Structural concrete behavior: coupled effect of drying and loading

Drying shrinkage may be a significant cause of deterioration of thin concrete repairs. Shrinkage-induced stresses can at least partially be relieved by tensile creep. Hydration effects and interface properties may have significant influence on concrete repair behaviour. An important experimental study was undertaken to understand the overall behaviour and to feed a numerical analysis tool. Different repair materials and setting techniques were studied. Long term and short term flexural tests were performed. Drying shrinkage and creep was found to be a very significant phenomenon for crack development. The used materials and setting techniques are shown to be very satisfying to restore structural capacity. The numerical formulation is presented in this paper. Both humidity effects and non-linear mechanical behaviour of the constitutive materials are taken into account. Phenomenological laws are used to describe mechanical damage and drying shrinkage. Moisture migration is described using a single diffusion equation. Numerical results show close agreement with experimental data.