=+61. In a discussion of the article “Tensile Behavior of Slurry Infiltrated Mat Concrete (SIMCON)” (ACI Materials J., 1998: 77–79), the discussant presented data on y 5 toughness (psi) and x 5 aspect ratio. He stated that “a (simple linear) regression analysis clearly shows that the aspect ratio is not a reliable variable that can be used to predict toughness.” The following observations were read from a graph in the article:

x: 500 500 500 500 500 715 715 715 715 715 y: 33 34 35 38 40 35 36 37 39 44