Title: 
            Crack Propagation and the Fracture of Concrete
        
        
            Author(s): 
            M. F. Kaplan
        
        
            
                Publication: 
                Journal Proceedings
            
            
                Volume: 
                58
            
            
                Issue: 
                11
            
            
                Appears on pages(s): 
                591-610
            
            
                Keywords: 
                none
            
            
                DOI: 
                10.14359/7999
            
        
        
            Date: 
            11/1/1961
        
        
            Abstract:
            The Griffith crack theory of fracture strength is discussed. Tests were performed on concrete beams with crack simulating notches, and two methods, which have been called the analytical and the direct experimental methods, were used to determine the critical strain-energy-release  rate  associated with the rapid extension of the crack. There was good agreement between Gc values for beams with different notch depths and which were loaded both by the third-point and center-point methods. However, 3 x 4 x 16 in. beams gave somewhat larger Cc values than did 6 x 6 x 20-in. beams. Although further research is necessary, the indications are that the Griffith concept of a critical strain-energy-release rate being a condition for rapid crack propagation and consequent fracture, i s applicable to concrete. The critical strain-energy-release rate may be ascertained by suitable analytical and experimental procedures and the fracture strength of concrete containing cracks can thereby be predicted.