Finite-Element Analysis of Highway Embankment Made from Tire-Derived Aggregate
Tire-derived aggregate (TDA) has been used in many civil engineering applications. Despite its successful use in the past, the amount of experimental research available on TDA applications is not sufficient to provide data for the evaluation of an appropriate constitutive model. The majority of TDA constitutive models have been developed from laboratory tests performed on tire chips smaller than those used in field applications. In this study, nonlinear elastic material models, with an elastic modulus that varies as a function of vertical stress, have been developed for TDA produced from passenger and light truck tire (PLTT) and off-the-road (OTR) vehicle tires. The material model for TDA is established based on previous large-scale laboratory constrained compression tests conducted on TDA up to 300 mm in size. The model is used in a finite-element (FE) analysis using geotechnical software to predict the settlement of full-scale test embankment during construction. The results indicate that the settlements obtained from the FE analysis agree with the settlements measured in the field during construction of full-scale test embankment. This paper also provides design charts to compute overbuild required on top of TDA layer(s) to compensate immediate compression under an applied load during the placement of cover on top of TDA.