*3.4. Compressive Strength at Elevated Temperatures*

Specimens described in Section 2 were heated up till the predetermined value of temperature (up to 100 or 200 ◦C) was achieved at the surface of the bar. Temperature values were registered with the use of thermocouples mounted under the ceramic wool (see Figure 2b). After removing the specimens from heating chamber, compression tests were performed with the pace of 1.5 mm/min. Maximum forces and temperatures at the surfaces at failure time were registered for each specimen.
