Consequences of aircraft operating conditions at military airbases: degradation of ordinary mortar and resistance mechanism of acrylic and silica fume modified cement mortar

Abstract

Concrete pavements at military airbases are often subjected to extreme aircraft operating conditions such as exposure to high thermal shocks and hydrocarbon fluids, which cause premature degradation and loss of strength. As part of this research project, we replicated aircraft operating circumstances, and investigated their consequences on plain cement mortar as well as on a special type of cement mortar that was prepared using cement, acrylic emulsion (AE) and silica fume (SF). All mortar specimens were repetitively exposed to aircraft operating conditions, which involved the application of aviation oils and high temperature for a short period, both separately and simultaneously. Although AE and SF modified fresh mortar showed saponification during the initial stage of hydration and had a detrimental effect on the compressive strength; the modified cement mortar showed significantly better resistance to the considered harsh conditions as determined by the residual compressive strength. Moreover, the crystalline minerals in AE and SF modified cement mortar were less attacked, decomposed, and found more durable compared to the plain mortar under the extreme conditions. Thus, the study elucidates the degrading mechanisms of plain cement mortar and the added resisting mechanisms of better performing AE and SF modified cement mortar under a replicated military airbase circumstances. This study also suggests limiting the dosage of AE into cement mortar to limit the observed negative impact on compressive strength.