Environmental Effects on Conductive Surface Sensors and Pattern Applications for Concrete Crack Localization

Detection of degradation has the potential to improve the long-term performance and integrity of concrete structures and pavements. Conductive surface sensors, specifically conductive paints, have been shown to be effective and adaptable when used as part of crack detection systems. The impact of environmental effects on conductive surface sensors must be known if these sensors will be used on structures or pavements exposed to environmental changes. This paper presents two experiments used to evaluate the effects of temperature and relative humidity on the behavior of a silver-based conductive paint and a more economical nickel-based conductive paint. Environmental effects on sensitivity to cracking and resistance were evaluated. A third experiment is presented that considered different patterns of conductive paint for use in crack localization applications. The results showed that the nickel-based and silver-based conductive paints perform comparably at detecting cracking and can be used over a range of temperature and relative humidity conditions. The patterns evaluated were shown to be effective at localizing cracking over an area, which is promising for application of this technology.