Dynamic Characterization of Tire Derived Aggregates

Abstract

Despite the recent efforts in characterizing and investigating the dynamic properties of tire-derived aggregates (TDA) and its use in civil engineering applications, the size of TDA used in most of the previous work was significantly smaller than the TDA size range mentioned in ASTM D6270 standards. There are two types of TDA, Type A and Type B, in which the maximum aggregate size of Types A and B are 200 and 450 mm, respectively. Thus, the availability of experimental data and shear modulus reduction curves for the dynamic behavior of TDA of larger sizes are deemed necessary for practical engineers to assess and investigate the behavior of such material under dynamic loads. This paper provides the results of large-scale undrained cyclic triaxial tests performed on Type A TDA at large strain amplitudes. The tests were performed under confining pressures ranging from 25 to 200 kPa and shear strain levels ranging from 0.1% to 10%. Furthermore, each test consisted of successive stages in which the number of cycles and axial strain levels varied. The shear modulus of Type A TDA has a range of 245–1,796 kPa, with a decreasing trend with increasing shear strain amplitudes. Furthermore, the dampening ratios were found to range from 11% to 23.5%. Finally, the shear modulus reduction curves were obtained through curve fitting techniques and nonlinear regression.