Use of Falling Weight Deflectometer Data to Quantify the Relative Performance of Reinforced Pavement Sections

Falling Weight Deflectometer testing was conducted in a Farm-to-Market Road (FM 2), located in Grimes County, Texas. The pavement involves eight different experimental cross sections including control section, base reinforced with 3 different geosynthetic products, lime stabilized subbase and combinations of the latter two. The subgrade is high plasticity clay, which, due to moisture fluctuations subjects the flexible pavement to environmental loading. The objective of this paper is to characterize the possible benefits of the 3 types of geosynthetic reinforcements as well as of lime stabilization and quantify the relative benefits of each stabilization technique. Deflection measurements from 9 field trips conducted from February 2006 to August 2009 are evaluated. Modified deflection basin parameters (DBPs) are defined to identify layer properties and are used to assess the relative damage to the base, subbase and subgrade for different sections. The variations in the DBPs over three periods of wetting and drying are presented along with analysis of the observed trends. In addition, condition survey was performed, during 3 years, to visually identify distresses in various sections. Thus, the deflection data analyses complemented by visual observations reveal the relative field performance of different geosynthetics and throws light on the relative merits of base reinforcement against lime stabilization.