Electrical resistivity measurement of concrete
Electrical resistivity (also known as resistivity, specific electrical resistance, or volume resistivity) is an intrinsic property that quantifies how strongly a given material opposes the flow of electric current. A low resistivity indicates a material that readily allows the movement of electric charge. Concrete electrical resistivity can be obtained by applying a current into the concrete and measuring the response voltage.
On-site electrical resistivity of concrete is commonly measured using four probes in a Wenner array. In this method four equally spaced probes are applied to the specimen in a line. The two outer probes induce the current to the specimen and the two inner electrodes measure the resulting potential drop. The probes are all applied to the same surface of the specimen and the method is consequently suitable for measuring the resistivity of bulk concrete in situ.
|ρ||Electrical resistivity (ohm*m)|
|α||The equal distance of the probes (m)|
|V||The voltage measured between the inner two probes (V)|
|I||The current injected in the two outer probes (A)|