Mechanical and thermo-chemical degradation of concrete exposed to simulated airfield conditions

Surface degradation at parking aprons of military airfields concerns jet aircraft safety. It is caused by the disintegration of coarse aggregates in concrete. This study aims to understand the effects of repeated exposure to various aviation oils and high-temperature on concrete constituent materials. An airfield exposure condition was created to expose samples made with different water to cement ratios (w/c). Samples were tested for residual mechanical properties, thermal conductivity, specific heat, thermogravimetric and microstructural analysis. Results show that the w/c ratio of concrete significantly influences the residual strength of the exposed samples. Moreover, aviation oils react with ordinary concrete at higher temperatures and produce harmful salts. Besides, thermal incompatibility between the aggregates and cement paste triggers microcracks in cement paste and thermal cracks in the coarse aggregate. Due to the simultaneous thermal and chemical attack, concrete suffers the disintegration of aggregates and flake-like concrete pieces on the top surface.