More info
Description / Abstract:
This test method covers the determination of the fracture energy
(Gf) of asphalt mixtures by means of the
semicircular bend geometry (SCB). The method also includes
procedures for calculating fracture toughness
(KIC) and stiffness (S). The SCB
specimen is a half disc with a notch (its length expressed in
meters) that makes an angle α with the vertical axis of the disc.
The SCB test can be used to determine mode I and mixed mode I and
II stress intensity factors (Lim et al., 1993). In this standard,
only mode I fracture toughness is addressed (α is equal to
zero).
The procedures in this standard provide parameters that describe
the fracture resistance of asphalt mixtures at low temperatures.
These parameters are used in the new low-temperature module of the
Mechanistic Empirical Pavement Design Guide.
These procedures apply to test specimens having a maximum
aggregate size of 19 mm or less. Specimens shall be 150 ± 9 mm in
diameter and 24.7 mm ± 2 mm thick. These procedures are valid at
temperatures below the performance grade (PG) lower limit of the
asphalt binder used to prepare the asphalt mixture plus 22°C.
This standard may involve hazardous materials, operations,
and equipment. This standard does not purport to address all of the
safety concerns associated with its use. It is the responsibility
of the user of this procedure to establish appropriate safety and
health practices and to determine the applicability of regulatory
limitations prior to use.