Fly ash concrete, its composition, process for its preparation by geopolymeric reaction of activated fly ash and use thereof

摘要

The present invention relates to fly ash concrete without cement wherein the preparation process thereof is characterized in that synthesis of geopolymers takes place due to alkali activation of a fly ash mixture at a temperature ranging from 40 to 80 degC, preferably with an alkali activator of water glass solution Nai2SiOi3 in an amount of 6 to 12 percent of dry matter to the weight of fly ash, and sodium hydroxide NaOH in an amount of 4 to 8 percent of dry matter per fly ash weight. In order to enhance consistency of the fly ash concrete it is possible to add water up to the total water coefficient water in solutions and water added, wherein {SIGMA}.v/pop equals to w 0.45 to 0.6. Free setting time after mixing of the fly ash concrete and subsequent thermal activation has positive effect on strength. By the amount of fly ash relative to aggregates, it is possible to regulate not only consistency of the fresh fly ash concrete, but also resulting strength and resistance to aggressive environment thereof.