Fig. 1. Illustration of loading mechanism by a tire and a loading head.

Fig. 2. Loading head details with diameter D and curvature r (y is deformation into asphalt mixture and A = π(H + 2x)²/4 is cross section area at depth y).

Fig. 3. S_D test molds for specimens with diameter of 150 mm (left) and 100 mm (right) with exchangeable loading-head holders.

Fig. 4. Typical failure modes of S = 100 mm specimens by 3(0.5) loading head (left) and 4(1.0) loading head (right).

Fig. 5. (a) S_D tester in loading press and (b) a load–deformation curve from a S_D test.

Fig. 6. A slab specimen used for phase three: (a) used for coring two samples and (b) used for wheel tracking test.

Fig. 7. Illustration of dynamic stability (DS) measured in linear portion between 500 and 2500 cycles in a WT up to 2700 cycles (speed = 30 cycles/min).

Fig. 8. A slab specimen used for phase two.

Fig. 9. Relationship of (a) DR vs. S_D and (b) DS vs. S_D by aggregate [loading head 30(5)].

Fig. 10. Relationship of (a) DR vs. S_D and (b) DS vs. S_D by aggregate [loading head 30(7.5)].

Fig. 11. Relationships of (a) DR vs. S_D and (b) DS vs. S_D by aggregate [loading head 40(5)].

Fig. 12. Relationships of (a) DR vs. S_D and (b) DS vs. S_D by aggregate [loading head 40(10)].

Fig. 13. Relationships of FD vs. S_D by aggregate [loading head 40(10)].

Fig. 14. Relationships of FD and S_D vs. DR from WT.

Fig. 15. Relationship showing typical repeatability of WT and S_D tests.

Designation of mixtures

Description of test variables

Summary of phase one results [9] and [10]

Note: S = specimen diameter, D = loading head diameter, r = curvature radius of loading head.

R² from correlation analyses of rut parameters with S_D for phases one and two [11]

Note: DR = final depth of rut, DS = dynamic stability.

S_D values using D = 30 mm loading head and corresponding rut parameters

… missing value.

S_D values using D = 40 mm loading head and corresponding rut parameters

Results of S_D test with 40(10) loading head and RLC test

Summary of R² from regression analyses of rut parameter vs. S_D by loading head

Summary of R² from regression analyses of rut parameter vs. S_D by various groups

Linear regression analysis results for repeatability examination