M 81 SPECIFICATIONS FOR MATERIALS
Standard Specification for
Cut-Back Asphalt (Rapid-Curing Type)
AASHTO DESIGNATION M 81-92
1. SCOPE shall not foam when heated to the appli- methods of the American Association of
cation temperature. State Highway and Transportation Offi-
cials:
1.1 This specification covers liquid
petroleum products, produced by fluxing 3. PROPERTIES Sampling ..........................................T 40
an asphaltic base with suitable petroleum Solubility .........................................T 44
distillates, to be used in treatment of road Penetration........................................T 49
surfaces. 3.1 Cut-back asphalt of the grade desig- Ductility............................................T 51
nated shall conform to the requirements Water ................................................T 55
1.2 The values stated in SI units are to be shown in Table 1 on page 66. Saybolt Furol viscosity ....................T 72
regarded as the standard. Distillation .......................................T 78
Flash point ........................................T 79
4. METHODS OF SAMPLING AND
2. GENERAL REQUIREMENTS Spot test.......................................... T 102
TESTING
Kinematic viscosity ........................T 201
Absolute viscosity .........................T 202
2.1 The cut-back asphalt shall show no 4.1 Sampling and testing cut-back as-
separation or curdling prior to use and phalt (rapid-curing type) shall be in
accordance with the following standard
TABLE I
RC-70 RC-250 RC-800 RC-3000
Min Max Min Max Min Max Min Max
Kinematic viscosity at 60°C (140°F) (See Note 1) mr2/s 70 140 250 500 800 1600 3000 6000
Flash point (Tag, open-cup), degrees C (F) - - 27 (80) - 27 (80) - 27 (80) -
Water, percent - 0.2 - 0.2 - 0.2 - 0.2
Distillation test:
Distillate, percentage by volume of total distillate to
360°C (680°F)
to 190°C (374°F) 10 - - - - - - -
to 225°C (437°F) 50 - 35 - 15 - - -
to 260°C (500ºF) 70 - 60 - 45 - 25 -
to 315°C (600°F) 85 - 80 - 75 - 70 -
Residue from distillation to 360°C (680°F) volume
55 - 65 - 75 - 80 -
percentage of sample by difference
Tests on residue from distillation:
Absolute viscosity at 60°C (140°F) (See Note 3) Pa•s 60 240 60 240 60 240 60 240
(poises) (600) (2400) (600) (2400) (600) (2400) (600) (2400)
Ductility, 5 cm/min at 25°C (77°F) cm 100 - 100 - 100 - 100 -
Solubility percent 99.0 - 99.0 - 99.0 - 99.0 -
Spot test (See Note 2) with
Standard naphtha Negative for all grades
Naphtha-xylene solvent, percent xylene Negative for all grades
Heptane-xylene solvent, percent xylene Negative for all grades
NOTE 1-As an alternate, Saybolt-Furol viscosities may be specified as follows:
Grade RC-70-Furol viscosity at 50°C (122°F)-60 to 120 s.
Grade RC-250-Furol viscosity at 60°C (140°F)-125 to 250 s.
Grade RC-800-Furol viscosity at 82.2°C (180°F)-100 to 200 s.
Grade RC-3000-Furol viscosity at 82.2'C (I 80°F)-300 to 600 s.
NOTE 2-The use of the spot test is optional. When specified, the engineer shall indicate whether the standard naphtha solvent, the naphtha-xylene
solvent or the heptanexylene solvent will be used in determining compliance with the requirement, and also, in the case of the xylene solvents, the
percentage of xylene to be used.
NOTE 3-In lieu of viscosity of the residue, the specifying agency, at its option, can specify penetration at 100 g: 5 s at 25°C (77°F) of 80-120 for
Grades RC-70, RC-250, RC-800. and RC-3000. However, in no case will both be required.
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