Although some would vehemently deny it, many specialists would agree that, since the 1977 death of Freudenthal, the research field of structural safety and reliability has been in a schism.

Alfred Freudenthal, the founder of this field of research in the 1960s, perceived the fields of (1) structural safety and (2) mechanics and physics of materials and structures as inseparable. He mastered both, and treated both to the depth of knowledge in his time. Since that time, unfortunately, most researchers have immersed themselves in one of these two fields in great detail and with high sophistication, while treating the other aspect simplistically and superficially. The connection has been weak.

On one side, there have been probabilists who develop and successfully market complex computer programs to assess safety, reliability, and lifetime of concrete structures without recognizing that failure probability of concrete structures cannot be predicted with simplistic or obsolete material models that eschew fracture mechanics and energetic size effect. Or there have been statistically minded experimenters who conduct extensive histogram testing of the strength of ceramics but ignore the scale effects, micromechanics, and microscale physics of failure.

On the other side, there have been mechanicians who construct highly refined constitutive and computational models for the mechanics of failure of concrete, geomaterials, and composites without recognizing that far greater prediction errors stem from simplistic or nonexistent treatment of the randomness of the material as well as the loads.

The present book attempts a step to rectify this schism. In a unified theoretical framework, it deals with the quasibrittle structures, which are those consisting of quasibrittle (or brittle heterogeneous) materials. These are commonplace materials, used more and more widely and increasingly important for modern technology, including much of high-tech. They encompass concretes (as the archetypical case), rocks, fiber composites, tough ceramics, sea ice, bone, wood, stiff soils, rigid foams, and so forth, as well as all brittle materials on the micrometer scale. They are characterized by a fracture process zone that is not negligible compared to the typical structural dimensions. This feature causes an intricate energetic size effect, which is intertwined with the classical statistical size effect, the only kind of size effect known in classical fracture mechanics of brittle materials.