1DBTERIORATION, SERVICE LIFE AND REPAIR OF CONCRETE STRUCTURES. KNOWLEDGE AND RESEARCH NEEDS

The fact that two destruction types might influence each other is never considered in normal service life modelling. It is shÑn by an example that the effect of such synergetic effects could be very big. The paper expresses the author's personal view concerning-the_ present st?lys within service Hfe ilesìign of concrete structures. It is stated that service life design is still in an embryonal stage, põssibly with the exception of reinforc ment corrosion. For other types of attack, there have b-een alniost no attempti to exchange the traditionally used but vagug concept''durabili-ty " for the more precise c^oncept "servlce üfe", by developing service tife models that are based on a deep uñderstanding of the destruction mechanisms. A very short discussion is made on different types of attack, and comments are made on re-search needed in order to refine existing servlce life models, and to develop new m_odels. Reinforcement corrosion has been the moit intensely studied durablity problem during thq lryt decades, and it is also the durability problem for which service life model'ling has been fairl