Microstructure of the interfacial transition zone and transport properties
- INSA Toulouse (France)
The Interfacial transition zone is an heterogeneous zone formed around the aggregate particles in concrete. This zone is generally explained by a wall-effect which implies a looser arrangement of the cement grains in the vicinity of aggregate particles and results in a locally higher water to cement ratio in fresh concrete. By comparison with the microstructure in a bulk cement paste, the microstructure of the ITZ is characterized by a higher porosity, coarser pores, larger crystals of hydrates and by a gradient in hydrates concentrations. These features affect the transport properties of the ITZ but there influence on the transport properties of concrete itself are more complex because the connectivity of the Transition Zones has to be considered. Experimental data on different transport properties (ion diffusivity, water absorption and gas permeability) are presented and analyzed by means of a geometrical model in relation to the ITZ characteristics.
- OSTI ID:
- 214889
- Report Number(s):
- CONF-950801--
- Country of Publication:
- United States
- Language:
- English
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