Estimation of crack risk in early age concrete : simplified methods for practical use

Sammanfattning: For many situations it is obvious that an understanding of how different types of cracks arise and methods to estimate the risk of early age cracking is needed. This thesis deals with parts of this phenomenon namely thermal through cracking caused by restraint from an adjoining structure. Different existing material models used in a thermal stress analysis are compared with a tested behaviour. The main work focus on evaluating simplified manual methods for thermal crack estimation that are based on direct formulations by means of the results from a more advanced differential type method. One of the studied methods is selected and formulated for practical use. Possilble measures against thermal cracking are described together with recommendations on how they may be implemented in the method. Comparisons with observations from full-scale castings give an indication about the accurary of the simplified method.