CONTRIBUTION TO THE FORMATION MECHANISM OF THE TRANSITION ZONE BETWEEN ROCK-CEMENT PASTE

A number of microstructural and mineralogical models for the rock-paste interface can be found in the literature. Similarly, there are also a few hypotheses relating to the mechanisms responsible for the formation of the interface zone. This paper addresses both of these questions. Based on results from various analysis techniques, it has been shown that a single model is insufficient to describe interface microstructure and mineralogy, since they depend on the type of cement used. The mechanisms responsible for the formation of the interface appear related to differential ion diffusion caused by the zone's higher porosity, resulting from the arrangement of the cement grains in contact with the rock. Furthermore, the findings reveal that these mechanisms also govern the concentration of alkalis in contact with the rock.