Varför spricker vissa delsträckor på E6 och E45 i Västra Götalands län?

Sammanfattning

Cracking has been observed on certain sections of the E6 and E45 highways in Västra Götaland County, Sweden, despite similar traffic conditions and pavement structures. The purpose of this study was to investigate possible material related factors contributing to asphalt pavement cracking. Historical quality control data, project documentation and new field investigations were used to compare cracked and non cracked road sections. Drilled core samples were tested for air void content, binder content, gradation, softening point, water sensitivity and layer thickness. The results showed no clear connection between cracking and individual parameters such as binder content, water sensitivity or layer thickness. Instead, the cracked sections showed larger variations in air void content during construction and a less homogeneous asphalt mixture. Visual assessment of the cores also revealed uneven binder distribution and locally dry areas. The results indicate that stiffer binders, higher softening points and wax additives may increase pavement brittleness and sensitivity to traffic related cracking. Overall, the study suggests that cracking is caused by several interacting factors rather than a single parameter.