MODELING OF CONCRETE AT EARLY AGE -BENCHMARK CARRIED OUT WITHIN COST TU 1404
Résumé
Predicting early-age cracking in concrete structures and its effects on serviceability, such as mechanical performances, durability and tightness, is still a complex task to achieve. Indeed, several complex phenomena occur simultaneously and separation is not straightforward in some cases due to couplings, e.g. coupling of thermal and autogenous strain. The heterogeneity of concrete complicates the analysis of experimental data: e.g. shrinkage occurs only in cement paste and is restrained locally by aggregates. Moreover, for determination of input data it involves a lot of experimental tests (calorimetry, measurements of autogenous shrinkage, mechanical properties, creep in tension etc.) which are not readily available for industrial practice. Therefore, COST Action TU 1404 [1] has been launched. The Working Group 2 of this Action focuses on modeling and numerical simulations. It will allow thus for transferring knowledge from research to the industry in the form of new guidelines and recommendations. The first stage of the benchmark program realized by WG2 has been performed at the microscopic and macroscopic scales. Simple examples have been chosen. The benchmark shows that predicting evolution of thermo-physical and mechanical properties of concrete from its mix design is still a difficult task (microscopic). At the macroscopic scale, the prediction of temperature in massive concrete structures is quite mastered if the model used contains known features such as the thermo-activation process. However, for the prediction of stresses, significant scattering of results has been observed, mainly due to different constitutive equations adopted by the teams for calculation of Young modulus evolution around setting.
Domaines
Génie civil
Origine : Fichiers produits par l'(les) auteur(s)
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