixture substantially homogenizes to form the modified binder. In one embodiment, BMP term is used for both binders modified polymer and bitumen modified polymer.

[0041] Advantageously, the method provided can achieve a modified binder with high polymer content and polymer-binder compatibility without having a long period of mixing time. The distribution of the heating process through various steps and the use of a catalyst in the mixing process significantly lowers the mixing period of the binder and the polymer, which may lead to reduced CO2 emissions.

[0042] Advantageously, the heating of the catalyst to the second temperature enables it to increase the temperature of the mixture when added.

[0043] Advantageously, adding the at least one polymer at room temperature avoids deterioration of the properties of the polymer and avoids polymer oxidation which would otherwise make it less compatible with the bitumen.

[0044] Bitumen, and PMB modified binders, are typically stored in a liquid state at elevated temperature during storage and transportation. The reason for this is that bitumen (modified binders) is adhesive at room temperature and agglomerates when stored and transferred. According, to one embodiment a method of producing a modified binder being a BMP is provided with a high concentration of polymer by weight which results in the polymer modified binder being much less adhesive, when compared with common polymer modified binders with low polymer content. This high polymer content also allows the material to be able to be shredded and pelletised and able to be stored and transported at ambient temperatures.

[0045] In one embodiment, the method further comprises a step of removing the catalyst after the second period of time to isolate the modified binder.

[0046] In one embodiment, the method further comprises a step of cooling the modified binder to a fifth temperature.

[0047] In one embodiment, the method further comprises a step of extruding the modified binder into a plurality of modified binder pellets.

[0048] In one embodiment, the method further comprises a step of shredding the modified binder into a plurality of modified binder shreds.

[0049] Advantageously, the modified binders are easily packaged for storage or delivery when it is in the form of modified binder pellets or modified binder shreds.

[0050] In one embodiment, the method further comprises a step of coating the modified binder with at least one additive.

[0051] Advantageously, the coating of the shredded or pelletised modified binders with additives enhances bulk transportation.

[0052] Coating further reduces the risk of agglomeration of the polymer modified binder during transport and storage by providing a layer of protection over the adhesive surface of pellets.

[0053] In one embodiment, the at least one binder is selected from a group consisting of bitumen, oil, resin, high aromatic content binder, Paraffin waxes, bio-oil and combinations thereof.

[0054] In one embodiment, the at least one polymer is selected from a group consisting of polyethylene, polypropylene, poly(styrene-butadiene-styrene), crumb rubber, Styrene-Ethylene-Butylene-Styrene (SEBS), Ethylene-Vinyl Acetate (EVA) and combinations thereof.

[0055] Advantageously, using high content polymers such as those listed above results in a modified binder having a high concentration of polymers. Modified binders with high polymer concentration are more easily stored or transported at solid-state and at room temperature substantially without any specialised equipment.

[0056] In one embodiment, the catalyst is particles. In one embodiment, the catalyst is fine particles such as hydrated lime, calcium carbonate, baghouse ash, fly ash, crushed fine glass, and / or a combination thereof. In one embodiment, if the catalyst is a common fine particle used in asphalt application, the catalyst does not require to be separated from the BMP.

[0057] In one embodiment, the size of the particles is between 1 nanometre and 200 millimetres. In one embodiment, the size of the particles is less than 1 mm if the catalyst does not require to be separated. In one embodiment, the size of the particles is more than 5mm when the catalyst is required to be separated. In one embodiment, the catalyst must be separated if pure BMP is required.

[0058] In one embodiment, the particles are metal elements.

[0059] In one embodiment, the metal element used is stainless steel.

[0060] Stainless steel can be a good catalyst due to its high density and high thermal conductivity. Stainless still is also durable and inexpensive.

[0061] In one embodiment, the metal elements are stainless steel.

[0062] Advantageously, stainless steel provides high density, high thermal conductivity, it is highly resistant against corrosion, and it is cost-effective.

[0063] In one embodiment, 20mm is a preferred diameter for the metal elements. In one embodiment, particles bigger than 200mm can be used as catalyst, but they lose efficiency, and the process takes more time for mixing.

[0064] In one embodiment, the shape of the metal elements is generally spherical.

[0065] Advantageously, the addition of hot metal particles to the mixture at the time of mixing elevates the temperature of the whole mixture and improves thermal conductivity which in turn improve consistency of temperature throughout the mixture. This allows the bitumen and polymer to be easily combined at minimal mixing time. The size and shape of the metal particles may be chosen such that the metal particles will have an increased contact surface between the bitumen and polymer which may shorten mixing time, also metal particles to be large enough to be easily separated from the mixture.

[0066] In one embodiment, the particles are glass elements.

[0067] In one embodiment, the third temperature is between 90°C and 200°C.

[0068] In one embodiment, a preferred third temperature when the at least one polymer is poly(styrene-butadiene-styrene) or polypropylene is about 180 degrees Celsius, when the at least one polymer is polyethylene it is about 160 degrees, when the at least one polymer is Crumb Rubber (CR) it is about 200 degrees and when the at least one polymer is Ethylene-Vinyl Acetate, it is about 130 degrees Celsius. If there is a mixture of different polymers used, then the higher of the above-mentioned temperatures is used.

[0069] In one embodiment, the first period of time is between 5 minutes and 2 hours.

[0070] In one embodiment, a preferred first period of time when the at least one polymer is poly(styrene-butadiene-styrene) is about 15 minutes, when the at least one polymer is crumb rubber, polyethylene or polypropylene is about 10 minutes and when the at least one polymer is Ethylene-Vinyl Acetate, is about 5 minutes. If there is a mixture of different polymers used, then the higher of the above-mentioned periods of time is used.

[0071] In one embodiment, the second period of time is between 1 second and 1 hour.

[0072] In one embodiment, the second period of time is between 2 minutes and 30 minutes.

[0073] In one embodiment, a preferred second period of time when the at least one polymer is poly(styrene-butadiene-styrene) is about 7 minutes, when the at least one polymer is crumb rubber, polyethylene or polypropylene is about 5 minutes and when the at least one polymer is Ethylene-Vinyl Acetate, is about 3 minutes. If there is a mixture of different polymers used, then the higher of the above-mentioned periods of time is used.

[0074] Advantageously, the mixing time is significantly lessened in the method provided to produce BMPs with high polymer-bitumen compatibility than PMBs.

[0075] In one embodiment, the at least one additive is added to the mixture and the catalyst.

[0076] In one embodiment, the at least one additive is added to the mixture after the step of mixing and then a second mixing is done with the at least one additive for a third period of time.

[0077] In one embodiment, the third period of time is between 30 seconds and 30 minutes.

[0078] In one embodiment, the third period of time is between 2 and 5 minutes.

[0079] In one embodiment, the at least one additive is fine particles.

[0080] In one embodiment, the mixture and the catalyst are mixed at up to 60 RPM.

[0081] According to a second aspect of the invention, a composition of a BMP is provided, the composition comprises: a. a binder in an amount ranging from about 30wt% to 80wt%; and b. a polymer in an amount ranging from about 20wt% to 70wt%.

[0082] In one embodiment, the composition comprises about 40wt% of a binder and about 60wt% of a polymer.

[0083] Advantageously, the composition above has enough high polymer content which improves polymer-bitumen compatibility. Furthermore, the high polymer concentration of the composition above allows the BMP to be dispersed into other batches of binders to modify an asphalt mixture. The polymer concentration selected above is not too high to cause the modified binder to act as a filler in the asphalt mixture. Advantageously, the composition above is suitable for polymers such as PEs, PP, EVA and combinations thereof.

[0084] In one embodiment, the composition comprises about 70wt% of a binder and about 30wt% of a polymer.

[0085] Advantageously, the composition above has enough high polymer content which improves polymer-bitumen compatibility. Furthermore, the high polymer concentration of the composition above allows the BMP to be dispersed into other batches of binders to modify an asphalt mixture. The polymer concentration selected above is not too high to cause the modified binder to act as a filler in the asphalt mixture. Advantageously, the composition above is suitable for polymers such as crumb rubber, SBS, SEBS and combinations thereof.

[0086] In one embodiment, the binder is selected from a group consisting of bitumen, oil, resin, high aromatic content binder, Paraffin waxes, bio-oil and combinations thereof.

[0087] In one embodiment, the polymer is selected from a group consisting of polyethylene, polypropylene, poly(styrene-butadiene-styrene), crumb rubber, Styrene-Ethylene-Butylene-Styrene (SEBS), Ethylene-Vinyl Acetate (EVA) and combinations thereof.

[0088] This invention may also be said broadly to comprise in the parts, elements, and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements, or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

[0089] To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

[0090] Provided is a method of blending modified polymer or polymers, where one or more polymeric materials are introduced into a mixer, and bitumen is fed into the mixer, creating a mixture of polymeric material and bitumen that is then extruded from the mixer.

[0091] Also provided is a method for size reduction of blended modified polymer or polymers, where a pelletiser or shredder is used, and fine particles are used to prohibit agglomeration and enhance storability, creating a mixture of polymeric material and bitumen that can be kept in room temperature and stored in bulk storage bags and 20 kg bags.

[0092] Further, the presently claimed composition of polymers and bitumen can be mixed with molten bitumen in a bitumen tank and with asphalt mixture in an asphalt mixing plant and disperse efficiently and quickly. The compositions achieve complete dissolution in bitumen tanks under agitation in less than 15 minutes and fully disperse in the asphalt plant mixer in under 55 seconds. An advantage is that rapid dispersion enables asphalt companies to produce PMBs onsite either by adding the BMPs to their bitumen tank or adding the BMPs in their asphalt mixers. Such rapid dissolution and dispersion were previously unattainable with any solid polymeric compositions.

[0093] Other aspects of the invention are also disclosed. Brief Description of the Drawings

[0094] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0095] Figure 1 shows a flow chart of a first embodiment of the present invention relating to a process for producing PMBs from a BMP;

[0096] Figure 2 shows a flow chart of a method of producing a PMB onsite using a transportable and storage stable BMP;

[0097] Figure 3 shows a flow chart showing a range of process sequences for producing a desired BMP with a select polymer and additives;

[0098] Figure 4 shows a flow chart of a process of producing BMP showing further processing steps including pelletising, coating conditions;

[0099] Figure 5 shows a flow chart of BMP produced from figures 3 and 4 being added to bitumen or asphalt onsite to produce a PMB with desired properties;

[00100] Figure 6 shows a flow chart of a further embodiment of a method of producing a modified binder according to the present invention;

[00101] Figure 7 shows a flow chart of yet a further embodiment of the method of producing a modified binder according to the present invention; and

[00102] Figure 8 shows a tabular chart of range of a third temperature based on a corresponding polymer used;

[00103] Figure 9 shows rutting resistance test results of SBS BMP added to asphalt compared with conventional PMB at 6% polymer concentration in the resultant PMB; and

[00104] Figure 10 shows test reults of resiliant modulus driven from a universal testing machine. Description of Embodiments

[00105] It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features.

[00106] It can be seen that the invention provides a method for blending modified polymer or polymers, where one or more polymeric materials are introduced into a mixer, and bitumen is fed into the mixer, creating a mixture of polymeric material and bitumen that is then extruded from the mixer.

[00107] Also provided is a method for size reduction of blended modified polymer or polymers, where a pelletiser or shredder is used, and fine particles are used to prohibit agglomeration, adjust density and enhance storability, creating a mixture of polymeric material and bitumen that can be kept in room temperature and stored in bulk storage bags and 20 kg bags.

[00108] Further, the presently claimed composition of polymers and bitumen that can be mixed with bitumen in bitumen tank and with asphalt mixture in asphalt mixing plants and disperse efficiently. The compositions achieve complete dissolution in bitumen tanks under agitation in less than 15 minutes and fully disperse in the asphalt plant mixer in under 55 seconds. The rapid dispersion enables asphalt companies to be able to produce their own desired PMBs either by adding the BMPs with their bitumen tank or adding the BMPs in their asphalt mixers. Such rapid dissolution and dispersion were previously unattainable with any solid polymeric compositions.

[00109] The process of creating the blend of BMP

[00110] Modified polymer may consist of polymer or polymers combined with bitumen. Bitumen blending with polymers can significantly increase the dispersion of polymers when they are added to bitumen or asphalt plants, the polymers can improve asphalt properties such as stiffness, viscosity, rutting resistance, temperature susceptibility, and moisture resistance. Examples of polymers used for bitumen modification include styrene-butadiene-styrene (SBS) rubber or crumb rubber (CR) polypropylene (PP), polyethylene (PE), Ethylene-vinyl acetate (EVA), or their combinations. The polymer additive can be included in the composition in any amount deemed effective for achieving the desired properties.

[00111] Mixing equipment

[00112] The feasibility of producing the mixture depends on the selection of components and the mixing equipment. High-shear force mixers are particularly effective for producing BMPs at various ratios of bitumen to polymer and fines. Among such mixers, extruders—both twin-screw and single-screw types—are well-suited for this purpose.

[00113] In an embodiment, the mixing apparatus can be a twin-screw extruder, such as a co-rotating twin-screw extruder. Bitumen can be added to the mixer (extruder) at multiple locations along the length of the extruder. Other materials, such as additives, can also be introduced into the extruder to be included in the extruded modified polymer composition.

[00114] A single-screw extruder has a helical screw rotating inside a barrel. The material enters through a hopper and is conveyed along the screw by rotational movement. As the material progresses, it is subjected to compression and shearing forces due to the narrowing channels and screw design. Shear forces occur as the material is forced through tight spaces between the screw and barrel walls, generating friction and heat. This combination leads to softening, blending, and homogenization of the materials.

[00115] Twin-screw extruders use two intermeshing screws rotating inside a barrel. These screws can either rotate in the same direction (co-rotating) or in opposite directions (counter-rotating). The intermeshing design creates regions of high shear as the material is compressed and kneaded between the screws and the barrel walls. Twin-screw extruders provide better control over shear forces and are more effective for blending because of their enhanced mixing zones and ability to handle higher viscosities. The screws can be designed with various sections, such as kneading blocks or mixing zones, to tailor the level and type of shear applied for specific materials and processes.

[00116] Shear forces in both types of extruders lead to the breakdown of agglomerates and promote intimate contact between components. The heat generated by friction further enhances blending by softening thermoplastic materials, allowing them to mix more uniformly. In cases where additives, fine particles, or polymers are involved, the shear force ensures proper dispersion and distribution throughout the material matrix.

[00117] Overall, both single-screw and twin-screw extruders effectively utilize shear force for blending, but twin-screw extruders provide superior control and versatility, making them ideal for more complex or demanding mixing applications.

[00118] Shear mills are designed to apply high shear forces to the liquid to break down and disperse any agglomerates or clusters that may be present and promote uniform mixing throughout the fluid. The shear mixer works by creating a high-velocity flow of liquid through a series of rotating blades or impellers that are designed to generate high shear forces. As the liquid flows through the blades, it is subjected to intense shear and frictional forces that break up any particles or agglomerates and promote mixing. A high-shear mill, such as a colloidal mill or rotor-stator system, is used inside a bitumen modification tank to generate intense shear forces by forcing bitumen and additives (e.g., polymers, crumb rubber, fillers) through a narrow gap at high speed. This process results in mechanical dispersion, size reduction, and homogenization of additives. As the bitumen passes through the shear zone, it undergoes lamination and elongational shear, leading to finer and more uniform polymer dispersion. These types of high shear mixers handle products with viscosities ranging from 1 centipoise (CPS) to 10,000 CPS.

[00119] Equipment like the shear-mill and the transporting equipment of PMBs already requires high energy inputs to properly work. When taking into account the polymer content to be added to the PMBs, the energy inputs drastically increase as temperature and mixing time increases. This process results to higher CO2 emissions potentially harming the environment.

[00120] Mixing condition

[00121] The temperature range of 160-200°C for BMP blends is used. This range is commonly used to ensure polymers like SBS (Styrene-Butadiene-Styrene) and others commonly used in PMB soften adequately, allowing for effective dispersion and mixing into the bitumen matrix and staying within this temperature range prevents the degradation of bitumen and polymers, which can occur at higher temperatures. Bitumen starts breaking down at temperatures exceeding 200-230°C, while polymers like SBS may also degrade or lose properties.

[00122] Regarding the feed locations in the extrusion apparatus, the polymeric material is typically introduced at the feed throat located at the upstream end of the extruder. The location and number of bitumen injection points can be adjusted, particularly the downstream injection points. To minimize risks such as polymer degradation, bitumen is preferably fed into the feed throat simultaneously with or immediately after the polymeric material.

[00123] Additional injections of bitumen downstream enable the adjustment of the mixture to achieve the desired formulation. In one embodiment, bitumen is added in a ratio to the polymeric material that keeps the modified bitumen composition just below total lubrication.

[00124] Similarly, the location and number of injection points for other materials, such as fine particles (calcium hydroxide, stabilisers, etc), can also be adjusted, particularly for downstream addition points, fine particles can influence the viscosity of the extruded modified polymer composition and also reduce the stickiness of the blend and enhance storability. Adding fine particles at the first injection port at the upstream end of the extruder, but fine particles are preferably introduced at one or more downstream injection points since they can reduce the temperature of the blend when added from upstream and have negative effects on the blend-ability of polymers with bitumen, in the case of Sulfur and other stabilisers, the very end of the extrusion since crosslinking between this material with polymers can change the properties of the blend. The aim is to minimise the amount of time sulfur, and stabilisers are in the blend at high temperatures to minimise chemical reactions. These materials will be activated later on when BMP is added to bitumen or asphalt mixture, and complete crosslinking occurs at that time.

[00125] In another embodiment, at least two extruders are utilized. Preferably, one extruder feeds into a second extruder. The purpose of the first extruder is to preblend the material and feed it to the second extruder.

[00126] In and embodiment, either of the extruders can be a mixer capable of imposing high shear to such high viscos polymeric materials with viscosities exceeding 10,000 cp.

[00127] Extruders impose intense shear forces on materials through their rotating screws and barrel geometry, ensuring efficient blending and mixing. Their ability to process materials with varying viscosities and compositions makes them an ideal choice for producing BMPs.

[00128] Mix Design

[00129] Three main components are used in the blend of BMPs; Bitumen, Polymer, and fine particles. Bitumen can be any type of bitumen from Performance Grades (PG) grades (include PG 46-34, PG 52-28, PG 58-22, PG 64-22, PG 70-22, PG 76-22, and PG 82-28), Penetration grades of bitumen include 60 / 70, 85 / 100, 40 / 50, and 100 / 120) to viscosity grades (VG-10, VG-20, VG-30, and VG-40) and grades (C170, C320, C450, etc), and any other grades of bitumen or bitumen that is not graded.

[00130] Polymers include styrene-butadiene-styrene (SBS), rubber or crumb rubber (CR), polypropylene (PP), polyethylene (PE), Ethylene-vinyl acetate (EVA), or their combinations.

[00131] The additives used in the BMP blend include hydrated lime (calcium hydroxide), sulfur, stabilizers, hydrogen sulfide scavengers, calcium carbonate, and other fine particles. Fine particles serves two primary purposes: reducing the blend's stickiness and increasing its density. This ensures that when BMP is added to the bitumen tank, its density is slightly higher than that of hot bitumen, allowing the particles to sink and integrate effectively into the binder. Other fine particles can be utilized for similar purposes, provided they have commonly used materials in bitumen modification or asphalt mixtures to avoid adverse effects or contamination. Sulfur is included in the blend to enhance the properties of the resulting polymer-modified bitumen through crosslinking effects. Similarly, other stabilizers or crosslinkers may replace sulfur or be used alongside it to achieve the desired performance improvements.

[00132]     2. Size reduction

[00133] Once the mixture is prepared, it can undergo shredding or pelletization to achieve a material of a desired size. This step is crucial for ensuring the product can be easily stored, transported, and used effectively. Smaller particles enhance the mixability of the BMP with bitumen and asphalt, allowing for quicker dispersion during application; other factors must be considered, including:

[00134] Stickiness of the Pellets: Excessive stickiness can cause handling difficulties and lead to clumping.

[00135] Agglomeration During Storage and Transport: Pellets need to resist clustering and maintain their integrity during storage and shipping.

[00136] High-Temperature Stability: The pellets must withstand exposure to high temperatures of up to 50°C without deformation or sticking together.

[00137] Underwater pelletisers and industrial shredders are used for this purpose. The underwater pelletiser is used to pelletise the BMP into the desired size, and since the palletisation occurs underwater, it achieves good resistance to stickiness. Fine particles such as talc are added to the water to enhance the anti-stick properties of the pellets. The underwater pelletiser is the preferred method due to its high performance and low operational costs.

[00138] While the pelletiser is generally the preferred method, especially for SBS and rubber, shredders can be effectively used for BMPs made from PP, PE, and EVA. Particularly for recycled PP and PE, contaminants in the BMP blend can damage the pelletiser, making shredding the preferred method.

[00139]     3- workability and storability

[00140] Once the BMP is pelletized or shredded, the material undergoes proprietary storage testing (storability protocols) to evaluate its resistance to agglomeration under pressure. This involves placing 1 kg of the pellets within a 10 cm x 10 cm area and applying a constant load of 20 kg (equivalent to a pressure of 2,000 kg / m2) at a temperature of 60°C for 48 hours. The test is considered successful if the pellets remain intact and do not agglomerate; otherwise, the material fails the test.

[00141] The type of polymer, the amount of coating agent, and the polymer-to-bitumen ratio play critical roles in performance. BMPs made by polymers like PE, PP, and EVA show minimal stickiness, and this test is mostly applied to BMPs made by SBS and Rubber. To improve workability and prevent agglomeration, various materials are used to coat BMP particles, such as hydrated lime, sulfur, stabilisers, and talc. Fine particles serve to cover the sticky surface with their surface area, creating a non-sticky shield. Sulfur and stabilisers have a dual function, acting as both anti-sticky agents and crosslinkers, activating as crosslinkers once the BMPs are added to bitumen or asphalt mixtures.

[00142]     4-BMP Performance

[00143] The performance of BMP pellets is assessed in two primary applications: when added to bitumen and when added to hot aggregates or hot asphalt. In both cases, the goal is the quick and complete dispersion of BMP pellets into the asphalt matrix, leading to the modification of the binder and the formation of high-quality polymer-modified bitumen (PMB). When BMP pellets are added to bitumen, the dispersion should enhance the binder's properties, with key properties evaluated including softening point, viscosity, torsional recovery, consistency at 60°C, and stiffness at 25°C and 15°C. Testing begins with the softening point, followed by torsional recovery for mixtures that show positive results, and further tests confirm overall performance. When BMP pellets are added to asphalt, the dispersion should effectively modify the asphalt binder to achieve a similar quality to industrial PMB. This modification is assessed by comparing the properties of BMP-modified asphalt with those made using industrial PMB, with key performance indicators including Marshall stability and flow, rutting resistance, stripping potential, and resilient modulus. The closer the results of BMP-modified asphalt are to those made with industrial PMB, the more effective the dispersion and modification are considered to be. This systematic approach optimizes both binder and asphalt performance in different applications of BMP pellets.

[00144]     1) Dispersion in Bitumen measure by softening point

[00145] Once BMP is mixed with hot bitumen, the ideal condition is that BMP can disperse as quick as possible under minimal agitation. To avoid a need for upgrading existing facility for customers and asphalt producers and PMB producers, we considered a typical bitumen storage tank condition, temperature of 180 degrees and agitation of 450 rpm, to achieve full dispersion of BMP into bitumen forming PMB in these conditions. Once the BMP is fully dispersed, the resultant PMB needs to perform similar to industrial made PMBs and meet the same specifications. So, we considered a limit for the outcome PMB that is made after adding BMP manufactured in accordance with the invention into molten bitumen. The mixing time we considered for this is 15 minutes to be short enough to not affect asphalt production.

[00146] Formulations of BMP comprising between 20%w / w to 90%w / w SBS block copolymer and between 80% and 10%w / w bitumen, were subjected to softening point test and dispersion test in molten bitumen. Results are shown in Table 1 below.

[00147] Table 1-the composition of BMP comprising SBS-bitumen and its effects on dispersion in molten bitumen (crumb rubber is behaving almost similar to SBS) Product Testing Dispersion in bitumen SBS Bnutnen Desired point Seftsning point results 1 90 10 02 44 Failed 2 80 30 S3 44 Fasten 3 70 30 02 44 Failed 4 ■S0 40 S3 44 Failed 5 50 50 02 44 Fssiad 6 40 50 S3 85 Passed 7 30 70 02 92 Passad a 20 SO 02 S3 Passed

[00148] It was found that Formulations of BMP with concentration of SBS of equal or less than 40%w / w and more than 60%w / w bitumen have sufficient dispersion. Table 1 shows the test results of different concentration of SBS polymer to bitumen in BMP and its effects on dispersion. The success of dispersion is measured by testing softening point of the resultant PMB after dilution of BMP with bitumen such that the concentration of SBS is 6.5% in the resultant PMB. And the desired softening point of 92 is based on the common PMBs in the market with the same SBS concentration.

[00149] Formulations of BMP comprising between 20%w / w to 90%w / w HDPE and between 80% and 10%w / w bitumen, were subjected to softening point test and dispersion test in molten bitumen. Results are shown in Table 2 below.

[00150] Table 2- the composition of polymer to bitumen for HDPE BMP and its effects on dispersion in bitumen (LDPE, LLDPE, EVA, and PP behaved almost similar to HDPE). to Prorioct Testing Dispersion in nitiireen HDPE Situmen Desired softening Softening paint results Trial 1 98 10 >52 44 PeSed 3 98 30 44 SaSsd [ a 70 30 >52 44 PsRed 4 68 40 >52 53 Passed 1 5 58 SO >52 53 Passed J S 48 so >52 S3 Passed | 7 38 70 >52 53 Passed | 8 28 80 >52 S3 Passed ]

[00151] It was found that Formulations of BMP with concentration of HDPE of equal or less than 60 %w / w and more than 40%w / w bitumen have sufficient dispersion. Table 2 shows the test results of different concentration of HDPE polymer to bitumen in BMP and its effects on dispersion. The success of dispersion is measured by testing softening point of the resultant PMB after dilution of BMP with bitumen such that the concentration of HDPE is 4.5% in the resultant PMB. And the desired softening point of more than 52 is based on the common PMB with the same HDPE concentration.

[00152] Storability

[00153] Formulations of BMP ranged from 25%w / w to 90%w / w SBS block copolymer and between 10% and 75%w / w bitumen. Each formulation was coated with high viscous layer coating and divided into three groupings defined by particle size. The products were subject to storability protocols. Results are shown in Table 3 below.

[00154] The BMP pellets need to meet storability test requirements that described earlier. This is to ensure and confirm that BMP products can be easily transported and stored. Table 3 and Table 4 show test results to understand the required number of fine particles to coat the pellets to prevent agglomeration.

[00155] It was found that for any SBS concentration more than 25%, 3% by weight of fine particles can prevent agglomeration in pelletised BMP and is sufficient for having storable product at ambient temperatures and above, which represents a surprising effect. Also when using HDPE a concentration of more than 40%, and 1% fine particles is shown to prevent agglomeration and is sufficient for having storable product.

[00156] Table 3- the composition of polymer to bitumen and fine particles required to coat the SBS BMP and its effects on storability (crumb rubber is almost behaving similar to SBS) Prceiee' Run S&S grturra-sn Fine paideia > try 1 Fins patecie a- tryi Fine psstrsies- try S nniy *c> tiiu      faysK <0 psRuts 0¾ 1% Sts 5 35 Fsii.sD Fated Failed 2 1« §0 Faits® Faits® Faiied 3 15 85 Fuiterf Feted Failed I 4 20 80 taiied Faded 25 7S tailed Failed Passed 3 20 70 t »<>• 6 Fated Passat! 7 33 65 Faiied Faiied Passed 3 40 sa Fa-ted Fated Passsei 45 55 Faiied Faii®« Passed 2« 53 $0 Faiied Faiied Farrsed j 11 55 45 Frs-ted Faiied Passat! 12 65 40 Failed Faiied Passed 1       13 65 35 Fated Fated Passed 7« 35 Fai!®® Faiis® Passed 15 75 25 Fstted Feted Pass-sei 1 00 20 Psssed Passed Passat! 17 85 15 Passed Passed Passed 1 00 15 Passed Passed PaSSfa?

[00157] Table 4- the composition of polymer to bitumen and fine particles required to coat the HDPE BMP and its effects on storability (LDPE, LLDPE, EVA, and PP almost behaved similar to HDPE) Product compos Mun addition of Ones to farm a high-viscos-layer coating each pellet Run HOPE Siteses Fine panicles- try 1 Fine particles- try 2 Only to the outer layer of pellets 0% 1% 1 5 85    [ Failed Failed 2 10 90 Failed Failed 3 15 85 | Failed Failed 4 20 90    | Failed Failed 5 25 75   | railed Failed 6 30 78 Failed Failed 7 35 85 railed Failed 8 45 68 Failed Passed 9 45 55 Failed Passed 10 58 58 | railed Passed 11 55 45    | Failed Passed 12 60 40 Failed Passed .13 35 38    | Passed Passed 14 70 30 Passed Passed 15 75 25    | Passed Passed IS 38 20    | Passed Passed 17 §5 15 Passed Passed 18 90 18    | Passed Passed

[00158] Effect of Particle Size on dispersion

[00159] Formulations comprised 30%w / w SBS block copolymer and between 70w / w bitumen, were divided into three particle size groupings. Each formulation was coated with high viscous layer coating. The products were subject to dispersion protocols described in example 1. Results are shown in Table 5 below.

[00160] Table 5- the effects of particle size on the dispersion of the SBS BMP pellets in the bitumen (similarly for crumb rubber) Product core position Particle size (mm) addition os fines to form a high-uiscos layer coating each pellet Dispersion (less than 15 minutes, at ISO degrees, 450 rpm) Desired particle size flue SBS Bitumen Storability (3% fine particles only to the outer layer of pellets) 1 30 70 2 Fa-ted Passed 2 30 70 5 Passed Passed Selected 3 30 7g 10 ____________Passed___________ __________Failed_________

[00161] Formulations comprised 60%w / w HDPE and between 40w / w bitumen were divided into three particle size groupings. Each formulation was coated with high viscous layer coating by addition of fines. The products were subject to dispersion protocols described in example 1. Results are shown in Table 6 below.

[00162] Table 6- the effects of particle size on the dispersion of the HDPE BMP pellets in the bitumen (similarly for LDPE, EVA, and PP BMPs) Product composition Particle size ;rrm; addi tion of fines to form a high-viscos layer coating each pellet Dispersion (less than 15 minutes, at 130 degrees. 450 rpm) Desired particle size Hun HOPS Bitumen Starability (1<& fine particles only to the outer layer of pellets) 1 80 40 2 Failed Passed 2 60 40 5 Pressed Pressed Selected 3 SO 40 10 ____________Passed____________ _________Failed_________

[00163] Settling Behaviour

[00164] BMP formulations comprised (i) 30%w / w SBS block copolymer and 70w / w bitumen; and (ii) 60%w / w HDPE and 40%w / w bitumen. Products were divided into groups according to particle size and coating. The BMP products were introduced into molten bitumen and subject to a settling protocol. Results are shown in Tables 7 and 8 below.

[00165] Table 7- the settling behaviour of SBS BMP being added into the hot bitumen at different concentration of fine particles (similarly for crumb rubber) Run P reduct co m posftio n Settling behaviour settling results SBS Bitumen Fine particles for outer layer Fine particles in the mix % % -¾ 1 30 70 3 0 Flotation Failed 2 30 70 3 5 Suspension Preferred 3 30 70 3 20 Sedimentation Failed

[00166] Table 8- the settling behaviour of HDPE BMP being added into the hot bitumen at different concentration of fine particles (similarly for LDPE, EVA, and PP BMPs) Bun Product composition Settling behav-our settling results MOPE Bitumen Fine particles for outer layer Fine particles in the mix % vs •% •% 1 60 40 1 0 Flotation Failed 2 60 40 1 5 Suspension Preferred 3 60 40 1 20 Sedimentation Failed

[00167] Overall test results of SBS BMPs after addition to hot bitumen

[00168] Each class of PMB has distinct performance characteristics. According to the Australian specification framework for PMB, the properties required for each class are characterised using the following tests:

[00169] Torsional recovery at 25°C, 30s (%);

[00170] Viscosity at 165°C (Pa.s); Softening point (°C);

[00171] Consistency at 60 °C (Pa.s); Stiffness at 25°C (kPa);

[00172] Segregation (%).

[00173] The torsional recovery test (AGPT-T122) is a simple method for evaluating the elasticity introduced by rubber or polymer in an asphalt binder. The test involves manually rotating a bolt assembly embedded in a sample by 180° over 10 seconds, then measuring its recovery after 30 seconds. The result is reported as a percentage.

[00174] A viscosity test (AS 2341.4) measures PMB flow resistance. The maximum viscosity at the recommended application temperature is often specified to ensure compatibility with standard equipment.

[00175] Softening point test (AGPT-T131) measures the temperature at which the PMB sample begins to soften, using a ring-and-ball apparatus. This test indicates the binder's resistance to heat, serving as a crucial quality control parameter to ensure optimal performance across various climates.

[00176] In Australia, a specialized instrument that is unique to Australia and is called “ARRB Elastomer” is used to evaluates the elasticity and consistency of PMBs under controlled conditions. The instrument shears an annular sample between concentric cylinders to a set strain level (loading phase), then measures strain recovery over time after removing the load (recovery phase). During the loading phase, both sample displacement and force are recorded. Consistency 6% at 60 °C (AGPT-T121) is calculated from the force at a sample strain of 0.06. The maximum force at the end of loading phase is also used to calculate the stiffness (AGPT-T121).

[00177] Segregation test (AGPT-T108) test method assesses a PMB's tendency to segregate after prolonged storage at high temperatures. The process involves heating a sample of the PMB in an oven at an elevated temperature, then measuring the softening points of the top and bottom halves of the sample after a specified time.

[00178] Table 9 and Table 10 show the comparison between BMP dilution in bitumen and conventional PMB based on different polymer concentrations. As the test results demonstrate, both methods have very similar results, proving the perfect dilution of BMP in bitumen.

[00179] Table 9- binder test results of SBS BMP addition to molten bitumen compared with conventional PMB at different polymer concentration in the resultant PMB. Meshed Polymer concentration in bit omen Viscosity at 185 °C Tossioriai recovery at 25C, 80s Pte Softeamg paint p'Ci Consistency 6to al 60 -C Stiffness at 15*Q (kPa) Segregation ' (¾) BMP added to bitemen 3¾¾ 0.3 35 55 450 38 0.1 Conventional PMB W 0.3 36 54 455 31 0.1 BMP added to fritetnert 0.3S 48 80 538 <15 8.1 Ccnveadot sal PMB 4¾ <3.35 46 60 535 43 8.1 BMP added to bitumen 0.41 53 71 735 51 0,2 Conventional PMB BMP added to bitomen 0.^2 73 78.5 35 751 1638 S3 0.2 0.2 Conventional PMB 8¾¾ 0.6 73 34 1630 *37 0.2

[00180] Table 10- binder test results of HDPE BMP dilution in bitumen compared with conventional HDPE PMB at 5% polymer concentration in the resultant PMB. Method       i Polymer Type Polymer concentration ■n bitumen Viscosity at 185 °C Torsional recovery at25C. 30s (to) Softening point (°C) Segregation BMP added tn    1 , .               :         HOPE Oilurttof!         : ................. 5¾     i 0-35 :    0.35 35 55     i     0.4 54     |     8.4

[00181]     Overall test results of SBS BMPs after dilution in asphalt

[00182] This modification is assessed by comparing the properties of BMP- modified asphalt with those made using industrial PMB, with key performance indicators including Marshall stability and flow, rutting resistance, stripping potential, and resilient modulus. The closer the results of BMP-modified asphalt are to those made with industrial PMB, the more effective the dispersion and modification are considered to be. SBS BMP is considered as the representative of all the polymers for asphalt testings. Marshall test results

[00183] As mentioned in ASTM 6927 minimum of three Marshall specimens, for each mix design, must be tested. Aggregates and bitumen are preheated for two hours, up to the mixing temperature. Then they are weighted and added to the mixer. The BMP pellets are added to the hot aggregates at the same time of adding the bitumen into the mix. All the pellets are introduced into the mix at room temperature. The whole mixture was mixed for 55 seconds under 30 rpm at 180 degrees.

[00184] For samples prepared with conventional method, hot PMB was added to the hot aggregates and mixed for 55 seconds.

[00185] Specimens are compacted by 50 blows at the temperature of around 150 ±3 °C, as specified in AS 2891. Then specimens are cooled to room temperature. The specimens are conditioned in the water bath for 30-40 min at the temperature of 60 °C before Marshall stability and flow are conducted.

[00186] Table 11- Marshall test results of SBS BMP added to asphalt compared with conventional PMB at different polymer concentration in the resultant PMB.

[00187] Run Binder content Method Polymer concent ration Stability Flow (mm) 5.5¾ BMP added directly to asphalt 0 6.5 5.8 2 5.5% BMP added directly to asphalt 3 7,6 2,9 3 5.5% BMP added directly to asphalt 4 8,1 2,6 4 5.5% BMP added directly to asphalt 5 9.2 2.5 5 5.5% BMP added directly to asphalt 5 10 2,6 6 5.5% BMP added directly to asphalt 7 12,5 2.2 7 5.5% PMB-corwendonai method 0 6.4 3 8 5.5% PM B-convent ion al met hod 3 8.3 2.8 9 5.5% PMB-conventional method 4 8.3 2.7 .1.0 5.5% PMB-conventional method 5 9.6 2.7 11 5.5% PM B-convent ional met hod 6 9.9 2.7 12 5.5% PM B convention al method 7 12.3 2.7

[00188] Table 11 shows the test results of Marshall properties of the BMP modified asphalt and PMB asphalts. The test results show that BMP pellets have effectively modified asphalt and resulted similar to BMP performance.

[00189] Indirect tensile strength ratio (ITSR) results

[00190] The stripping potential of asphalt was measured according to indirect tensile strength ratio test according to Austroads Test method ATM 232.

[00191] Tabulated information in table 12 shows that both methods have similar performance against stripping potential, BMP diluted in the asphalt mixture slightly outperformed conventional method of PMBs.

[00192] Table 12- Indirect tensile strength ratio test results of SBS BMP added to asphalt compared with conventional PMB at 6% polymer concentration in the resultant PMB. BMP added into asphait______________________________________ BMP added into asphalt i                 [ Average |                   [ Tensile Ratio 0.92 i Conditioned_______|_________________________ i Unconditioned | 852 981 Asphalt mads by PMB I Conditioned [ 825 0,90 --------„-----------------------------1------------------ Asphalt made by PMB I Unconditioned i 920

[00193] Wheel tracking test results

[00194] The deformation resistance of the asphalt mixtures modified by BMP and made by conventional PMBs measured by wheel tracking machine according to AGPT / T231. The results are shown in figure 9. BMP added into the asphalt performed better than conventional PMBs in terms of rutting resistance in 10,000 cycles at 60 degrees.

[00195] Resilient Modulus results

[00196] The resilient modulus of the asphalt mixture modified by BMP and made by conventional PMBs measured according to AS / NZS 2891.13.1.

[00197] Figure 10 shows an example of the test reults of resiIiant modulus driven from the universal testing machine. Table 13 compares the test results of both methods and demonstrates that both methos have almost similar resiliant modulus result on asphalt modification. Furthur highlughting fully dilution of BMP into the apshalt matrix in 55 seconds.

[00198] Table - 13 -Resilient Modulus test results of SBS BMP added to asphalt compared with conventional PMB at 6% polymer concentration in the resultant PMB. Mix DGA Max aggregate size 20 Binder ranteet 0.052 Compaction Gyro compactor Number of Cycles 150 Standard AS / NZS 2891.13.1 Specimens Diameter (mm) 150 Specimen Height jw) 85 temperature C'Ci Binder type BMP added into asphait Aspimit made by PMS AV % 0.048 0.046 Resident Moduius 5581.4 5407.7 CV% 0.87 0.08

[00199] First Embodiment Method

[00200] Referring to figures 1 to 5, there is shown a process for preparing BPMs having between bitumen in an amount ranging from about 75wt% to 30wt%; and a polymer in an amount ranging from about 25wt% to 70wt%. Polymers are selected from styrene-butadiene-styrene (SBS), rubber or crumb rubber (CR), polypropylene (PP), polyethylene (PE), Ethylene-vinyl acetate (EVA), or their combinations.

[00201] In figure 1, a select polymer or combinations thereof are mixed with bitumen and fine particles to form a BMP 101 at a temperature of between about 160 to 200 degrees C in a high-shear force extruder. The fine particles such as hydrated lime sized less than 1mm and are introduced into the extruder downstream from the polymer and bitumen. The number of fine particles in the BMP ranges up to about 20%w / w combined with 100% polymer / bitumen in the total BMP. The hydrated lime fine particles increase the density of the resultant BMP allowing BMP pellets to remain suspended in molten bitumen during dispersion in the molten bitumen to form PBMs.

[00202] The mixture 101, 201 is subjected to blending at a high shear force. Intense shear forces are imposed on the materials through rotating screws and barrel geometry of the extruder, which provides effective blending and mixing of the components.

[00203] The resulting composition is pelletised 102 to obtain a desired size which is convenient for transfer and conveying onsite. Pelletising to obtain the desired size is performed underwater. During this process, fine particles such as talc sized between less than 0.1 mm are added to the water to enhance the anti-stick properties of the resultant pellets. The pellets are effectively coated with the talc., which provides a barrier to agglomeration at ambient temperatures. The pelletising of BMP product allows the BMP to be easily stored, transported, and used effectively. The pellets of smaller particles enhance the mixability of the BMP with bitumen and asphalt, allowing for quicker dispersion in molten bitumen 103.

[00204] The resulting BMP pellets have a density equal to or higher than hot bitumen allowing the pellets to sink and disperse effectively and quickly into a molten tank of bitumen onsite. The BMP pellets coated with fine particles is storage stable at ambient temperatures.

[00205] As shown in figure 2, the BMP 201 is storable at ambient temperatures, i.e. no need for high temperatures to avoid phase separation. When used to produce a PMB, the BMP 201 is transported from storage at ambient temperature to a facility for onsite of asphalt production dispersion 202 with molten bitumen or asphalt. Onsite of asphalt production, the BMP is added to molten bitumen 203 in an amount which produces a PMB having up to about 10% by weight of polymer, or as required, in bitumen useable as a binder having properties to extend the lifetime of roads, footpaths and other like constructions. Figures 3 to 5 show a variety of combinations of polymers and bitumen and particulates which can be used in the present invention to form BMPs for use in preparing PMBs without the need for high energy requirements of conventional PMBs. This represents a clear improvement over the prior art. The ability to transport BMPs makes it very useful and practical for long trips to regional areas for example without consuming vast quantities of energy and harmful effects.

[00206] High shear refers to a condition where a material is subjected to intense mechanical forces that cause adjacent layers to move at significantly different speeds. This generates shear stress, which can break down, deform, or blend materials.

[00207] Further Embodiment Method

[00208] Figure 6 shows a method 1000 of producing a modified binder. The method 1000 comprises a series of steps. The first step 1001 is defined as heating a binder to a first temperature between 80°C and 180°C to produce a heated binder and heating of a catalyst to a second temperature between 180°C to 300°C to produce a heated catalyst. The second step 1002 is adding of polymers to the heated binder to produce a mixture such that the polymer forms at least 20% of the total weight of the produced mixture. Adding the polymer at room temperature to the binder avoids deterioration of the properties of the polymer and avoids polymer oxidation which would otherwise make the polymer less compatible with the binder. The third step 1003 is adding of heated catalyst to the mixture. The adding of the pre-heated catalyst to the mixture helps in increasing the temperature of the mixture. The fourth step 1004 is heating of the mixture and the heated catalyst to a third temperature ranging from about 90°C to 200°C.

[00209] From the fourth step 1004, the method 1004 branches out to two alternative steps. The first alternative series of steps starts with a first alternative fifth step 1005 of maintaining the third temperature of the mixture and heated catalyst for a first period of time between 5 minutes and 2 hours. The first alternative sixth step 1006 is mixing the mixture and heated catalyst at the third temperature for a second period of time between 1 minute to 1 hour. In a preferred embodiment, the second period of time is between 2 minutes and 30 minutes. The end result after mixing is the modified binder.

[00210] The second alternative fifth step 1005’ of mixing the mixture and heated catalyst at the third temperature for the second period of time. The end result is the modified binder.

[00211] In an embodiment, the mixing speed in first alternative sixth step 1006 and the second alternative fifth step 1005’ is between 1 RPM to 1000 RPM.

[00212] In a preferred embodiment, the mixing speed in first alternative sixth step 1006 and the second alternative fifth step 1005’ is between 30 RPM to 100 RPM.

[00213] Second Embodiment Method

[00214] Figure 2 shows a method 2000 of producing a modified binder. The method 2000 comprises the steps discussed above and additional steps comprising either shredding or pelletizing, coating, and packaging of the modified binder.

[00215] From the step of forming the modified binder 1007, the materials are expelled 1008. The method 2000 branches out to two alternative series of steps. The first alternative series of steps starts with a first alternative ninth step 1009 of cooling the hot modified binder to ambient temperature to achieve the modified binder. The first alternative tenth step 1010 is shredding the modified binder into a plurality of modified binder shreds. The first alternative eleventh step 1011 is coating the modified binder shreds with additives to produce coated modified binder shreds. The coated modified binder shreds are then packaged for storage, transportation, or delivery.

[00216] The second alternative series of steps starts with a second alternative ninth step 1009’ of extruding the hot modified binder to produce an extruded hot modified binder. The second alternative tenth step 1010’ is cooling the extruded hot modified binder to ambient temperature to arrive at an extruded modified binder. The second alternative eleventh step 1011’ is pelletizing the extruded modified binder to produce modified binder pellets. The second alternative twelfth step 1012’ is coating the modified binder pellets with additives to produce coated modified binder pellets. The coated modified binder pellets are then packaged for storage, transportation, or delivery.

[00217] Types of bitumen

[00218] Different types of bitumen may be used in any of the foregoing methods for producing the modified bitumen. The bitumen that may be used are any class of bitumen, or combination of any class of bitumen with oil, resin, high aromatic content binder, bio-oil, paraffin wax, and / or combination thereof.

[00219] Types of polymers

[00220] Likewise, different kinds of polymers may be used in any one of the foregoing methods for producing the modified binder. The polymers that may be used are polyethylene, polypropylene, poly(styrene-butadiene-styrene) (SBS), crumb rubber, Styrene-Ethylene-Butylene-Styrene (SEBS), Ethylene-Vinyl Acetate (EVA), and / or combinations thereof. [00221 ] Types of catalysts

[00222] The catalysts used in any of the foregoing methods for producing the modified binder are defined as a plurality of particles of a type of material. The catalyst may be a plurality of particles of metal elements having a size and shape. In a preferred embodiment, each particle may have a size ranging from 1 nanometre to 200 millimetres and each particle may have a generally spherical shape. In another preferred embodiment, the spherical metal elements have a diameter of 20mm.

[00223] Alternatively, the particles that can be used as catalysts may be glass elements.

[00224] In general, high turbulence can be beneficial for mixing two viscous. That is because it can help to break up stagnant regions and increase the mixing efficiency by chaotic and irregular flow patterns with fluctuations in velocity and pressure, which can mix the fluid more thoroughly.

[00225] Embodiments of the invention add solid particles into the liquid, acting as mechanocatalysts. This leads to a significant improvement in mixing efficiency and also obviates the need for a shear mill. The process utilizes a mixing tank filled with metal balls (free solid particles). The size of the balls can vary depending on the size of the mixer; however, 20 mm balls have been found to be practical. In this process the solid particles (metal balls or other solid particles) are the catalyst of the reactions themselves. The collision and movements of the solid particles provide energy and shearing forces for the reactions.

[00226] Introducing metal balls (solid particles) in a flowing liquid also can disturb the smooth flow of the liquid and create turbulence which helps mixing.

[00227] Particles also promote better mixing by enhancing heat transition throughout the mixture. Polymers are added into the mixture at room temperature, since heating up polymers in contact with air can deteriorate its properties and also hinder its compatibility with bitumen due to oxidation.

[00228] When polymers are added into the hot binder (bitumen), the temperature of the overall mixture drops significantly, from approximately 180 degrees down to 100 degrees. Given that polymers generally exhibit very low thermal conductivity, it takes a long time for the overall mixture to raise its temperature to the mixing temperature (around 160 to 200 degrees) as the thermal conductivity of the plastic + bitumen is still very low.

[00229] However, by introducing hot particles (metal balls) at 200 degrees, or higher, firstly the overall temperature of the mixture increases quickly to approximately 160 degrees or higher and, secondly, the overall thermal conductivity of the mix of solid particles + bitumen + polymer is significantly increased and leads to enhanced heat transition throughout the mixture. This shortens the mixing time, saves energy, and improves productivity.

[00230] In embodiments of the present invention, polymer and hot bitumen are introduced together into the preheated mixer, such that their total volume equals the volume of the metal balls (catalysts).

[00231] Third temperature ranges, first period of time ranges, and second period of time ranges based on the polymer used.

[00232] The third temperature in the foregoing methods is dependent on the type of polymer used. As shown in Figure 4, each polymer corresponds to a certain third temperature range. If the polymer used is Polyethylene (PE), the third temperature is 160°C. If the polymer used is Polypropylene (PP), the third temperature ranges is 180°C. If the polymer used is Poly(styrene-butadiene-styrene) (SBS), the third temperature ranges is 180°C. If the polymer used is Styrene-Ethylene-Butylene-Styrene, the third temperature is between 150°C - 180°C. If the polymer used is Crumb rubber, the third temperature is between 160°C - 200°C. If the polymer used is Ethylene-Vinyl Acetate, the third temperature is 130°C. In another embodiment, a combination of the foregoing polymers may be used. If there is a mixture of different polymers used, the higher of the above-mentioned temperatures corresponding to the polymer mixed is used.

[00233] The first period of time in the foregoing methods is dependent on the type of polymer used. If the polymer used is either Crumb Rubber, polyethylene or polypropylene, the first period of time is about 10 minutes. If the polymer used is poly(styrene-butadiene-styrene), the first period of time is about 15 minutes. If the polymer used is Ethylene-Vinyl Acetate, the first period of time is about 5 minutes. In another embodiment, a combination of the foregoing polymers may be used. If there is a mixture of different polymers used, the higher of the above-mentioned periods corresponding to the polymer mixed is used.

[00234] The second period of time in the foregoing methods is dependent on the type of polymer used. If the polymer used is either crumb rubber, polyethylene or polypropylene, the second period of time is about 5 minutes. If the polymer used is poly(styrene-butadiene-styrene), the second period of time is about 7 minutes. If the polymer used is Ethylene-Vinyl Acetate, the second period of time is about 3 minutes. In another embodiment, a combination of the foregoing polymers may be used. If there is a mixture of different polymers used, the higher of the above-mentioned periods corresponding to the polymer mixed is used.

[00235] Types of additives

[00236] As shown in Figure 2, the modified binder shreds or the modified binder pellets may be coated with additives. These additives may be fine particles and fibres such as hydrated lime, baghouse ash, calcium carbonate, fly ash, recycled plastic, crushed glass, cellulose fibres, and / or a combination thereof.

[00237] In an alternative embodiment (not shown), the additives may be added to the heated catalyst and the mixture in the fourth step 1004 (as shown in Figure 1).

[00238] In another alternative embodiment, the additives are added to the mixture and heated catalyst after steps 1006 or 1005’ (As shown in Figure 1) and are mixed together at a third period of time between 30 seconds to 30 minutes. In a preferred embodiment, the third period of time is between 2 to 5 minutes.

[00239] Composition of the BMP

[00240] In any of the foregoing embodiments, the amount of bitumen used is between from about 75wt% to 30wt% and the amount of polymer used ranges from about 25wt% to 60wt%. As a result, the modified binder achieved may have any combination of binder to polymer ratio corresponding to the foregoing ranges which sufficiently adds up to a 100wt% composition. In a preferred embodiment, the bitumen to polymer ratio is 40wt% to 60wt%, respectively. [00241 ] Composition of binder and polymer of the BMPs

[00242] In any of the foregoing embodiments, the amount of bitumen used is between from about 25wt% to 75wt% and the amount of polymer used ranges from about 25wt% to 75wt% As a result, the BMP achieved may have any combination of binder to polymer ratio corresponding to the foregoing ranges which sufficiently adds up to a 100wt% composition. In a preferred embodiment, the polymer to bitumen (binder) ratio is 33wt% to 67wt%, respectively, when SBS and Crumb's rubber is used in direct-to-asphalt plant applications. 25wt% to 75wt%, respectively when SBS and Crumb rubber are used for direct to bitumen tank applications. 40wt% to 60wt%, respectively, when EVA, PP, and PE are used for direct to asphalt mixer applications. 60wt% to 40wt%, respectively, when EVA, PP, and PE are used for direct to bitumen tank. In the case of recycled plastics, where the component of each polymer is unknown, a polymer-to-bitumen content of 25wt% to 75wt% is preferred, respectively. The higher bitumen content is selected to ensure that impurities and additives in the recycled polymers do not hinder the dispersion of the polymer into the binder matrix.

[00243] The above-mentioned compositions excluded the fine particles and additives for simplicity.

[00244] The number of fine particles can range from 0% to 10% of the total weight of polymer and bitumen to prevent agglomeration. However, 1% is sufficient to prevent stickiness in PP, PE, and EVA BMPs and 3-5% is sufficient for SBS and crumb rubber BMPs.

[00245] The number of fine particles can range from 0% to 10% of the total weight of polymer and bitumen to promote settling behaviour. However, 5% is sufficient for hydrated lime.

[00246] Addition of sulfur for cross-linking and preventing segregation can range from 0% to 2%. However, the preferred concentration of sulfur and hydrogen sulfide (H2S) scavengers are 0.6% of the total weight of BMP (70% sulfur with 30% hydrogen sulfide (H2S) scavengers). Example composition of the commercial product. Product 1 - 33% SBS, 67% bitumen, 3% hydrated lime (or any other fine particles) Product 2 - 40% CR, 60% bitumen, 5% hydrated lime (or any other fine particles). Product 3 - 33% SBS, 67% bitumen, 3% hydrated lime (or any other fine particles), 0.6 to 1% Sulfur or other stabilisers. Product 4 - 25% SBS, 75% bitumen, 3% hydrated lime (or any other fine particles), 0.6 to 1% Sulfur or other stabilisers. Product 5 - 25% PE and / or PP recycled waste plastic, 75% bitumen, 3% hydrated lime (or any other fine particles). Product 6 - 60% PE and / or PP, 40% bitumen, 1 % hydrated lime (or any other fine particles). Product 7 - 60% EVA, 40% bitumen, 1% hydrated lime (or any other fine particles). Product 8 - 10% PE and / or PP, 40% CR, 50% bitumen, 1% hydrated lime (or any other fine particles). Product 9 - 30% SBS, 60% bitumen, 10% PE, 3% hydrated lime (or any other fine particles). Product 10 - 33% SBS, 67% bitumen, 5% hydrated lime (or any other fine particles), 3% talc, 0.6 to 1 % Sulfur or other stabilisers. Product 11 - 20% CR, 20% SBS, 60% bitumen, 5% hydrated lime (or any other fine particles). Interpretation “About” The word “about’ when used in this specification includes variations to the measure of plus or minus 5%. Markush Groups

[00247] In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognise that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group. Chronological sequence

[00248] For this specification, where method steps are described in sequence, the sequence does not necessarily mean that the steps are to be carried out in chronological order in that sequence, unless there is no other logical manner of interpreting the sequence. Embodiments:

[00249] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[00250] Similarly it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Description of Embodiments are hereby expressly incorporated into this Description of Embodiments, with each claim standing on its own as a separate embodiment of this invention.

[00251] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. Different Instances of Objects

[00252] As used herein, unless otherwise specified the use of the ordinal adjectives “first”, “second”, “third”, etc., to describe a common object, merely indicate that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner. Specific Details

[00253] In the description provided herein, numerous specific details are set forth.lt is understood, however, that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. Terminology

[00254] In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. The invention is, however, not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as “forward”, “rearward”, “radially”, “peripherally”, “upwardly”, “downwardly”, and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

[00255] As used herein the term “and / or” means “and” or “or”, or both.

[00256] As used herein “(s)” following a noun means the plural and / or singular forms of the noun. Comprising and Including

[00257] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” are used in an inclusive sense, i.e., to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

[00258] Any one of the terms: including or which includes or that includes as used herein is also an open term that also means including at least the elements / features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising. Scope of Invention

[00259] Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[00260] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

[00261] Terms Meaning Bitumen Bitumen is a binding agent produced from petroleum. Bitumen is known for being strongly adhesive and resistant to damage from water and oil spills. This makes bitumen the ideal binder for asphalt because asphalt is commonly used as a surface for roads, car parks and driveways. Asphalt Asphalt consists of bitumen, aggregates, sand, and stones. Bitumen, derived from petroleum, binds together the other materials as an adhesive. The ingredients are heated, dried, and mixed at a plant into a composite called asphalt. This solid mixture is then applied on-site to construct durable road surfaces. Binder bitumen, oil, resin, high aromatic content binder, biooil, paraffin wax, and / or combination thereof BMP Bitumen Modified Polymer and / or Binder Modified Polymer BMP pellets Pellets of BMP PMB Polymer Modified Bitumen SBS poly(styrene-butadiene-styrene)

[00262] Industrial Applicability

[00263] It is apparent from the above, that the arrangements described are applicable to the roadway and pathway construction, asphalt and bitumen industries and general construction industry.

Claims

1. A method of producing a modified binder including a percentage of bitumen or asphalt, wherein the modified binder is formed by:a. Selection of component parts of bitumen, polymer and additivesb. Use of particular mixing equipment providing high shear mixing of the selection of component partsc. Provision of mixing conditions of the mixed selection of component parts to provide a modified binder.

2. A method of producing a modified binder according to claim 1 wherein the method also includes size reduction of components.

3. A method of producing a modified binder according to claim 1 wherein the modified binder provides a modifier in the form of a bitumen modified polymer (BMP) to provide a transportable modifier at ambient temperature in order to be mixed for short period of time with bitumen or asphalt mixture to form the desired polymer modified binder (PMB) onsite of asphalt and / or PMB production.

4. A method of producing a modified binder according to claim 3 wherein the BMP has a ratio of polymer to bitumen in the range of 25% to 70% and is usable to form onsite the modified binder with a polymer to bitumen ratio of less than about 10%.

5. A method of producing a modified binder according to claim 4 wherein the BMP compositions is formed to be easily mixable with bitumen in a bitumen tank and with asphalt mixture in asphalt mixing plants and disperse efficiently.

6. A method of producing a modified binder according to claim 5 wherein the BMP compositions achieve complete dissolution in bitumen tanks under agitation in less than 15 minutes at 180 degrees and fully disperse in the asphalt plant mixer in under 55 seconds at 180 degrees.

7. A method of producing a modified binder according to claim 1 wherein bitumen modified polymer (BMP) composition for use in preparing a polymer modified bitumen (PMB), the composition comprising: bitumen in an amount ranging from about 30wt% to 75wt%; and a polymer in an amount ranging from about 25wt% to70wt%; wherein the BMP composition is stable, transportable at ambient temperature and disperses effectively in bitumen to produce the PMB.

8. A method of producing a modified binder according to claim 7 wherein the polymer used to form the BMP is styrene-butadiene-styrene (SBS) block copolymer.

9.

6. A method of producing a modified binder according to claim 7 or 8 wherein the BMP composition of the invention can be provided in the form of pellets including a coating of fine particles which assists in substantially minimising or avoiding agglomeration and wherein the BMP composition has a density equal to or greater than the density of the molten bitumen used for the PMB.

10. A method according to any one of the preceding claims wherein the method includes the steps comprising blending a select polymer and bitumen at a temperature within the range of about 160 to 200 degrees C in a high-shear force mixer in the presence or not presence of fine particles; subjecting the blended composition to a process of shredding or pelletising to obtain a desired size; wherein the density of the pelletised BMP is equal to or higher than that of hot bitumen allowing the particles to sink and disperse effectively and quickly into a binder; and wherein the pelletised BMP is storage stable.

11. A method of producing a modified binder according to claim 10 wherein the high shear mixer is at least two extruders where a first extruder feeds into the second extruder, wherein the first extruder initially prepares the polymer and bitumen material and feeds it to the second extruder.

12. A method of producing a modified binder according to claim 10 wherein the fine particles used in the BMP blend includes one or more of hydrated lime (calcium hydroxide), sulfur, stabilizers, and other fine particles for the two primary purposes of:a. reducing the blend's stickiness andb. increasing its density.

13. A method of producing a modified binder according to claim 10 wherein the process of pelletising to obtain a desired size is performed underwater to achieving good resistance to stickiness and agglomeration.

14. A method of producing a modified binder according to any one of the preceding claims wherein the method includes the steps of:a. heating at least one binder to a first temperature and heating a catalyst to a second temperature;b. adding at least one polymer to the at least one binder to form a mixture when the at least one binder has reached the first temperature, such that the at least one polymer is at least 20% of the total weight of the mixture;c. adding the catalyst to the mixture;d. heating the mixture and the catalyst to a third temperature and maintaining the third temperature for a first period of time; ande. either at the time of heating the mixture and the catalyst to a third temperature or after the first period of time, mixing the mixture and the catalyst at the third temperature for a second period of time until the mixture substantially homogenizes to form the modified binder.

15. The method of producing a modified binder according to claim 1 further comprising a step of removing the catalyst after the second period of time to isolate the modified binder.

16. The method of producing a modified binder according to claim 1 further comprising a step of cooling the modified binder to a fourth temperature.

17. The method of producing a modified binder according to claim 1 further comprising a step of extruding the modified binder into a plurality of modified binder pellets.

18. The method of producing a modified binder according to claim 1 further comprising a step of shredding the modified binder into a plurality of modified binder shreds.

19. The method of producing a modified binder according to claim 1 further comprising a step of coating the modified binder with at least one additive.

20. The method of producing a modified binder according to claim 1, wherein the at least one binder is selected from a group consisting of bitumen, oil, resin, paraffin wax, high aromatic content binder, bio-oil and combinations thereof.

21. The method of producing a modified binder according to claim 1, wherein the at least one polymer is selected from a group consisting of polyethylene (PE),polypropylene (PP), poly(styrene-butadiene-styrene) (SBS), crumb rubber, Styrene-Ethylene-Butylene-Styrene (SEBS), Ethylene-Vinyl Acetate (EVA) and combinations thereof.

22. The method of producing a modified binder according to claim 1, wherein the catalyst is particles.

23. The method of producing a modified binder according to claim 9, wherein the size of the particles is between 1 nanometre and 200 millimetres.

24. The method of producing a modified binder according to claim 23, wherein the size of the particles is less than 1mm if the catalyst does not require to be separated.

25. The method of producing a modified binder according to claim 23, wherein the size of the particles is more than 5mm when the catalyst is required to be separated.

26. The method of producing a modified binder according to claim 10, wherein the particles are metal elements.

27. The method of producing a modified binder according to claim 11, wherein the shape of the metal elements is generally spherical.

28. The method of producing a modified binder according to claim 12, wherein the diameter of the spherical metal elements is 20mm.

29. The method of producing a modified binder according to claim 9, wherein the particles are glass elements.

30. The method of producing a modified binder according to claim 1, wherein the third temperature is between 90°C and 200°C.31 .The method of producing a modified binder according to claim 8, wherein the third temperature is about 180 degrees Celsius when the at least one polymer is poly(styrene-butadiene-styrene) or polypropylene, temperature is about 200 degrees Celsius when the at least one polymer is Crumb Rubber, the third temperature is about 160 degrees when the at least one polymer is polyethylene, and the third temperature is about 130 degrees Celsius when the at least one polymer is Ethylene-Vinyl Acetate.

32. The method of producing a modified binder according to claim 16, wherein the higher of the third temperatures is used when there is a mixture of different polymers used.

33. The method of producing a modified binder according to claim 1, wherein the first period of time is between 5 minutes and 2 hours.

34. The method of producing a modified binder according to claim 8, wherein the first period of time is about 15 minutes when the at least one polymer is poly(styrene-butadiene-styrene), the first period of time is about 10 minutes when the at least one polymer is crumb rubber, polyethylene or polypropylene, and the first period of time is about 5 minutes when the at least one polymer is Ethylene-Vinyl Acetate.

35. The method of producing a modified binder according to claim 19, wherein the higher of the first periods of time is used when there is a mixture of different polymers used.

36. The method of producing a modified binder according to claim 1, wherein the second period of time is between 1 minute and 1 hour.

37. The method of producing a modified binder according to claim 21, wherein the second period of time is between 2 minutes and 30 minutes.

38. The method of producing a modifier binder according to claim 8, wherein the second period of time is about 7 minutes when the at least one polymer is poly(styrene-butadiene-styrene), the second period of time is about 5 minutes when the at least one polymer is crumb rubber, polyethylene or polypropylene, the second period of time is about 3 minutes when the at least one polymer is EthyleneVinyl Acetate.

39. The method of producing a modified binder according to claim 23, wherein the higher of the second periods of time is used when there is a mixture of different polymers used.

40. The method of producing a modified binder according to claim 6, wherein the at least one additive is added to the mixture and the catalyst.41.The method of producing a modified binder according to claim 27, wherein the at least one additive is added to the mixture after the step of mixing and then a second mixing is done with the at least one additive for a third period of time.

42. The method of producing a modified binder according to claim 28, wherein the third period of time is between 30 seconds and 30 minutes.

43. The method of producing a modified binder according to claim 29, wherein the third period of time is between 2 and 5 minutes.

44. The method of producing a modified binder according to claim 6, wherein the at least one additive is fine particles.

45. The method of producing a modified binder according to claim 1, wherein the mixture and the catalyst are mixed at between 1 RPM to 1000RPM.

46. The method of producing a modified binder according to claim 1, wherein the mixture and the catalyst are mixed at between 30 RPM to 100RPM.

47. A pelletised composition of a modified binder comprising:a. a binder in an amount ranging from about 30wt% to 75wt%; andb. a polymer in an amount ranging from about 25wt% to 70wt%.

48. A composition of a modified binder as claimed in claim 46, comprising about 40wt% of a binder and about 60wt% of a polymer.

49. The pelletised composition of a modified binder according to claim 46, wherein the binder is selected from a group consisting of bitumen, oil, resin, paraffin wax, high aromatic content binder, bio-oil and combinations thereof.

50. The pelletised composition of a modified binder according to claim 46, wherein the polymer is selected from a group consisting of polyethylene, polypropylene, poly(styrene-butadiene-styrene), crumb rubber, Styrene-Ethylene-Butylene-Styrene (SEBS), Ethylene-Vinyl Acetate (EVA) and combinations thereof.SELECTION OF POLYMER / BITUMEN / PARTICLES | FOR BMP101PROVIDE IN PELLETISED FORM WITH COATING TOPROVIDE PELLETISED BMP102USE PELLETISED BMP TO MODIFY BITUMEN TOFORM PMB103FIGURE 1PROVIDE BMP AT HIGH RATIO OF        |POLYMER / BITUMEN IN TRANSPORTABLE FORMAT |201TRANSPORT BMP TO SITE OF USE OF ASPHALT ORBITUMEN202MIX BMP ON SITE WITH ASPHALT OR BITUMEN TOFORM PMB HAVING LOWER RATIO OFPOLYMER / BITUMEN IN USABLE FORMAT203FIGURE 2Process uf making bitumen-modiried polymerFIGURE 3Process of making bitumen-modified polymerBulk storage stability under high temperature and high pressureCoating with fine particlesFIGURE 4BMP PerformanceBMP added toBMP added tobitumenasphaltBitumen tests                 Asphalt testsOptimum design is selectedOptimum design is selectedFIGURESFIGURE 6FIGURE 7TYPE OF POLYMER THIRD TEMPERATURE RANGES AND VALUES Polyethylene 160°C Polypropylene 180°C Poly(styrene-butadiene-styrene) 180°C Styrene-Ethylene-Butylene-Styrene 150°C-180°C Crumb rubber 160°C-200°C Ethylene-Vinyl Acetate 130°CFIGURESRut Depth (mm)" Asphalt made by PMB1.41.210.80.60.40.200           2000         4000         6000         8000         10000Number of PassesBMP added into asphaltFIGURE 9FIGURE 10

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