Infra-Red Tool in Building Material

To understand the chemistry of thaumasite formation. An academic study was performed on pure systems composed of different silica source: silica gel and water glass supplied as liquid silicate and another supplied in the form of sodium meta silicate. The behavior of the silica sources were studied in mixes containing gypsum or ettringite in presence and absence of calcite and stored in water 28 days and 3 months at RT and 7oC. The effect of portlandite and magnesium sulfate on the behavior of mixes containing the silica source, ettringite, and calcite under the same conditions was studied. The expansion of Portland limestone mortars made of CEM I 32.5 with up to 25% calcite replacement was investigated in water and magnesium sulfate solution at RT and 7oC. Measurements relied mainly on infrared method of analysis, but also X-ray diffraction and scanning electron microscopy were used in the characterization procedures.