CRMB  CRMB Sure about the 100% pure quality if you buy from us. © 2010  Made with GCT Co. l. INTRODUCTION Flexible pavements with asphaltic concrete are widely used all over the world. Asphalt acting as a binder for aggregates is a very important ingredient affecting the life cycle and travel comfort on roads. It has been an established fact that normal bituminous course can not cope up with the following problems:                                  i.   Increasing traffic on road / endemic overloading of vehicles leading to undulations, rutting, cracking, deformations, potholing and shortening of life of asphaltic pavements. ii.  High range of temperatures causing pavements to become softer in summer and brittle in winter. iii. Rains / water causing extensive stripping problems in asphaltic pavements.                                                                       To overcome the above problems in the entire world it has become a regular practice to use modifier as additives to strengthen the asphalt for making longer lasting asphalt mixes.  This has been a very important development in the last  3 decades and has lead not only to huge saving by delaying the maintenance cycles of the road but also its importance has been felt in countries where aggregates and asphalt are in short supply .                                                                                   NBP super is a crumb rubber based asphalt modifier. It is manufactured by blending chemically treated crumb rubber, natural asphalt and Bismides chemicals. Natural asphalt is a naturally occurring hydrocarbon mineral that is high in asphaltense and high in the Nitrogen.  When added to asphalt it dramatically increases the asphalt's viscosity, lowering penetration while increasing the softening point.                   The chemically treated crumb rubber and Bismides have been designed to rapidly blend in to asphait.  The addition of rubber gives the additional binding strength, increasing elasticity and softening point of the asphalt. Carbon present in rubber acts as an anti-oxidant and prevents asphalt from ageing and oxidization with sun. The blend of these two i.e. NBP-Super is a complete modifier which gives over all improvement when mixed with Asphalt by way of better resistance against hot , cold and wet weather conditions. It also gives increased binding strength.                                                   ll.   PHYSICAL PROPERTIES Physical properties of the Modifier are as follows: Particle Size ( 2.35 mm sieve )    100% passing     ASTM : D-5644 Water content %wt.                  0.75 max          ASTM : D-1864 Solubility in toluene%wt.      35 min          ISO : 4650 Ash content %wt.                  7.0 max          ASTM : D-482 lll. ADVANTAGES NBP-Super modifier substantially improves the vital properties of asphalt. NBP- Super can eaily be blended with conventional grades of asphalt giving following benefits to the base asphalt. i.     Increase of Softening point by at least 25%-thereby giving it protection against hot climatic conditions. ii.     Increase in Elastic Recovery by at least 400% - thereby improving resistance to cold climatic conditions and resistance to cracking under stress. iii.    Lower penetration thereby making harder grade of asphalt, giving additional strength to the road and reduces water damage. iv.    Improvement in Ageing Characteristics thereby giving longer life to the roads. v.     Improved Adhesion thereby giving better strength, stability and longer life. vi.    Reduce noise pollution. vii.   Saves energy and natural resources. Further more, NBP-Super has unique characteristics against other polymers thet it does not require specialized equipment for mixing it with asphalt and also heating and reheating of asphalt has minimal effect on the properties of the modifier. lV. CONCLUSION The NBP-Super product has been designed to incorporate the proven benefits of natural asphalt and visco-elastic properties of rubber. The mixture is intended to be cost effective and easy to use. The most critical elements is even dispersion of modifier through out asphalt matrix. i.    Cost increase in modified asphalt is around 25-30% in comparison to the plain asphalt. ii.   Cost increase in hot mix is around 10-12%. iii.   The life of pavement goes up by 2-2.5 times. iv.   Binder content in hot mix designs reduces by 8-10% depending upon the aggregates and asphaltic mix design. GRADE  60/70 SPECIFICATIONS    60/70 60/70 + 12% NBP-SUPER       TEST METHOD Penetration(25 °C)(0.1 mm)( °C)             65 40 ASTM  D-5 Softening Point ( ring & ball) (°C)             49.5 64 ASTM  D-36 Elastic Recovery of Half. Thread in Ductilometer at 15 C% min                                                10 60 IRC:SP:53:02 Specific Gravity (25 °C)                        1.015 1.04 ASTM  D-70 Elastic Recovery after TFOT @ 25 °C, cm 6 45 IRC:SP:53:02 Retained Penetration after TFOT @ 25 °C, % OF                         66 72 ASTM  D-5 Viscosity @ 135°C, cst                        310 1540 ASTM  D-2170 Flash point                                                327 365 ASTM  D-92   GRADE 80/100 SPECIFICATIONS 80/100       85/100 + 12% NBP-SUPER TEST METHOD Penetration(25 °C)(0.1 mm)( °C)                     89 50 ASTM  D-5 Softening Point ( ring & ball) (°C)                     47 57 ASTM  D-36 Elastic Recovery of Half. Thread in Ductilometer at 15 °C% min         10 50 IRC:SP:53:02 Specific Gravity (25 °C)                               1.02 1.012 ASTM  D-70 Elastic Recovery after TFOT @ 25 °C, cm                                              6 40  IRC:SP:53:02 Retained Penetration after TFOT @ 25 °C, % OF Original                       63 70 ASTM  D-5 Viscosity @ 135°C, cst                                 228 1235 ASTM  D-2170 Flash point                                                         321 365 ASTM  D-92 Asphalt Grade         Binder         Air Void        Marshall Stability       Predicted Cycles                                Content     Content       (75 blow)                    To Km. Rut                                                                       At 60 °C Minimum Depth (ESALs) 60/70                        4.9 %    3-4 % 1200                        12.1 Million 60/70 + NBP Super 4.4 %    3-4 % 1800                         30.4 Million Bituminous mixes made with NBP-Super show the following improvement in the properties in comparison to the bituminous mixes made with ordinary bitumen: 1. Increase in Marshall Stability 2. Increase in Fatigue life 3. Elastic Modulus gets enhanced 4. Improves Water Repellent Properties 4. Improves Skid Resistance during hot and wet conditions 5. Improves Ageing Resistance
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