STATISTICS AND SIZE EFFECT IN CEMENTITIOUS MATERIALS

The statistical size effect in cementitious beams is examined using th e assumption that the critical threshold stress to cause a strain-soft ened fracture process zone to be initiated follows the Weibull distrib ution, The fictitious crack line model and the K-superposition theory, in combination with the statistical strain-softening relationship, ar e used to determine the strength of plain and notched beams. For notch ed beams the statistical effect on the strength is only important for small beams, but causes a large variation in all sizes of plain beams.