Table 5 Assignments of the absorption bands and peak positions (in cm− 1) corresponding to Si-O, S-O, and Al-O vibrations in the MIR spectra of SCC-0 and SCC-60 before firing (δ – bending vibrations, ν – stretching).

From: Influence of post-fire recuring regimes on the properties of self-compacting concrete with heavyweight aggregate

Recorded vibrations/cm− 1

Assignment

1180 (m)

3 (S-O) in \(\:{\text{S}\text{O}}_{4}^{2-}\) from barite70

1083 (s)

3 (S-O) in \(\:{\text{S}\text{O}}_{4}^{2-}\) from barite and 3 (Si-O) from a quarzt71,72

988, 983 (s)

3 (Si-O) of Q2 \(\:\text{i}\text{n}\) C-(A-)S-H, 1 (S-O) in \(\:{\text{S}\text{O}}_{4}^{2-}\) from barite

797, 780 (w)

1 (Si-O) from quartz, ν(Al-OH) in Al(OH)6 from AFm73

635, 609 (w)

2 (O-S-O) in \(\:{\text{S}\text{O}}_{4}^{2-}\) from barite

570, 518 (m)

4 (O-Si-O),

460 (s)

4 (O-Si-O) from quartz, 4 (S-O) from barite

420 (w)

4 (O-S-O)74

  1. s – strong, m – medium, w – weak.