Assessment of Repair Quality in Airfield Pavement Restoration Using Surface Profiling Devices

Abstract: The assessment of pavement surfaces following repairs, especially craters in military airbases, is critical for maintaining the structural integrity and operational safety of airfields, for both military environments and civilian airports. This study investigates alternative methods for evaluating pavement surfaces post-repair, focusing on profile measurement procedures and the existing deflection Repair Quality Criteria (ROC). The research aligns with relevant Department of Defense (DoD) and the Federal Aviation Administration (FAA) standards, including Tri-Service Pavements Working Group (TSPWG), Unified Facilities Guide Specifications (UFGS), and Advisory Circular (AC), to potentially refine or revise these guidelines.
A full-scale pavement test was conducted at an airbase located in the U.S. to compare the effectiveness of different profiling methods. The analysis aimed to address the lack of specific guidance for evaluating small repaired areas within airfield pavements, an issue that current procedures, such as International Roughness Index (IRI) or Profilograph Index (PI), which was designed for highway pavement conditions or longer pavement sections (> 500 feet), fail to adequately address. To this end, this study adopted procedures for the Boeing Bump Index (BBI) computation for small pavement area repairs less than 500 feet, as it is designed to measure aircraft response to surface irregularities that could lead to its fatigue failure. Software capable of simulating aircraft response was identified and used to compute the G-force of selected aircraft over small repaired areas or simulated small repaired areas with shorter wavelengths. The findings from the pavement tests revealed significant differences in performance across the three profiling methods evaluated: a 12-foot Straightedge, customized Straight Bar, and a Walk-Behind profiler. While the inertial profiler, mounted on a survey vehicle, enables rapid data collection over full-length runways, it suffers from lower accuracy and repeatability, particularly in localized repair areas such as craters or patches. Moreover, it requires extensive manual processing to extract data specific to repair sites, making it unsuitable for sections shorter than 500 feet or those involving localized repairs. Conversely, the Walk-Behind profiler provided better repeatability and accuracy, though at the cost of increased measurement time comparing to the inertial profiler. One of the key insights from this study is that the current deflection threshold, used as a quality criterion for small area repairs such as craters, is overly conservative based on the materials and structural configurations tested. This finding suggests a need to adjust the threshold to better reflect more realistic conditions, improving both the accuracy and efficiency of pavement evaluation. Ultimately, the study’s results will inform revisions to airfield pavement guidelines concerning smoothness and roughness evaluations for small pavement areas in new and in-service pavements, respectively. The research underscores the importance of selecting appropriate profiling tools and thresholds to optimize maintenance and repair outcomes, contributing valuable insights to Quality Assurance (QA)/Quality Control (QC) procedures in airfield pavement management.