Model for moisture content evolution in porous building elements with hygro-thermal bridges and air voids

Addressing the effects of moisture movement and residual moisture-contents is becoming a recognized part of performance-based design of buildings. However, the multi-directional moisture-movement and subsequent moisture-content evolution in most common building elements with hygro-thermal bridges, without or with air-voids, has yet not been investigated. An integral presentation was utilized to establish the coupled heat and
mass transfer field equations for these cases, and for their reduction to a discrete set of algebraic equations. An interactive converging numerical process solves the implicit set of algebraic non-linear equations. Results address some examples for verification of the computational procedure, and a symmetric drying process of an autoclaved-aeratedconcrete block-wall with cementitious-mortar joints and renderings, with and without airvoids.