Creep and shrinkage effects in composite elements

This chapter is aimed at providing basic concepts to understand effects produced by time-dependent behaviour of concrete and at introducing most common structural analysis procedures. A first section presents the basics of time-dependent effects in concretes. A subsequent section delivers conceptual descriptions, supported by some quantitative results, of time-dependent phenomena in composite elements with reference to beams subjected to bending. The last section presents procedures for time-dependent analysis for generic purposes; the general step-by-step method and the most used algebraic methods are presented; effectiveness of various algebraic methods in analysing composite elements is discussed. A final example to show the systematic use of the modular ratio method proposed by the main design codes is presented.