On the compressibility of tire-derived aggregate: comparison of results from laboratory and field tests

Abstract

Compression behavior of tire-derived aggregate (TDA) was investigated through relatively small-scale and large-scale laboratory one-dimensional compression tests, as well as a full-scale field test. Two types of TDA produced from passenger and light truck tire (PLTT) and off-the-road (OTR) tire were tested. The influence of initial void ratio (e0), particle size, tire source, and testing method on the compression behavior of TDA was investigated. The results indicated that the compressibility of TDA was primarily dominated by its e0. OTR yielded lower e0 than PLTT with similar particle size and the same compaction method. TDA in the field was pre-compressed by self-weight, resulting in lower e0 and compressibility compared with laboratory samples. At relatively high stress levels, all TDA exhibited similar void ratio–stress curves regardless of e0, particle size, tire source or testing method. High e0, small particle size, and granular particle shape facilitated the sliding and rolling of TDA particles, resulting in high plastic strain. The elastic deformation of TDA, reflecting the elastic behavior of tire rubber, was primarily dominated by the average contact area ratio of the TDA particles, depending mainly on the sample void ratio.