Effect of Resilient Modulus on Inverted Base Pavements—A Theoretical Study

Inverted base pavement is a new type of pavement structure in which a good quality unbound granular aggregate base (GAB) layer is placed between a stiff cement treated base (CTB) layer and bituminous concrete (BC) layer. Inverted base pavements are being used in many countries due to its various advantages. The major advantage of inverted base pavements over conventional pavements includes thinner BC layer as compared to conventional pavements. Therefore in this paper, an attempt has been made to model an inverted base pavement section using finite element software and predicting its response by varying the resilient modulus of different layers. Though the response of pavement depends on both layer thickness and resilient modulus, this study is limited to study only the effect of resilient modulus on pavement performance. The approach of the study is to develop finite element model using ABAQUS software followed by validation of results of base model in IIT_PAVE software and then to study the response of a typical inverted base pavement using ABAQUS. By varying the resilient modulus of layers, total of 13 cases were considered in this study. The results indicated that BC modulus significantly affects strain values at the bottom of BC layer, GAB modulus affects the BC layer on its surface as well as at the bottom of BC layer and also the subgrade, whereas CTB modulus significantly affects the vertical strain in the subgrade and hence can be used to prevent excessive deformation problems in inverted base pavements.