Violeta Bokan Bosiljkov and Andreja Padovnik are members of the international organization RILEM. They attended the kick-off meeting of the new RILEM technical committee LHS: Specifications for testing and evaluation of lime-based repair materials for historical structures. Leading European researchers in the field of development of lime-based repair materials are members of the RILEM LHS. The meeting took place from 12 to 13 October 2017 at the Aristotle University of Thessaloniki (AUTH) in Greece. At the meeting, they presented the research and the results that are being carried out at UL FGG in the field of cultural heritage materials. A large part of the lecture was devoted to the presentation of the J2-8194 project and the first results of the project. They showed how different mixers and different mixing times can affect the rheological properties of injection grouts in the fresh state, and hence their properties in the hardened state. Within the framework of the LHS Technical Committee, a program of work and working groups were established for a period of five years. Working groups cover different areas of testing materials for cultural heritage, namely: report of the functional role of mortars and grouts - performance requirements; analysis of binding systems mechanisms of different binders in HS; modern binders - regulative frames; collection and analysis of existing testing procedures at laboratories and literature on repair lime-based materials; determination of a necessary number of modification test methods according to their binder type; validation of laboratory modified test methods in relation to conditions i.e. indoors/outdoors; formulation of new modified testing procedures (new instruments); etc. By active work of Violeta Bokan Bosiljkov and Andreja Padovnik in the committee, the research achievements of the J2-8194 project can be transmitted directly to the international research community.
B.04 Guest lecture
COBISS.SI-ID: 8312929Knowing how the microstructure of cement based materials (CBMs) develops at an early hydration age is of vital importance, since it directly affects the physical and mechanical properties and thereby the functional properties of the hardened CBMs. The research for the following master%s thesis was conducted within the international COST TU1404 project and is based on the study of hydration kinetics and the development of CBMs mechanical properties at an early age. Using an advanced ultrasonic (US) method, characteristic setting and hardening points of CBMs were determined. The frequency spectrum of the US waves method has proved to be reliable and accurate in monitoring changes in the CBM microstructure. The results of nuclear magnetic resonance (NMR) in monitoring the development of the CBM structure are very promising. The main part of the thesis focused on the comparison between advanced and standardized testing methods on hardened CBMs. Simultaneous longitudinal and shear US waves transmission velocity measurements enabled us to determine dynamic elastic parameters. These were compared to static elastic parameters obtained through standard methods. The correlation between the compressive strength and the dynamic elastic modulus and shear modulus was analyzed. Since the velocity of US waves travelling through CBMs depends mainly on their elastic moduli, which are closely related to their strength, a further analysis of the interdependence between the compressive strength and the travel velocity of longitudinal and shear US waves was carried out. Results have shown that both transmission velocity of longitudinal US waves and transmission velocity of shear US waves are an effective parameter for estimating the rigidity and strength of early - age CBMs.
D.10 Educational activities
COBISS.SI-ID: 8206945The Doctoral dissertation presents a new model of water adsorption in microporous aluminophosphates and a comparison with the experiments.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 3095652