Autogenous and Stimulated Healing of UHPC Under Torsion Induced Cracking

Autogenous and stimulated healing capacity of UHPC is well known, though in the entirety of studies cracks induced by means of flexural or direct tension tests have been studied. In the attempt of widening the case study database and promote self-healing cement-based materials into a variety of structural applications and broaden its concept to the upkeep of the material and structural load bearing capacity, this study focuses on the effects of self-healing in UHPC under torsional behaviour. Both autogenous and stimulated, via crystalline admixture, healing capacity have been considered, investigating cylinder specimens submitted to torsional behaviour. The capacity of the material not only to heal the induced skew cracks, under wet/dry exposure conditions, but also to maintain its multiple cracking capacity and to promote, upon successive reloading after healing, the formation of new cracks instead of the simple reopening of closed ones. A validation of the experimental campaign is also proposed via fracture-mechanics based finite element analysis.