Triaxial mechanical behaviour of mortar : effects of drying

Ismael Yurtdas (1) , Nicolas Burlion (1) , Frédéric Skoczylas (1)

1 LML - Laboratoire de Mécanique de Lille - FRE 3723

The analysis of concrete structure durability is based on the investigation of the material long-term behaviour. Such behaviour is influenced by mechanical, hydrous and thermal actions applied to structures. The main purpose of this study concerns the characterisation of the coupled effects between drying shrinkage and damage for a cementitious material. An experimental study on a normalised mortar (European norm) is then presented to characterise the damage effect, induced by drying and desiccation shrinkage on the multiaxial compressive behaviour. Triaxial compression tests are carried out at different times of drying. The observed increase in deviatoric strength and decrease of Young's modulus and Poisson's ratio are related to the loss in mass of specimens. These results are commented through the damage processes of material because the drying phenomenon causes microcracking by exceeding tensile strength. This microcracking will have a strong influence on the damage process of the material and then on its failure behaviour. Furthermore, the effect of drying leads to an increase of the capillary suction into the mortar, hence, to an increase of the specimen strength. Such couplings have to be taken into account in a reliable modelling.

Mots clés: Triaxial mechanical behaviour; Mortar; Drying; Desiccation shrinkage; Coupling

Ismael Yurtdas, Nicolas Burlion, Frédéric Skoczylas. Triaxial mechanical behaviour of mortar : effects of drying. Cement and Concrete Composites, 2004, 34 (7), pp.1131-1143. ⟨10.1016/j.cemconres.2003.12.004⟩. ⟨hal-00136812⟩