What is the softening point of bitumen?

The softening point of bitumen is the temperature at which it begins to soften and lose its solid properties during heating. Generally speaking, the higher the softening point of bitumen, the better its resistance to deformation and cracking, but the less its plasticity and flexibility. Therefore, in different applications, need to choose different softening point bitumen.

Factors affecting the softening point of bitumen

1. Source and composition of bitumen

The softening point of bitumen from different sources and compositions will be different. For example, bitumen from different petroleum refineries may have different softening points.

2. Processing of bitumen

The processing of bitumen also affects its softening point. For example, processing temperature, processing time, processing pressure and other factors will have an impact on the softening point of bitumen.

3. The quality of bitumen

The quality of bitumen will also affect its softening point. For example, the degree of oxidation of bitumen, impurity content, stability and other factors will have an impact on its softening point.

Bitumen softening point test methods

1. Global softening point test method

Global softening point test method is a commonly used method of testing the softening point of bitumen. Test, the bitumen samples into the global softening point instrument, heated to a certain temperature, and then use the global conical needle pressed into the sample, record the depth of the needle down, that is, the softening point.

2.Sliding softening point test method

Sliding softening point test method is also a commonly used method of testing the softening point of bitumen. Test, the bitumen sample into the sliding softening point instrument, heated to a certain temperature, and then use the standard steel ball pressed into the sample, record the temperature of the ball began to slide, that is, the softening point.

Application of bitumen softening point

The softening point of bitumen is one of the important indexes to measure the performance of bitumen. In the field of road construction, waterproofing engineering, roof waterproofing, etc., the selection of different softening point of bitumen can achieve different performance requirements. For example, in the highway and other occasions that require high strength and high durability, you need to choose a higher softening point of bitumen; and in the low temperature environment, you need to choose a lower softening point of asphalt, in order to ensure its plasticity and flexibility.

In short, the softening point of bitumen is one of the important indicators to measure its performance, the influence of more factors, test methods are more diverse. In practical applications, it is necessary to select bitumen with different softening points according to different occasions to meet different performance requirements.

With the passage of time, the softening point of bitumen will undergo some changes. Generally speaking, the softening point of bitumen will increase with aging.

Bitumen can be affected by a variety of factors during use, such as temperature, light, and oxygen. These factors may lead to chemical changes in the bitumen molecules, resulting in an increase in molecular weight and viscosity, leading to an increase in softening point. In addition, if there are more light components (e.g., oil) present in the bitumen, these components may volatilize or oxidize over time, further increasing the softening point.

However, the exact changes will also be influenced by factors such as the type of bitumen, its quality, the conditions of use, and the environment. Different types of bitumen may behave differently during the aging process. Therefore, in practice, regular testing and evaluation of bitumen is required to ensure that its performance meets the requirements.

Then how should we improve the softening point of bitumen?

To improve the softening point of bitumen, you can try the following methods:

Choose the right type of bitumen: Different types of bitumen have different softening points. You can choose an asphalt with a higher softening point, such as modified bitumen or high performance bitumen.

Adding modifiers: Adding appropriate modifiers to bitumen, such as polymers, sulfur, rubber, etc., can improve the properties of bitumen, including increasing the softening point. These modifiers can react or form complexes with the bitumen to increase its strength and heat resistance.

Optimize the mixture formulation: Adjusting the formulation of the bitumen mixture, for example, increasing the particle size and hardness of the aggregate and reducing the amount of asphalt, can improve the softening point of the overall mixture.

Control of construction conditions: During construction, pay attention to control the temperature and time, avoid too high temperature and too long heating time, so as not to lead to excessive aging of bitumen and lower softening point.

Storage and Protection: Store bitumen properly and avoid exposure to sunlight and harsh environments to minimize aging.