Claims:We Claim:

1. A process for preparing a sulfur polymer modified bitumen mixture, the process comprising employing a sulfur polymer in the preparation of said bitumen mixture, wherein the sulfur polymer is obtained by co-polymerization of sulfur with a vinylic co-monomer and optionally in presence of an end capping agent.

2. The process as claimed in claim 1, wherein the vinylic co-monomer is selected from a group consisting of divinyl benzene, polyvinyl chloride, dicyclopentadiene, trivinyl cyclohexane, divinyl adipate and combinations thereof.

3. The process as claimed in claim 1, wherein the end capping agent is an epoxy compound selected from a group consisting of bisphenol A, epoxidized soya oil, diglycidyl ether, any epoxy containing compound and combinations thereof.

4. The process as claimed in claim 1, wherein the sulfur polymer is obtained by reacting sulfur with a vinylic co-monomer and optionally in presence of an end capping agent; or reacting sulfur with bitumen followed by addition of a vinylic co-monomer and optionally an end capping agent.

5. The process as claimed in claim 1, said process comprising:
a. reacting sulfur with a vinylic co-monomer, optionally in presence of an end capping agent and additives to form the sulfur polymer; and
b. melt mixing of the sulfur polymer with bitumen to prepare the sulfur polymer modified bitumen mixture.

6. The process as claimed in claim 1, said process comprising:
a. melt mixing of sulfur with bitumen to form a mixture; and
b. adding a vinylic co-monomer, optionally in presence of an end capping agent and additives to prepare the sulfur polymer modified bitumen mixture.

7. The process as claimed in claim 1, wherein said process is carried out at a temperature ranging from about 120 ? to 190 ?, and for a time-period ranging from about 0.5 hours to 5 hours.

8. The process as claimed in claim 1, wherein the sulfur and the vinylic co-monomer is employed at a weight ratio ranging from about 50:50 to 99.9:0.01.

9. The process as claimed in claim 1, wherein the sulfur, the vinylic co-monomer and the end capping agent is employed at a weight ratio ranging from about 50:50:10 to 99.9:0.1:0.1.

10. The process as claimed in claim 1, wherein said process results in reduced emission of toxic gases during the preparation of the sulfur polymer modified bitumen mixture; and wherein the gases are H2S, SOx, or a combination thereof.

11. A process for preparing a sulfur polymer, said process comprising co-polymerizing sulfur with a vinylic co-monomer, optionally in presence of an end capping agent.

12. The process as claimed in claim 11, wherein the vinylic co-monomer is selected from a group consisting of divinyl benzene, polyvinyl chloride, dicyclopentadiene, trivinyl-cyclohexane, divinyl adipate and combinations thereof.

13. The process as claimed in claim 11, wherein the end capping agent is an epoxy compound selected from a group consisting of bisphenol A, epoxidized soya oil, diglycidyl ether, any compound containing epoxy group and combinations thereof.

14. The process as claimed in claim 11, wherein the sulfur and the vinylic co-monomer is employed at a weight ratio ranging from about 50:50 to 99.9:0.1.

15. The process as claimed in claim 11, wherein the sulfur, the vinylic co-monomer and the end capping agent is employed at a weight ratio ranging from about 50:50:10 to 99.9:0.1:0.1.

16. A sulfur polymer modified bitumen mixture comprising the sulfur polymer, prepared by the process according to claim 1.

17. The sulfur polymer modified bitumen mixture as claimed in claim 16, wherein said sulfur polymer modified bitumen mixture possesses unaltered or improved properties selected from a group consisting of ductility, softening point, water resistance, marshal stability, marshal flow, fatigue performance and combinations thereof.

18. An asphalt composite mixture comprising aggregate, sand, dust, fillers and the sulfur polymer modified bitumen mixture of claim 16.

Dated this 21st day of May, 2019

DURGESH MUKHARYA
IN/PA-1541
Of K&S Partners
To: Agent for the Applicant
The Controller of Patents,
The Patent Office, at: Mumbai
, Description:TECHNICAL FIELD
[001]. The instant disclosure is in the field of chemical sciences, more particularly towards polymer science and synthetic chemistry. The present disclosure relates to a process of preparing sulfur polymer modified bitumen composition/mixture and corresponding products thereof.

BACKGROUND OF THE DISCLOSURE
Viscosity grade bitumen is used for surface-dressing, spraying, construction and paving of roads. Sulfur is blended with bitumen to increase its performance mainly in terms of mechanical strength (rutting properties) and water resistance. However, while blending sulfur with bitumen and asphaltous mix compression, there is emission of H2S and SO2 which is harmful to human beings. Occupational Safety and Health Act (OSHA) has established a permissible exposure limit (PEL) for emission of H2S [8-hour time-weighted average (TWA) of 10 ppm and acceptable ceiling concentration of 20 ppm].

While different technologies have been used for the suppression of H2S and SOx emissions during the preparation of sulfur based bitumen and its asphaltous mix, the known technologies have shown limited success in the suppression of H2S and SOx emissions. Further, the preparation of sulfur based bitumen and its application in laying roads is usually carried out at elevated temperatures. Thus, direct mixing of sulfur with bitumen is not practically tenable due to severe probability of exposure of human beings to these toxic H2S and SOx gasses.

Therefore, there is a need to develop an effective and more efficient process of sulfur addition to bitumen, which gives advantages in performance over bitumen, at reduced emissions. The present disclosure tries to address said need.

SUMMARY OF THE DISCLOSURE
[002]. The present disclosure relates to a process for preparing sulfur polymer modified bitumen mixture and corresponding products thereof.

[003]. In an embodiment, the disclosure relates to a process for preparing sulfur polymer modified bitumen mixture by employing a sulfur polymer.

[004]. In an exemplary embodiment, the present process for preparation of sulfur polymer modified bitumen mixture comprises employing a sulfur polymer in the preparation of said bitumen mixture, wherein the sulfur polymer is obtained by co-polymerization of sulfur with a vinylic co-monomer and optionally in presence of an end capping agent.

[005]. In an embodiment, the present process for preparation of sulfur polymer modified bitumen mixture comprises:
a. reacting sulfur with a vinylic co-monomer, optionally in presence of an end capping agent to form the sulfur polymer; and
b. melt mixing of the sulfur polymer with bitumen to prepare the sulfur polymer modified bitumen mixture.

[006]. In another embodiment, the present process for preparation of sulfur polymer modified bitumen mixture comprises:
a. melt mixing of sulfur with bitumen to form a mixture; and
b. adding a vinylic co-monomer, optionally in presence of an end capping agent to prepare the sulfur polymer modified bitumen mixture.

[007]. In an embodiment, the present disclosure further provides a process for preparing a sulfur polymer, said process comprising co-polymerizing sulfur with a vinylic co-monomer, optionally in presence of an end capping agent.

[008]. The present disclosure also provides products including sulfur polymer modified bitumen mixture and asphalt composite mixture comprising said bitumen mixture.

STATMENT OF THE DISCLOSURE
The present disclosure relates to a process for preparing a sulfur polymer modified bitumen mixture, the process comprising employing a sulfur polymer in the preparation of said bitumen mixture, wherein the sulfur polymer is obtained by co-polymerization of sulfur with a vinylic co-monomer and optionally in presence of an end capping agent.

The present disclosure further relates to a process for preparing a sulfur polymer, said process comprising co-polymerizing sulfur with a vinylic co-monomer, optionally in presence of an end capping agent.

The present disclosure also provides a sulfur polymer modified bitumen mixture prepared by the process described above.

The present disclosure additionally relates to an asphalt composite mixture comprising aggregate, sand, dust, fillers and the sulfur polymer modified bitumen mixture as described above.

DESCRIPTION OF THE DISCLOSURE
[009]. As used herein, the term ‘bitumen’ refers to a sticky, black, and highly viscous liquid or semi-solid form of petroleum, and is a liquid binder that holds asphalt together.

[0010]. As used herein, the term ‘asphalt’ refers to a composite mix comprising aggregate, bitumen and sand.

[0011]. As used herein, the phrases ‘bitumen mixture’, ‘sulfur polymer modified bitumen mixture’, ‘sulfur polymer enhanced bitumen’, ‘sulfur polymer extended bitumen’ and ‘bitumen mixture comprising sulfur polymer’ are employed interchangeably in the present disclosure and refers to the bitumen product of the present disclosure comprising sulfur polymer as described herein.

[0012]. The present disclosure relates to a process for preparing a sulfur polymer modified bitumen mixture, the process comprising employing a sulfur polymer in the preparation of said bitumen mixture, wherein the sulfur polymer is obtained by co-polymerization of sulfur with a vinylic co-monomer and optionally in presence of an end capping agent.

[0013]. In an embodiment of the present disclosure, the vinylic co-monomer is selected from a group consisting of divinyl benzene, polyvinyl chloride, dicyclopentadiene, trivinyl cyclohexane, divinyl adipate and combinations thereof.

[0014]. In another embodiment of the present disclosure, the end capping agent is an epoxy compound selected from a group consisting of bisphenol A, epoxidized soya oil, diglycidyl ether, any epoxy containing compound and combinations thereof.

[0015]. In yet another embodiment of the present disclosure, the sulfur polymer is obtained by reacting sulfur with a vinylic co-monomer and optionally in presence of an end capping agent; or reacting sulfur with bitumen followed by addition of a vinylic co-monomer and optionally an end capping agent.

[0016]. In still another embodiment of the present disclosure, the above described process comprises:
a. reacting sulfur with a vinylic co-monomer, optionally in presence of an end capping agent and additives to form the sulfur polymer; and
b. melt mixing of the sulfur polymer with bitumen to prepare the sulfur polymer modified bitumen mixture.

[0017]. In still another embodiment of the present disclosure, the above described process comprises:
a. melt mixing of sulfur with bitumen to form a mixture; and
b. adding a vinylic co-monomer, optionally in presence of an end capping agent and additives to prepare the sulfur polymer modified bitumen mixture.

[0018]. In still another embodiment of the present disclosure, the above described process is carried out at a temperature ranging from about 120 ? to 190 ?, and for a time-period ranging from about 0.5 hours to 5 hours.

[0019]. In still another embodiment of the present disclosure, the sulfur and the vinylic co-monomer in the above described process is employed at a weight ratio ranging from about 50:50 to 99.9:0.01.

[0020]. In still another embodiment of the present disclosure, the sulfur, the vinylic co-monomer and the end capping agent in the present process is employed at a weight ratio ranging from about 50:50:10 to 99.9:0.1:0.1.

[0021]. In still another embodiment of the present disclosure, the above described process results in reduced emission of toxic gases during the preparation of the sulfur polymer modified bitumen mixture; and wherein the gases are H2S, SOx, or a combination thereof.

[0022]. The present disclosure further relates to a process for preparing a sulfur polymer, said process comprising co-polymerizing sulfur with a vinylic co-monomer, optionally in presence of an end capping agent.

[0023]. The present disclosure further provides a sulfur polymer modified bitumen mixture prepared by the process described above.

[0024]. In an embodiment of the present disclosure, the sulfur polymer modified bitumen mixture possesses unaltered or improved properties selected from a group consisting of ductility, softening point, water resistance, marshal stability, marshal flow, fatigue performance and combinations thereof.

[0025]. The present disclosure additionally relates to an asphalt composite mixture comprising aggregate, sand, dust, fillers and the sulfur polymer modified bitumen mixture as described above.

[0026]. In the present disclosure, a process is provided to synthesize sulfur polymer which can be further employed as bitumen extender/enhancer. In particular, in order to address the limitations as stated in the background, the present disclosure provides a process for preparing sulfur polymer modified bitumen composition/mixture.

[0027]. The present disclosure provides a process for preparing a bitumen mixture, wherein said process employs a sulfur polymer which is obtained by co-polymerization of sulfur with a vinylic co-monomer and optionally in presence of an end capping agent. In particular, the present disclosure describes sulfur intercalating network development by co-polymerization of sulfur with a vinylic co-monomer optionally in presence of an end capping agent, where the sulfur gets converted to polymeric form to produce sulfur polymer.

[0028]. In an embodiment of the present disclosure, the sulfur polymer is prepared separately by co-polymerizing elemental sulfur with a vinylic co-monomer, optionally in presence of an end capping agent. The obtained sulfur polymer is melt mixed with bitumen to prepare the bitumen mixture of the present disclosure.

[0029]. In another embodiment of the present disclosure, the sulfur polymer is synthesized in-situ during the preparation of bitumen mixture. In an exemplary embodiment, elemental sulfur is reacted with bitumen to obtain a homogenous mixture. This is followed by addition of a vinylic co-monomer to the homogenous mixture, optionally in presence of an end capping agent to prepare the bitumen mixture of the present disclosure.

[0030]. In an exemplary embodiment of the present disclosure, sulfur polymer is synthesized by melting sulfur granules and reacting it with unsaturated vinylic co-monomer and optionally an epoxy based capping agent at a temperature of about 160-190 °C, with the co-monomer loading from about 0.1 to 50 wt%. This is followed by melt mixing of the synthesized sulfur polymer with bitumen in the range of about 1 to 40 wt % at a temperature of about 140-160°C to produce the resultant bitumen mixture.

[0031]. In a preferred embodiment of the present disclosure, the process of preparing the bitumen mixture comprises:
(a) reacting sulfur with a vinylic co-monomer to form sulfur polymer; and
(b) melt mixing of the sulfur polymer with bitumen to prepare the bitumen mixture.

[0032]. In another preferred embodiment of the present disclosure, the process of preparing the bitumen mixture comprises:
(a) reacting sulfur with a vinylic co-monomer and an end capping agent and additives to form sulfur polymer; and
(b) melt mixing of the sulfur polymer with bitumen to prepare the bitumen mixture.

[0033]. In an embodiment of the process described above, the reaction of sulfur and the vinylic co-monomer in step (a) employs sulfur at concentrations ranging from about 50 wt% to 99.9 wt%, and the vinylic co-monomer at concentrations ranging from about 0.1 wt% to 50 wt%.

[0034]. In another embodiment of the process described above, the reaction of the sulfur, the vinylic co-monomer and the end capping agent in step (a) employs sulfur at concentrations ranging from about 50 wt% to 99.9 wt%, the vinylic co-monomer at concentrations ranging from about 0.1 wt% to 45 wt%, and the end capping agent at concentrations ranging from about 0.1 wt% to 5.0 wt%.

[0035]. In yet another embodiment of the process described above, the melt mixing of the sulfur polymer and the bitumen in step (b) employs sulfur polymer at concentrations ranging from about 99 wt % to 50 wt %, and the bitumen at concentrations ranging from about 1 wt% to 50 wt%.

[0036]. In another exemplary embodiment of the present disclosure, the bitumen mixture is prepared in a single step. Particularly, the bitumen and sulfur granules are melt mixed in a stirred reactor at a temperature of about 140-190°C. After homogenization, vinylic co-monomer is charged to the reactor, followed by addition of the end capping agent. The reaction is carried out till conversion of monomeric sulfur to polymeric form is achieved.

[0037]. In a preferred embodiment of the present disclosure, the process of preparing the bitumen mixture comprises:
(a) melt mixing sulfur with molten bitumen to form a homogenized reactant mixture; and
(b) adding a vinylic co-monomer to the homogenized reactant mixture to prepare the bitumen mixture.

[0038]. In still another preferred embodiment of the present disclosure, the process of preparing the bitumen mixture comprises:
(a) melt mixing sulfur with molten bitumen to form a homogenized reactant mixture; and
(b) adding a vinylic co-monomer and an end capping agent and additives to the homogenized reactant mixture to prepare the bitumen mixture.

[0039]. In an embodiment of the process described above, sulfur is employed at concentrations ranging from about 50 wt% to 99.9 wt%, and the vinylic co-monomer is employed at concentrations ranging from about 0.1 wt% to 50 wt%.

[0040]. In another embodiment of the process described above, the sulfur is employed at concentrations ranging from about 50 wt% to 99.9 wt%, the vinylic co-monomer is employed at concentrations ranging from about 0.1 wt% to 45 wt%, and the end capping agent is employed at concentrations ranging from about 0.1 wt% to 5 wt%.

[0041]. In an embodiment of the processes described above, the vinylic co-monomer is preferably divinyl benzene, polyvinyl chloride, dicyclopentadiene, trivinyl cyclohexane, or divinyl adipate, or any combinations thereof.

[0042]. In another embodiment of the processes described above, the end capping agent is an epoxy compound, preferably bisphenol A, epoxidized soya oil, diglycidyl ether, any epoxy containing compound, or any combinations thereof.

[0043]. In an embodiment of the present disclosure, it was identified that when granular sulfur is present in monomeric form, it is susceptible for reaction which leads to emissions by the way of H2S and SOx. It undergoes polymerization after heating above 160°C. However, it again converts into monomeric form after cooling. Accordingly, the present inventors have employed the concept of converting sulfur into polymeric form by inserting vinylic monomers into sulfur chain. This approach makes the polymeric sulfur stable. The synthesized polymeric sulfur has -SH (thiol) as an end group, which could again be prone to generation of H2S. Therefore, the concept of end capping the thiol group was carried out. Accordingly, every sulfur polymer chain is sturdy and stable which leads to significant reduction in emissions during its processing/preparation.

[0044]. In an embodiment of the present disclosure, the developed sulfur polymer is thermally stable material, which does not emit toxic gasses such as H2S and SOx while mixing with bitumen as well as while compression of asphaltous composite mix. Additionally, the performance properties of the bitumen mixture and the asphaltous composite mix remains intact by employing the sulfur polymer of the present disclosure.

[0045]. In another embodiment, the bitumen mixture of the present disclosure is tested for properties including softening point, penetration and ductility. The results show that said properties are either unaltered or improved, as also indicated in the Examples section below. Moreover, as described above, the preparation and application of present bitumen mixture results in significantly lower emissions of H2S and SOx. In an embodiment of the present disclosure, the melt mixing process to prepare the bitumen mixture, and preparation and compaction of asphaltous composite mix results in an emission of less than 5 ppb H2S and less than 25 ppb SOx.

[0046]. ADVANTAGES/BENEFITS:
The processes of preparing the sulfur polymer, the bitumen mixture; and the corresponding bitumen mixture and asphaltous composite mix products of the present disclosure have several advantages/benefits, including, but not limiting to the following:
(a) sulfur intercalating network development by co-polymerization of sulfur with vinylic co-monomer optionally in presence of an end capping agent, where all the sulfur gets converted to polymeric form to yield sulfur polymer.
(b) melt mixing of the sulfur polymer with bitumen to produce the bitumen mixture (or sulfur polymer enhanced bitumen) which has significantly lower emissions of H2S and SOx while processing at high temperature. Particularly, significantly lower emissions, for instance, less than 5 ppb H2S and 25 ppb SOx is achieved while preparing the bitumen mixture, and the preparation and compaction of asphaltous composite mix.
(c) since as sulfur is added in a more stable form in the form of the specific sulfur polymer as described herein, the prepared bitumen mixture (or sulfur polymer modified bitumen) of the present disclosure has improved mechanical properties including fatigue performance, and improved ductility and water resistance.
(d) the present bitumen mixture can be prepared by a single step process by carrying out sulfur co-polymerization in molten bitumen.
(e) employing the synthesized sulfur polymer as a low-cost bitumen extender/enhancer showing equivalent physical properties to that of normal/conventional bitumen.
(f) employing unsaturated vinylic co-monomer and end capping agent for achieving stable sulfur polymer as described herein.

[0047]. Additional embodiments and features of the present disclosure will be apparent to one of ordinary skill in art based upon description provided herein. The embodiments herein provide various features and advantageous details thereof in the description. Descriptions of well-known/conventional methods/steps and techniques are omitted so as to not unnecessarily obscure the embodiments herein. Further, the disclosure herein provides for examples illustrating the above described embodiments, and in order to illustrate the embodiments of the present disclosure certain aspects have been employed. The examples used herein for such illustration are intended merely to facilitate an understanding of 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 following examples should not be construed as limiting the scope of the embodiments herein.

EXAMPLES
[0048]. Exemplary experiments were performed with divinyl benzene as the vinylic co-monomer, and epoxidized soya oil or Synpol 220 as the end capping agent.

EXAMPLE 1:
Synthesis and properties of bitumen mixture/asphaltic composite mixture

EXAMPLE 1A:
[0049]. 194 gm of sulfur granules were taken in round bottom flask and heated at 130°C, till all the granules get melted. It was then gradually heated to 180°C, till initiation of self-polymerization. Thereafter, 6 gm of divinyl benzene was added gradually under continuous stirring. Reaction was carried out for 30 minutes and the resultant sulfur polymer was taken out from the reactor. H2S and SO2/SO3 emissions were monitored during the polymer synthesis. For synthesis of bitumen mixture, 850 gm of VG30 grade bitumen was charged to the reactor and heated to 120°C. Thereafter, powdered sulfur polymer was charged to the reactor, and the reaction temperature was increased to 150°C, and the reaction was carried out for 2 hours. H2S and SO2/SO3 emissions were monitored at reactor top and at two feet height, while melt mixing of the sulfur polymer with bitumen. It was found that H2S concentration was 2 ppm close to reactor top, whereas it was less than 0.1 ppm at two feet height. The resultant bitumen mixture obtained was tested for softening point, penetration and ductility.

EXAMPLE 1B:
850 gm of VG30 grade bitumen was charged to the reactor and heated to 120°C. 145.5 gm of sulfur granules were charged to the reactor and allowed to melt mix at 130°C. After homogenization, 4.5 gm of divinyl benzene was added gradually under continuous stirring, and the temperature was increased to 180°C. The reaction was carried out for 2 hours at 180°C. The resultant bitumen mixture comprising sulfur polymer was taken out from the reactor. H2S and SOx emissions were monitored at reactor top and at two feet height, during the bitumen mixture synthesis. It was found that H2S concentration was 1 ppm close to reactor top, whereas it was less than 0.1 ppm at two feet height. The resultant bitumen mixture was tested for softening point, penetration and ductility.

EXAMPLE 1C:
850 gm of VG30 grade bitumen was charged to the reactor and heated to 120°C. 144 gm of sulfur granules were charged to the reactor and allowed to melt mix at 130°C. After homogenization, 4.5 gm of divinyl benzene was added gradually under continuous stirring, and the temperature was increased to 180°C. After 30 minutes, 1.5 gm of epoxidized soya oil was charged to the reactor and the reaction was carried out for 2 hours at about 180°C. The resultant bitumen mixture comprising sulfur polymer was taken out from the reactor. H2S and SOx emissions were monitored at reactor top and at two feet height, during the bitumen mixture synthesis. It was found that H2S concentration was 1 ppm close to reactor top, whereas it was less than 0.1 ppm at two feet height. The resultant bitumen mixture was tested for softening point, penetration and ductility.

The bitumen mixture synthesized according to Examples 1A, 1B and 1C were tested for softening point and penetration as per IS: 15462:2004, and also for ductility. The results provided under Table 1 below shows that the penetration and softening points remain unaltered, and there is an improvement in ductility.

Table 1: Analysis of softening point, penetration and ductility
Properties Only Bitumen (VG30) Example 1A Example 1B Example 1C
Penetration at 25°C, 0.1 mm, 5s 49 mm 50 mm 46 mm 52 mm
Softening point, (R&B), °C, min 53°C 49°C 57°C 49°C
Ductility at 25°C, cm 63 cm
100+ cm 100+ cm 100+ cm

EXAMPLE 1D:
172 gm of sulfur granules were taken in round bottom flask and heated at 130°C, till all the granules get melted. It is followed by addition of 20 gm powdered refinery spent catalyst. The mixture was then gradually heated to 170°C, till initiation of self-polymerization. Thereafter, about 6 gm of divinyl benzene and 2 gm of Synpol 220 (epoxy based end capping agent) were added gradually under continuous stirring. The reaction was carried out for 30 minutes and the resultant sulfur polymer was taken out from reactor. H2S and SOx emissions were monitored during sulfur polymer synthesis.

For sulfur polymer modified asphaltous composite mix preparation, weighed amount of heated aggregate were poured into reactor. About 30% of the required bitumen was then charged to the reactor, followed by sulfur polymer addition under continuous stirring. After 5 minutes of stirring, rest of the bitumen was added and mixing was continued for 5 more minutes. The prepared asphaltous composite mix was used for specimen preparation required for carrying out Marshal and Fatigue tests. The emissions monitored were less than 5 ppb H2S and less than 25 ppb SOx while preparing the sulfur polymer modified asphaltous composite mix.

Samples were prepared with 4.5% binder with 10% replaced with sulfur polymer. The following Table 2 shows the Marshall Stability and flow values. Based on the MoRTH (2013) guidelines, it was seen that DBM with 4.5% satisfy the air voids.

Table 2: Fatigue Performance and Volumetric Properties of Sulfur Polymer Substituted DBM with 4.5% Binder
Performance Specifications VG30 Bitumen (without Sulfur Polymer) Sulfur Polymer Modified Bitumen mixture (10% substitution)
Fatigue Response (No. of cycles at 50% stiffness) - AASHTO: T321 - 5116 12872
Marshal Stability (kN at 60°C) - MoRTH (2013) Min 12.0 18.77 18.27
Marshal Flow (mm) - MoRTH (2013) 2.5 - 4.0 2.73 3.29

AASHTO: T321 defines fatigue failure as the number of cycles at which the stiffness of the material decreases by 50%. Here, the initial stiffness is considered as the stiffness modulus corresponding to 50th cycle. Sulfur polymer modified bitumen mixture sustained 50% stiffness for 12872 cycles as compared to 5116 cycles by bitumen without Sulfur Polymer, which signifies double road life when the sulfur polymer modified bitumen mixture of the present disclosure is employed.

Further, Marshal stability data indicates that strength of the asphaltous road remains similar by replacing 10% bitumen with the sulfur polymer modified bitumen mixture of the present disclosure. Additionally, improvement in Marshal Flow by the present sulfur polymer modified bitumen mixture indicates that at similar load conditions, road prepared with the present sulfur polymer modified bitumen mixture will accommodate itself against higher load, and avoid road deformation.

[0050]. Additional embodiments and features of the present disclosure will be apparent to one of ordinary skill in art based on the description provided herein. The embodiments herein provide various features and advantageous details thereof in the description. Descriptions of well-known/conventional methods and techniques are omitted so as to not unnecessarily obscure the embodiments herein.

[0051]. The foregoing description of the specific embodiments fully reveals 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 in this disclosure 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.

[0052]. Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising” wherever used, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0053]. With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

[0054]. Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

[0055]. While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.