No. 188. Fatigue of Concrete Structures - State-of-the-Art Report (1988; 306 pages). Available only as downloadable PDF file.
The product of the first task of the Group , to produce a state-of-the-art report , is contained in th is Bulletin . It is
presented in seven chapters , prepared by acknowledged experts and each is written as a separate treatise in its own right .
The text was reviewed and revised by the Group and care was taken to ensure consistency between the various sections .
Because of the different sources of the material and the various disciplines involved , it was not always possible or indeed desirable to adopt a common system of notation throug hout the report . The main objectives of the Bulletin are:
In chapter 1 Dr Lovegrove has summarised the work of previous international organizations , for example RILEM's 36 ROL and 65 MOB committees . A very useful collection is presented of fatigue case histories for different concrete structures, including bridges , pavements, cranes and industrial buildings . The commonly used statistical methods of analysing and representing S-N fatigue performance data are described . The more commonly used fatigue terms are defined so that the scene is set for the more specialist chapters that follow.
Chapter 2 concerns loading and cont ains contribut ions from Professor Konig , Professor Owen , Mr Steml and , Mr Sturm and Dr Tepfers. In designs where fatigue is to be assessed in detail , it is necessary to have an understanding of the loading applied to the structure . Loading can be due to environmental factors such as wind , waves , temperature differences and freezing , or to mechanical effects such as the passage of vehicles , machine tool loading , and impacts . The chapter concentrates on the phenomena and representation of wind , waves and traffic.
In chapter 3 Dr Cornelissen has prepared a fully comprehensive review of the fatigue of plain (unre inforced ) concrete. There are sections on plain concrete in compression, tension, and tension - compression. Other topics included are variability of test results , composition and quality of concrete , light weight concrete , stress rate (frequency of loading ), rest periods, remnant strength and stiffness, moisture conditions , confining pressure , cryogenic conditions, eccentric loading , variable-amplotude loading , constitutive relations and evaluations . The subject of the criteria for damage ac cumulation and methods for cycle counting are also discussed.
Chapter 4 concerns fatigue of reinforcing and prestressing steel and contains contributions from Dr Tilly and Mr Sturm. For reinforcing steel there are sec ions on the fatigue performances of high strength deformed bars, including effects of method of testing , surface geometry and bending, performances of different types of connection incuding laps, mechanica sleeves and but welding, and lower bound representations of the S-N curves including al lowances for the deleterious ef fects of corrosion . For prestressing stee l there are sections on ef fec ts of fretting , interact ion between tendons and bars, fatigue limit, partially prestressed beams and splicing connections.
In chapter 5 Dr Tepfers has addressed the performance of components and structures. This relates to the overall behaviour of the steel-and-concrete composite material where as Chapters 3 and 4 deal with the constituent materials on the irown . Consideration is given to failure by bending , shear or bond, de formations and crack widths, methods for analysing damage in structures, use and performances of connections, anchor bolts and splices.
In chapter 6 Dr Gylltoft has reviewed methods of structural analysis, and fracture mechanics . Both linear and non linear behaviour are considered . The use of fracture mechanics for analysis of concrete is discussed and it is noted that for concrete non-linear fracture mechanics is applicable but linear fracture mechanics should be used somewhat restrictedly.
In chapter 7 Dr Frey has looked at a selection of relevant sections of recent codes of practice and has given a brief description of how fatigue of concrete is treated . A direct comparison of the codes is difficult because philosophies are so different ; in some codes provisions are given in a section dealing with concrete structures, in others there are more details and aspects such as fatigue loading are defined . There are sections on range of application , design principles, fatigue assessment and methods of analyses .
