Gypsum composition with siltstone-based mineral modifier

Abstract

The paper presents the results of studies of the structure and properties of the gypsum composition comprising 3% of crushed siltstone, a metamorphic rock. The structure and physicochemical properties of siltstone were studied, which predetermine its usage as a structuring additive in gypsum compositions. Adding crushed siltstone to the composition of a gypsum binder is shown to cause the compaction of the structure of the gypsum matrix due to changes in the morphology of crystalline hydrates of calcium sulfate and monolithic structure in general, and, consequently, the enhanced mechanical characteristics of the gypsum composition. Using scanning electron microscopy, differential thermography, and IR spectral analysis explain the change in the physicomechanical properties of the gypsum binder.