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Thermal and chemical degradation of Portland cement concrete in the military airbase
conference contributionposted on 2017-01-01, 00:00 authored by Sukanta Shill, S Al-Deen, Mahmud AshrafMahmud Ashraf
© Advancement of Construction Management and Real Estate, CRIOCM 2017.All right reserved. The military airbase especially aprons and the rigid pavement are often exposed to engine oil, hydraulic fluid, Jet oil, extreme heat shocks, and varied lengths of repetitive cyclic heat loading. Oils spillage during maintenance of aircraft on the parking apron or venting of oil from the aircraft after the main engine starting is a common phenomenon and inevitable in the airbase. Considering this, the paper presents the degrading mechanism of ordinary Portland cement (OPC) and Portland limestone cement (PLC) concrete in the parking apron and rigid pavement of military airbase. This study identifies the potentially damaging compounds (hydrocarbons) likely present on the airbase. The chemical reactions between Portland cement and the hydrocarbons and their consequences in the airbase concrete are also presented in the study. The effect of auxiliary power units (APUs) exhaust temperature on the airbase concrete and the combined effect of heat and spilled chemical is explained in the present study. The study reveals that APUs exhaust temperature is sufficient enough to develop thermal cracks in the concrete, as a result, the permeability of concrete increases that allows more chemical spillage in the concrete. The spilled hydrocarbons react greatly with the Portland cement and produce soft salty brittle materials on the top cementitious layer of OPC and PLC concrete that is known as scale. The APUs exhaust temperature accelerates the pace of chemical reaction and the surface degradation process of OPC and PLC concrete in the military airbase.