Damage study in concrete subjected to various loading by monitoring the surface resistivity

Abstract

Detection of damages and cracks and their progress in concrete structure is a grave concern. Incipient damages are often not noticeable and hence visual inspections or using of low frequency response methods and other NDE techniques may not give a significant reflection on the same. Permitting the damages/cracks to progress until they are well noticeable and making an attempt to detect and restore the structure would be a serious threat to the reliability and service life of the structure at least in case of a strategically vital one. With the advantages of non-invasion, non-radiation, low-cost and high-speed, electrical resistance measurement is a promising technique in this regard. In this study an attempt is made to analyse the changes in electrical resistivity of concrete structural elements when subjected to different types of loading. Electrical resistivity measurements were carried out on specimens like cubes, beams and cylinders under the action of compressive, flexural and tensile load respectively. In addition, study was conducted on cubes under repeated cycles of compressive loading.