Mechanical Response and Damage Behavior of Asphalt Pavements with Variable Structural Configurations

Demirtürk D.

Uluslararası Mühendislik Araştırma ve Geliştirme Dergisi, cilt.18, sa.3, ss.45-58, 2026 (TRDizin)

Özet

This study evaluated the influence of crushed aggregate subbase stiffness and thickness on flexible pavement performance. Two pavement configurations were evaluated under dual-wheel loading to assess surface deformation, fatigue and rutting damage, and depth-dependent stress–strain responses. The results indicated that increasing SB2 elastic modulus improved load distribution and reduced surface vertical displacement in both configurations, with the five-layer system consistently exhibiting lower surface deformation due to improved stiffness gradation. However, responses at the bottom of the asphalt layer were configuration-dependent: increasing SB2 stiffness reduced tensile strain and fatigue damage in the four-layer system but increased fatigue demand in the five-layer system because of strain redistribution near the asphalt-base interface. At the top of the subgrade, both systems exhibited identical stiffness-dependent response trends, while the five-layer configuration primarily reduced response magnitudes. Quantitative damage analysis demonstrated that the five-layer system achieved 40–55% lower fatigue damage and up to 85% lower rutting damage compared to the four-layer system, whereas increasing subbase thickness provided a secondary but consistent benefit. Overall, fatigue cracking controlled pavement performance, highlighting the dominant role of pavement configuration over subbase stiffness.