Bitumen, a binding material commonly derived from crude oil, is a key component in road construction. Its adhesive, waterproofing, and durability properties make it essential for creating long-lasting pavements and surfaces. However, not all bitumen is the same; various grades and types are specifically formulated to meet the demands of different environments, traffic loads, and construction techniques. This guide explores the main types of bitumen used in road construction, including penetration grade, viscosity grade, polymer modified, oxidized bitumen, bitumen emulsions, and liquid bitumen.
Penetration Grade Bitumen
Penetration grade bitumen is classified based on the depth a standard needle penetrates the bitumen sample under specific conditions (temperature, weight, and time). This grade is widely used in road construction due to its flexibility and ability to withstand different climate conditions. The penetration grade bitumen is ideal for moderate climates and offers good durability and elasticity.
Common Penetration Grades
1. Bitumen 60/70
Bitumen 60/70 is one of the most popular grades for road construction, especially in moderate climates. Its penetration value indicates a balanced hardness that provides resistance to deformation under heavy traffic, while still being flexible enough to prevent cracking. It is commonly used for asphalt mixes in highways, roads, and other heavy-duty pavements.
2. Bitumen 80/100
This grade is slightly softer than 60/70, with a higher penetration value. Bitumen 80/100 is suitable for warmer climates where the pavement needs a softer material to accommodate expansion without cracking. It’s often used in rural road construction and areas with lighter traffic loads.
Viscosity Grade (VG) Bitumen
Viscosity grade bitumen is categorized based on its viscosity, which measures the fluidity of the bitumen at 60°C. This method is considered more accurate than penetration testing as it accounts for temperature effects on bitumen consistency, making it suitable for different climate zones. Viscosity grade bitumen is primarily used in areas with extreme temperatures.
Common Viscosity Grades
1. VG-10
VG-10 is a soft viscosity grade bitumen that flows easily, making it suitable for surface dressing and spraying applications. It is often used in cold climates where a lower viscosity is beneficial for workability.
2. VG-30
VG-30 is commonly used in asphalt production for heavy-duty roads that experience high traffic. This grade offers better resistance to rutting in high-temperature climates and ensures durability under heavy loads.
3. VG-40
VG-40 is the hardest viscosity grade, designed for extremely hot conditions and heavy traffic. It is used in highways, industrial areas, and places with significant load-bearing requirements.
Performance Grade (PG) Bitumen
Performance grade (PG) bitumen is classified based on its performance under specific temperature ranges, both high and low, rather than traditional penetration or viscosity methods. This approach ensures that the bitumen performs well under the temperature conditions it will experience in the field. PG bitumen is popular in regions with extreme climate variations and heavy traffic.
Examples of PG Grades
- PG 64-22: Suitable for climates where the maximum temperature is 64°C and the minimum is -22°C.
- PG 76-10: Designed for hotter climates with a maximum of 76°C and a minimum of -10°C, making it ideal for regions with high heat stress on the pavement.
Performance grading helps construction professionals choose bitumen tailored to local climate conditions, ensuring greater durability and reduced maintenance.
Polymer Modified Bitumen (PMB)
Polymer Modified Bitumen (PMB) is a specialized type of bitumen modified with polymers, such as elastomers and plastomers, to enhance its properties. PMB is especially useful for projects requiring high durability, flexibility, and resistance to extreme weather conditions. It provides a high resistance to deformation, fatigue cracking, and rutting, making it ideal for high-stress areas like highways, airports, and heavy-traffic roads.
Types of Polymer Modified Bitumen
- SBS (Styrene-Butadiene-Styrene) Modified Bitumen: Improves elasticity and temperature resistance.
- EVA (Ethylene Vinyl Acetate) Modified Bitumen: Increases stiffness and resistance to aging.
- CRMB (Crumb Rubber Modified Bitumen): Utilizes recycled rubber to improve elasticity and resilience, making it more eco-friendly.
Oxidized Bitumen
Oxidized bitumen, also known as blown bitumen, is produced by passing air through heated bitumen, which increases its softening point and decreases its ductility. This process creates a harder, more temperature-resistant product, which is ideal for industrial applications and waterproofing rather than traditional road paving.
Common Oxidized Bitumen Grades
1. Bitumen 115/15
This grade has a high softening point and low penetration value, making it highly resistant to flow at elevated temperatures. Bitumen 115/15 is commonly used for roofing, pipe coating, and industrial applications where a rigid binder is required.
2. Bitumen 90/15
With a lower softening point than 115/15, Bitumen 90/15 is slightly more flexible and is used in applications like waterproofing membranes and sealing materials. It’s also suitable for industrial uses where moderate flexibility is needed.
Bitumen Emulsions
Bitumen emulsions are a mix of bitumen and water with added emulsifying agents, which allow the bitumen to remain in a liquid form at lower temperatures. Emulsions are eco-friendly as they do not require heating for application, reducing energy consumption and emissions. Emulsions are suitable for a variety of road construction and maintenance applications, including patching, sealing, and surface dressing.
Common Emulsion Types
1. SS-1 (Slow Setting)
SS-1 is a slow-setting emulsion, suitable for surface dressing, sealing, and tack coating applications. It allows for better adhesion and longer working times, making it ideal for surface treatments on roads with lighter traffic.
2. CMS (Cationic Medium Setting)
CMS emulsion is a medium-setting emulsion commonly used for patching and repairs. Its cationic nature helps it bond effectively with aggregates, providing durability and resistance to detachment.
Liquid Bitumen (Cutback Bitumen)
Cutback bitumen, or liquid bitumen, is bitumen that has been blended with a solvent or petroleum distillate to reduce its viscosity, allowing it to flow easily and be applied at lower temperatures. Cutbacks are used in road construction, especially in colder climates, where the bitumen must be workable without heating.
Common Liquid Bitumen Grades
1. MC-30 (Medium Curing)
MC-30 is a medium-curing cutback bitumen that is often used for prime coats in road construction. It has a low viscosity, allowing it to penetrate and bind well with the underlying layer, providing a strong base for subsequent layers.
2. MC-70
MC-70 has a slightly higher viscosity than MC-30 and is commonly used for tack coats, which help bond new layers of asphalt to existing pavement. Its slower evaporation rate makes it ideal for regions with warmer climates.
Comparing Different Types of Bitumen for Road Construction
| Type | Grades | Key Applications | Benefits |
|---|---|---|---|
| Penetration Grade | 60/70, 80/100 | Road paving, asphalt mix | Flexibility, durability |
| Viscosity Grade | VG-10, VG-30, VG-40 | Heavy-duty roads, hot climates | Temperature resistance, consistency |
| Performance Grade (PG) | PG 64-22, PG 76-10 | Areas with extreme temperature variations | Tailored for specific climates |
| Polymer Modified (PMB) | SBS, EVA, CRMB | High-stress roads, highways, airports | High flexibility, durability |
| Oxidized Bitumen | 115/15, 90/15 | Industrial uses, waterproofing | High temperature resistance, rigidity |
| Emulsions | SS-1, CMS | Surface dressing, patching, sealing | Eco-friendly, cold application |
| Cutback (Liquid) Bitumen | MC-30, MC-70 | Prime coats, tack coats, cold regions | Easy application, reduced heating required |
Types of packaging
1. Drum
2. Bitutainer
Bitumen fill in bitutainer and deliver to project and by steam cyrculation or hot oil it will meltdown.some of them working by coil heat.
3. Bitugmen in 50Kg bags
In 50Kg bag is different that 25kg and protected by different layer and composited with yarn and craft. This type of bag is possible to fill it and stuff in container without pallet.
4. Bitumen in 300Kg polycube bag
Polycube is just useful for export and in case you load in truck will leak and damage. Even at destination should be delivered to final destination and then discharge to prevent damage. It is designed as per of dimension of container and container protecting the bags and outside of container if you carry will damage!
5. Bitumen in Jumbo bag
Bitumen bag should be easily dissolved at 160C and start to melt from 110C.this type of bitumen bag is normally using for penetration grade of bitumen.In summer time outside temperature in port of loading is very hot and should be taken more care on compress of bag since it is liquid at more than 60C.So it should be protected by bracket or case.
bitumen in jumbo bag is most safe and easy handling from loading to destination. Jumbo bag should be designed for bitumen and if you buy from market and fill bitumen will become fat or collapse. Normally design of bitumen in jumbo bag is in the bottom the size is bigger than top and should have angle to become stable.
Density of bitumen
Density is between 1.01 to 1.06 (Kg/dm3)
It means that 1.010kg to 1.060kg is one desi cubic meter.
Each tons of asphalt needed 70Kg bitumen and the rest is aggregates.
Supply capacity of bitumen
Able to supply 30000MT monthly packed in drum, bag and bulk.
The volume quantity is exporting by since we are in contact with seven refineries of in North, East, West and South so Turkey ,UAE and other neighbor country can purchase with less transport cost.
Bitumen refineries
Most famous bitumen refineries is Tupras and Socar. Apart from these which selling bitumen, there are some other private factories that making bitumen with VB (Vacuum bottom) of refineries. The bitumen quality is Ok if they use pure VB and price compatible since their cost is much less.
ATDM selling bitumen packed in steel drum and bag also supplying bitumen 80/100 the material in bulk vessel which public refineries unable to arrange such service in the same time.