Claims:

1. A fuel resistant bituminous composition, the composition comprising: a bituminous component; Poly(styrene-butadiene-styrene) polymer; and Fischer Tropsch wax, wherein said composition exhibits dynamic modulus of at least 30000 MPa when measured at 5°C and at a frequency of 25 Hz, and wherein said composition exhibits dynamic modulus of at least 3000 MPa when measured at 55°C and at a frequency of 25 Hz.

2. The composition as claimed in claim 1, wherein said composition comprises the bituminous component in an amount ranging from 91% to 98% by weight of the composition.
3. The composition as claimed in claim 1, wherein said composition comprises the bituminous component in an amount of about 93% by weight of the composition.
4. The composition as claimed in claim 1, wherein said composition comprises Poly(styrene-butadiene-styrene) polymer in an amount ranging from 1% to 5% by weight of the composition.
5. The composition as claimed in claim 1, wherein said composition comprises Poly(styrene-butadiene-styrene) polymer in an amount of about 4% by weight of the composition.
6. The composition as claimed in claim 1, wherein said Fischer Tropsch wax comprises sasobit.
7. The composition as claimed in claim 1, wherein said composition comprises Fischer Tropsch wax in an amount ranging from 1% to 4% by weight of the composition.
8. The composition as claimed in claim 1, wherein said composition comprises Fischer Tropsch wax in an amount of about 3% by weight of the composition. , Description:
FIELD OF THE INVENTION
[0001] The present disclosure generally relates to a fuel resistant bitumen composition. Specifically, the present disclosure relates to a fuel resistant bituminous composition including a bituminous component, poly(styrene-butadiene-styrene) polymer, and Fischer Tropsch wax. The present disclosure also relates to a method of preparation of such a fuel resistant bitumen composition.

BACKGROUND OF THE INVENTION
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Bitumen is a viscous liquid or a solid consisting principally of hydrocarbons and their derivatives. It dissolves in trichloroethylene and softens progressively when heated. Bitumen may be combined with aggregate to provide asphalt.
[0004] Bituminous compositions are used as paving and coverings for a variety of surfaces, for example, roads and air fields. Such compositions comprise mixtures of aggregate and bitumen in specific proportions, and are generally laid and compacted while hot to provide a dense and durable surface. For many applications, bitumen renders a sufficiently durable and adhesive binder for the aggregate. However, for high load applications, bitumen alone suffers from several disadvantages.
[0005] Fuels, such as diesel and gasoline have a damaging effect on bitumen. These fuels tend to dissolve or soften the bitumen component of bituminous surfaces. Thus, with prolonged use, the aggregate components of such surfaces tend to become less well bound, so the surface tends to disintegrate. Runways laid with bituminous mixtures are subjected to softening and stripping of the coating of the aggregate particles due to fuel spillage during aircraft movement. Such scenario also exists in industrial storage yards as well as petrol retail outlets.
[0006] The runways and industrial storage yards are subjected to a substantial amount of wear and tear due to the landing and take-off maneuver (runway) and turning and braking maneuver (industrial storage yards) and hence none of the current standalone additive based technologies can be used since they are not designed to take such loads. This leads to premature rutting and fatigue cracking. Such scenarios are detrimental to the effective functioning of the infrastructure.
[0007] Thus, for high load applications, additives may be added to bitumen in order to improve its mechanical properties. Various additives have been proposed for this purpose, including polymers such as ethylene and vinyl acetate co-polymers. More recently, synthetic waxes comprising blends of synthetic aliphatic hydrocarbons have also been used in bitumen blends. Such blends tend to be more resistant to deformation under high loads compared to their corresponding wax-free counterparts.
[0008] Still, for the production of Fuel Resistant Bitumen (FRB), two main challenges exist. The first challenge is related to the addition of large dosage of polymers such that the resulting FRB can provide the required fuel resistance. This is facilitated by creating at the macromolecular level, a dense network of polymers such that the proximity of fuel does not lead to softening and dissolution of the binder. Such increased density of polymer network comes at a cost in terms of increased viscosity which can lead to difficulty in handling during the production process and also during the usage of FRB during the construction of bituminous layers. The second challenge is to lower the temperature of the production process such that an improved network of polymers is obtained in the bitumen at reduced production temperature. This involves identifying an appropriate additive which will not interact with the polymer but will facilitate the production process at a lower temperature.
[0009] Most of the commercially manufactured polymer modified binders restrict their use to not more than 3.5% of polymermic additives. In most cases, a small dosage of sulfur is added to develop cross-linking. Few other commercial products also use a combination of more than two polymers and even in such cases, the dosage does not increase beyond 4%. The addition of more than 8% polymer is challenging in terms of the production process as well as the development of phase inversion. Instead of the polymeric network present in the bituminous matrix, the bitumen is dispersed in a polymeric matrix. It is necessary that one quantifies that the reversed network can indeed provide the required load resisting capability through the measurement of an appropriate mechanical property.
[00010] Polymers commercially used to enhance the efficiency of asphalt binders are only partially miscible with asphalt. Experimental investigations have proved that phase separation occurs upon cooling the binder from the high production temperatures (180°C – 200°C). Even at these high production temperatures, some polymer modified bitumen may already show phase separation. The extent of this phase separation is dependent on the bitumen type, the concentration and the characteristics of the polymer. The literature on the morphology of polymer modified binders has indicated that phase separation is dependent on the thermal history of the binders, for instance, the heating and cooling conditions. It is also well known that the morphology has a significant influence on the rheological behavior of the binder.
[00011] In view of above stated shortcomings, there exists a need for a fuel resistant bituminous composition that exhibits improved mechanical properties than that of a conventional bitumen composition, and has the capability to withstand large pressure, especially more so during runway operation.

OBJECTS OF THE INVENTION
[00012] Primary object of the present disclosure is to provide a modified bitumen composition having improved resistance to fuel damage/cracking.
[00013] Another object of the present disclosure is to provide a modified bitumen composition having improved temperature performance.
[00014] Another object of the present disclosure is to provide a modified bitumen composition having improved total strain.
[00015] Another object of the present disclosure is to provide a modified bitumen composition having improved dynamic modulus.
[00016] Another object of the present disclosure is to provide a modified bitumen composition having capability to withstand large tire pressure.
[00017] Another object of the present disclosure is to provide a modified bitumen composition having suitable viscosity that does not lead to difficulty in handling during the production process.
[00018] Another object of the present disclosure is to provide a modified bitumen composition having an improved network of polymers at reduced production temperature.
[00019] Another object of the present disclosure is to provide a method of preparation of a modified bitumen composition having improved resistance to fuel damage/cracking.
[00020] Other objects of the present disclosure will be apparent from the description of the invention herein below.

SUMMARY OF THE INVENTION
[00021] The present disclosure generally relates to a fuel resistant bitumen composition. Specifically, the present disclosure relates to a fuel resistant bituminous composition including a bituminous component, poly(styrene-butadiene-styrene) polymer, and Fischer Tropsch wax. The present disclosure also relates to a method of preparation of such a fuel resistant bitumen composition.
[00022] An aspect of the present disclosure relates to a fuel resistant bituminous composition, the composition comprising: a bituminous component; Poly(styrene-butadiene-styrene) polymer; and Fischer Tropsch wax, wherein said composition exhibits dynamic modulus of at least 30000 MPa when measured at 5oC and at a frequency of 25 Hz, and wherein said composition exhibits dynamic modulus of at least 3000 MPa when measured at 55oC and at a frequency of 25 Hz. In an embodiment, said composition includes a bituminous component in an amount ranging from 91% to 98% by weight of the composition. In an embodiment, said composition includes a bituminous component in an amount of about 93% by weight of the composition. In an embodiment, said composition includes Poly(styrene-butadiene-styrene) polymer in an amount ranging from 1% to 5% by weight of the composition. In an embodiment, said composition includes Poly(styrene-butadiene-styrene) polymer in an amount of about 4% by weight of the composition. In an embodiment, said Fischer Tropsch wax includes sasobit. In an embodiment, said composition includes Fischer Tropsch wax in an amount ranging from 1% to 4% by weight of the composition. In an embodiment, said composition includes Fischer Tropsch wax in an amount of about 3% by weight of the composition.

BRIEF DESCRIPTION OF THE DRAWINGS
[00023] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present disclosure, the inventions of which can be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.
[00024] FIG. 1 illustrates variation of polymer area (polymer distribution) as a function of digestion time for a Fuel Resistant Bitumen (FRB) composition, in accordance with an embodiment of the present disclosure.
[00025] FIG. 2 illustrates Black diagram after 19 hours digestion time for a Fuel Resistant Bitumen (FRB) composition, in accordance with an embodiment of the present disclosure.
[00026] FIG. 3 illustrates results of high-temperature performance of for a Fuel Resistant Bitumen (FRB) composition compared with conventional compositions (VG30 and PG70-16 binders), in accordance with an embodiment of the present disclosure.
[00027] FIG. 4 illustrates results of total strain of for a Fuel Resistant Bitumen (FRB) composition compared with conventional compositions (VG30 and PG70-16 binders) at a range of temperature, in accordance with an embodiment of the present disclosure.
[00028] FIG. 5A-B illustrates variation of dynamic modulus vs. frequency for various temperatures for a Fuel Resistant Bitumen (FRB) composition wearing course mixture along with an unmodified binder, in accordance with an embodiment of the present disclosure.
[00029] FIG. 6A-B illustrates comparison of dynamic modulus vs. frequency at 5°C and 55°C of a Fuel Resistant Bitumen (FRB) composition of present disclosure with the commercially available FRB, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION
[00030] The embodiments herein and the various features and advantageous details thereof are explained more comprehensively with reference to the non-limiting embodiments that are detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of the ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[00031] Unless otherwise specified, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions may be included to better appreciate the teaching of the present invention.
[00032] As used in the description herein, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[00033] As used herein, the terms “comprise”, “comprises”, “comprising”, “include”, “includes”, and “including” are meant to be non- limiting, i.e., other steps and other ingredients which do not affect the end of result can be added. The above terms encompass the terms “consisting of” and “consisting essentially of”.
[00034] As used herein, the terms “composition” “blend,” or “mixture” are all intended to be used interchangeably.
[00035] The terms “weight percent,” “wt-%,” “percent by weight,” “% by weight,” and variations thereof, as used herein, refer to the concentration of a substance as the weight of that substance divided by the total weight of the composition and multiplied by 100. It is understood that, as used here, “percent,” “%,” and the like are intended to be synonymous with “weight percent,” “wt-%,” etc.
[00036] The present disclosure generally relates to a fuel resistant bitumen composition. Specifically, the present disclosure relates to a fuel resistant bituminous composition including a bituminous component, poly(styrene-butadiene-styrene) polymer, and Fischer Tropsch wax. The present disclosure also relates to a method of preparation of such a fuel resistant bitumen composition.
[00037] An aspect of the present disclosure relates to a fuel resistant bituminous composition, the composition comprising: a bituminous component; Poly(styrene-butadiene-styrene) polymer; and Fischer Tropsch wax, wherein said composition exhibits dynamic modulus of at least 30000 MPa when measured at 5oC and at a frequency of 25 Hz, and wherein said composition exhibits dynamic modulus of at least 3000 MPa when measured at 55oC and at a frequency of 25 Hz. In an embodiment, said composition includes a bituminous component in an amount ranging from 91% to 98% by weight of the composition. In an embodiment, said composition includes a bituminous component in an amount of about 93% by weight of the composition. In an embodiment, said composition includes Poly(styrene-butadiene-styrene) polymer in an amount ranging from 1% to 5% by weight of the composition. In an embodiment, said composition includes Poly(styrene-butadiene-styrene) polymer in an amount of about 4% by weight of the composition. In an embodiment, said Fischer Tropsch wax includes sasobit. In an embodiment, said composition includes Fischer Tropsch wax in an amount ranging from 1% to 4% by weight of the composition. In an embodiment, said composition includes Fischer Tropsch wax in an amount of about 3% by weight of the composition.
[00038] In an embodiment, said fuel resistant bituminous composition includes a bituminous component as its principal constituent. The bituminous component used can be bitumen obtained from different origins. The bituminous component which can be used according to the present disclosure can be bitumen(s) of natural origin, such as those contained in deposits of natural bitumen, natural asphalt or bituminous sands. The bituminous component which can be used according to the present disclosure can also be a bitumen or a mixture of bitumens originating from the refining of crude oil such as bitumens from direct distillation or bitumens from distillation under reduced pressure or also blown or semi-blown bitumens, residues from deasphalting with propane or pentane, visbreaking residues, these different cuts being able to be alone or in a mixture. The bituminous components used can also be bitumen(s) fluxed by adding volatile solvents, fluxes of petroleum origin, carbochemical fluxes and/or fluxes of vegetable origin. In an embodiment, synthetic bitumens also called clear, pigmentable or colourable bitumens can also be used as a bituminous component. The bituminous component can be a bitumen of naphthenic or paraffinic origin, or a mixture of these two bitumens.
[00039] In an embodiment, said fuel resistant bituminous composition can also optionally include adhesiveness additives and/or surfactants utilized conventionally. In an embodiment, said adhesiveness additives and/or surfactants can be selected from alkyl amine derivatives, alkyl polyamine derivatives, alkyl amidopolyamine derivatives, alkyl amidopolyamine derivatives and quaternary ammonium salt derivatives, alone or in a mixture. The most commonly used are the tallow propylene-diamines, tallow amido-amines, quaternary ammoniums obtained by quaternization of tallow propylene-diamines, tallow propylene-polyamines.
[00040] In an embodiment, said fuel resistant bituminous composition includes Poly(styrene-butadiene-styrene) polymer as an important constituent. In an embodiment, said Poly(styrene-butadiene-styrene) polymer can suitably be used for achieving an increase in elasticity properties. In an embodiment, it is also preferred to use block copolymers of the vinyl aromatic compound, preferably styrene, and the diene, preferably butadiene or isoprene as copolymer. The block copolymers may be linear or radial or mixtures of these. When the block copolymer is linear, the block copolymer is preferably selected from the groups consisting of those of formulae A(BA)m, wherein A represents a block of poly (vinyl aromatic compound), wherein B represents a block of poly(butadiene) or poly(isoprene), and wherein m represents an integer ?1. Most preferably, the block copolymer is a linear styrene-butadiene-styrene block copolymer of formula A(BA)m wherein A is a polystyrene block, B is a polybutadiene block and m=1.
[00041] When the block copolymer is a radial polymer the arms suitably consist of one or more blocks of poly (vinylaromatic compound) and one or more blocks of poly(diene). The number of blocks per arm may vary and is suitably from 2 to 6. The vinylaromatic compound is preferably styrene and the diene is preferably butadiene or isoprene. The arms are connected to a coupling agent. Suitable coupling agents include silicon compounds and oligomers of divinylbenzene. Examples of suitable silicon compounds are silicon tetrahalides, bis(trihalosilyl)alkane, such as bis(trichlorosilyl)ethane, and hexahalosilane, such as X3SiSiX3, wherein the halogen may be fluorine, chlorine or bromine. The number of arms may vary from 3 to 20. When the block copolymer is a radial copolymer, it is preferably selected from the groups consisting of those of formulae (AB)nX, wherein A represents a block of poly(vinylaromatic compound), wherein B represents a block of poly(butadiene) or poly(isoprene), wherein X represents the moiety of a multivalent coupling agent, and wherein n represents an integer ?3. In an embodiment, the weight average molecular weight of the copolymer can normally be in the range of from 100,000 to 500,000, preferably from 250,000 to 450,000 and more preferably, from 300,000 to 400,000. When the copolymer is a block copolymer the blocks of poly (vinyl aromatic compound) suitably have a molecular weight ranging from 3,000 to 100,000, preferably from 5,000 to 40,000. The blocks of polydiene suitably have a molecular weight of from 10,000 to 250,000, preferably from 40,000 to 200,000.
[00042] In an embodiment, said Fischer-Tropsch wax is generally prepared by reacting carbon monoxide with hydrogen, typically at elevated pressures on a metallic catalyst. The Fischer-Tropsch wax described in this document is Fischer-Tropsch wax including a mixture of paraffins. The Fischer-Tropsch wax includes a majority of n-paraffins, often more than 90%, the remainder being constituted by iso-paraffins. In an embodiment, the average length of the paraffinic chains of the Fischer-Tropsch wax is between 30 and 115 carbon atoms, preferably between 40 and 100, more preferentially between 60 and 90. The Fischer-Tropsch wax have a melting point (freezing point) included between 65 and 105° C., preferably between 68 and 100° C. The Fischer-Tropsch wax used in the invention can be partially oxidized or fully oxidized.
[00043] In a preferred embodiment, said Fischer-Tropsch wax is that sold under the brand name Sasobit®, which has a freezing point of 100° C (ASTM D 938), a penetrability at 25° C less than 1 1/10 mm, (ASTM D 1321) and a penetrability at 65° C. of 7 1/10 mm (ASTM 1321). Other types of Fischer-Tropsch waxes that can be used are the Fischer-Tropsch waxes that contain a somewhat larger quantity of isomerized paraffins than the standard Fischer-Tropsch waxes. These Fischer-Tropsch waxes including more iso-paraffins are characterized by a freezing point (ISO 2207) comprised between 85 and 120° C. and a PEN value at 43° C., expressed in 0.1 mm, determined according to IP 376, greater than 5.
[00044] In an embodiment, said fuel resistant bitumen composition includes Poly(styrene-butadiene-styrene) polymer and Fischer-Tropsch wax in a specific proportion. The melting point of Fischer-Tropsch wax (Sasobit) is greater than 100oC. When Sasobit is blended into said a bituminous component to form a mixture, at temperatures higher than its melting point, it completely dissolves into the bitumen and reduces viscosity of said mixture. This in turn reduces working temperature of production of said fuel resistant bitumen composition as well as in the application during construction of bituminous layers by at least 20-30oC.
[00045] In an embodiment, the present disclosure relates to a method for preparing a fuel resistant bituminous composition as defined above, in which the following are heated at between 120° C and 200° C, preferably between 140° C and 190° C, more preferentially between 160°C and 180° C, and homogenized for a period of 30 minutes to 30 hours, preferably 4 hours to 24 hours, more preferentially 8 hours to 16 hours: at least one bituminous component, at least one Poly(styrene-butadiene-styrene) polymer, and at least one Fischer Tropsch wax.
EXAMPLES
[00046] A Fuel Resistant Bituminous Composition
Ingredient/Component Amount
(%Wt. by composition)
Bitumen (VG-30 bitumen) 93%
SBS 4%
Sasobit 3%

[00047] Method of preparation of Fuel Resistant Bituminous Composition
[00048] VG-30 bitumen and SBS were first melt mixed at a temperature of about 170°C followed by mixing with molten sasobit. The resultant mixture was homogenized for a period of about 6 hours to prepare the fuel resistant composition (hereinafter referred to as FRB).
[00049] The method for preparing fuel resistant bituminous composition was effected through careful monitoring of polymer network created during addition of said Poly(styrene-butadiene-styrene) polymer. The monitoring was facilitated through image processing of the polymer network developed at various stages of digestion, using fluorescence microscopy.
[00050] Polymer molecules have property of emitting light when excited with a certain wavelength of light, characteristic of the polymer. This property of emitting light can be effectively used to observe the polymer modified bitumen composition under a fluorescence microscope and view how effectively the polymer network has developed in the bitumen composition. Utilizing the above stated concepts, parameters associated with the production of said fuel resistant bitumen composition was determined as described in the following.
[00051] The fuel resistant bitumen composition was studied with an inverted fluorescence microscope - Olympus 17VI microscope equipped with a Samsung camera. UV light source comes from a high-pressure mercury arc lamp. The microscope uses a three-filter system; an excitation filter, a beam splitter and an emission filter. From the light source, the light first goes through the excitation filter which transmits light with a wavelength of 450 to 490 nm. When the light of this wavelength hits the surface of the sample, part of this incident light is reflected and a part is emitted by the sample. The emitted light has a longer wavelength than the incident light. The reflected and emitted light will hit the beam splitter, where only wavelengths longer than 510 nm are transmitted. Finally, this transmitted light hits a third filter which has a high transmission for wavelengths longer than 515 nm.
[00052] The precision of the polymer network formed depends on the manner in which the samples are prepared. A unique sample preparation process for capturing the network formed was developed and it consists of the following steps:
a. The samples were prepared at five different temperatures, 120, 140, 160, 180 and 200 °C. The samples were left in the oven undisturbed for a time period of 10-20 minutes. They were then taken out and a very small drop of the bitumen composition was placed on the glass slide. The glass slides were then immediately placed back in the oven and kept for another 15 minutes undisturbed. The glass slides were then removed from the oven and immediately placed in the freezer maintained at -35°C for 30 minutes.
b. The purpose of putting the sample at low temperature is to ensure that the properties of the bitumen composition developed at the appropriate conditioning temperatures are locked and can be seen under the microscope.
c. The glass slides were then taken and viewed under the microscope at a magnification of 10X and the images were recorded. A cover slide was used to prevent the sample from getting stuck to the microscope.
[00053] Digestion hours for the production of fuel resistant bitumen (FRB) composition were varied and the samples were taken out for image processing at various digestion hours and the polymer network was captured at five different temperatures. The digestion time vis-à-vis the aerial representation of polymer network was captured and the digestion time which resulted in the maximum polymer density was chosen for further production. FIG. 1 illustrates variation of polymer area as a function of digestion time, in accordance with an embodiment of the present disclosure (Data as shown in Table 1).
Table 1: Variation of polymer area as a function of digestion time
Digestion time
(hours) Polymer Distribution
(%)
3.00 4.032
3.00 4.218
3.00 4.298
4.00 4.619
6.00 5.673
6.00 6.098
7.00 5.467
7.00 5.882
9.00 6.084
9.00 6.454
9.00 6.524
11.00 6.954
13.00 7.546
15.00 7.410
15.00 7.961
17.00 7.776
19.00 7.654
19.00 7.325
19.00 7.659
21.00 7.747
21.00 7.659
23.00 7.769
23.00 7.469
25.00 7.750
25.00 7.698

[00054] To independently verify the choice of digestion time which will lead to the development of the required polymer network for fuel resistant bitumen (FRB) composition, detailed rheological investigations were conducted on samples corresponding to different digestion time. Frequency sweep tests were conducted at different temperatures ranging from 35 to 95 ºC. The parallel plate geometry of 25 mm diameter with 1 mm gap was used for shearing. During shearing, the frequency was decreased from 25 Hz to 0.5 Hz and the strain amplitude of 0.005% was used. The dynamic modulus of the material plotted as a function of phase lag at different temperature represents the Black diagram. FIG. 2 illustrates Black diagram after 19 hours digestion time, in accordance with embodiments of the present disclosure (Data is shown in Table 2). A continuous and smooth transition over the range of temperature illustrates that the internal structure does not exhibit any transitory response.
Table 2: Dynamic modulus of the composition as a function of phase lag at different temperatures (35°C to 95°C)
35°C 45°C 55°C 65°C
Phase angle (degrees) Dynamic Modulus (Pa) Phase angle (degrees) Dynamic Modulus (Pa) Phase angle (degrees) Dynamic Modulus (Pa) Phase angle (degrees) Dynamic Modulus (Pa)
44.93 1.99E+06 50.86 616017.1 53.09 643878.9 56.74 217322.2
40.63 3.81E+06 47.80 1.68E+06 53.49 508843.1 56.90 190784.5
40.91 3.67E+06 48.00 1.53E+06 53.71 440668.9 57.05 158985.5
41.27 3.53E+06 48.33 1.42E+06 53.96 371776.7 57.17 132486.6
41.58 3.39E+06 48.59 1.31E+06 54.85 198458.3 57.25 116308.3
41.84 3.22E+06 48.92 1.21E+06 54.44 282504.8 57.40 100784.5
42.09 3.10E+06 49.26 1.06E+06 54.59 238331.4 57.60 86202.6
42.47 2.94E+06 49.49 971754.5 55.15 165257.8 57.76 70905.31
42.90 2.75E+06 49.76 898710.7 55.30 127216.8 58.03 59087.17
43.22 2.61E+06 50.10 842052.9 55.57 96662.87 58.23 49884.29
43.64 2.55E+06 50.38 748918.2 55.98 72495.66 58.51 39976.98
43.96 2.33E+06 50.58 683662.3 56.17 61966.08 58.99 30017.57
44.50 2.15E+06 51.10 569713 - - 60.08 18062.9
45.45 1.82E+06 51.24 506700.3 - - 61.03 13043.21
45.98 1.59E+06 51.69 433388.9 - - - -
46.77 1.26E+06 52.08 361153.9 - - - -
47.34 1.11E+06 52.58 285681.7 - - - -
48.35 842052.9 53.30 185879.2 - - - -
49.58 600178.6 48.44 171480 - - - -
47.37 583843 - - - - - -

Table 2 (Continued)
75°C 85°C 95°C
Phase angle (degrees) Dynamic Modulus (Pa) Phase angle (degrees) Dynamic Modulus (Pa) Phase angle (degrees) Dynamic Modulus (Pa)
59.17 75258.78 63.34 13739.89 61.22 13378.09
59.37 61088.15 63.73 12380.15 61.82 11766.09
59.69 50236.48 64.17 11010.59 62.46 10348.32
60.02 40777.35 64.61 9665.688 63.16 9338.137
60.60 34419.64 65.05 8375.148 63.84 8212.931
61.01 28676.83 65.54 7546.482 64.52 7285.402
61.43 24523.42 66.12 6624.927 65.22 6518.181
62.06 20431.76 66.98 5520.723 65.80 5881.888
62.57 17472.52 67.57 4846.548 66.63 4999.019
62.99 14748.33 68.22 4199.632 67.59 4359.184
63.42 12777.78 69.02 3545.514 68.19 3933.648
63.94 11070.51 69.77 3032.528 68.77 3580.168
64.51 9467.11 70.54 2593.765 69.45 3148.773
65.13 8309.833 71.36 2161.404 70.29 2817.177
65.80 7294.023 72.04 1848.639 71.02 2477.719
66.29 6402.388 72.58 1622.853 72.72 1789.732
67.02 5619.749 77.43 1520.008 73.86 1249.264
67.62 4932.78 - - 74.69 710.07
68.12 4273.7 - - 81.04 613.5272

[00055] To check on the improved performance of the fuel resistant bitumen (FRB) composition, the performance grade tests were carried out in accordance with ASTM D7175-08. Figure 3 illustrates the results of high-temperature performance of FRB compared with conventional VG30 and PG70-16 binders, both of which are unmodified binders and normally used in surface layer construction (Data is shown in Table 3). The improved performance of the FRB can be clearly seen.
Table 3: High-temperature performance of FRB compared to that of conventional VG30 and PG70-16 binders at different temperatures
VG 30 PG 70-16 FRB (present invention)
Temperature (°C) G*/Sind Temperature (°C) G*/Sind Temperature (°C) G*/Sind
70 3.580 70 9.055 83 11.266
76 1.817 76 4.744 92 6.923
- - 82 2.533 98 4.296
- - 88 1.416 104 2.675
- - - - 110 1.699

[00056] The Multiple Stress Creep and Recovery (MSCR) test as per AASHTO TP 70 conducted on the short-term aged binder is currently being used for grading modified binders under different traffic conditions. This test consists of 1s loading and 9s recovery period. Two level of stress magnitude, 0.1 kPa, and 3.2 kPa were used and the material in this test was subjected to 10 cycles of loading (1s) and recovery (9s) period at each stress level. The creep response as the function of time for two different stress levels was recorded. Figure 4 illustrates the results of total strain of FRB compared with conventional VG30 and PG70-16 binders at a wide range of temperature (Data is shown in Table 4). The improved performance of FRB can be clearly seen.
Table 4: Total Strain of FRB compared with conventional VG30 and PG70-16 binders at different temperatures
Temperature (°C) Strain (%)
FRB PG 70-16 VG 30
46 16.956 106.397 169.130
52 31.397 172.950 471.151
58 37.695 351.305 1283.050
64 45.689 902.332 4591.850
70 74.572 2273.240 8795.060

[00057] For carrying out the design using mechanistic-empirical pavement design method, dynamic modulus is the design parameter to be used. Dynamic Modulus is the norm of the complex modulus calculated by dividing the peak-to-peak stress by the peak-to-peak strain for a material subjected to a sinusoidal loading. Bituminous mixtures (mixtures of aggregate particles of appropriate gradation as per existing design guidelines with FRB) were produced and compacted to cylindrical samples following AASHTO TP79-2010. Since this invention is about the production of FRB such that it can be used as a structural layer without the necessity of an additional coating, the dynamic modulus values were measured for all the temperatures (5°C to 55°C) and for a range of frequencies (25, 20, 10, 5, 2, 1, 0.5, 0.2, 0.1 and 0.01 Hz).
[00058] FIG. 5A-B illustrates variation of dynamic modulus vs. frequency for various temperatures for FRB wearing course mixture along with an unmodified binder, in accordance with embodiments of the present disclosure (Data is shown in Tables 5a and 5b).
Table 5A: Variation of dynamic modulus vs. frequency at different temperatures for FRB of the present invention
Frequency (Hz) Dynamic Modulus (MPa)
55°C 45°C 35°C 25°C 15°C 5°C
0.01 476.47 1235.89 1792.44 4071.90 8630.73 15934.66
0.10 794.32 1700.33 3423.06 7558.87 12037.72 20469.11
0.20 965.24 2235.65 3723.97 7325.04 13189.80 22013.35
0.50 1306.45 3043.08 4219.61 8214.69 14856.86 24097.09
1.00 1499.12 3681.00 4783.99 9220.25 16156.53 25519.31
2.00 1714.88 4344.07 5398.03 10275.47 17554.91 27285.34
5.00 2232.01 5279.41 6431.39 11897.06 19544.11 29348.05
10.00 2728.74 6094.79 7320.25 13129.10 21192.84 30947.73
20.00 3264.67 6941.18 8264.71 14563.76 22799.05 32603.00
25.00 3336.56 7266.35 8589.90 15011.44 23320.28 33124.23

Table 5B: Variation of dynamic modulus vs. frequency at different temperatures for conventional binder (VG-30)
Frequency (Hz) Dynamic Modulus (MPa)
55°C 45°C 35°C 25°C 15°C 5°C
0.01 3.02 94.06 522.13 781.43 2035.73 5641.17
0.10 177.79 302.00 949.41 1884.21 3993.09 8533.85
0.20 253.07 540.81 1372.02 2556.20 4586.33 9824.45
0.50 381.79 814.30 1898.58 3446.23 5606.09 11269.38
1.00 503.03 1115.40 2305.81 4125.51 6472.44 12492.88
2.00 637.09 1402.39 2933.01 5041.85 7456.84 13749.32
5.00 903.09 2076.52 3879.27 6311.24 8845.25 15460.86
10.00 1284.01 2712.61 4787.38 7457.51 9991.52 16811.20
20.00 1756.81 3423.48 5753.41 8661.57 11246.56 18168.36
25.00 1916.65 3651.38 6015.29 9127.53 11661.57 18685.34

[00059] FIG. 6A-B illustrates comparison of dynamic modulus vs. frequency at 5°C and 55°C of FRB of present disclosure with the commercially available FRB, in accordance with embodiments of the present disclosure (Data is shown in Tables 6a and 6b). The improved performance of FRB can be identified.
Table 6A: Comparison of dynamic modulus at varying frequencies at 5°C
Frequency (Hz) Dynamic Modulus (MPa)
HINCOL - Runway binder FRB
0.01 7131.56 12375.79
0.10 9264.80 15795.45
0.20 13556.82 24569.37
0.50 14470.59 25555.50
1.00 15811.77 28467.12
2.00 17152.94 30370.57
5.00 18776.47 32679.84
10.00 20258.82 34398.01
20.00 21741.18 36163.07
25.00 22094.12 36708.48

Table 6B: Comparison of dynamic modulus at varying frequencies at 55°C
Frequency
(Hz) Dynamic Modulus (MPa)
HINCOL - Runway binder FRB
0.01 123.56 145.86
0.10 402.44 413.59
0.20 664.86 984.56
0.50 846.56 1223.25
1.00 1014.21 1437.80
2.00 1101.79 1702.78
5.00 1301.00 2190.55
10.00 1482.08 2646.98
20.00 1730.41 3175.95
25.00 1792.36 3296.15

[00060] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

ADVANTAGES OF THE INVENTION
[00061] The present disclosure provides for a modified bitumen composition having improved resistance to fuel damage/cracking.
[00062] The present disclosure provides for a modified bitumen composition having improved temperature performance.
[00063] The present disclosure provides for a modified bitumen composition having improved total strain.
[00064] The present disclosure provides for a modified bitumen composition having improved dynamic modulus.
[00065] The present disclosure provides for a modified bitumen composition having capability to withstand large tire pressure.
[00066] The present disclosure provides for a modified bitumen composition having suitable viscosity that does not lead to difficulty in handling during the production process.
[00067] The present disclosure provides for a modified bitumen composition having an improved network of polymers at reduced production temperature.
[00068] The present disclosure provides for a method of preparation of a modified bitumen composition having improved resistance to fuel damage/cracking.