This book provides a new solid background for the design of reinforced concrete structures. The practice of using f'c as a design parameter has been successful in the past and will continue to do so since there are numbers of strength reduction and load enhancement factors incorporated in the current design codes, which are entirely based on compressive strength of concrete. As a consequence the current design practice is not only leading to a more expensive design solution but also on the other hand suggests periodic revision of the building codes, as the upper limit of the concrete's compressive strength has never been a constant. Having said that, the optimistic solution for the problem is the incorporation of fracture mechanics in the current design codes in general and more specifically concrete structures can also be designed based on the characteristic length of the concrete mix.