BS EN 14769:2012 pdf download – Bitumen and bituminous binders — Accelerated long-term ageing conditioning by a Pressure Ageing Vessel (PAV) 5.7Vacuum oven (optional), which shall be capable of maintaining a temperature up to 180 °C with anaccuracy of ± 5 °℃. The vacuum system shall be capable of maintaining pressures below (15,0±2,5) kPa absolute. Alternatively,the pressure vessel itself may be used in lieu of the vacuum oven if it is capable of maintaining a temperatureof 180 °c and a vacuum of (15,0±2,5) kPa. 5.8Commercial bottled air, which is suitable for the purpose of providing a sufficient supply of pressurizedair to carry out the test. (Only bottled air is suitable.) 6 Procedure SAFETY PRECAUTIONS — Use laboratory safety procedures when handling the hot bituminousbinders and preparing the specimens and when removing the residue from the pressure vessel. Takeparticular care when lifting the lid of the pressure vessel. 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 ageing/conditioning 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. fallowed 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 withEN 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...
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