PSI - Issue 64

Laurena De Brabandere et al. / Procedia Structural Integrity 64 (2024) 97–104 Laurena De Brabandere et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 4. M/A∙Δx as a function of time for (a) a w/c of 0.4 and NaCl, (b) a w/c of 0.4 and LiCl, (c) a w/c of 0.7 and NaCl and (d) a w/c of 0.7 and LiCl.. Error bars represent the standard error.

4.3. Gas permeability (CEMBUREAU method)

Fig. 5 shows the gas permeability coefficient k a for concrete with CEM I, CEM II and CEM III and w/c 0.4 and 0.7. These are the results calculated for dry specimens (S = 0%) at a pressure of 3 bar. The values represent the average of 2 measurements on 2 samples each time. For a w/c of 0.4, k a is the highest for concrete with CEM III, which corresponds with the worst performance, followed by concrete with CEM I and then CEM II. For a w/c of 0.7, there is a clear increase in gas permeability coefficient between CEM I, CEM II and CEM III. The results for the w/c of 0.4 correspond with the results obtained in the capillary imbibition test and the water vapour diffusion test, where CEM III also had an inferior performance. However, the results for concrete with a w/c of 0.7 do not follow the same trend in comparison with the previous tests. Here, k a has the highest value for the concrete mix with CEM III.

Fig. 5. Gas permeability coefficient k a for concrete with a w/c of 0.4 and 0.7 and CEM I, CEM II and CEM III as a binder.