One of the current topics addressed at the Institute of Geotechnics is thermomechanics of rocks. The aim is to study the influence of temperature on the properties of rock mass. As part of a pilot study, a set of laboratory tests were carried out on bodies made of Kulm crumb. The bodies were fired at temperatures up to 1200 °C before testing to simulate, for example, the effects of fire. The tests were subsequently carried out according to standard rock mechanics methodology. The topic is dealt with by Ing. Marek Brabec. More information here: https://www.vut.cz/en/students/final-thesis/detail/152637
Principle of uniaxial compression test (left) and drawing of Mohr’s circle for uniaxial compressive testing (right), σc – uniaxial compressive strength
Principle of the Brazilian/transverse tensile test (left) and drawing of the Mohr circle for transverse tensile strength (right), σt – strength determined
Hoek’s cell principle (left) and Mohr’s circle plot for triaxial compressive strength (right), σ1 – axial stress induced by press, σ3 – chamber stress induced by hydraulic oil (red)
Dependence of the volume of the fired body from the offal on the firing temperature
Dependence of the volume weight of the fired body from the offal on the firing temperature
Dependence of the uniaxial compressive strength of the crumb on the firing temperature: values determined on bodies with cracks marked with a light grey border, discarded strength value marked with a cross, strength classes of rocks according to ČSN 73 6133
Dependence of the transverse tensile strength of the offal on the firing temperature: value determined on the body with the crack marked with a light grey edge
Fired carcasses from offal broken in transverse tension
Representation of the results of destructive tests carried out on burnt bodies made of offal as a function ofi σ1 and σ3
Dependence of cohesiveness and internal friction angle of fired offal on firing temperature
Dependence of the RGB component values on the firing temperature, for each temperature the analyzed cutout from the surface photograph and the corresponding averaged color is also attached
Fotografie leštěných průřezů zkušebních těles z hrubozrnné droby po výpalu
Photographs of rock cuttings made from fired clasts for studying the effect of temperature on the individual components of this clast – quartz, feldspar, muscovite, biotite and clay shale
Statistical evaluation of normalized values of fine-grained offal parameters as a function of firing temperature
Statistical evaluation of normalized values of coarse-grained offal parameters as a function of firing temperature