Crumb Rubber Modified Bitumen (CRMB) Crumb Rubber Modified Bitumen (CRMB) is a hydrocarbon binder obtained through physical and chemical interaction of crumb rubber (produced by recycling used tyres) with bitumen and some specific additives. It is used worldwide to increase the flexibility of worn-out pavements. Research worldwide has shown that the addition of crumb rubber to bitumen produces binders with improved resistance to combat pavement distresses such as rutting and fatigue cracking. This adequately demonstrates that Crumb Rubber Modified Bitumen is a superior binder that has immense application in highly trafficked National and State Highways of India. The current price of Crumb Rubber Modified Bitumen in India is Rs. 30,000/metric ton. Crumb Rubber can be added to the bituminous mixtures as a filler. The time and temperature of digestion of Crumb rubber modifier with Bitumen are known to have an important effect on the resulting Crumb Rubber Modified Bitumen. The major effect is due to absorption by the rubber particles of aromatic oil in the Bitumen. This causes softening and swelling of rubber particles so that a comparatively large proportion of binder (CRMB) consists of soft rubber. Significance : Some of the most remarkable aspects of CRMB are : 1. It produces an environment-friendly product. 2. Greater cost savings, lower energy consumption, and lower environmental pollution. 3. The highways made using CRMB have performed better and for longer as compared to those that are produced using much costlier polymers.
Advantages :
1. CRMB reduces deformation on road 2. It extends the life of a pavement by 50% to 100% 3. CRMB improves resistance to cracking resulting in stronger and more durable overlays. 4. It promotes binder adhesion and cohesion to mineral aggregates. 5. The striping level and reviling of aggregate from the surface are reduced and offer resistance to creep deformation Types of CRMB : 1. CRMB 60 2. CRMB 55 3. CRMB 50