Long-Term Field Evaluation of a Geosynthetic-Stabilized Roadway Founded on Expansive Clays

Abstract

This paper presents an evaluation of the long-term field performance of Farm-to-Market Road 2, the construction of which involved geosynthetic stabilization to address concerns related to the presence of expansive clays and associated environmental loads. A comprehensive study was conducted to quantify the benefits of geosynthetic stabilization in the performance of the roadway after having been subjected to 9 years of wet and dry season cycles. Control sections and seven design schemes (including various combinations of geosynthetic-stabilized base and lime-stabilized subbase courses) were incorporated in 32 test sections. Evaluation of the development of environmental longitudinal cracks over the 9-year period showed that the use of geosynthetics to stabilize the roadway base led to a significantly improved performance, as quantified based on the extent and length of environmental load–induced longitudinal cracks. The improvement, observed for all the geosynthetics considered in this study, was found to be more significant during dry seasons, which is when environmental longitudinal cracks develop. In addition, results from the field performance monitoring program revealed that lime stabilization of the subbase not only did not help but generally compromised the performance of road sections subjected to environmental loads.