Civil Engineering Reference
In-Depth Information
FIGURE 9.20
Absolute viscosity test apparatus.
Distillation of Cutback and Emulsion
The distillation test of cutback asphalt
(ASTM D402) measures the amount and character of volatile constituents it
contains. The procedure requires that the percentages, by volume, of the dis-
tillate fractions at specified temperatures be determined. The distillation
test of emulsified asphalt (ASTM D244) determines the percent of residue
and oil distillates by weight.
Saybolt Furol Viscosity of Emulsion
Emulsion viscosity is an important fac-
tor in field applications. When applied in a spray, the emulsion must be
thin enough to be uniformly applied through the spray bar of the distribu-
tor truck, yet viscous enough that it will not flow from the crown or grade
of the road. Emulsion viscosity is measured using the Saybolt-Furol vis-
cometer, as shown in Figure 9.21 (ASTM D244). In this test, the emulsion
is bought to a temperature of either 25°C (77°F) or 50°C (122°F) and allowed
to flow through a specific orifice. The Saybolt-Furol viscosity is the time
(in seconds) required to fill a special flask.
FIGURE 9.21
Saybolt Furol viscosity.
Search WWH ::
Custom Search