Hydrothermal reaction products of brick recyclates

Abstract This paper deals with possibilities of the brick-grind-dust application as a precursor for hydrothermal synthesis. Currently, this brick dust is partially reused in brick masonry or buried to the landfill site. The basic idea of this paper was to examine possibilities of the reaction of phases in brick dust with lime under hydrothermal conditions. The aim of the work was to find out an optimal ratio between lime and brick dust for maximal production of tobermorite. Physical and chemical properties of the brick-grind-dust were studied, and then a series of samples in autoclaves were prepared. The maximum amount of tobermorite after 24 hours of reaction was found in samples with addition of 25% lime. Phase composition of raw material and products of hydrothermal synthesis were analysed by powder X-ray diffraction analysis and differential thermal analysis. Structure of prepared samples was observed by scanning electron microscope.