Modeling of Water Contents in Concrete Using Electromagnetic Guided Waves
XIAO ; IHAMOUTEN ; VILLAIN ; DEROBERT ; TIAN
Type de document
COMMUNICATION AVEC ACTES INTERNATIONAL (ACTI)
Langue
anglais
Auteur
XIAO ; IHAMOUTEN ; VILLAIN ; DEROBERT ; TIAN
Résumé / Abstract
Concrete has been widely used as a building material for the last decades. As we know, the degradation of concrete happens mostly with the presence of water, to which the electromagnetic waves are sensitive. The information of water content in concrete structure thus becomes an interesting subject for ground penetrating radar (GPR). In this study, we use an experimental set-up of imbibition to model the water content in concrete. Our main objective is to monitor the water transfer through time by electromagnetic (EM) guided waves. A new empirical model - arctan(x) model is proposed here to approximate the distribution of dielectric constant in concrete slabs during imbibition time, based on the measurements of gammadensimetry. The determination procedure includes the requirement of guided waves, the extraction of phase velocity dispersion curves and the inversion of gradient curves. The inversion of this model has been validated first by synthetic model in Matlab ® , then by numerical model using GPR modeling software GprMax 2D, where the concrete with gradient was approximated by a 27-layer medium. The model will be further validated by experimental studies. The GPR equipped with antennas at 1.5 GHz will be applied to the measurements of guided waves using common mid-point (CMP) configuration. It can help us to design and develop new microwave (MW) sensing and imaging systems for structural health monitoring of multiple layers of concrete.
