These conclusions can also be confirmed by the analysis of the capillary HA14-1 coefficients where it is expected that the mixes with higher absorption coefficients (indicating a faster absorption) will have more capillary pores of greater size (binary mixes with LF). As for the mixes with lower absorption coefficients (indicating a slower absorption), more capillary pores of smaller size are expected, i.e. as initially mentioned, the SCC3.FA mixes’ pore network is characterised by a larger number of macropores linked both to the exterior and to one another by a network of micropores or smaller capillary pores, relative to the SCC2.LF mixes.
The water penetration under pressure depth results and the corresponding permeability coefficients were globally very low in all the SCC mixes. These results indicate a high compacity of the paste matrix and a poorly interconnected pore system.
Generally, it is found that the water permeability results agree with the water absorption by immersion and the capillarity results. As seen for capillarity and even the microstructure, the ternary mixes had extremely favourable permeability results, even at 28 days. This is due to the water permeability and capillarity being more related to the size and type of pores than to total porosity. The better results of the mixes with FA and the ternary ones may be attributed to the refinement of the microstructure of the cement paste matrix, through the filling of the porous structure by the hydration products, making it less interconnected and therefore less accessible.