Title : ELECTRICAL RESISTANCE TOMOGRAPHY ON REINFORCED CONCRETE
Authors : Amir Asgharzadeh, Kenji Reichling, Michael Raupach
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Price : 250
Abstract : The electrical resistivity of concrete is an important material parameter that can be correlated with different durability related parameters, e. g. the water content, the corrosion rate of the reinforcement and the chloride diffusion coefficient. The concrete resistivity in existing structures is usually determined by drilling out cores and measuring the resistivity in the laboratory. This procedure goes along with a local destruction of the concrete. Alternatively, the parameter can be determined non-destructively using a Wenner probe. The determination of the resistivity is usually based on the assumption of a homogeneous half-space with a homogeneous resistivity. In practice, however, there are distinctive heterogeneities (e. g. reinforcement or moisture distributions), which can lead to significant misinterpretations. The application of the Electrical Resistance Tomography (ERT) has been studied to counteract this problem. This method is based on the measurement of several apparent resistivity values based on different electrode spacings and positions. The actual resistivity distribution in the concrete is calculated by inverse calculations based on iterative numerical methods. This allows to consider the effect of heterogeneities and to reconstruct the distribution of the actual concrete resistivity. This paper focuses on the applicability of ERT on reinforced concrete structures.