ABSTRACT
A study performed for the State of Maryland Department of Transportation, SHA, for utilizing proven nondestructive testing techniques to monitor the performance of concrete bridges as a methodology of their routine periodic inspection and evaluation, identified two types of evaluations: global evaluation and local evaluation. The paper presents an analysis of the local evaluation aspect, i.e., the material integrity. The most practical and feasible technique in the determination of material integrity was found to be the Impact Echo method, which is based on emitting a signal at a point in a bridge’s element and picking it up at another point. Experimental as well as numerical analysis of the response of concrete elements to such signals for both sound and artificially flawed concrete elements are presented. The methodology of the determination of the size and location of internal flaws in concrete elements is also presented. The method can thus enable the determination of physical properties and physical defects of the main bridge elements and any degradation that occurs during the bridge’s life.
