Effect of Modified Soil on Shear Strength
Mentor:Binod Tiwari, Associate Professor, California State University Fullerton
There is an increasing demand to find alternative uses or safe disposal methods for trashed rubber tires due to the major fire hazard they pose, and the lack of space to dispose them in landfills. Consequently, various applications for the use of these waste tires have been proposed by the geotechnical community including the use as a fill material for sidewalks and other walkways, and to increase the stability of slopes. Commercially available shredded rubber tires varying from 0.6 mm to 4.75 mm in size were purchased. The rubber tires were mixed with two soil types –Sand and Clay. The soil mixtures had tire proportions ranging from 2% to 10% by weight. The testing was performed using the Direct Shear Testing Method (ASTM D3080) and Standard Test Method for Unconfined Compressive Strength of Cohesive Soil (ASTM D2166) to evaluate the shear strength of soil modified with tire. Based on the results, there was a 2% to 11% increase in the angle of friction, and/or cohesion, with the introduction of shredded rubber tires; making it desirable to replace natural soil with rubber tire mixed soil for embankments. The benefit of using recycled materials is that they can be attained easily; they are cost effective, and environmentally friendly.