6
fatigue (Navarro
et al
., 2002). As the deformation increases, it was found that the non-linear viscoelastic behavior was
apparent due to the relaxation and creep of polymer blends and the movement of the aggregate (Sombat, 2009).
From Table 1, the stress of Cauchy’s deformation at 0.5 (less time in the compression), it was found that the
stress increased when aggregate size decreased. In addition, the relationship of compression modulus – time, the
compression modulus also increased by smaller aggregates. Due to aggregate size smaller, the internal friction
between the aggregate surface increased (Chiu and Lu, 2007) and the adhesion between the rubber modified asphalt
and the aggregate surface increased (Estevez, 2009). As a result, the stress increased.
- Effect of the speed of the compression
The effects of the speed of the compression on the compression properties of natural rubber - asphalt -
aggregate blends. The results are shown in Figures 7 – 12.
Figure 7
Stress
-
Cauchy’s deformation, the speed of the compression (Speed) at 50, 150 and 250 mm/min, the
amount of natural rubber (Rubber, R) 0 % wt, aggregate size, diameter of 4.75 - 9.50 mm (Small, S) and the time at 0
min for mastication (Masticate).
Figure 8
Compression modulus (D (t)) - time, the speed of the compression (Speed) at 50, 150 and 250 mm/min, the
amount of natural rubber (Rubber, R) 0 % wt, aggregate size, diameter of 4.75 - 9.50 mm (Small, S) and the time at 0
min for mastication (Masticate).
