*3.3.1 High-temperature effects on surface properties of concrete*

As seen in **Figure 2**, some color changes happen on the surface of concrete samples due to high temperature effects. As a result of these color changes the range of temperature values can be certainly appraised. It can be seen that cracking, rupture, and color changes happened much more in the concrete samples exposed to 900°C than the ones with 400 and 600°C.
