CRMB 55 | Crumb Rubber Modified Bitumen for High-Stress Pavements

Engineering Purpose of CRMB 55

CRMB 55 is a performance grade crumb rubber modified bitumen developed for pavement sections exposed to higher mechanical stress, heavier axle loads, and prolonged high-temperature conditions.

Compared to lower CRMB grades, CRMB 55 offers a balanced combination of elasticity and stiffness, allowing it to maintain structural stability while still providing sufficient flexibility to control cracking and fatigue.

This grade is typically selected when conventional CRMB or penetration grade bitumen reaches its performance threshold.

Where CRMB 55 Is Technically Justified

CRMB 55 is not a general-purpose binder.
It is specified when pavement design requires controlled deformation resistance without sacrificing elastic recovery.

Typical engineering scenarios include:

• High-speed highways with continuous heavy truck traffic

• Urban arterial roads with frequent braking and acceleration

• Industrial access roads subjected to repetitive loading

• Pavement layers exposed to sustained high surface temperatures

• Overlay projects where rut resistance is critical

In these applications, CRMB 55 provides better shape retention under load compared to softer rubber-modified binders.

Performance Behavior in Asphalt Mixtures

When used in asphalt production, CRMB 55 contributes to:

• Improved resistance to permanent deformation (rutting)

• Stable performance at elevated pavement temperatures

• Enhanced fatigue life under cyclic loading

• Reduced crack propagation in high-stress zones

From a functional perspective, CRMB 55 acts as a load-bearing elastic binder, supporting pavement integrity in demanding service conditions.

Handling, Storage, and Supply

CRMB 55 should be handled using standard hot bitumen handling procedures.

• Maintain appropriate storage temperature to ensure homogeneity

• Avoid prolonged overheating to preserve elastic properties

• Prevent contamination with water or foreign materials

CRMB 55 is supplied in bulk tanker trucks or steel drums depending on project volume and logistics requirements.

CRMB 55 vs Other Binder Options

CRMB 55 is typically chosen when:

• Penetration grade bitumen lacks rutting resistance

• CRMB 50 provides insufficient stiffness

• PMB is technically excessive or economically unjustified

This makes CRMB 55 a cost-effective, performance-driven alternative for heavy-duty pavement designs.

Typical Applications of CRMB 55

• Expressways and freight corridors

• Industrial road networks

• High-load intersections and roundabouts

• Logistics hubs and port access roads

• Long-life pavement structures in hot climates

Summary

CRMB 55 is a technically balanced rubber modified binder engineered for pavements that demand higher rutting resistance without losing elastic performance. It is best suited for projects where durability, load resistance, and long-term performance are critical design parameters.