Analysis of excess noise sources in concrete composite materials and impact on electromagnetic emission measurement

This paper deals with an excess noise sources in concrete materials. The theoretical description is put forward as well as supporting experiments of real samples. Physical variables under consideration are spectral densities of voltage and/or current fluctuation for different sample dimension and electrical excitation. It managed to get information about Johnson-Nyquist noise, 1/f noise and Polarization noise contributions. These individual components define detection limit or ability to recognize electromagnetic emission signal when mechanical load is applied and micro-cracks are created. Described investigations also pointed out real requirement on noise sensing equipment and sample preparation methodology.