Abstract:
Using tire wastes as lightweight materials in highway embankment construction has many benefits in environmental and geotechnical aspects. Tire waste additions to sand enhance the shear strength of soil for embankment construction leading to lower settlement and higher bearing capacity. The objective of this thesis is to investigate the effect of the tire waste inclusions to sand on shear strength of the mixture. In this study, three different parameters as tire waste shape, tire waste content, and tire waste aspect ratio are examined. By using granular shape and fiber shape tire wastes, three different experimental programs are performed. Quick and consolidated drained (CD) triaxial compression tests are conducted by using a standard triaxial test equipment, and CBR tests are conducted by using a standard CBR test equipment. In the first part, tire crumb, tire buffings and their mixtures with sand are tested in CBR test. In the second and third parts, the same materials are tested in the quick triaxial compression and consolidated drained (CD) triaxial tests. The quick triaxial compression tests are conducted on dry specimens. At the last part, the test results are compared with the literature. The results indicate that tire shape, tire aspect ratio, and tire content have a significant effect on the shear strength parameters and the CBR value of the composition. The triaxial test results show that the optimum results are obtained by 5 per cent tire buffings addition to the sand. It is concluded that fiber shaped tire inclusions influences the shear strength parameters and the CBR value better compared to granular tire inclusions. Also, the CBR test results indicated that as the aspect ratio increases, the effectiveness of the reinforcements increase. From the literature study and this study it is revealed that processing type of tire waste affects the shear strength values.
