Oxidized Bitumen 90/40 Industrial Blown Bitumen for Waterproofing, Coating & Infrastructure Applications

Oxidized Bitumen 90/40 is a semi-hard blown asphalt grade produced through a controlled air-blowing process. With a softening point around 90°C and penetration of approximately 40 dmm, this grade provides a balanced combination of workability, adhesion, and thermal stability.

It is widely used in waterproofing systems, corrosion protection, and industrial coating applications where moderate rigidity and reliable long-term performance are required.

Main Applications of Oxidized Bitumen 90/40

Oxidized Bitumen 90/40 is commonly used in:

• Asphalt-based protective paints for metal corrosion resistance

• Pipe coating and anti-corrosion systems

• Damp-proofing and waterproofing membranes

• Hydraulic and public infrastructure structures

• Portland cement pavement applications

• Bituminous mastics and caulking compounds

• Adhesives in electrical laminates

• Base material for synthetic turf systems

Its controlled hardness makes it suitable for applications requiring structural stability without excessive brittleness.

Surface Preparation Before Application

For optimal performance, surfaces must be:

• Clean and completely dry

• Free from dust, loose particles, and slurry

• Free from curing compounds or formwork residues

• Structurally sound and uniform

Proper surface preparation ensures strong adhesion and long-term durability.

Heating & Handling Guidelines

Since oxidized bitumen is solid at ambient temperature, it must be heated before application.

• Typical handling temperature range: 140°C to 200°C

• For highly oxidized grades, temperatures up to 230°C may be used under inert atmosphere

• Recommended flow temperature: approximately twice the softening point

Overheating or prolonged exposure to oxygen can negatively affect product properties and long-term performance. Controlled heating is essential to maintain quality.

Chemistry of the Bitumen Blowing Process

The production of Oxidized Bitumen 90/40 involves a controlled air-blowing process where hot penetration-grade bitumen reacts with oxygen.

This process includes:

• Oxidation

• Dehydrogenation

• Polymerization

During this transformation, oxygen reacts with the bitumen matrix, forming:

• Hydroxyl groups

• Carbonyl groups

• Acid groups

• Ester groups

These structural changes increase softening point and reduce penetration, resulting in improved rigidity and thermal stability. The chemical modification enhances resistance to aging and deformation under load.

Thermal Stability & Performance Considerations

When handled correctly, Oxidized Bitumen 90/40 can be reheated or maintained at elevated temperatures without significant degradation.

However, improper handling such as:

• Excessive overheating

• Prolonged exposure to oxygen

• Rapid uncontrolled heating

may alter physical properties and affect long-term performance in waterproofing or coating systems.

Controlled temperature management ensures consistent viscosity and predictable behavior during application.