INFLUENCE OF SUPPLEMENTARY CEMENTITIOUS MATERIALS ON THE AUTOGENOUS SELF-HEALING OF CRACKS IN CEMENTITIOUS MATERIALS

摘要

The natural, e.g. autogenous, healing capacity of cementitious materials in concrete is a promising path to overcome the ecological problems and durability preoccupations inherent to civil engineering. But, recovery of mechanical from autogenous healing are due to ongoing hydration reactions highly dependent on the binder. In this study, the healing potential of different mixtures incorporating supplementary cementitious materials is discussed both from a mechanical and a permeability point of view. Mortars with a 25% cement mass substitution ratio by metakaolin or blast furnace slag were compared to reference ones. Healing performances were quantified after cracking at early age using three-point-bending tests. Recovery in mechanical properties were calculated from reloading curves while permeability recovery was estimated using a novel air permeability device. It appears that the blast furnace slag mixture exhibits very good performance compared to the reference and the one including metakaolin is relatively close to the reference.