Proposal of an Index for Evaluating the Condition of a Cement-Treated Base Layer Using the Ground Penetrating Radar

Evaluating the underlying pavement conditions can be a challenge on the development of maintenance projects, especially when destructive tests should be avoided. This difficulty is a common topic of discussion, and there are several research pursuing nondestructive alternatives. The present study aimed to validate the Ground Penetrating Radar (GPR) as a complementary tool to evaluate the pavement conditions of a cement-treated base (CTB) layer with critical functional conditions. This chapter presented a case history study developed for a Brazilian road implemented with a semirigid structure roughly 10 years ago and with a long history of maintenance work. A methodology to calculate a pavement soundness index to classify the pavement condition was proposed. The proposed classification combines functional and structural parameters collected on monitoring campaigns with the results of a GPR survey to identify underlying layer conditions and the results of a back-calculation process to determine elastic modulus on each pavement layer. The study proposed a methodology to identify the critical areas on CTB pavements, assisting road managers on diagnostics to stablish correct maintenance strategies.