Numerical investigation of salt-frost damage of pervious concrete at the scale of a few aggregates

In this study, we aim to gain insight into the damage mechanisms of pervious concrete subject to frost attacks in the presence of salt. We perform numerical simulations using a poroelastic model on system geometries representing pervious concrete at the scale of one or a few aggregates: (1) one aggregate coated with cement paste, (2) one aggregated coated with a cracked layer of cement paste, and (3) two aggregates coated and bonded with cement paste. The numerical simulations indicate that the damage is more likely to occur at the contact between aggregates. Furthermore, we observe significant shear stress at the vicinity of the paste/aggregate interface. We undertake a thorough parametric study to evaluate the impact of various boundary conditions, initial conditions, and materials parameters on the stresses generated during one or several freeze-thaw cycles. The insights can provide guidelines to design pervious concretes with enhanced freeze-thaw durability.