Modelling the mechanical strength of fractal aggregates

Variations in the mechanical strength of aggregates with aggregate cross-sectional area have been modelled in this work. The fractal structures of aggregates were considered in conjunction with fundamental mechanisms of aggregate formation and rupture during the modelling. A quantitative expression of aggregate porosity and characteristic length in terms of aggregate fractal dimensions was derived from fractal dimensional analysis. Predictions from this expression and the Rumpfʹs equation demonstrated that tensile strengths of aggregates decreased with increasing aggregate cross-sectional area. An experimentally determined function was introduced into the model to account for the effect of fractal characteristic length on aggregate strengths, enabling one to predict the compression strength of aggregates. The predictions of compression strength agree well with the experimental data measured for latex aggregates when compressed between two parallel plates.