The influence of mineralogical composition and texture on functional properties of silicate stone

Author, Institution: Marius Baltakys, Kaunas University of Technology

Science Area, Field of Science: Technological Sciences, Chemical Engineering – 05T

Scientific supervisor: Prof. Dr. Raimundas ŠIAUČIŪNAS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T).

Dissertation Defence Board of Chemical Engineering Science Field:
Prof. Dr. Rimvydas KAMINSKAS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T) – chairman;
Dr. Valentin ANTONOVIČ (Vilnius Gediminas Technical University, Technological Sciences, Materials Engineering – 08T);
Prof. Dr. Jonas BALTRUŠAITIS (USA Lehigh University, Technological Sciences, Chemical Engineering – 05T);
Assoc. Prof. Dr. Zenonas VALANČIUS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T);
Prof. Dr. Virgilijus VALEIKA (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T).

The doctoral dissertation is available at the library of Kaunas University of Technology (K. Donelaičio g. 20,Kaunas)

Annotation:
Various raw material processing technologies, the composition of formation mixtures, and different hardening treatment are used during the manufacturing of products with particular characteritistic. Therefore, calcium silicate hydrates with different basicity can form in the products. These C-S-H significantly influence the mechanical and perfomance properties of products. The conditions of formation and stability of calcium silicate hydrates are governed by the duration and temperature of hydrothermal treatment; the CaO/SiO2 molar ratio of initial mixture; the composition and purity of raw materials; used additives; stirring intensity and other factors. It is important to examine the formation kinetic of calcium silicate hydrates in model and industrial systems in order to optimize the technological parameters of autoclaved aerated concrete production and expand its rational application areas.
In this work the influence of synthesis parameters on the calcium silicate hydrates formation kinetics in porous and dense silicate stone and in unpressed samples were determined as well as the dispersibility, texture and stability of formed products were evaluated. It was determined that various materials containing soluble environmental aggressive transition metal ions can be intercalated, thereby dispose, into the crystal lattice structure of calcium silicate hydrates during the hardening treatment of products. Besides, recommendations for the improvement of autoclaved aerated concrete technology was proposed in order to reduce the amount of binder material in products, cost and suggest new application areas.