Mechanical Behavior of Waste Tire Crumbs-Sand Mixtures Determined by Triaxial Tests

In the last three decades, the use of scrap tires in a number of forms such as whole tires, shredded, chips, ground tire or powder tire shapes has already been common in many geotechnical applications. One of the main reasons of using shredded tires is the fact that it is cost-effective and environmental concerns. While, scrap tire improves sand behavior; so, it is suitable to transform tire to shredded for using in many industrial applications. In this research, in order to investigate the behavior of the tire-sand mixtures (small tire crumbs), drained triaxial tests have been performed. Effects of parameters such as size of tires, tire content (by weight) and confining pressure on the sand's behavior have been studied. For achieving this objective, two sets of tire (granulate and powder tire), four various tire contents (5, 10, 20 and 30%) and three confining pressures (50, 100 and 200 kPa) have been employed. The test results showed that unlike some previous studies in which tire crumbs act as reinforcement and increase shear strength of sand-tire mixtures, shear strength mixtures have been found to decrease with the increase in the amount of tire crumbs. This study concentrates on the stress-strain and volumetric strain behavior of the tire-sand mixtures. Moreover, the angle of friction, cohesion and elastic modulus for each mixture are presented.