CONCLUSIONS
The review of published data on the influence of environmental parameters upon concrete permeability suggests the following
1. Gas permeability is significantly increased as the capillary pores in the concrete are emptied; the channels available for
gas flow increase in volume and connectivity. A further increase of permeability can be observed with severe drying,
depending upon the temperature and duration of treatment. This is probably due to changes of microstructure in the
cement paste matrix.