An experimental study of the fractal scaling of concrete fracture is described. A concrete beam subjected to three-point bending in flexure was loaded to failure and the fracture surface viewed at various magnifications using a scanning electron microscope (SEM). The fractal dimension was then computed for 50 samples using the variable bandwidth technique. The results indicate that the fractal dimension tends towards unity at high magnification, indicating a return to Euclidean form. This suggests that the crack surface has a cut-off in fractal scaling in the region 0.63 to 4.57 nm. (C) 2001 Elsevier Science Ltd. All rights reserved.