PMB is typically made by combining bitumen with a styrene-butadiene-styrene (SBS) copolymer. The addition of the polymer makes the bitumen more elastomeric in nature. Some of the desirable properties of polymer modified bitumen include improved strength, cohesiveness and resistance to fatigue and deformation.
Product Specifications ( as per IS:15462:2004) Properties of tiki polymer and rubber modified bitumen |
|||||||
---|---|---|---|---|---|---|---|
Designation | Elastomeric Thermoplastic Based |
Crumb Rubber Modified Binders |
Method of tests |
||||
PMB 120 |
PMB 70 |
PMB 40 |
CRMB 50 |
CRMB 55 |
CRMB 60 |
||
Penetration, at 25°C, 100g, 5 sec, in 1/100cm | 90 to 150 | 50 to 90 | 30 to 50 | < 70 | < 60 | < 50 | IS: 1203-1978 |
Softening poing, (R&B), °C, Minimum | 50 | 55 | 60 | 50 | 55 | 60 | IS: 1205-1978 |
Frass Breaking Point, °C, Maximum | -20 | -16 | -12 | – | – | – | IS: 9381-1978 |
Flash Point by COC, °C, Minimum | 220 | 220 | 220 | 220 | 220 | 220 | IS: 1448(P-69) |
Elastic Recovery of Half Thread in Ductilometer at 15°C, %, Minimum | 70 | 70 | 70 | 50 | 50 | 50 | IS: 15462 Annex A |
Seprtation Difference in Softening Point (R&B), °C,Maximum | 3 | 3 | 3 | 4 | 4 | 4 | IS: 15462 Annex B |
Viscosity at 150°C , Poise | 1-3 | 2-6 | 3-9 | 1-3 | 2-6 | 3-9 | IS: 1206 (P-I) |
This Film Oven Test (TFOT) on Residue (IS:9382-1992) | |||||||
Loss in Mass % Maximum | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | IS: 9382-1992 |
Increase in softening point (R&B) °C Maximum | 7 | 6 | 5 | 7 | 6 | 5 | IS: 1205 |
Reduction in Penetration of Residue at 25°C % Maximum | 35 | 35 | 35 | 40 | 40 | 40 | IS: 1203 |
Elastic Recovery of Half thread in Ductilometer at 25°C % Min | 50 | 50 | 50 | 35 | 35 | 35 | IS: 15462 Annex A |