VTT PUBLICATIONS 358 TECHNICAL RESEARCH CENTRE OF FINLAND ESPOO 1998 Constitutive modelling of fibre-reinforced brittle materials Jyrki Kullaa VTT Building Technology Dissertation for the degree of Doctor of Technology to be presented with due permission for public examination and debate in Auditorium Ko 216 at Helsinki University of Technology (Espoo, Finland) on the 4 th of September, 1998, at 12 o'clock noon.