Saturation vapor pressure; BEWEHRUNGSFASERN (BAUSTOFFE); HIGH STRENGTH CONCRETE (BUILDING MATERIALS); Pore pressure; Ideal gas law; PLASTERS + RENDERS (BUILDING MATERIALS); HOCHFESTER BETON (BAUSTOFFE); PP-fibers; Hydrothermal model; Permeability; Vapor flow in porous media; Ultra-high performance concrete (UHPC); FIRE BEHAVIOUR AND FIRE RESISTANCE OF BUILDING ELEMENTS AND MATERIALS (FIRE FIGHTING AND PROTECTION); REINFORCEMENT FIBRES (BUILDING MATERIALS); PUTZE + PUTZMASSEN + VERPUTZE (BAUSTOFFE); BRANDVERHALTEN UND FEUERFESTIGKEIT VON BAUSTOFFEN UND BAUMATERIALIEN (BRANDBEKÄMPFUNG UND BRANDSCHUTZ); Eplosive spalling