Increase and Decrease Viscosity of Bitumen – Complete Guide by Basekim
In the construction and industrial sectors, the viscosity control of bitumen directly affects its performance, application method, and long-term reliability. Consequently, understanding how to control this critical property becomes essential for engineers, contractors, and material specialists. In this article, we at Basekim explain in detail how to increase or decrease bitumen viscosity using effective, practical, and proven methods.
What Is Bitumen Viscosity?
To begin with, viscosity refers to a material’s resistance to flow. In the case of bitumen, high viscosity means it is thick and slow-moving, while low viscosity means it flows more easily. The viscosity level impacts how bitumen is applied, how it sets, and how it performs under environmental stress.
Therefore, in hot climates or heavy-duty applications, increasing viscosity becomes necessary. Meanwhile, in cold conditions or spray systems, reducing viscosity helps with easier application.
Methods of how to control bitumen viscosity
Let’s now explore how to make bitumen thicker and more resistant to flow. These methods help strengthen bitumen performance for tough environments.
1. Air Blowing (Oxidation Process)
First and foremost, air blowing is the most common way to control and increase bitumen viscosity. During this process, air is passed through hot bitumen, which causes a chemical reaction. As a result, the bitumen becomes harder, more elastic, and significantly more viscous.
At Basekim, we specialize in producing oxidized bitumen 115/15 and 90/10, which are ideal for insulation, roofing, and high-temperature applications.
2. Polymer Modification
In addition, adding polymers such as SBS or APP is another effective solution. These materials chemically bond with bitumen, increasing its viscosity, flexibility, and durability.
When roads or structures must withstand heavy loads and weather changes, polymer-modified bitumen offers excellent results. Fortunately, Basekim can supply tailor-made polymer-modified bitumen for various international projects.
3. Heavy Oil Blending
Moreover, in special applications, manufacturers may blend bitumen with heavier hydrocarbon oils or asphaltenes. This method increases bitumen viscosity or control, but it requires advanced formulation expertise to ensure product stability.
Methods to Decrease Viscosity of Bitumen
In contrast, certain projects require a bitumen grade that flows easily and can be applied at lower temperatures. Here’s how you can achieve lower viscosity in a safe and controlled manner.
1. Heating the Bitumen
The simplest and most widely used method is heating. As temperature rises, bitumen softens and flows more smoothly. This technique is perfect for onsite applications where material needs to be pumped or sprayed.
However, overheating can damage the chemical structure of bitumen, so proper temperature control is essential. That’s why Basekim provides technical guidance with every shipment.
2. Producing Cutback Bitumen to control bitumen viscosity
Another reliable method involves adding a solvent like kerosene or naphtha. This creates cutback bitumen, which flows easily at room temperature. After application, the solvent gradually evaporates, leaving behind a solid, durable bitumen layer.
Basekim manufactures multiple cutback types, including Medium-Curing (MC), Rapid-Curing (RC), and Bitumen Slow-Curing (SC) grades, each designed for different climatic and operational conditions.
3. Using Bitumen Emulsions
Furthermore, bitumen emulsion is a modern solution for low-temperature or eco-friendly projects. In this method, bitumen is mixed with water and surfactants to form a liquid that spreads easily without heating.
Once applied, the water evaporates, and the bitumen sets into a strong, adhesive layer. At Basekim, our emulsified bitumen complies with international standards and ensures both performance and environmental safety.
Why Viscosity Control Matters in Bitumen Applications
Clearly, control viscosity of bitumen is not just a laboratory number—it directly affects the handling, mixing, spraying, and curing of bitumen in real-world projects. If the viscosity is too low or too high for the application, problems like poor adhesion, cracking, or uneven surface formation may occur.
In contrast, when you choose the right viscosity, you ensure better performance, longer durability, and smoother installation.
Why Choose Basekim for Bitumen Solutions?
With over a decade of global experience, Basekim is more than just a bitumen manufacturer—we are a full-service partner. We offer:
Premium-grade oxidized bitumen, penetration, emulsion, and cutback bitumen
Customized solutions for viscosity and application method
High-volume export capability (over 200,000 MT annually)
Fast delivery and multilingual technical support
Safe, certified packaging (drums, polybags, and bulk)
In every step, from consultation to delivery, Basekim ensures your project receives the right bitumen—with the right viscosity—on time.
To summarize, controlling the viscosity of bitumen and how to control bitumen viscosity allows you to match product performance with environmental and operational demands. You can increase viscosity through air blowing, polymer modification, or heavy oil blending. Alternatively, you can decrease viscosity by heating, emulsifying, or creating cutback types.
Regardless of your needs, Basekim provides the quality, expertise, and support to help your business succeed. Contact our team today and discover how our bitumen solutions can add value to your operations.
