Šimková I., Greif V., Kompaníková Z. & Brček M., 2012: Study the change of thermophysical properties of natural stone in the conditions of cyclic freezing. Acta Geologica Slovaca, 4, 1, 23–30. (in Slovak with English summary)

Štúdium zmien termofyzikálnych vlastností prírodného kameňa v podmienkach cyklického zmrazovania

Study the change of thermophysical properties of natural stone in the conditions of cyclic freezing

Ivana Šimková, Vladimír Greif, Zuzana Kompaníková & Martin Brček

Katedra inžinierskej geológie, Prírodovedecká fakulta, Univerzita Komenského v Bratislave, Mlynská dolina G, 842 15 Bratislava; simkova@fns.uniba.sk, greif@fns.uniba.sk, kompanikova@fns.uniba.sk, brcek@fns.uniba.sk

Abstract

Evaluation of the influence of freeze-thaw cycle of rock is closely related to understanding the physical processes of weathering, the rock disintegration and rock decay. In research were used thermophysical methods: termodilatometry (VLAP 04) and “hot ball” method (RTM 1.03). Those methods can simulate the conditions of rock destruction behaviour due to cyclic freezing. Authors submit short-time research information about the continuous measurement of changes sample length of travertine from Spišske Podhradie, thermal conductivity and temperature during period 8 days. The experiment was divided into 4 - freeze-thaw cycles (progressive five grams water) and time on which the sample was exposed only to a chamber temperature. The research showed linear progress of deformation and coefficient of thermal expansion (α = 7.5·10°C^-1) of travertine sample in conditions without previous saturation. After ice crystallization was travertine’s coefficient of thermal expansion with water greater than coefficient of thermal expansion without water. The preliminary results showed that significant changes of sample length were caused ice crystallization. The same changes of deformation were visible even on thawing temperatures around 0°C. In the analysis of moisture through the "hot ball" probe in laboratory conditions showed that value of the parameter q/Tm are representative for the detection of moisture during the reference material. More detailed knowledge of the distribution of temperature and humidity will help to better understand the principles and mechanisms of degradation during cyclic freezing.

Key words: thermophysical methods, travertine, freeze-thaw cycle, water saturation

Manuscript received: 2012-02-15

Revised version accepted: 2012-05-17