2 May 2025

Mobile Runway Edge Sheave Anchor Criteria in Asphalt Concrete Pavement

Abstract: The Mobile Runway Edge Sheave (MRES) is used in conjunction with the Mobile Aircraft Arresting System (MAAS) for setback aircraft arresting system (AAS) installations in expedient or temporary situations. There are existing criteria and tactics, techniques, and procedures (TTPs) for MRES installations on portland cement concrete (PCC) pavement and soil, but these criteria have not been developed for asphalt concrete (AC) pavements. The US Air Force Civil Engineer Center (AFCEC) tasked the US Army Engineer Research and Development Center (ERDC) to develop anchor criteria for the MRES in AC pavement and to perform full-scale load testing on the MRES to evaluate system response under representative loads. Three anchor stake layouts were evaluated under static and cyclic loading conditions: a 32-stake layout, a 16-stake layout, and an 8-stake layout. Elastic-plastic deflection data from the three test series were comparatively analyzed and show that the performance of the 16-stake layout was similar to that of the 32-stake layout for the given loading condition and pavement structure.

29 May 2024

Finite Element, Petrographic, and Mechanical Analyses of Field-Cored Concrete Fairlead Beam Anchor Rods from Luke Air Force Base

Abstract: The fairlead beam is used to accomplish installation of the Barrier Arresting Kit 12 energy absorber for setback aircraft arresting system (AAS) installations at permanent operating facilities. Typical fairlead beams are affixed to a Portland cement concrete (PCC) foundation pad by a series of anchor assemblies made up of steel anchor rods set in grout inside galvanized pipe sleeves. US Air Force Civil Engineering Center (AFCEC) subject matter experts have identified a pattern of premature failures in these steel anchor assemblies when they are nondestructively inspected during AAS overhauls. The US Army Engineer Research and Development Center was tasked by AFCEC to investigate potential reasons for these premature failures. This report outlines methods and results of a finite element analysis of the anchorage, a visual and petrographic analysis of field-cored PCC anchor rods from Luke Air Force Base, and a mechanical analysis of specimens taken from the anchor rods within the PCC cores. Multiple modes of PCC distress were observed, and corrosion was evident in and around the anchor assemblies. Mechanical testing of specimens from the anchor rods indicated that an inferior grade of steel was used to fabricate these particular assemblies. Finally, observed deviations from design intention are discussed.