P. B. Sassmann, O. Weichold
6th International Conference on Concrete Repair (Concrete Solutions), Thessaloniki, 2017, S. 235–238.

Development of Electrically Conductive Resins for the On-Site Fabrication of Sensors for Corrosion Detection and Risk Assessment in Reinforced Concrete

ABSTRACT: Assessing the risk of corrosion in steel-reinforced concrete can be accomplished using different types of sensors such as anode ladders or multi-ring electrodes. The former are unsuitable for retrofit installations, while the latter require the use of embedding mortars to achieve conductive connections with the surrounding concrete. However, the porosity of the embedding mortar differs from that of the concrete and the retrofitting action introduces additional moisture. This interferes with resistivity and/or potential measurements and makes interpretations of the actual situation problematic. To circumvent these disadvantages, we have developed a liquid reactive polymer resin with high electrical conductivity that can be used to fabricate sensors directly inside drill holes. The mixture solidifies in a short time and its adhesive properties provide an excellent conductive connection to the concrete walls. The resin contains no water so that reliable values can be obtained immediately after solidification. By changing the additives both resistivity and potential sensors can be obtained. The mixture is cheap so that large sensor networks can be installed at reasonable costs. Such networks are ideal for the precise localization of corrosion events and more importantly for risk assessment in steel-reinforced structures.