Abstract: The purpose of this research is to obtain the shear performance of scrap tire strip-loess mixture, thus improving the recycled utilization through optimizing the dosage and shape parameter of scrap tire strip. Indoor shear tests were conducted on large-scale direct shear apparatus Shear Trac-Ⅲ. The dosage of scrap tire strips were designed at 0%, 10%, 20%, 30%, 100%, and the length-width ratio of scrap tire strip at 1, 2, 4, and 8 to examine the influences of dosage and shape parameter on the shear strength of the mixture. Results revealed that except for plain soil and soil mixture with 10% of scrap tire strip, the mixture specimens all displayed strain hardening behavior. Increments in dosage and length-width ratio of scrap tire strip had evident impact on improving cohesion, but small impact on internal friction angle. Within the test range, the optimal dosage of scrap tire strip is 20%. At this dosage, the cohesion of soil mixture increased by 56.5% compared with that of plain soil. Under normal stress of 24 kPa and 48 kPa, the soil mixture had large shear strength when the optimal length-width ratio was 4, while under normal stress of 96 kPa and 144 kPa,large shear strength can be achieved when the length-width ratio equaled 2. The shear strength of scrap tire strip-loess mixture was up to 22% higher than that of plain soil, indicating a remarkable amelioration of loess by using scrap tire strips.

Key words: large-scale scrap tire strip, loess, dosage, length-width ratio;shear performance