Bitumen is a sticky, black, and highly viscous liquid or semi-solid form of petroleum. It is an essential component in the construction of roads and highways due to its waterproofing and binding properties. Without bitumen, modern road networks would not be possible.
Roads are essential for economic development and social mobility, and the use of bitumen in road construction has played a significant role in the development of modern infrastructure. The unique properties of bitumen make it an ideal binding agent for the aggregates used in road construction. Bitumen ensures that the road is durable and long-lasting, able to withstand heavy traffic and extreme weather conditions. In this blog post, we will explore the various uses of bitumen in road construction, the different types of bitumen, and the process of laying bitumen on roads.
Different Types of Bitumen Used in Road Construction
Depending on the climate, traffic conditions, and other factors, different types of bitumen may be used for specific road construction projects. The most commonly used types of bitumen in road construction are:
Penetration Grade Bitumen
Penetration grade bitumen is one of the most commonly used types of bitumen in road construction. It is a type of bitumen that has been tested for its consistency, and graded based on its hardness or softness. The penetration grade of bitumen is determined by measuring the depth in millimeters to which a standard needle will penetrate the bitumen sample under specified conditions of temperature, time, and loading.
Other methods for classifying paving bitumen grades used wordwide are viscosity based grading and performance grading.
Polymer Modified Bitumen
Polymer modified bitumen is another commonly used type of bitumen in road construction. This type of bitumen is created by adding polymers to bitumen, which can improve its performance characteristics. Polymer modified bitumen is known for its superior strength, durability, and resistance to deformation, cracking, and other forms of damage.
Crumb Rubber Modified Bitumen
Crumb rubber modified bitumen is a type of bitumen that is made by blending bitumen with crumb rubber obtained from scrap tires. This type of bitumen has excellent resistance to cracking, deformation, and other types of damage. It is also known for its noise reduction properties, making it a popular choice for highways and other busy roads.
Importance of Selecting the Appropriate Type of Bitumen
Choosing the appropriate type of bitumen for a specific road construction project is crucial. Different types of bitumen have different properties and characteristics, and selecting the wrong type can lead to premature failure and costly repairs. Factors such as climate, traffic volume, and the type of pavement structure must be considered when selecting the appropriate type of bitumen for a specific road construction project.
Road Construction Process Using Bitumen
Once the appropriate type of bitumen has been selected for a road construction project, the process of laying the bitumen begins. The road construction process involves several steps, including preparing the roadbed, placing the base course and binder course, and finishing with the surface course. Here is an overview of the road construction process using bitumen:
1. Preparation of the Roadbed
The first step in the road construction process is preparing the roadbed. This involves removing the topsoil and any other debris, levelling the ground, and compacting the soil. The goal is to create a stable foundation that will support the weight of the road.
2. Placing the Base Course
Once the roadbed is prepared, the base course is placed. The base course is made up of coarse aggregates, such as gravel, crushed stone, or sand, mixed with a bituminous binder. The base course provides a stable foundation for the road and helps to distribute the weight of the traffic.
3. Placing the Binder Course
After the base course is placed, the binder course is added. The binder course is made up of smaller aggregates, mixed with a bituminous binder. The binder course provides a smooth and stable surface for the road and helps to protect the base course from water damage.
4. Finishing with the Surface Course
The final step in the road construction process is adding the surface course. The surface course is made up of smaller aggregates, mixed with a bituminous binder, and is the layer that comes in direct contact with the traffic. The surface course provides a smooth and durable driving surface, protecting the road from wear and tear.
In conclusion, bitumen is an essential component in the construction of roads and highways. Its unique properties make it an ideal binding agent for the aggregates used in road construction, ensuring that the road is durable and long-lasting, able to withstand heavy traffic and extreme weather conditions. By understanding the different types of bitumen and selecting the appropriate type for specific road construction projects, premature failure and costly repairs can be avoided.
TEC’s MEST BitutainerTM is a fully equipped bitumen storage container designed to simplify the road spraying process. With the MEST BitutainerTM, bitumen can be stored on site, making filling of the sprays much easier and more cost-effective. Contact us today to learn more about how our products can improve your road construction projects.