Accession Number : ADA260937


Title :   Damage of Concrete Parking Aprons From Auxiliary Power Unit (APU) exhaust and Spilled Jet Oils


Descriptive Note : Interim rept. Jun-Sep 91,


Corporate Author : AIR FORCE CIVIL ENGINEER SUPPORT AGENCY TYNDALL AFB FL


Personal Author(s) : McVay, Michael C ; Murfee, Jim ; Manzione, Charlie W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a260937.pdf


Report Date : Apr 1992


Pagination or Media Count : 28


Abstract : The precise cause for concrete damage observed in the vicinity of parked B-1 and F/A-18 aircraft has been determined. The combination of downward- directed auxiliary power unit (APU) blast and spilled aircraft oils are responsible for the scaling observed at these sites. Laboratory tests confirmed that ester-based lubricating oils and hydraulic fluids are chemically reacting with the calcium hydroxide in the concrete and destroying the mortar-aggregate bonds. The cyclic heating of the pavement by the APU greatly accelerates the reaction and facilitates the mixing and refluxing of aircraft fluids with the aqueous calcium hydroxide present. A variety of sophisticated tests were conducted to verify these findings, including X-ray diffraction and mass spectroscopy. In addition, the damage observed at military installations was duplicated under controlled laboratory conditions. After five weeks of subjecting a test slab to cyclic heat and jet oils, damage similar to that observed in the field was produced.


Descriptors :   *HYDRAULIC FLUIDS , *LUBRICATING OILS , *EXHAUST GASES , TEST AND EVALUATION , CALCIUM , LABORATORY TESTS , AIRCRAFT , DAMAGE , X RAY DIFFRACTION , CONCRETE , PAVEMENTS , MASS SPECTROSCOPY , HEATING , POWER EQUIPMENT , FLUIDS , LABORATORIES , MIXING , POWER , HYDRAULICS , ESTERS , MORTARS , BLAST , HYDROXIDES , OIL SPILLS


Subject Categories : Ceramics, Refractories and Glass
      Construction Equipment, Materials & Supplies


Distribution Statement : APPROVED FOR PUBLIC RELEASE