The Effect of the Interfacial Transition Zone on Concrete Properties: The Dilute Limit

摘要

The interfacial transition zone (ITZ) that exists in the cement paste near sand particles and rocks in concrete to be considered as a (at least) three-phase composite: (1) bulk cement paste, (2) ITZ cement paste, and (3) rock and sand, collectively called aggregates. In reality, the ITZ contains a gradient of properties. but can be approximated as a single property shell with some finite thickness. This paper discusses how this gradient of properties can be quantitatively mapped into a single property shell, for the case of ionic diffusivity (electrical or thermal conduction), using an exact analysis of the dilute composite limit, in which the volume fraction of (spherical) aggregates is small.