Use of lamb waves to predict current damaged state of mortar

This paper describes the experimental and analytical results for the development of a methodology for predicting the current state of simulated concrete (mortar) in infrastructure. The nondestructive Lamb wave technique is used to experimentally identify the disturbance (damage) before and after mechanical testing of mortar specimens, which is used in the initial research as a substitute for concrete. The mortar specimens are tested to measure their stress-strain response under uniaxial compression and tension loading. The results of the nondestructive and mechanical stress-strain testing are correlated to develop the model based on the Disturbed State Concept (DSC), a unified approach for modeling material behavior. This model can allow evaluation of the deformation moduli, strength and degredation (damage) at a given state during the life of the material. This information can be used to design rehabilitation strategies. It can also lead to the development of new computer based equipment that can be used in the field for defining the remaining life. At this time, the research involved one-dimensional testing. The proposed methodology can, however, be extended and improved by conducting two- and three-dimensional testing of concrete specimens.