FE 07.0303 / 2019 / EGB - Resistance to permanent deformation and cold properties - Determination of the precision in proficiency testing.

The test methods for addressing the resistance to permanent deformation of asphalt (uniaxial pressure swell test and dynamic stamp penetration test) and for addressing the cold properties of asphalt (uniaxial tensile test (UTST), cooling test (TSRST)) have been known for many years. The procedures are described in DIN EN 12697-25 and TP Asphalt-StB, part 25 A 1 and B 1 as well as DIN EN 12697-46 and TP Asphalt-StB, part 46 A. No round robin tests have been carried out so far, so the precision is still unknown. Therefore, these test methods for control tests or other use cases with a contractual background are only of limited use.

The precision of the test methods must be determined in the context of interlaboratory tests.

The subject of the present research project are proficiency tests to determine the characteristic values for the accuracy (correctness and precision) according to the "Information sheet on the statistical evaluation of test results" of the FGSV. To ensure the functionality of the testing machines used, they must be subjected to a calibration and system test in advance of the round robin tests ("device audit"). The respective test center may only take part in the interlaboratory test with a demonstrably successful participation.

As part of the round robin tests, cast asphalt for the TP Asphalt-StB, part 25 A 1 5 and rolled asphalt for the TP Asphalt-StB, part 25 B 1 5. For the round robin test of TP Asphalt-StB, part 46 A, 5 mixes are also to be examined. The mixes should be selected so that different measurement levels can be expected.

The aim should be to involve 12 test centers per test type in the proficiency test. At least 2 results per measurement level must be determined for each test center.