BS EN 12697-25:2016 PDF Download

BS EN 12697-25:2016 is a standard that specifies three test methods for assessing the resistance of bituminous mixtures to permanent deformation due to cyclic compression tests with confinement. These tests are primarily used to rank different mixtures or to determine the acceptability of a specific mixture. However, they do not provide a quantitative prediction of rutting in real-world conditions.

Test methods A1 and A2 outline procedures for measuring the creep characteristics of bituminous mixtures using a uniaxial cyclic compression test with some level of confinement. In these methods, a cylindrical test specimen is subjected to a cyclic axial stress. Method A2 is recommended for mastic asphalt, while Method A1 is suitable for other asphalt mixtures. To ensure confinement, the loading platen's diameter is smaller than that of the test specimen. Method A1 utilizes block-pulses for loading, whereas Method A2 applies haversine loading with rest time.

Test method B describes how to evaluate the creep characteristics of bituminous mixtures through the triaxial cyclic compression test. This method involves subjecting a cylindrical test specimen to both a defined confining stress and a cyclic axial stress. It is commonly used for assessing and developing new types of mixtures.

This standard is applicable to test specimens prepared in a laboratory or obtained from roads. The maximum aggregate size allowed for testing is 32 mm. The use of confinement in the test specimen is crucial to replicate realistic rutting behavior, particularly for gap-graded mixtures that have a large stone fraction. The specific test conditions for Type Testing can be found in EN 13108-20.