Experimental investigation of shredded tire as trench backfill material

Developed and industrialized countries face a monumental problem in terms of the disposal of used tires leading to waste tire management becoming a serious global concern. Millions of waste tires are generated and stockpiled every year, often in an uncontrolled way causing a major environmental problem. One of the solutions to the problem can be found in the interest in sustainable development which includes the recycling of tire wastes. One possible application is to use shredded tires alone or mixed with soil as fills and backfills. Field and laboratory studies have confirmed that in the form of shreds tires exhibit very good frictional properties alone or mixed with soil by enhancing the strength of soil internally providing them with stability and inducing negligible differential settlement. In this thesis a comprehensive laboratory study was performed in order to evaluate a shredded tire-sand mixture as a backfill material in trench conditions. A steel frame test tank which replicated a classical trench section in field conditions was used in the laboratory studies. Vertical surcharge loads were applied using air pressure membranes from the top of the trench backfill. In the tests, different mixture proportions and densities of the tire-sand mixture were evaluated. The results of the test demonstrated that tire shredded mixed with sand can be effectively used as backfill material for buried pipe installations