Thermogravimetry on calcined mass basis — hydrated cement phases and pozzolanic activity quantitative analysis

• Published in: Journal of thermal analysis and calorimetry 2009-07, Vol.97 (1), p.85-89
• Main Authors: Dweck, J., Cherem da Cunha, A. L., Pinto, Carolina Afonso, Pereira Gonçalves, J., Büchler, P. M.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Applied sciences; Buildings. Public works; Cement concrete constituents; Cements; Chemistry; Chemistry and Materials Science; Exact sciences and technology; Inorganic Chemistry; Materials; Mathematical analysis; Measurement Science and Instrumentation; Miscellaneous; Moisture content; Oxides; Phases; Physical Chemistry; Polymer Sciences; Quantitative analysis; Roasting; Thermal analysis
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-008-9761-0

When cement hydrated compositions are analyzed by usual initial mass basis TG curves to calculate mass losses, the higher is the amount of additive added or is the combined water content, the higher is the cement ‘dilution’ in the initial mass of the sample. In such cases, smaller mass changes in the different mass loss steps are obtained, due to the actual smaller content of cement in the initial mass compositions. To have a same mass basis of comparison, and to avoid erroneous results of initial components content there from, thermal analysis data and curves have to be transformed on cement calcined basis, i.e. on the basis of cement oxides mass present in the calcined samples or on the sample cement initial mass basis. The paper shows and discusses the fundamentals of these bases of calculation, with examples on free and combined water analysis, on calcium sulfate hydration during false cement set and on quantitative evaluation and comparison of pozzolanic materials activity.