Multiphysics Lattice Discrete Particle Model for the Simulation of Concrete Thermal Spalling

Explosive thermal spalling behavior during fire exposure is one of the major issues in the design of modern reinforced concrete structures. However, spalling mechanisms and their interaction still remain in dispute in the scientific community. In order to shed some light on this phenomenon, a discrete hygro-thermal model of concrete at high temperature called DTemPor3 is proposed and a full coupling scheme between DTemPor3 and the Lattice Discrete Particle Model (LDPM) is adopted. The proposed multi-physical coupled model features the effect of pore pressure and temperature on the mechanical response as well as the impact of cracking on moisture mass transport and heat transfer. This proposed model can reproduce the explosive spalling phenomenon and only when the effect of thermal stresses is taken in account along with the effect of pore pressure on crack initiation, as demonstrated by the numerical simulations.