Water Ingression and Compression Properties of Epoxy Containing Ash Particles withtheri Surfaces Containing Paraffin Oil film

摘要

Epoxy system having 10% by vol.of fly ash fillers withtheir surfaces covered by paraffin oil was made and the responses to exposure by immersion in watr at 75 deg C in one case and water containing smaller amounts of dilute acid in the other were monitored.Weight recordings up to 100h were noted regularly on the test coupons exposed to the two media.The samples exposed to 100h duration were later on subjected to compression test to evaluate the strength.In one case,a set of samples were immersed in water for a prolonged period of 1000 h before subjecting these also to compression tests.The result showed increased absorption in acid bearing medium.The strength of the plain water exposed smaples wer lower htan the dry counterparts.samples that had an immersion in medium containing acid showed a further but marginal plain wate rimmersed sampel exhibited considerable drop in strength.These are dexplained using scanning fractography where surface features of compression failed samples are recorded.The plain water as well as the acid media exposed ones show a plasticised matrix and in some places a cavity-like feature,left by the separating ash particles,whose number showed a perceptible increase for the acid bearing system compared to the plain wate rcase.Longer exposed samples showed the loss of fly ash due to the surface of the matrix holding them showing a step-like expanded appearance indicating th einterfacial regions being affected by the prolonged exposure time.These and other features are dicussed in this report.