Chemical Damage to Airfield Concrete Aprons From Heat and Oils

An increase has been observed of airfield concrete apron distress in the form of surface scaling when the aprons are exposed to cyclic heat, spilled lubricants, and/or hydraulic fluids. Chemical analysis of the damaged concrete reveals that the spilled fluids are undergoing hydrolysis accompanied by the consumption of calcium hydroxide, plus hydrated silicate and aluminate phases. The damage was reproduced in the laboratory on 3 ft x 4 in. thick slabs during 5 weeks of exposure to lubricants and cyclic heat. Use of penetrating sealants, coatings, and/or neutral pH concretes is suggested for pavements exposed to this type of environment.