Table 1 Assignments to the peaks observed in Figs. 1, 2, 3, 4, 5, and 6.

I

842–910 cm⁻¹: ν₂—out of plane vibration of CO₃²⁻

II

1,070–1,085 cm⁻¹: ν₁—symmetric stretching of CO₃²⁻

III

1,200 cm⁻¹ narrow peak: unknown, formed directly after addition of water to cement 1,200 cm⁻¹ broad peak: Si–O stretching of condensed silica

IV

1,425–1,590 cm⁻¹: ν₃—asymmetric stretching of CO₃²⁻

V

1,600–1,700 cm⁻¹: bending mode of H₂O

VI

1,800 cm⁻¹: ν₄ + ν₁ of CO₃²⁻

VII

2,500 cm⁻¹: ν₄ + ν₃ of CO₃²⁻

VIII

Broad band >3,000 cm⁻¹: stretching of OH

IX

3,643 cm⁻¹: stretching of OH in Ca(OH)₂

X

1,100–1,200 cm⁻¹: S–O stretching of SO₄²⁻