Development of Self-Sensing Coatings for Concrete Applications

Abstract

Structural Health Monitoring is currently becoming more vital as it detects the damage and warns user in early stages. SHM helps in assessing the buildings and infrastructure during the service life and after the critical events such as earthquakes and landslides. This experimental investigating is carried out to develop self-sensing coating for concrete surfaces. For this, graphite micropowder (GMp) and graphite nanopowder (GNp) were used as functional fillers. Graphite micropowder is incorporated at percentage of 1%,2,%,5%and10% whereas GNp was incorporated at 1% and 2% by weight.Initially,electrical conductivity test is carried out , Impedance (Z) and Phase angle(Ɵ) were recorded for various percentages using LCR meter. Out of all considered filler concentration, (1%, 2%, 10%) of GMp and (1%, 2%) of GNp is considered for further testing. Prepared concrete samples with coatings were tested under compressive and flexural loading and self-sensing response was recorded. Additionally, bond strength tests are also performed on the samples. Test results indicates that GNp 2% is showing the maximum FCR around 400% and 100% for monotonic and cyclic loading respectively, shows good repeatability and stability under the applied loadings. Hence, GNp (2%) is considered for durability testing (Temperature and Humidity Cycles) and corrosion detection.Durability testing shows that humidity and temperature variation impact the functioning of the prepared coating whereas coating is capable of detecting early stage corrosion which is indicated by indirect relation between Z and section loss.