ÖNORM EN 12697-25

This European Standard describes two test methods (A and B) for determining the resistance of bituminous mixtures to permanent deformation. Test method A describes the method for determining the creep characteristics of bituminous mixtures by means of an uniaxial cyclic compression test with some confinement present. In this test a cylindrical specimen is subjected to a cyclic axial stress. To achieve a certain confinement, the diameter of the loading platen is taken smaller than that of the sample. NOTE 1 Confinement of the sample is necessary to predict realistic rutting behaviour, especially for gap-graded mixes with a large stone fraction. Test method B describes the method for determining the creep characteristics of bituminous mixtures by means of the triaxial cyclic compression test. In this test a cylindrical specimen is subjected to a confining stress and a cyclic axial stress. This test is most often used for the purpose of evaluation and development of new types of mixtures. This European Standard applies to specimens prepared in the laboratory or cored from the road. The maximum size of the aggregates is 32 mm. NOTE 2 For purposes of compliance with EN 13108, the test conditions are given in prEN 13108-20.