Alkalescence Excitated Gelatification On The Rapid Technology Of Full Thickness Asphalt Pavement

Recently, with the development of modern road repair technology and being deeply understood for the Potential effect of fly ash and slag, the study of using high volumes of fly ash and slag in road engineering is paid more and more attention, especially in road repair. However, researches are also indicated that the problem of over—low early strength should be concerned because of high volumes fly ash and slag, if fly ash and slag can be activated through suitable technological way and the distribute of its potential activity can be adjusted during hydrating Period, then the early strength of RAP can be obviously increased, the technology of utilizing fly ash on a large scale will be undoubtedly promoted to be perfect and practical. Meanwhile, the mechanism of activating fly ash and slag is theoretical foundation on the design and application of road repair and difficult point in this field.This article depends on the national key topic—863topic(2009AAHZ106)《Central thchnolegy and equipment of full thickness Asphalt Pavement Cold Recycling》 under the guide of the theory and experiences of foreign study about it. This paper focuses attention on the investigations of fly ash and slag activator. Chemical measure was taken to activate fly ash and slag. Firstly, the worn asphalt admixture was selected as test carrier(fly ash50%+cement50%, by weight), seeking for activators that showed remarkable result. Secondly, examining the effect of combining activators and getting final prescriptions after optimizing activators dosage by means of orthogonal design. In the system of alkali inspire fly ash-cement base and fly ash-slag base, A/S=1/5～5/5, cement0-8%, fly ash0～10%,slag0～10%alkali0-12%, different RAP component, red clay and sandy soil have better performance.The results show that fly ash was activated in early hydrate. The structure of silieon-oxygen and aluminum-oxygen was partly depolymerized into little activated molecular. And the net-modified ion (such as K, Na)or net-neutral ion (AI) from activator destroyed low activated glassiness in fly ash. Thus the more hydrated products owning early strength was appeared, such as hydrate calcium silicate, hydrate aluminum silicate and ettringite.