8 Pages

The French National Project CEOS.FR: Assessment of cracking risk for special concrete structures under THCM stresses

A. Sellier C. La Borderie

The current European standard design code (EN 1992-1-1 (2004)) proposes empirical methods for assessing cracking risk and deducing reinforcement rates. Nevertheless, it is observed in the field that these rules sometimes lead to a non-optimal distribution of rebars in massive structures, where cracking can occur despite the fulfillment of the design rules. The problem seems to be linked to the fact that the present design rules were mainly worked out to control cracking in common slender structural elements (namely beams and columns of buildings). In large structures, phenomena like early age heating due to cement hydration or autogenous shrinkage play a major role and can no longer be neglected. Also, in large structures, the traditional simplified approaches based on approximations of the kinematics (Navier’s assumption for example) or simplified concrete behavior laws (without softening) are not sufficient and three-dimensional non-linear finite element analyses should should constitute a reference background for determination of the provisions which can ensure control of cracking.