BS EN 14769:2012 pdf free.Bitumen and bituminousbinders – Accelerated long-term ageing conditioningby a Pressure Ageing Vessel(PAV).
BS EN 14769 Pre-heat the PAV vessel or forced draft oven to the ageing temperature. The binder is firstly pre-conditionedas necessary, prior to the long-term ageing procedure.The procedure used shall be stated in the report.
lf it is necessary to prepare more than one set of samples in the short-term ageinglconditioning procedure(using either EN 12607 series or a stabilisation procedure) in order to obtain sufficient quantity for thisprocedure, sub-samples shall be combined and homogenised before the test.The stabilisation procedureshall be stated in the report.
NOTE1 The hot residue may be poured immediately into the container or allowed to cool for PAv ageing later. lfallowed to cool, the container with the binder should be covered and stored at ambient temperature.When it is to be used,the sample should be re-heated in accordance with EN 12594 for the minimum possible time and stirred prior to pouringinto the container.
NOTE2 Pre-heating the vessel up to 15 C above the conditioning temperature may be used to reduce the drop inPAV temperature during the loading process and minimise the time required for stabilisation of the set temperature afterloading. However, pressurising the vessel causes an increase in temperature and the vessel may cool slowly, making itdifficult to achieve the specified temperature at the start of the test.
Pre-heat the container to the PAV conditioning temperature.Place the heated container on a balance andpour (50,0±0,5) g into the container. Ensure that the binder is distributed over the entire base of the containerby tilting the filled container if necessary.
NOTE3 The binder flm thickness will be about 3,2 mm. The number of containers per binder will depend on theamount of binder required for subsequent testing. The heating of the container should be sufficient to enable the flow ofthe binder.
NOTE4(50,0±0.5)g refers to containers conforming to EN 12607-2.When using containers of a different diameter, therequirement is that sufficient binder shall be poured such that the film thickness will be about 3,2 mm (see 5.5)
Place the pan holder inside the heated pressure vessel and set the ageing temperature to the specfiedtemperature.
NOTE5 Typical conditioning temperatures are 85 °C,90 °C， 100 C and 110 C. Typical ageing times found to besuitable are 20 h ±10 min for the 9o °C, 100 °C and 110 °C temperature conditions, and 65 h ± 30 min for the 85 °ctemperature condition.BS EN 14769 pdf download.