Modeling of material crushing in granular road bases

摘要

Crushing of a granular material was investigated. The material was subjected to compressive loads and a combination of compressive and shear loads. These type of loads are effective in granular bases under flexible pavements. The crushing tests used a weak material (sugar) and standard geotechnical engineering equipment (a compression and a direct shear apparatus). Sieve analysis and photographs obtained using a microscope were made before and after testing in order to evaluate the level of crushing in the samples. The Young's modulus of elasticity, E, of the samples was evaluated from the compression tests. E increased in value as a result of particle rearrangement and particle abrasion during compression and was found to decrease slightly as a result of particle crushing. The results from the direct shear tests show that the angle of shearing resistance of the samples decreased slightly as a result of crushing. A combination of low values of shear and compressive stresses produced a degree of crushing in the samples that was similar to that produced when a high level of compression was used alone.