Stress level dependent behavior of sand-rubber mixtures

This study investigates the mechanical behavior of sand-rubber mixtures, focusing on the influence of stress levels. Quantitative analysis reveals significant effects of stress levels on void ratio and coordination number, which become more pronounced with increasing rubber content. Small-strain stiffness could be affected by stress level by demonstrating unified relationships between small-strain stiffness and conventional state variables, with the coefficients of determination for fitted relationships increasing from 0.66 to 0.95 as rubber content increases from 0% to 80%. This is attributed to the impact of stress levels on conventional state variables. Alternative state variables that exclude rubber materials more effectively describe the small-strain characteristics of sand-rubber mixtures, suggesting that rubber materials should be excluded when considering these characteristics in practical engineering for conservation purposes. The stress level effect is also evident in the variation of stress ratios with axial strain, particularly when rubber content exceeds 25%, showing that higher stress levels restrict the mobilization of stress ratios for rubber materials. This study highlights the importance of considering stress level effects in the mechanical analysis of sand-rubber mixtures, which exhibit unique characteristics compared to natural sands in both compression and shearing behavior.