Evaluation of surfacing materials for firm base tactical airfields : bare base support
Burns, Cecil D.; Brabston, W. N. (William Newell)
Miscellaneous PaperAbstract: The objective of the project reported herein was to find a means of rapidly establishing surfacing on a stable base on tactical assault airfields. Specifically, it was desired to evaluate several types of production and experimental membranes to determine the ability of each membrane to withstand the abrasive and tearing effects caused by aircraft tires during ground operations of fighter and heavy cargo aircraft. The objective was accomplished in two general steps. First, related programs and research conducted by the U.S. Army Engineer Waterways Experiment Station (WES) were examined to determine existing or potential techniques or materials that could be adapted to the Bare Base requirements for surfacing, and secondly, field tests were conducted on the items selected. Investigations conducted for the U.S. Army Materiel Command indicated that WX18, a four-ply neoprene-coated nylon membrane, was capable of withstanding C-130 traffic; thus this membrane was a primary test item. Other materials selected for testing included T16 single-ply neoprene-coated nylon membrane, T1 vinyl-coated duck membrane with a double bituminous surface treatment (DBST), and an 11-mil-thick high-strength steel membrane. Field tests consisted of subjecting the surfacings to locked-wheel skid and short-radius turn tests utilizing equivalent F-4C and C-130 aircraft wheel loads. Equivalent F-4C loads consisted of a 25,000-lb single-wheel load (SWL) on a 30x11.5, 24-ply rating (PR) tire inflated to 250 psi. Equivalent C-130 loads consisted of a 30,000-lb SWL on a 20x20, 22-PR tire inflated to 100 psi. Initial locked-wheel skid tests utilizing F-4C loadings were conducted. on a subgrade designed for static and rolling F-4C wheel loads (strength of top 12 in. of soil was approximately 24 CBR). However, the additional load generated by the locked-wheel skid tests caused severe rutting and subsequent immobilization of the load wheel. Subsequent tests were conducted successfully in areas having a higher subgrade strength (strength of top 12 in. of soil was 45 to 50 CBR). All materials were subjected to one or more locked-wheel skid tests using F-4C loads. WX18, the only membrane that withstood the initial tests, was subjected to locked-wheel skid loads using C-130 loads and to short-radius turn tests using F-4C loads; The WX18 membrane successfully withstood all the tests, although the neoprene coating was worn off the WX18 in several areas. The T16, T1 with DBST, and 11-mil steel membranes ruptured during skid tests with F-4C loadings. From the results of this study, it was concluded that: (A.) WX18 membrane can be used as an expedient surfacing material on an assault airfield having adequate soil strength and will withstand the abrasions of ground operations of fighter and heavy cargo aircraft. However, minor maintenance will be required in areas subjected to severe abrasions. (B.) T1 overlaid with DBST, T16, and 11-mil steel membranes cannot withstand the abrasive effect of locked-wheel skids of fighter aircraft. (C.) The soil strength stipulated by design criteria for assault fields based on static and rolling loads may not be adequate in all cases to provide surfacing that will withstand the increased loads caused by locked-wheel skids. Therefore, additional investigation should be conducted in this area. NOTE: This file is large. Allow your browser several minutes to download the file.
U.S. Army Engineer Waterways Experiment Station.Engineer Research and Development Center (U.S.)
Aircraft landing areas; Airfields; Expedient surfacing materials; Membranes; Runways; Coated fabrics; Trafficability
Approved for public release; distribution is unlimited.