Optimisation of gradation based on fractal dimension for large-size graded crushed stone

To improve the mechanical properties of large particle size graded crushed stone mixture and obtain the optimal grading. By using different design methods to obtain the grading of large particle size graded crushed stone, the maximum dry density test, CBR penetration test, static pressure test, and cyclic repeated compaction test were conducted on the large particle size graded crushed stone samples. Finally, fractal theory was introduced to quantitatively calculate the grading of large particle size graded crushed stone, and the fractal dimension of large particle size graded crushed stone was obtained. The relationship between the fractal dimension of large particle size graded crushed stone and density, CBR value, compressive strength, and deformation resistance was analyzed through grey correlation analysis. The experimental results show that large particle size graded crushed stone has better skeleton performance than conventional graded crushed stone; The density, CBR value, compressive strength, and deformation resistance of large-sized graded crushed stone are related to the grading. The skeleton dense grading ratio has stronger mechanical properties compared to the suspended dense grading and skeleton interlocking grading. And the optimal fractal dimension for the optimal configuration should be between 2.59−2.61.