Modeling frost heave damages throughout the asphalt layer
Time: Fri 2022-12-16 09.00
Location: E2, Osquars backe 2, campus, videolänk saknas
Subject area: Civil and Architectural Engineering, Structural Engineering and Bridges
Doctoral student: Saeed Vosoughian , Bro- och stålbyggnad
Opponent: Professor Inge Hoff, NTNU
Supervisor: Romain Balieu, Bro- och stålbyggnad
There are various distresses arising from traffic loads and the surrounding environment to whichan asphalt pavement is subjected during its life span. The environment-associated damages aremore severe during winter when abundant moisture and freezing temperature are presentsimultaneously. Damage caused by frost heave is one of the important winter-related damagesresulting in severe cracks and bumpy road surfaces. Since the frost heave-induced cracks areusually wide, they can make the pavement more prone to other types of damage by leaving theopen space for water and moisture penetration. Simulating the response of the pavement whenit is subjected to frost heave is the aim of this licentiate thesis. Attaining this objective requirescoupling a frost heave model with a damage model representing the mechanistic behavior ofthe asphalt material. With regard to the brittle behavior of the asphalt at cold temperatures, aviscoelastic damage model for asphalt material is coupled with a thermomechanical frost heavemodel. The thermomechanical approach couples the physical processes involved in frost actioninside the soil. To elucidate more, in this method the thermal and mechanical fields are coupledby the porosity evolution function which implicitly takes into account the effect of the hydraulicfield. On the other hand, the continuum viscoelastic damage model for asphalt material isdeveloped within the infinitesimal strain context by applying the thermodynamical restrictionsof irreversible processes. The suggested framework was employed in different finite elementmodels to simulate damages caused by frost heave in asphalt pavements. The results indicatethat it predicts the damage distribution and evolution in the asphalt. Furthermore, it was shownthat the uneven frost heave and physical processes taking place in the soil during frost actionsuch as cryogenic suction force creation, porosity evolution, ice formation, etc., can also besimulated.