AASHTO R 78:16(2020) Standard Practice for Recovering Residue from Emulsified Asphalt Using Low- Temperature Evaporative Techniques.
Silicone Mat—The mat used can be similar to that specified in NF EN 13074 or any mat that will allow an emulsified asphalt spread rate of 1.5 to 2.0 kg/m2 (0.31 to 0.41 lb/ft2) for Procedure A or a 0.381-mm (0.015-in.) wet film thickness for Procedure 13. The mat may have a lip to contain the emulsified asphalt in the appropriate area.
Note 2 —A silicone mat can be purchased at restaurant supply stores. The size of the mat should be larger than the wet film applicator or other suitable sample-spreading tool. The mat size should be sufficient to produce a sample of the desired volume for subsequent testing. A good size for this application is a half-sheet pan size, which will fit in most laboratory ovens.
4.2. Flat Oven Tray—A flat oven tray or other flat heat-resistant tray or pan to support the silicone mat and allow easy transfer to the oven.
Note 3——A metal cookie sheet, slightly larger than the silicone mat, works well. The tray and silicone mat must fit on a rack in the forced-draft oven.
4.3. Spatula—A spatula or palette knife for spreading the emulsified asphalt.
4.4. Rods—Rounded-end glass or metal rods of sufficient diameter and length to roll up the residue sample.
4.5. Forced-Drafi Oven—Horizontal air flow, mechanical convection oven meeting the requirements of ASTM E145, Type hA, at 25°C (77°F) and 60°C (140°F). Racks shall be spaced a minimum of 10cm (4 in.) from the top and bottom of the oven and with a minimum spacing of 4cm (1.6 in.) between racks with samples. Use a bubble level of 25-cm (10-in.) minimum length to ensure the racks are level from side to side and front to back in the oven in its operating location.
Note 4 —Ambient laboratory conditions (22 to 28°C) (72 to 82°F) may be used for the 25°C (77°F) temperature curing for Procedure A if the sample is placed in a dust- or contaminant-free environment with some air flow. A laboratory hood with an operating fan is a suitable alternative.
4.6. Wet Film Applicator—A wet film applicator designated to produce a wet film thickness of 0.381 mm (0.015 in.) [a gap depth of 0.762 mm (0.030 in.)] and a width of less than the application direction of the silicone mat.
Note 5 Examples of applicators that work arc Bird-type film applicators and 8-sided applicators.
Pour the required amount of emulsified asphalt onto a silicone mat supported by a fiat oven tray, and spread it evenly with a spatula to produce a spread rate of 1.5 to 2.0 kg/m2 (0.31 to 0.41 lb/ft2) of ernulsi lied asphalt. Use Table I as a guide for the quantities of emulsi fled asphalt necessary to produce the appropriate spread rate fbr a given area.
AASHTO R 78 pdf download.