BS EN 12697-22:2020 pdf free.Bituminous mixtures一Test methods.
BS EN 12697-22 This document describes test methods for determining the susceptibility of bituminous materials to deform under load. The test is applicable to mixtures with upper sieve size less than or equal to 32 mm.The tests are applicable to specimens prepared from asphalt mixtures that have either been manufactured in a laboratory or cut from a pavement; test specimens are held in a mould with their surface flush with the upper edge of the mould.The susceptibility of bituminous materials to deform is assessed by the rut formed by repeated passes
of a loaded wheel at constant temperature. Three alternative types of device can be used according to this standard: large-size devices, extra large-size devices and small-size devices. With large-size devices and extra large-size devices, the specimens are conditioned in air during testing. With smal-size devices, specimens are conditioned, in either air or water. NOTE
Large-size and extra large-size devices are not suitable for use with cylindrical cores.Sample table, constructed so as to enable a rectangular laboratory-prepared test specimen to be held firmly in place with its upper surface horizontal and in the required tracking plane and with its centre positioned to ensure symmetrical tracking motion. Wheel-tracking machine, constructed so as to enable the test specimen in its cradle to be moved backwards and forwards under the loaded wheel in a fixed horizontal plane or the loaded wheel to be moved backwards and forwards on the fixed specimen. The centre-line of the tyre track shall be not more than 5 mm from the theoretical centre of the specimen. The centre of the contact area of the tyre shall describe simple harmonic motion with respect to the centre of the top surface of the test specimen with a total distance of travel of (230土10) mm and a frequency of (26,5土1,0] load cycles per 60 s for the test device.BS EN 12697-22 pdf downlaod.