Activity Of Low-grade Fly Ash Provocation Test

This paper recommends the problems about the characteristic and concrete about Power Coal Ash by discussion from the form process of Power Coal Ash to its physical properties and chemical properties. Focused on activate of reactivity of fly ash and the mechanism.Introduce hydrothermal activating and high temperature steam curing method into activation of low fly ash. Specifically, the measures are as follows: Firstly, the cement mortar was selected as test carrier, seeking for activators that showed remarkable result. Secondly, examine the effect of combining activators and getting final prescriptions after optimizing activators dosage by means of orthogonal design. Then take the hydrothermal activating and high temperature steam curing on optimum formula to maximize the potential active of fly ash by the greatest extent. At the same time by means of XRD and SEM to observe and analysis major components and microcosmic frame of the cement mortar, the paper opens out the filling body's microcosmic configuration.The performance of activated cement has remarkably improved; when the mixing amount of fly ash cement was 40%, 3 days flexural strength and compressive strength increase 64.7% and 59.4%, which means early strength of activated silicate cement improves greatly. The results show that fly ash was activated in early hydrate. The performance of activated cement has remarkably improved; when the mixing amount of fly ash cement was 35%, The 3 day's flexural strength and compressive strength increase 64.7% and 59.4%, which means early strength of activated silicate cement improves greatly. The structure of silicon-oxygen and aluminum-oxygen was partly depolymerized into little activated molecular. could accelerate the fracture and depolimerization of low fly-ash vitreous body, The obtained high activity small molecules consumed the hydration product of cement is Ca(OH)2, Thus the more hydrated products owning early strength was appeared, such as hydrate calcium silicate, hydrate aluminum silicate and ettringite. Through the analyzing of modern test means on activated silicate cement, the results show that hydration reaction occurs early and much hydrates of ettringite, Ca(OH)2 etc appears. The SEM photographs of 3d hydrates show that the structure is packed closely and it appears flocculating. It is the function of activator to destroy the six-coordination structure of glassiness, and those depolymerized little molecular joined early hydrating reaction, so the early activation of fly ash was improved. Effect of combining activators and getting final prescriptions after optimizing activators dosage by means of orthogonal design.