The importance of cracks on the depletion of cementitious materials is usually assumed to be high. In this paper, similarity properties of diffusion dominated mass transport coupled with Calcium dissolution in cracked cementitious materials are presented. Together with model-based simulations…
The importance of cracks on the depletion of cementitious materials is usually assumed to be high. In this paper, similarity properties of diffusion dominated mass transport coupled with Calcium dissolution in cracked cementitious materials are presented. Together with model-based simulations that confirm the self-similar prop- erties of diffusion dominated mass transport in the fracture, it is shown that diffusion dominated transport does not significantly accelerate the Calcium leaching of the bulk material. In tum, a first estimate of the effect of Calcium leaching on the brittleness of the material predicts an increase in ductility. INTRODUCTION y Cracks and fractures in low permeable porous mate- 2b rials have long been suggested to affect the overall mass transport and related chemo-physical phenom- ena, such as phase-change, dissolution and sorption <D processes. And in some industrial concrete applica- c c tions, cracks are considered critical to the long-term ~ _g dimensional stability of structures. This is the case 0 ~ in e.g. nuclear waste disposal structures, subjected Porous medium .2 Porous medium to the critical design scenario of calcium leaching 0 ~ by permanently renewed water (Adenot et al. 1999). LL For containment structures, critical crack size criteria are often suggested as a quality control to ensure the i durability performance of concrete containers, barri- v "- x ers and encasement.