Title: The Fracture Surface Roughness of Concrete with Different Aggregate Sizes and loading Rates
Author(s): Y.-S. Roh and Y. Xi
Publication: Symposium Paper
Appears on pages(s): 35-54
Keywords: aggregate size; fractal; fracture; loading rate;
Fracture surface provides valuable information on internal structure and mechanical behavior of composite materials. Loading rate affects the roughness of the fracture surface of composites. A higher loading rate, in general, results in a smoother fracture surface. Similarly, aggregate size influences the roughness of the fracture surface. Larger aggregates cause a rougher fracture surface under the same loading rate. The roughness of the fracture surface of concrete is experimentally studied using concrete specimens made of the different aggregate sizes under different loading rates. Fractal dimension is used to evaluate the surface roughness of concrete specimens. A new fractal fracture model is developed which correlates the fractal dimension with concrete mix design parameters, such as volume fraction and size of aggregate, as well as loading rate. The model prediction agrees with test data very well.