11th International Symposium on Nondestructive Characterization of Materials, Berlin, Almanya, 24 - 28 Haziran 2002, ss.373-380
The results of measurement of reflection and transmission properties of mortar and concrete specimens at their early stage (1-10 days) obtained by using a simple and an inexpensive measurement system at microwave frequencies (X-band) are presented. Dependencies of the reflection and transmission signals on time, thickness and water-to-cement ratio of the specimens are demonstrated. It is shown that the cement-based materials can be characterized by the amplitudes of reflection and transmission signals together with thickness of the specimens.