Effects of desiccation on mechanical behaviour of concrete

The objective of this work is experimental characterisation and numerical modelling of coupled behaviours between drying shrinkage and plastic damage in concrete. In the first part, we present an original experimental study on an ordinary concrete in order to determine material damage induced by drying shrinkage. Uniaxial compression tests are performed on samples dried for different periods. It is shown that material damage can be caused by drying process. Mechanical behaviour becomes more brittle with higher damage kinetics when concrete is dried. In the second part, a constitutive model is proposed in order to describe coupled hydro-mechanical behaviour of partially saturated concrete. This model takes into account induced damage, mechanical and capillary plastic deformations. Numerical simulations of experimental tests are presented, and show a qualitatively good agreement with experimental data. The results are relevant with respect to the importance of drying process in the durability study of concrete structures.