Page 166 - Mechanics of Asphalt Microstructure and Micromechanics

158 Ch a p t e r Fiv e

P
The three spheres are equal in diameter Binder between the two bottom
particles may be subjected to tensile
forces.
Restrain from C
surrounding
medium
A B

a) Tensile Stress Induced by a Compressive Loading
The three spheres are equal in diameter Binder between Particles A and C
may be subjected to tensile forces.
T

C
Restrain from
surrounding
medium
A
B

b) Tensile Stress Induced by a Shear Loading
FIGURE 5.8 Illustration of potential tensile stress induction by compressive or shear loading.

of the mastics are two important factors that may affect the location where the top-
down cracking initiates and the number of cyclic loads needed to initiate and propagate
the cracking.
Figure 5.9 presents an illustration of the location of the maximum tensile forces,
where the top-down cracking most likely takes place. Due to the symmetry of loading,
there would be no tensile forces between Particles 2 and 3, 3 and 4, and 4 and 5. The

P

3 4
1 2 5 6

σ σ
t max t max
FIGURE 5.9 Illustration of locations where large tensile stress exists.