Geopolymer mortar durability under coupled effects of jet exhaust and chemical oils

Frederick Funnell


Degradation and scaling is occurring on Portland cement aprons that house Air Force aircraft. This phenomenon is attributed to the coupled effects of heat exhaust from jet engines and exposure to aviation oils from normal operation/maintenance. Geopolymer mortar based on alkali activated fly ash has been proposed as a top layer patch to protect the Portland cement aprons. Whilst there has been extensive research into heat and chemical resistance separately the coupled effect is not well understood. The mix design affects the mortar’s durability and can be explored experimentally through testing multiple variations of the mix design under the same conditions. Through the variation of the fly ash range and fly ash to alkali liquids ratio their effects on durability can be observed. This research intends to correlate the number of experimental exposures to the test conditions and the scaling resistance of the mortar. The primary findings were that 80 cycles of the test conditions did not induce scaling of the geopolymer mortar, a saponification reaction occurred that reacts in the test conditions possibly weakening the strength of the mortar and the alkali quantity effects this reaction’s intensity. The primary aim of this research is to determine which mixture proportions effect the durability of geopolymer mortar and it has been identified that the alkali to fly ash range impacts durability significantly.

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