The Fraass breaking point is an important test parameter for evaluating the low-temperature brittleness of bitumen and bituminous binders. According to EN 12593, the test determines the temperature at which a thin bitumen film develops its first crack during controlled cooling and bending.

A common question is whether a lower Fraass breaking point means better low-temperature cracking resistance. Generally, a lower value indicates that the binder can withstand a lower temperature before becoming brittle and cracking. However, the result should be interpreted as an indicator of binder behavior rather than a complete prediction of asphalt pavement performance.

1. What Is the Fraass Breaking Point?

The Fraass breaking point is the temperature at which the first visible crack appears in a bitumen film during the Fraass test.

For example, if one binder has a breaking point of −15°C and another has a breaking point of −25°C, the second binder reaches its brittle cracking condition at a lower temperature under the test conditions.

Therefore, the Fraass breaking point provides a useful indication of the low-temperature brittleness of bituminous binders.

2. Does a Lower Value Mean Better Low-Temperature Performance?

In general, yes.

A lower Fraass breaking point means that the binder remains resistant to brittle cracking at a lower temperature. This generally indicates:

 • Better low-temperature flexibility

 • Lower temperature susceptibility to brittle cracking

 • Greater ability to withstand low-temperature conditions

When comparing similar binders using the same test method, a lower Fraass breaking point is generally considered a favorable characteristic for low-temperature performance.

3. Does It Directly Predict Asphalt Pavement Cracking?

Not by itself.

The Fraass test evaluates the behavior of the binder, while actual asphalt pavement cracking is affected by many factors, including:

 • Binder properties

 • Aggregate and mixture composition

 • Binder aging

 • Temperature changes

 • Pavement structure

 • Traffic and environmental conditions

Therefore, a lower Fraass breaking point should not be interpreted as a guarantee of better overall pavement cracking resistance.

4. Fraass Breaking Point vs. BBR

The Fraass test and Bending Beam Rheometer (BBR) test are both used to investigate low-temperature binder behavior, but they use different principles.

The Fraass test determines the temperature at which cracking occurs during bending, while BBR evaluates low-temperature stiffness and creep behavior.

Therefore, these tests can provide different but complementary information about asphalt binder performance. For comprehensive low-temperature characterization, engineers may use more than one test method.

5. What About Polymer-Modified Bitumen?

The interpretation of Fraass results can be more complicated for polymer-modified bitumen (PMB).

Polymer modification changes the rheological and mechanical behavior of the binder, and recent research has identified limitations in using the Fraass breaking point alone to characterize some highly polymer-modified binders.

For this reason, additional low-temperature and rheological tests may be required when evaluating advanced or highly modified asphalt binders.

6. Why Is Accurate Testing Important?

Reliable Fraass testing requires consistent sample preparation and controlled test conditions. Factors such as film thickness, cooling rate, bending procedure, temperature measurement, and identification of the first crack can affect the result.

A properly designed Fraass Breaking Point Apparatus helps provide controlled cooling and repeatable bending conditions, allowing laboratories to obtain more consistent results according to the applicable test standard.

Conclusion

A lower Fraass breaking point generally indicates better low-temperature flexibility and lower brittleness temperature of a bituminous binder. However, it should be considered one indicator of binder performance rather than a standalone prediction of asphalt pavement cracking resistance.

For conventional bitumen, the Fraass breaking point is a useful parameter for low-temperature brittleness evaluation. For polymer-modified and more complex binders, additional tests such as BBR may provide a more comprehensive understanding of low-temperature behavior.