Title: 
            Advancements and New Applications in Impact-Echo Testing
        
        
            Author(s): 
            M. Sansalone, Y. Lin, D. Pratt, and C. C. Cheng
        
        
            
                Publication: 
                Symposium Paper
            
            
                Volume: 
                128
            
            
                Issue: 
                
            
            
                Appears on pages(s): 
                135-151
            
            
                Keywords: 
                artificial intelligence; beams (supports); columns; (supports) impact tests; instruments; nondestructive tests; voids; General
            
            
                DOI: 
                10.14359/3639
            
        
        
            Date: 
            11/1/1991
        
        
            Abstract:
            This paper summarizes recent developments in the impact-echo technique  for locating defects in concrete structures. First, the impact-echo principle is reviewed and frequency analysis of impact-echo signals is explained for those unfamiliar with the technique. Advancements in signal processing that have been aimed at simplifying and automating data  interpretation are discussed, and examples from the use of an artificial-intelligence technique for automated interpretation of signals from plate-like structures are shown. Impact-echo instrumentation is reviewed and an impact-echo field system is described. The newest application for the method is testing bar-like structures, such as columns and beams. Numerical and experimental controlled-flaw studies established the basis for the use of impact-echo for this application. Representative results obtained from impact-echo studies carried out on reinforced  concrete columns with circular and rectangular cross sections are presented. Finally, an overview of ongoing research is presented.