ABSTRACT
The ability to quantify the performance benefits of geosynthetic inclusions in granular pavement layers is a unique challenge. Geosynthetic products in the current market have varying aperture sizes, material types, and manufacturing processes that intend to improve pavement performance through a variety of mechanisms, making quantification of the potential of individual geosynthetic products and the development of a universal design procedure problematic. One approach to quantifying performance benefits is the assessment of geosynthetic inclusions in full-scale testing. While it could be argued that full-scale evaluations provide the most realistic assessment of anticipated performance, full-scale experiments can be logistically burdensome and, at times, cost prohibitive. On the other hand, large-scale laboratory box testing reduces the amount of required materials, reduces required testing time, and reduces required capital investments. Large-scale laboratory box testing has been used for well over 30 years to investigate geosynthetic stabilized pavement structures with well-documented success. However, a comprehensive testing program to assess the repeatability of large-scale laboratory box testing has not been conducted. In the absence of a comprehensive testing program, two historical studies with multiple test items conducted at the U.S. Army Engineer Research and Development Center were selected to assess the repeatability of current large-scale laboratory test procedures. The two historical studies included multiple pavement profiles representative of both a thick airfield pavement subjected to heavy loading conditions and an aggregate-surfaced pavement subjected to highway loading conditions. The assessment of the test procedure included a statistical and engineering evaluation of the reported surface deformation data to estimate repeatability in large-scale box test results and an investigation of potential sources of variability that could influence performance outcomes. The results of these assessments of the large-scale laboratory box experimental procedure represent an initial step to identify expected variability in large-scale box testing.
