Accelerated thermal history analysis of light-burnt magnesium oxide by surface properties

Abstract

Homogeneity is of utmost importance in some applications of light-burnt magnesia (LBM), such as shrinkage compensation of cement composites, because if it is not detected reliably before application, it causes unpredicted expansion and cracking. This paper presents an accelerated method for homogeneity and thermal history detection in LBM. The proposed method provides an equation for computing the weighted mesopore probability distribution of light-burnt magnesia (LBM). Then, it deconvolutes the distribution's peaks by Lorentz peak functions to analyze homogeneity. The method's performance is evaluated by examining LBM samples produced by calcining magnesite at four temperatures and walking through several scenarios, including the mixtures of these samples. The results confirmed that the method accurately detects inhomogeneity and gives calcination temperatures and percentages of fractions of magnesia mixtures. These findings make it possible to prevent unpredicted expansion in cement composites incorporating expansive magnesia and can be employed to detect inhomogeneities in other porous materials applications.

Keywords

• Light-burnt magnesia
• Homogeneity
• Thermal history
• Adsorption mechanism
• Pore size distribution
• Deconvolution