Crumb rubber modified bitumen and process of production thereof

Abstract

The invention discloses anchoring of crumb rubber in asphalt using waste plastic particularly polyethylene terephthalate (PET) derived terepthalamide along with bi-functional reactive compounds. The invention also discloses a process for the production of storage stable crumb rubber modified bitumen by incorporating various components such as waste PET, waste crumb rubber powder and bi-functional reactive compounds in bitumen.

Claims

1. A crumb rubber modified bitumen composition comprising: (a) Asphalt in the range of 50 to 90% by weight of the composition; (b) crumb rubber in the range of 5 to 30% by weight of the composition; (c) PET derivatives in the range of 0.1 to 10% by weight of the composition; and (d) bi-functional reactive compounds in the range of 0.1 to 10% by weight of the total composition; wherein, Asphalt is having penetration in the range of 30 to 150 dmm; wherein the bi-functional reactive compounds are selected from pimelic acid, suberic acid, azelaic acid, sebacic acid and dodecanedioic acid.

2. The composition of claim 1 wherein the asphalt is natural asphalt or obtained from petroleum residue, or may be a mixture thereof.

3. The composition of claim 1 wherein crumb rubber is obtained from grinding of used truck tyres or automobile tyres, or from any other source of rubber.

4. The composition of claim 1 wherein PET derivatives include waste PET derivatives comprising terephthalamide chemical compounds obtained by aminolysis of waste PET.

5. A crumb rubber modified bitumen composition as claimed in claim 1 for use in paving roads.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) While the invention is susceptible to various modifications and alternative forms, specific embodiment thereof will be described in detail below. It should be understood, however that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

(2) The following description is of exemplary embodiments only and is not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention.

(3) The terms comprises, comprising, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that one or more processes or composition/s or systems or methods proceeded by comprises . . . a does not, without more constraints, preclude the existence of other processes, sub-processes, composition, sub-compositions, minor or major compositions or other elements or other structures or additional processes or compositions or additional elements or additional features or additional characteristics or additional attributes.

(4) Definitions

(5) For the purposes of this invention, the following terms will have the meaning as specified therein:

(6) Anti-stripping: Separation of bitumen from aggregates in the presence of water is called stripping of bitumen. Prevention of stripping is called anti-stripping. Generally anti-stripping agents are added in bitumen to prevent stripping.

(7) Penetration: Consistency of bituminous material expressed as the distance in tenths of mm that standard needle vertically penetrates a sample of the material under known condition of loading, time, temperature (i.e. 100 gm, 5 sec., 25 C.).

(8) Softening Point: Softening point is the temperature at which the substance attains a particular degree of softening under specified condition of the test.

(9) Anchoring: Bonding of crumb rubber particles with bitumen is called anchoring of crumb rubber modified bitumen.

(10) Penetration range: The range in which the penetration values of bitumen falls.

(11) The authors of the present invention have discovered that by adding bi-functional reactive and PET derivatives to asphaltic bitumen modified with crumb rubber, bitumen/crumb rubber systems completely stable to storage are achieved.

(12) Using this system, the composition of the invention is maintained stable during prolonged time periods in the storage tanks, without the need for stirring.

(13) Therefore, the first aspect of the present invention relates to a crumb rubber modified bitumen composition which comprises bitumen, crumb rubber, PET derivatives and bi-functional reactive compound.

(14) In another aspect, the crumb rubber modified bitumen composition comprises bitumen, crumb rubber, waste PET derivatives and bi-functional reactive compounds.

(15) The terms bitumen or asphalt in the present invention may be natural asphalt or obtained from petroleum residue and bearing a penetration range from 30 to 250 dmm (deci-milli-meter) or may be mixture of natural and petroleum asphalt. Asphalt is present in the composition in the range between 30 to 90% by weight of the composition.

(16) The term crumb rubber as used herein includes crumb rubber obtained from grinding of used truck tires or automobile tires, or from any other appropriate source of ground rubber, such as natural rubber.

(17) In a preferred embodiment, the crumb rubber has the percentage in which it enters the mixture is between 1% and 50% by weight of the final composition. Preferably, the crumb rubber is present in the composition in a range between 1% and 30% by weight of the final composition.

(18) PET is abbreviated form of polyethylene terephthalate, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food, water bottles, liquid containers, other plastic packaging items, thermoforming applications.

(19) Waste PET derivatives in the present invention comprise terephthalamide chemical compounds obtained by aminolysis of waste PET. Aminolysis of waste PET involves the reaction of one or more amines and polyamines along with waste PET flacks in a suitable solvent and it is according to our co-pending application, Indian Patent Application No. 1049/MUM/2014 (corresponding U.S. application Ser. No. 14/659,089, published as US 2015/0274974 A1).

(20) The percentage wherein the PET enters to form part of the crumb-rubber mixture is between 0.01% and 20% by weight of the total composition. Preferably, PET derivatives are present in the composition in a range between 1% and 10% by weight of the total composition.

(21) In the present invention, we have developed storage stable crumb rubber modified bitumen composition by using waste PET derivatives along with bi-functional reactive compounds. The combination of bi-functional reactive compounds along with waste PET derivatives promote the anchoring of crumb rubber in bitumen and produces highly storage stable crumb rubber modified bitumen composition.

(22) The bi-functional reactive compounds are generally chosen from aliphatic, cycloaliphatic and aromatic well known in the art, and mixture of these compounds.

(23) Exemplary aliphatic reactive bi-functional compounds include compounds having general formula as given below.
X(CH.sub.2).sub.nY wherein X and YOH, COOH, NH.sub.2, CONH.sub.2, COOR, CHO, OR, epoxides, acrylate etc. or X and Y may be same or different;

(24) 0wherein R may be any alkyl group; and wherein n=1-10.

(25) Aliphatic may be any alkane or alkene chain.

(26) Illustrative examples of aliphatic bi-functional compounds can be ethylenediamine, ethylene glycol, ethanolamine, adipic acid, pimelic acid, suberic acid, azelaic acid, amino acids, sebacic acid, dodecanedioic acid etc.

(27) The bi-functional compounds can also be cycloaliphatic and aromatic bi-functional compounds as well. Illustrative examples of cycloaliphatic bi-functional compounds isophorone disocyanate (IPDI), cyclopentylene-1,3-diisocyanate, cyclohexylene-1,2-diisocyanate etc.

(28) Illustrative examples of aromatic bi-functional compounds are benzidine, phathalic acid, p-phenylenediamine, 4,4-diphenyl disocyanate (MDI) and its isomers such as 2,4- and 2,2-diphenylmethane disocyanate, toluene disocyanate (TDI) and isomers thereof, particularly the 2,4- and 2,6-toluene disocyanate etc.

(29) The examples of aliphatic bi-functional compounds, cycloaliphatic bi-functional compounds and aromatic bi-functional compounds herein are illustrative in nature, and should not be considered as restricting the invention.

(30) The percentage wherein these bi-functional reactive compounds enter the mixture are between 0.01% and 20%. Preferably, bi-functional reactive compounds are present in the composition in a range between 0.1% and 10% by weight of the total composition.

(31) The present invention also discloses the process for the incorporation of PET derivatives and bi-functional reactive compound along with crumb rubber in bitumen which leads to anchoring of crumb rubber in bitumen to get highly storage stable crumb rubber modified bitumen composition.

(32) Several blends with various compositions of crumb rubber, PET derivatives along with bi-functional reactive compound have been prepared to get storage stable crumb rubber modified bitumen.

(33) The process comprises incorporation of various components in bitumen to get highly storage stable crumb rubber modified bitumen comprises following steps. Adding to heated neat asphalt 30-90% said PET derivatives 0.01-20%, bi-functional reactive compounds 0.01-20% crumb rubber 1-30%, and mixed it properly with the help of agitator for few minutes to few hrs. Crumb rubber may be added initially in heated bitumen or may be added after adding PET derivatives and bi-functional reactive compounds. Bi-functional reactive compounds may be added before adding crumb rubber or after adding crumb rubber in heated asphalt. Bi-functional reactive compounds or crumb rubber may be added simultaneously in heated neat asphalt. The temperature range should be 160-170 C. throughout the process.

(34) Neat bitumen can be easily heated at 150-170 C. However, maintaining the temperature range between about 160 C. to 170 C. is of critical importance in the aforesaid process as the temperature of the mixture gradually decreases on addition of neat bitumen. Proper reaction cannot be carried out at 150 C.

(35) The developed storage stable crumb rubber modified bitumen composition of the present invention was evaluated for several physical and rheological properties by using various test methods and it has been found that the developed crumb rubber modified bitumen has high storage stability with improved performance properties.

(36) In one aspect, the present invention is directed to the anchoring of crumb rubber with the help of PET derivatives along with bi-functional reactive compounds to produce crumb rubber modified bitumen with high storage stability.

(37) In one more aspect, the present invention has solved a major problem of transportation of crumb rubber modified bitumen.

(38) In another aspect, the present invention is directed to enhance the composition of waste crumb rubber in asphalt to get cost effective storage stable crumb rubber modified bitumen.

(39) In yet another aspect, the present invention is directed to the production of storage stable crumb rubber modified from waste tyre rubber and waste plastics which further provides an alternate way for the disposal of waste keeping the environment free of pollution and hazardous materials.

(40) Having described the basic aspects of the present invention, the following non-limiting examples illustrate specific embodiment thereof.

EXAMPLE-1

(41) Asphalt in the present invention may be natural asphalt or obtained from petroleum residue and bearing a penetration range from 30 to 250 dmm or may be mixture of natural and petroleum asphalt.

(42) Crumb rubber may be obtained from grinding of used truck tyres or automobile tyres, or from any other appropriate source of ground rubber.

(43) Neat asphalt was heated to a temperature range between 150 C. to 170 C. Then crumb rubber was added and stirred for one hr. After that PET derivatives derived from waste PET were added in bitumen followed by stirring for 1 hr. Then ethylene diamine was added in bitumen and mixed properly for 1-2 hrs within a temperature range between 160 C. to about 170 C.

(44) TABLE-US-00001 TABLE 1 Bi-functional (Diff. in reactive upper and compound lower soft. pt) Crumb PET (Ethylene- ( C.), (W.S) Rubber derivatives diamine) (Storage S.N. Asphalt (%) (%) (%) Stability) 1. Pen-80-100 10 2 1 2.5 W.S: Without Sieving

EXAMPLE-2

(45) Asphalt in the present invention may be natural asphalt or obtained from petroleum residue and bearing a penetration range from 30 to 250 dmm or may be mixture of natural and petroleum asphalt.

(46) Crumb rubber may be obtained from grinding of used truck tyres or automobile tyres, or from any other appropriate source of ground rubber.

(47) Neat asphalt was heated to a temperature range between 150 C. to 170 C. Then crumb rubber was added and stirred for one hr. After that PET derivatives derived from waste PET were added in bitumen followed by stirring for 1 hr. Then ethanolamine was added in bitumen and mixed properly for 1-2 hrs within a temperature range between 160 C. to about 170 C.

(48) TABLE-US-00002 TABLE 2 Bi-functional (Diff. in reactive upper and compound lower soft. pt) Crumb PET (Ethanol- ( C.), (W.S) Rubber derivatives amine) (Storage S.N. Asphalt (%) (%) (%) Stability) 1. Pen-80-100 10 2 1 3 W.S: Without Sieving

EXAMPLE-3

(49) Asphalt in the present invention may be natural asphalt or obtained from petroleum residue and bearing a penetration range from 30 to 250 dmm or may be mixture of natural and petroleum asphalt.

(50) Crumb rubber may be obtained from grinding of used truck tyres or automobile tyres, or from any other appropriate source of ground rubber.

(51) Neat asphalt was heated to a temperature range between 150 C. to 170 C. Then crumb rubber was added and stirred for one hr. After that PET derivatives derived from waste PET bottles were added in bitumen followed by stirring for 1 hr. Then sebacic acid was added in bitumen and mixed properly for 1-2 hrs within a temperature range between 160 C. to about 170 C.

(52) TABLE-US-00003 TABLE 3 Bi-functional (Diff. in reactive upper and compound lower soft. pt) Crumb PET (sebacic ( C.), (W.S) Rubber derivatives acid) (Storage S.N. Asphalt (%) (%) (%) Stability) 1. Pen-80-100 10 2 1 2 W.S: Without Sieving

EXAMPLE 4

(53) Properties of Claimed Modified Bitumen after Sieving.

(54) Asphalt in the present invention may be natural asphalt or obtained from petroleum residue and bearing a penetration range from 30 to 250 dmm or may be mixture of natural and petroleum asphalt.

(55) Crumb rubber may be obtained from grinding of used truck tires or automobile tires, or from any other appropriate source of ground rubber.

(56) Neat asphalt was heated to a temperature range between 150 C. to 170 C. Then crumb rubber was added and stirred for one hr. After that PET derivatives derived from waste PET bottles were added in bitumen followed by stirring for 1 hr. Then sebacic acid was added in bitumen and mixed properly for 1-2 hrs within a temperature range between 160 C. to about 170 C.

(57) Crumb rubber modified bitumen produced in the present invention was sieved and followed by storage stability test using standard test method IS 15462:2004(ANNEX B).

(58) TABLE-US-00004 TABLE 4 (Diff. in Bi-functional upper and reactive lower soft. pt) compound ( C.), (After Crumb PET (sebacic Sieving) Rubber derivatives acid) (Storage S.N. Asphalt (%) (%) (%) Stability) 1. Pen-80-100 10 2 1 1

EXAMPLE-5

(59) Effect on storage stability due to the addition of crumb rubber along with bi-functional reactive compounds and PET derivatives in asphalt.

(60) The bi-functional compound is generally chosen from aliphatic, cycloaliphatic and aromatic well known in the art, and mixture of these compounds.

(61) Neat asphalt was heated to a temperature range between 150 C. to 170 C. Then bi-functional compound (sebacic acid), crumb rubber and PET derivatives derived from waste PET bottles were added in asphalt and mixed properly within a temperature range between 160 C. to about 170 C.(1-6 hr)

(62) TABLE-US-00005 TABLE 5 Bi-functional (Diff. in reactive upper and compounds lower soft. pt) PET Crumb (sebacic ( C.), (W.S) derivatives Rubber acid) (Storage S.N. Asphalt (%) (%) % Stability) 1. Pen 80-100 1 10 0.5 1.9

(63) From the above examples, Example 3 may be considered as the best working example in the present specification.

COMPARATIVE EXAMPLES: EXAMPLES 6 TO 9

(64) The following examples 6 to 9 encapsulate the comparative examples, where the essential ingredients of the present invention are either missing or are outside the claimed range. Such examples show inferior properties in tabular format. Here property parameters of comparative examples are same with property parameters of the working examples.

EXAMPLE 6

(65) Effect of storage stability when asphalt is not within range (Pen<30 dmm, and >250 dmm)

(66) Neat asphalt (Pen:20 and Pen:280) was heated to a temperature range between 150 C. to 170 C. Then crumb rubber was added and stirred for one hr. After that PET derivatives derived from waste PET bottles were added in bitumen followed by stirring for 1 hr. Then bi-functional reactive compound (sebacic acid) was added in bitumen and mixed properly for 1-2 hrs within a temperature range between about 160 C. to about 170 C.

(67) Crumb rubber modified bitumen produced in the present invention was sieved and followed by storage stability test using standard test method IS 15462:2004(ANNEX B).

(68) TABLE-US-00006 TABLE 6 Bi-functional (Diff. in reactive upper and compound lower soft. pt) Crumb PET (sebacic ( C.), (W.S) Rubber derivatives acid) (Storage S.N. Asphalt (%) (%) (%) Stability) 1. Pen: 20 6 1 0.5 >5 2. Pen: 280 30 15 7 >5

EXAMPLE-7

(69) Effect on storage stability due to the addition of crumb rubber in asphalt.

(70) Asphalt in the present invention may be natural asphalt or obtained from petroleum residue and bearing a penetration range from 30 to 250 dmm or may be mixture of natural and petroleum asphalt.

(71) Crumb rubber may be obtained from grinding of used truck tyres or automobile tyres, or from any other appropriate source of ground rubber.

(72) W.S: Without Sieving

(73) Neat asphalt was heated to a temperature range between 150 C. to 170 C. Then 10% crumb rubber was added to it and then mixed homogenously with the help of agitator for 2-4 hours within a temperature range between 160 C. to about 170 C. The test data for separation difference in softening point without sieving as shown below in table.

(74) TABLE-US-00007 TABLE 7 Crumb (Diff. in upper and lower soft. Rubber pt) ( C.), (W.S) (Storage S.N. Asphalt (%) Stability) 1. Pen-80-100 10 8

EXAMPLE-8

(75) Effect on storage stability due to the addition of crumb rubber along with PET derivatives in asphalt.

(76) PET is abbreviated form of polyethylene terephthalate, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers, thermoforming applications and engineering resins.

(77) Neat asphalt was heated to a temperature range between 150 C. to 170 C. Then crumb rubber and PET derivatives derived from waste PET bottles were added in asphalt and mixed properly within a temperature range between 160 C. to about 170 C.

(78) TABLE-US-00008 TABLE 8 (Diff. in upper and PET Crumb lower soft. pt) derivatives Rubber ( C.), (W.S) S.N. Asphalt (%) (%) (Storage Stability) 1. Pen-80-100 2 10 4

EXAMPLE-9

(79) Effect on storage stability due to the addition of crumb rubber along with bi-functional compound in asphalt.

(80) Neat asphalt was heated to a temperature range between 150 C. to 170 C. Then crumb rubber and PET derivatives derived from waste PET bottles and bi-functional compound (sebacic acid) were added in asphalt and mixed properly with in a temperature range between 160 C. to about 170 C.

(81) TABLE-US-00009 TABLE 9 Bi-functional (Diff. in upper and compound Crumb lower soft. pt) (sebacic acid) Rubber ( C.), (W.S) S.N. Asphalt (%) (%) (Storage Stability) 1. Pen-80-100 0.5 10 3.5

EXAMPLE-10

(82) Data regarding anti-stripping properties

(83) Example-1 shows best anti-stripping properties. Rest of the others also shows good anti-stripping properties.

(84) TABLE-US-00010 TABLE 10 Bi-functional reactive Crumb PET compound (Anti- Rubber derivatives (Sebacic acid) stripping) S.N. Asphalt (%) (%) (%) (%) 1. Pen 80-100 10 2 1 98

(85) Anti-stripping can be observed by standard test method (ASTM D 3625-96) given as follow.

(86) Hot Water Immersion Tests: Boiling Water Test is a visual rating of the extent of stripping after the mixture is boiled. 238 grams of washed and dry aggregate and the 12 gm of melted bitumen is doped with the anti-stripping agent, mixed properly and are kept in oven at 85-100 C. Then a 2,000 ml beaker is filled halfway with distilled water and boiled. The mixture is placed in boiling water for 10 minutes. Asphalt cement that is floating is skimmed off from the top. The water is cooled to room temperature and then poured off. The aggregate mixture is emptied onto a white paper towel and graded, then visually observed for the remaining percentage of coated area (not stripped by water). After 24 hours the aggregate mixture is observed again.

EXAMPLE-11

Effect on physicochemical properties due to the addition of PET derivatives along with bi-functional compound in bitumen.

(87) Anchoring-1: Asphalt+crumb rubber+bi-functional reactive compounds+PET Derivative.

(88) TABLE-US-00011 TABLE 11 S.N. Property CRMB-55 Anchoring-1 1. Penetration at 25 C., 1/10 46 53 mm, 5 sec. 2. Softening point, (R&B), C. 57 57 3. Elastic Recovery of half 65 69 thread in ductilometer at 15 C., % 4. Viscosity at 150 C., Poise 3.86 4.60

(89) All physicochemical properties have been carried out by standard test method as given as follow.

(90) Penetration Hardness; ASTM D5: Specimens are prepared in sample containers exactly as specified (ASTM D5-97) and placed in a water bath at the prescribed temperature of test for 1 to 1.5 hours before the test. For normal tests the precisely dimensioned needle, loaded to 1000.05 g, is brought to the surface of the specimen at right angles, allowed to penetrate the bitumen for 50.1 s, while the temperature of the specimen is maintained at 250.1 C. The penetration is measured in tenths of a millimetre (deci-millimetre, d-mm).

(91) Ring and Ball Softening Point (RBSP); ASTM D36: This test method covers the determination of the softening point of bitumen in the range from 30 to 157 C. [86 to 315 F.] using the ring-and-ball apparatus immersed in distilled water [30 to 80 C.] or USP glycerine (above 80 to 157 C.). The values stated in either SI units or inch-pound units are to be regarded separately as standard.

(92) Elastic Recovery ASTM D6084-06: The elastic recovery is measured by the percentage to which the asphalt residue will recover its original length after it has been elongated to a specific distance at a specified rate of speed and then cut in half. The distance to which the specimen contracts during a specified time is measured and the elastic recovery is calculated.

(93) Rotational Viscometer (RV); ASTM D4402/D4402MThis test method outlines a procedure for measuring the apparent viscosity of asphalt from 38 to 260 C. [100 to 500 F.] using a rotational viscometer and a temperature-controlled thermal chamber for maintaining the test temperature.

EXAMPLE-12

(94) High performance and rheological properties of crumb rubber modified bitumen due to addition of PET derivatives along with bi-functional compounds in bitumen.

(95) DSR: Dynamic Shear Rheometer

(96) RTFO: Rotating Thin Film Oven

(97) BBR: Bending Beam Rheometer (for bending beam creep stiffness test)

(98) Anchoring-1: Asphalt+crumb rubber+Bi-functional compounds+PET Derivative.

(99) Dynamic Shear, ASTM D7175, is determined both before and after simulated aging in the Rolling Thin Film Oven (RTFO) test to determine minimum binder stiffness as exhibited in freshly paved roads up to one year in age.

(100) Bending Beam Creep Stiffness, ASTM D 6648, is determined after RTFO aging to determine the low thermal cracking of asphalt. The Bending Beam Creep Stiffness test measures low temperature stiffness characteristics. A 12.7 cm0.6 cm1.3 cm (5) beam of binder material is moulded, cooled to testing temperature, and subjected to an imposed weight load. Load versus deflection data is collected for 240 seconds. The low temperature specification values are based on the stiffness value determined at 60 seconds and the absolute value of the slope (m-value) of the time vs. log (Stiffness) curve determined at 60 seconds.

(101) Storage stable crumb rubber modified asphalt developed in the present invention, exhibits acceptable and better data for low temperature creep stiffness and m values than exhibited by neat asphalt, when tested at low temperatures ranging from 42 C. to 0 C. according to ASTM D6648 test method. A comparative study of Bending Beam Creep Stiffness test data for the various blends having different composition is given in Table 12 below.

(102) Storage stable crumb rubber modified asphalt developed in the present invention, exhibiting improved Dynamic Shear Rheometer stiffness values for original binder as well as after RTFO of modified asphalt, which when tested with a dynamic shear rheometer at temperatures ranging from 58 C. to 82 C., exhibits G*/sin () stiffness values which are greater than stiffness value for neat asphalt as shown in data given in table below.

(103) Anchoring-1: Asphalt+crumb rubber+bi-functional reactive compounds+PET Derivatives.

(104) TABLE-US-00012 TABLE 12 Requirement as per ASTM An- S.N. Property D6373-07 CRMB-55 choring-1 1. DSR-Original Binder, 1.00 Min 1.87 1.08 G*/Sin -Value (Kpa) at 70 C. at 82 C. 2. DSR-(After-RTFO), 2.20 Min. 2.76 2.25 G*/Sin -Value (Kpa) at 70 C. at 82 C. 3. BBR (After-RTFO) m Value 0.300 0.24/300 0.30/186 m-Value/Estimated Min/Estimated at 18 C. at 18 C. Stiffness (MPa) Stiffness < 300

(105) The DSR and BBR values of the product of the invention meet as per required ASTM D6373-07. It means product has good performance properties. (Rutting, Fatigue and low temperature stiffness properties.)

EXAMPLE-13

(106) Hybrid bitumen produced in the present invention meets with all modified bitumen specifications as per IS 15642:2004/IRC: SP: 53-2010 and ASTM D6373-07.

(107) Hybrid bitumen can also be produced in the present invention by using PET derivatives, bi-functional compounds and crumb rubber from bitumen with penetration range of 80-100 dmm. Hybrid bitumen produced in the present invention meets with all modified bitumen specifications as per IS 15642:2004/IRC: SP: 53-2010 and ASTM D6373-07.

(108) TABLE-US-00013 TABLE 13 Modified CRMB-60 bitumen PMB-40 Specification Specification Specification As per As per IRC SP As per Type- IS: 15462- 53-2010 for above Hybrid B, IS: 15462- 2004 for 35 C. highest S.N. Property Bitumen 2004 CRMB-60 mean air temp. 1. Penetration at 25 C., 47 30-50 <50 30-50 1/10 mm, 5 sec. 2. Softening point, 61 60 Min. 60 Min. 60 Min. (R&B), C. 3. Elastic Recovery of 72 70 Min. 50 Min. 60 Min. half thread in ductilometer at 15 C., % 4. Viscosity at 6 3-9 3-9 5-9 150 C., Poise 5. Separation Test 2.5 (Without .sup.3 Max. 4 Max (With 3 Max (With (Difference in Sieving) Sieving) Sieving) softening point, (R&B), C.