12 June 2020

Séminaire Navier : Ilias Tahiri (doctorant, multi-échelle)

Investigation of the durability of pervious concrete subject to frost attacks

Pervious concrete is a type of concrete characterized by a high volume of inter-granular pores. This structure is obtained by using single-sized aggregates and by limiting the use of fine aggregates. This relatively high porosity allows water to drain easily from the surface to the soil. Even though pervious concrete has substantial benefits, it is subject to many durability challenges such as freeze-thaw cycles and clogging. In fact, in cold regions, pervious concrete structures are subjected to freeze-thaw cycles which deteriorate the material. The aim of the PhD is first to understand the damage behavior of pervious concrete in saturated conditions and in the presence of deicing salts subject to freeze-thaw, and second to optimize the mix design to increase the number of freeze thaw cycles the porous concrete can sustain before damage. In order to reach these goals, experimental and modeling approaches are considered. First an experimental assessment of freeze-thaw resistance of various formulations of decimeter-sized samples of pervious concrete is performed. Every mix design contains an additive that potentially enhances the resistance to freeze-thaw. In terms of modelling, the aim is to understand why porous concrete gets damaged when subject to freeze-thaw cycles by understanding the relevant physical processes that might be involved, using a freeze-thaw model and the in-house code Bil.

12 June 2020, 14h0015h00