ETL 1110-l-139
22 Jun 90
Table 4
Asphalt Cement Selection Criteria Based on Pavement Temperature Index
Pavement Temperature
Temperature
Asphalt Cement
Index, Cumulative
("C)
Region
Selection Criteria
Less than 30 (16.7)
Cold
Penetration-viscosity method
for cold regions (Table 5)
30 to 80 (16.7 to 44.4)
Warm
85 to 100 penetration
(original asphalt)
Greater than 80 (44.4)
Hot
60 to 70 penetration
(original asphalt)
are used to differentiate between climates in cold temperature
regions. A DFI of 3,000 degree-Fahrenheit-days (degree-days) or
1,667 degree-Celsius-days is used as the delineation between moderately cold
and severely cold (extremely cold) climates. Moderately cold climates have
up to 3,000 degree-days , and sev.erely cold climates have DFI's greater
than 3,000 degree-days.
Penetration-Viscosity Number: For Cold Regions
Penetration-Viscosity Number (PVN), also called
Pen-Vis Number, is an
empirical correlation between asphalt cement factors
and low temperature pave-
ment cracking experiences in Canada. Asphalt cement
factors considered in the
original correlation were penetrations at 77" F (25"
C), viscosity at 275" F
C), and penetration
proposed
for selecting asphalt
cements to prevent low temperature cracking of asphalt concrete pavements.
The PVN method is used to quantify temperature susceptibility of an asphalt
cement and estimate its ability to prevent low-temperature cracking.
Required input data are penetration at 77" F
C) and kinematic vis-
cosity at 275" F
C). Figure 1 allows estimation of PVN for asphalt
cements in cold regions. Table 5 provides minimum PVN selection criteria for
asphalts in cold regions. Table 5 and Figure 1 should always be used when
selecting asphalts for use in cold regions. Table 5 also shows requirements
for airfields and roads and other pavements. A design index is required for
2
Ad Hoc Committee, "Design Techniques to Minimize Low-Temperature Asphalt
Pavement Transverse Cracking," Research Report 81-1, Asphalt Institute,
1981.
N. W., "A
Survey of Low-Temperature Transverse Pavement
Cracking on Three Ontario Test-Roads," Proceedings, Association of Asphalt
Paving Technologists, Vol. 41, 1972.
5
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