1、Standard Practice for Recovering Residue from Emulsified Asphalt Using Low-Temperature Evaporative Techniques AASHTO Designation: PP 72-11 (2013)1American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-2a PP 72-1 AASHTO St
2、andard Practice for Recovering Residue from Emulsified Asphalt Using Low-Temperature Evaporative Techniques AASHTO Designation: PP 72-11 (2013)11. SCOPE 1.1. This practice covers two methods for recovering the residue from emulsified asphalts such as those specified in M 140 and M 208, using low-tem
3、perature evaporative techniques that are similar to pavement conditions. The recovered residue can be used for further testing as required. 1.2. The values stated in SI units are to be regarded as the standard. 1.3. This standard may involve hazardous materials, operations, and equipment. This stand
4、ard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO S
5、tandards: M 140, Emulsified Asphalt M 208, Cationic Emulsified Asphalt T 59, Emulsified Asphalts 2.2. ASTM Standard: E 145, Standard Specification for Gravity-Convection and Forced-Ventilation Ovens 2.3. French Standard Institute: NF EN 13074, Recovery of Binder from Bitumen Emulsions by Evaporation
6、 Note 1The EN 13074 Standard is published and distributed through AFNOR (French Standard Institute) and is available online at www.afnor.fr. 3. SIGNIFICANCE AND USE 3.1. Use the procedures described in this practice to obtain a residue from emulsified asphalt for further testing in devices such as a
7、 dynamic shear rheometer. The lower evaporative temperatures of these procedures provide conditions that are very close to that of application techniques for these materials. Use this practice in place of recovery techniques such as those in T 59; the temperatures used in that standard may negativel
8、y affect the residue. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a PP 72-2 AASHTO 4. APPARATUS 4.1. Silicone MatThe mat used can be similar to that specified in NF EN 13074 or any mat that will
9、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 B. The mat may have a lip to contain the emulsified asphalt in the appropriate area. Note 2A silicone mat can be purchased at restaurant supply
10、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 lab
11、oratory 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 3A metal cookie sheet, slightly larger than the silicone mat, works well. The tray and silicone mat must fit on a rack in the forced-draf
12、t oven. 4.3. Spatula A spatula or palette knife for spreading the emulsified asphalt. 4.4. RodsRounded-end glass or metal rods of sufficient diameter and length to roll up the residue sample. 4.5. Forced-Draft OvenHorizontal air flow, mechanical convection oven meeting the requirements of ASTM E 145
13、, Type IIA, at 25C (77F) and 60C (140F). Racks shall be spaced a minimum of 10 cm (4 in.) from the top and bottom of the oven and with a minimum spacing of 4 cm (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 a
14、nd front to back in the oven in its operating location. Note 4Ambient laboratory conditions (22 to 28C) (72 to 82F) may be used for the 25C (77F) 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 operat
15、ing fan is a suitable alternative. 4.6. Wet Film ApplicatorA 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 5Examples of applicators that work are
16、Bird-type film applicators and 8-sided applicators. 5. PROCEDURE A 5.1. Pour the required amount of emulsified asphalt onto a silicone mat supported by a flat 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 emulsified asphalt. Use Ta
17、ble 1 as a guide for the quantities of emulsified asphalt necessary to produce the appropriate spread rate for a given area. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a PP 72-3 AASHTO Table 1Em
18、ulsion Spread Rate Guidance Emulsified Asphalt Spread Rate Emulsified Asphalt Quantity in Grams for Each Area, m2(ft2) 0.01 m2(0.11 ft2) 0.0225 m2(0.24 ft2) 0.04 m2(0.43 ft2) 0.0625 m2(0.67 ft2) 1.5 kg/m2(0.31 lb/ft2) 15.0 g 33.75 g 60.0 g 93.75 g 2.0 kg/m2(0.41 lb/ft2) 20.0 g 45.0 g 80.0 g 125.0 g
19、Note: The area dimensions correspond to the following square and circle sizes in millimeters. Area Square Circle 0.01 m2(0.11 ft2) 100 100 mm (3.9 3.9 in.) 56.4-mm (2.22-in.) radius 0.0225 m2(0.24 ft2) 150 150 mm (5.9 5.9 in.) 84.6-mm (3.33-in.) radius 0.04 m2(0.43 ft2) 200 200 mm (7.8 7.8 in.) 112.
20、8-mm (4.44-in.) radius 0.0625 m2(0.67 ft2) 250 250 mm (9.8 9.8 in.) 141.0-mm (5.55-in.) radius 5.2. Place the sample into a 25C (77F) forced-draft oven for 24 1 h. 5.3. Transfer the sample to a 60C (140F) forced-draft oven for 24 1 h. 5.4. Remove the sample from the oven, and allow it to cool at roo
21、m temperature for 1 h prior to removal from the mat. 5.5. Carefully peel the emulsified asphalt residue from the mat using a wooden or plastic utensil, taking care not to damage the silicone mat. The residue can be kneaded into the appropriate sample size for testing (see Section 3.1) if appropriate
22、 gloves are worn to prevent skin contact with the residue. Note 6For softer binders, it may be necessary to cool the mat and residue in a refrigerator prior to removal. Note 7Examples of a wooden or plastic utensil may be a tongue depressor, silicone spatula, or plastic knife. Note 8The recovered bi
23、nder may be stored in a sealed container at ambient laboratory conditions for up to 1 week prior to testing. Note 9The recovered binder properties may change if the sample is heated to a liquid state for further testing. 6. PROCEDURE B 6.1. Pour the emulsified asphalt onto the silicone mat and, in o
24、ne continuous motion, spread it evenly using the wet film applicator. Support the silicone mat with an oven tray or other flat tray or pan to allow easy transfer to the oven. Note 10The amount of emulsion should be appropriate for the size of the silicone mat, applicator, and applied sample size des
25、ired. Approximately 50 g is sufficient for a half-sheet silicone mat and a Bird-type applicator. 6.2. Place the sample into a 60C (140F) forced-draft oven for 6 h 15 min. 6.3. Remove the sample from the oven. While it is still hot, place a glass or metal rod on the surface of the sample, near an edg
26、e, and allow the sample to cool at room temperature for 15 min prior to removal from the mat. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a PP 72-4 AASHTO 6.4. Carefully peel the emulsified aspha
27、lt residue from the mat using a uniform rolling motion of the glass or steel rod to prevent damage to the silicone mat. Without warming the material, obtain a representative sample from the rod and shape it into the appropriate size for testing (see Section 3.1). Wear appropriate gloves to prevent skin contact with the residue. 7. KEYWORDS 7.1. Emulsified asphalt. 1This provisional standard was first published in 2011. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
