Performance Grade 76 16

Performance Grade Bitumen – 76/
76/16
Performance Grade Bitumen is graded based on pavement temperatures. In Super-pave grading system,
binders are classified according to their Performance in extreme hot and cold temperatures and called as Performance
Grade Bitumen. The main purpose of grading and selecting asphalt binder using the Performance Grade system is to
make certain that the binder has the appropriate properties for environmental conditions in the field. Performance
Grade asphalt binders are selected to meet expected climatic conditions as well as traffic speed and volume
adjustments. Therefore, the Performance Grade system uses a common set of tests to measure physical properties of
the binder that can be directly related to field performance of the pavement at its service temperatures by engineering
principles. Performance grade bitumen generally are mostly applied in paving constructions and reconstructions,
sealing of edges, crack sealing, spray applications for the bridge deck, and in both dense-graded and open-graded Hot
Mix Asphalt (HMA). PG grades that are well-structured against thermal cracking are PG 58-34, PG 64-22, PG 64-28,
and PG 76-22. PG grades that are resistant to rutting are PG 70-22, PG 70-28, PG 76-28, and PG 82-22.PG 58-28 is
specifically used in very cold regions.
Property Results Test Method

Average 7-day maximum pavement Design Temperature, °C 76
minimum pavement Design Temperature, °C > -16
Original Binder
Flash Point Temperature Minimum °C 230 AASHTO T48
Viscosity maximum 3 Pa.s, Test Temperature,°C 135 AASHTO T316
Dynamic Shear G*/sin minimum 2.2 KPa Test Temperature,°C 76 AASHTO T315
Rolling Thin Film Oven Test
Mass change maximum percent 1.00 AASHTO T240
Dynamic Shear G*/sin minimum 2.2 KPa Test Temperature, @ 10 rad/s °C 76 AASHTO T315
Pressure Aging Vessel
PAV aging Temperature, °C 100 AASHTO R28
Dynamic Shear G*/sin maximum 5000 KPa Test Temperature, @ 10 rad/s °C 34 AASHTO T315
Creep Stuffiness S maximum 300 Mpa m-value minimum 0.300 Test Temp,@ 60s °C -6 AASHTO T313
Direct Tension Failure strain minimum 1 % Test Temp@ 1mm/min, °C -6 AASHTO T314
Critical low cracking Temperature Critical cracking determined by PP42 Test Temp -6 AASHTO PP42
Advantages
1) Empirical methods such as viscosity and penetration grading systems were developed based on old
experiences and can be applicable if those conditions still exist. But, climatic and current traffic conditions are
rapidly changing and past experiences can no longer be defining criteria. In the PG system, it is possible to use
actual traffic volume and vehicle speed which represents the duration of loads are applied.
2) Common tests are conducted at a single test temperature which is 25°C in penetration and 60°C in viscosity
test, which means that they cannot give any details about how the bitumen would behave in low or high
temperatures. Superpave grading indicates a working temperature range of binder and therefore, helps with
choosing the best type according to the condition each project demands.
3) Because of the visco-elastic properties of bitumen, the rate of load application and temperature have a great
effect on its behavior.
4) Although the behavior of bitumen in lower loading rates corresponds to that of higher temperatures, none of
the other grading systems doesn’t take the rate of load into account except for Superpave.
5) While Superpave can be easily used for both unmodified and modified bitumen, conventional methods are
used only for unmodified bitumen types,
6) Conventional methods ignore the long-term aging of binders and its behavior. But Superpave takes both long-
term aging -using with the pressure aging vessel (PAV)- and short-term aging -using the rolling thin film oven
test (RTFOT)- into account.
7) Bitumen properties indicated at different temperatures contribute to resistance to the distresses in a different
level. Bitumen contributing in a better rutting resistance is measured at maximum pavement temperatures and
which leads to a more elastic and stiffer binder. Bitumen contributing to fatigue resistance is the most crucial
at average pavement temperatures and it requires a softer bitumen while it still favors an elastic binder.
Bitumen contribution to thermal cracking is sensitive at minimum pavement temperatures and it demands a
less elastic and soft bitumen.

Performance Grade 76 16

Uploaded by

Copyright:

Available Formats

Performance Grade 76 16

Uploaded by

Document Information

Original Title

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

Performance Grade 76 16

Uploaded by

Copyright:

Available Formats

Performance Grade Bitumen – 76/

Property Results Test Method

You might also like