DIN EN 12697-25/A1 PDF Download

The DIN EN 12697-25/A1 standard specifies three test methods (A1, A2, and B) for evaluating the resistance of bituminous mixtures to permanent deformation through cyclic compression tests with confinement. These tests are used to compare different mixtures or evaluate the acceptability of a particular mixture, but they do not provide a quantitative prediction of rutting in real-life conditions.

Methods A1 and A2 outline procedures for determining the creep characteristics of bituminous mixtures using a uniaxial cyclic compression test with some level of confinement. A cylindrical test specimen is subjected to cyclic axial stress, with Method A2 preferred for mastic asphalt and Method A1 for other asphalt mixtures. To achieve confinement, the diameter of the loading platen is smaller than that of the test specimen. Method A1 utilizes block-pulses loading, while Method A2 utilizes haversine loading with rest time.

Method B describes the evaluation of creep characteristics using the triaxial cyclic compression test. In this test, a cylindrical specimen is subjected to a defined confining stress and cyclic axial stress. This method is commonly used for evaluating and developing new types of mixtures.

The standard applies to test specimens prepared in the laboratory or obtained from roads, with a maximum aggregate size of 32 mm. Confinement is necessary to replicate realistic rutting behavior, particularly for mixtures with large stone fractions. It is important to note that the test conditions specified in EN 13108-20 are used for type testing purposes.