Author, Institution: Agnė Šmigelskytė, Kaunas University of Technology
Science area, field of science: Technological Sciences, Chemical Engineering T 005
Scientific Supervisor: Prof. dr. Raimundas Šiaučiūnas (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T 005).
Dissertation Defence Board of Chemical Engineering Science Field:
Prof. Dr. Kęstutis Baltakys, (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T 005) – chairman;
Assoc. Prof. Dr. Anatolijus Eisinas (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T 005);
Prof. Dr. Habil. Aivaras Kareiva (Vilnius University, Natural Sciences, Chemistry, N 003);
Prof. Dr. Linas Kliučininkas (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T 005);
Prof. Dr. Martin-Tchingnabe Palou (Slovak University of Technology, Slovakia, Technological Sciences, Materials Engineering, T 008).
The doctoral dissertation is available on the internet and at the library of Kaunas University of Technology (K. Donelaičio g. 20, Kaunas).
In the doctoral dissertation rankinite – low-lime calcium silicate – synthesis and carbonation process was investigated and discussed. Rankinite can be used as an alternative binder with a synthesis temperature 200 °C lower than that of ordinary Portland cement clinker. The production of rankinite binder also requires 2 times less calcareous raw materials and ~20 % less fuel, which results in lower CO2 emissions, while the emitted gas can be sequestered in stable carbonates in the concrete structure during the hardening process. Due to these reasons rankinite binder is a suitable cementitious material for production of various concrete products, thus reducing the environmental impact of the cement production. After examining the synthesized binder and its carbonation hardening process, it was determined that the obtained material satisfies the essential requirements with regard to the currently existing state of the art technologies and can be characterized by the required physico-chemical and mechanical properties. Concrete with a compressive strength of ~45 MPa and high durability can be produced from rankinite binder and sand mixtures, after carbonating for relatively short time. Rankinite binder paste samples reached significantly high compressive strength values exceeding 100 MPa as a result of calcium carbonate formation and silica gel polymerization that leads to a denser microstructure and thus a higher compressive strength.