CRUMB RUBBER MODIFIED BITUMEN (CRMB)

Crumb Rubber Modified Bitumen (CRMB) is a high-quality road construction material made by adding finely ground rubber particles to bitumen. The rubber particles are obtained from scrap tires that are first shredded into small pieces and then further processed to remove any impurities. The resulting crumb rubber is then blended with bitumen in a specific ratio to produce CRMB. This material is typically black in color, with a soft and sticky consistency. It has excellent elasticity, which allows it to withstand traffic loads and temperature changes without cracking or deforming.

Petro Naft manufactures the highest quality Crumb Rubber Modified Bitumen (CRMB) in different types and grades and exports them from Iran and the UAE to other countries around the world.

Iran Crumb Rubber Modified Bitumen ( Iran CRMB )
UAE Crumb Rubber Modified Bitumen ( UAE CRMB )

WHAT IS CRUMB RUBBER MODIFIED BITUMEN (CRMB)?

CRMB is a modified bitumen material that combines the benefits of bitumen and rubber to produce a durable and flexible road construction material. It is a sustainable solution that recycles waste tires and reduces the environmental impact of road construction activities. CRMB can be used as a binder in asphalt concrete, which is the most common type of pavement used on roads and highways worldwide. It improves the performance of asphalt concrete by increasing its resistance to deformation, cracking, and aging.

CRUMB RUBBER MODIFIED BITUMEN (CRMB) HISTORY

The use of rubber in road construction dates back to the early 1900s when Henry Ford used rubberized asphalt to pave his automobile factory’s parking lot. However, the commercial use of rubberized asphalt did not become widespread until the 1960s when the first rubber-modified asphalt was produced in the United States. Since then, the use of crumb rubber in road construction has become increasingly popular, especially in countries with large quantities of scrap tires.

CRUMB RUBBER MODIFIED BITUMEN OTHER NAMES

1. Rubberized Bitumen – Commonly used to emphasize the addition of rubber.
2. Rubber Modified Asphalt – Highlights its use in asphalt applications.
3. Crumb Rubber Asphalt – Specifically denotes the use of crumb rubber in asphalt.
4. CR-Modified Bitumen – Abbreviation for crumb rubber modified bitumen.
5. Recycled Rubber Bitumen – Indicates the use of recycled rubber.
6. Bitumen-Rubber – A simple term used in various contexts.
7. Rubberized Asphalt Concrete (RAC) – Used in pavement and road construction.
8. Rubberized Asphalt Binder – Focuses on its role as a binding agent in asphalt.
9. Rubberized Hot Mix Asphalt – Emphasizes the hot mix process in asphalt applications.
10. Crumb Rubber Binder – Highlights its function as a binder in construction.
11. Rubber-Infused Bitumen – Indicates the infusion of rubber into bitumen.
12. Rubber-Modified Binder – General term for bitumen modified with rubber.
13. Crumb Rubber Pavement Binder – Used in the context of pavement construction.
14. Rubberized Road Binder – Highlights its application in road construction.
15. Rubber-Tire Asphalt – Refers to the use of tire-derived rubber in asphalt.
16. Elastomer-Modified Bitumen – Emphasizes the elastic properties imparted by rubber.
17. Rubberized Sealant – Used in sealing applications for roads.
18. CR Bitumen – Abbreviation often used in technical documents.

CRUMB RUBBER MODIFIED BITUMEN (CRMB) COMPONENTS AND MATERIALS

Crumb Rubber Modified Bitumen (CRMB) presents a sustainable, high-performance choice for a variety of applications within the paving industry. This innovative road construction material blends scrap tires, also known as crumb rubber, with traditional bitumen, creating an enhanced binder with improved properties.

The components of CRMB chiefly consist of two main elements:

1. Crumb Rubber: Derived from waste tires that are mechanically ground into small particles, typically between 0.6 to 0.8 mm. This recycling process not only reduces landfill waste but also harnesses the physical properties of rubber for enhancing the overall characteristics of bitumen.

2. Bitumen: A highly viscous, sticky substance that’s a byproduct of petroleum refining. Known for its exceptional waterproofing and adhesive qualities, bitumen serves as the binder in CRMB, ensuring strong cohesion with aggregates in asphalt mixtures.

CRMB’s production involves blending these components under specific conditions—temperature, duration, and the amount of crumb rubber—to achieve the desired specifications.

CRUMB RUBBER MODIFIED BITUMEN (CRMB) PRODUCTION PROCESS

The production process of Crumb Rubber Modified Bitumen (CRMB) or rubberized asphalt involves a series of well-defined stages, resulting in a product that optimally combines the advantageous properties of bitumen and crumb rubber. Here is a generalized process:

1. Crumb Rubber Production: This is the initial phase where waste tires are mechanically ground into fine particles, creating the crumb rubber. The size of these particles typically ranges between 0.6 to 0.8 mm.

2. Preliminary Blending: The crumb rubber is added to hot bitumen, usually at temperatures around 180°C. The high temperature is necessary for the rubber particles to swell and absorb the bitumen.

3. Digestion Phase: The mixture is kept at the high temperature for a specific period, known as the digestion or reaction time. This period can vary between 1 to 2 hours and allows for the complete assimilation of the crumb rubber into the bitumen. During this process, the rubber particles swell, soften, and partially dissolve, creating a thicker, more viscous material.

4. Final Blend: Following the digestion phase, the blend is stirred thoroughly to ensure the crumb rubber is evenly dispersed within the bitumen. This can be achieved by using high-speed shear mills.

5. Filtration and Storage: The CRMB is filtered to remove any large, undissolved rubber particles. It is then stored at high temperatures to prevent separation before use.

6. Use in Asphalt Mixture: The final CRMB product is mixed with aggregate material (stones, sand, etc.) to create the asphalt mixture that is used for paving.

Please note that the specifics of the production process may vary depending on the required properties of the CRMB, local regulations, and the technology available. Regardless of these factors, the goal is always to produce a superior pavement binder that can resist deformation, cracking, and weathering more effectively than conventional bitumen.

CRUMB RUBBER MODIFIED BITUMEN (CRMB) GRADES, TYPES, AND FORMS

Crumb Rubber Modified Bitumen (CRMB) is an innovative form of bitumen, fortified by the inclusion of crumb rubber, which are finely ground particles extracted from waste tires. This unique combination boosts the performance and durability of bitumen, significantly enhancing road longevity. The varied grades of CRMB, differentiated by the rubber content and the production method, are specifically designed for distinct climates, road networks, and traffic volumes.

The three primary grades of CRMB are:

1. CRMB 60: Tailored for warm climates, this grade blends bitumen with crumb rubber to enhance the elasticity of bitumen and increase its softening point, making it more resistant to high temperatures. It consequently reduces the risk of rutting and heat-related damage to the road surface.

2. CRMB 55: This grade is suitable for general climates where temperatures fluctuate considerably throughout the year. It ensures optimal performance under a range of temperatures and is ideal for a variety of road construction projects, including highways, urban roads, and residential streets.

3. CRMB 50: For colder climates with frequent sub-zero temperatures, CRMB 50 is the preferred choice. This formulation maintains flexibility at lower temperatures, thereby reducing the likelihood of thermal contraction-induced cracking. The added crumb rubber enhances the bitumen’s resistance to cold-temperature cracking and thermal fatigue.

Additionally, CRMB is available in different types based on the rubber content:

1. Type A CRMB: Comprising 18-22% rubber, it’s produced by adding dry crumb rubber to hot bitumen. This type is ideal for high-traffic roads and highways, where the pavement must withstand heavy loads and extreme weather conditions.

2. Type B CRMB: Contains 12-16% rubber and is produced by integrating wet crumb rubber with hot bitumen. It’s suitable for low-traffic roads and pavements, where the pavement must endure moderate loads and weather conditions.

3. Type C CRMB: Comprising 6-10% rubber, this type is generated by adding wet crumb rubber to cold bitumen. It’s appropriate for thin pavements such as bike lanes and footpaths, where the pavement needs to be flexible and resilient.

CRMB can be procured in two forms: wet mix and dry mix. Wet mix CRMB is created by adding wet crumb rubber to hot bitumen and thoroughly amalgamating the components. Dry mix CRMB, on the other hand, is created by adding dry crumb rubber to hot bitumen and blending the mixture using a high-speed mixer.

The various grades, types, and forms of CRMB have a multitude of applications in road construction, determined by the pavement’s design, traffic volume, and climate conditions. High-traffic roads usually employ Type A or wet mix CRMB for its homogeneous and durable mixture. Conversely, low-traffic roads opt for Type B or dry mix CRMB due to its ease of handling and storage. Type C CRMB is typically used for thin pavements like bike lanes and footpaths, where flexibility and durability are crucial.

The production of CRMB can be achieved using two methods: the wet process and the dry process. Both involve blending crumb rubber with hot bitumen in a high-speed mixer. The wet process employs wet crumb rubber, whereas the dry process uses dry crumb rubber ground into a fine powder. The resulting CRMB is stored in a heated storage tank and transported to the construction site in insulated tankers, ensuring its optimal quality and performance for the specific application.

CRUMB RUBBER MODIFIED BITUMEN (CRMB) SPECIFICATIONS

CRMB must meet specific specifications to ensure its quality and performance in road construction. The specifications may vary depending on the country and the project requirements, but the most common ones are as follows:

• Penetration: the depth in tenths of a millimeter to which a standard needle will penetrate the CRMB sample under specified conditions of temperature and loading.
• Softening point: the temperature at which the CRMB sample softens and deforms under specified conditions of heating.
• Viscosity: the resistance of the CRMB sample to flow under specified conditions of temperature and shear rate.
• Elastic recovery: the percentage of the original deformation that the CRMB sample recovers after being subjected to a specified deformation and relaxation cycle.
• Fatigue life: the number of load repetitions that the CRMB sample can withstand before failure under specified conditions of temperature and loading.

Specifications For All Grades of CRMB

Benefits of Opting for CRMB Instead of Traditional Bitumen

CRUMB RUBBER MODIFIED BITUMEN (CRMB) HS CODE, CHEMICAL FORMULA AND CAS NUMBER

CRMB is a mixture of bitumen and crumb rubber and does not have a specific chemical formula or CAS number. However, it is classified under the Harmonized System (HS) code 2715.00.90, which covers bituminous mixtures based on natural asphalt, petroleum bitumen, mineral tar or mineral asphalt, mineral wax, and mixtures thereof. The HS code is used by customs authorities to classify goods and determine the applicable duties and taxes.

CRUMB RUBBER MODIFIED BITUMEN (CRMB) PROPERTIES

CRMB has several properties that make it an attractive alternative to conventional bitumen in road construction. Some of these properties are:

• Improved fatigue resistance: CRMB can withstand repeated loading cycles without cracking or breaking, which improves the pavement’s durability and lifespan.
• Increased stiffness: CRMB has a higher stiffness modulus than conventional bitumen, which reduces rutting and deformation under heavy loads and high temperatures.
• Improved adhesion: CRMB forms a stronger bond with aggregates and other materials than conventional bitumen, which improves the pavement’s resistance to water and shear stresses.
• Reduced aging: CRMB contains antioxidants and anti-oxidant additives that reduce the effects of oxidation and aging, which improves the pavement’s resistance to cracking and embrittlement.
• Reduced noise: CRMB has a higher content of crumb rubber, which improves the pavement’s noise-absorbing properties and reduces tire-pavement noise.

CRUMB RUBBER MODIFIED BITUMEN (CRMB) ADVANTAGES AND BENEFITS

CRMB has several advantages over conventional bitumen in road construction, such as:

1. Improved pavement performance: CRMB improves the pavement’s durability, stability, and resistance to deformation, fatigue, and cracking, which reduces maintenance costs and extends the pavement’s lifespan.
2. Environmental benefits: CRMB recycles waste tires and reduces their disposal in landfills, which reduces the environmental impact of waste and conserves natural resources.
3. Cost-effectiveness: CRMB is cost-effective compared to other pavement materials, such as concrete, and reduces the construction time and traffic disruptions.
4. Versatility: CRMB can be used in various pavement applications, such as high-traffic roads, low-traffic roads, thin pavements, and urban areas, which increases its versatility and adaptability to different design and climate conditions.

CRUMB RUBBER MODIFIED BITUMEN (CRMB) SAFETY TIPS

CRMB is a hazardous material and requires proper handling, storage, and transportation to ensure the safety of workers, the public, and the environment. Some safety tips for handling CRMB are:

Wear protective clothing and equipment, such as gloves, goggles, and respirators, when handling CRMB to prevent skin contact, eye irritation, and inhalation of fumes.

Store CRMB in a heated storage tank or insulated container to prevent it from freezing or solidifying, which can cause blockages and accidents.

Transport CRMB in insulated tankers or containers that are properly labeled and secured to prevent spills, leaks, and fires.

Dispose of used CRMB and contaminated materials in accordance with local regulations and guidelines to prevent environmental contamination and health hazards.