GEOPOLYMER ARTIFICIAL AGGREGATE FOR CONCRETE FROM UNFIRED DREDGED SLUDGE, FLY ASH AND CERAMIC WOOL, AND THE PROCESS FOR PRODUCING THIS AGGREGATE

Abstract

The invention relates to a geopolymer aggregate for concrete made from unburned dredged mud, fly ash, and waste ceramic wool, and a process for producing such aggregate. The aggregate is in pellet form, made from a mixture of dried and finely ground but unburned activated dredged mud, fly ash, waste aluminosilicate ceramic wool that has been ground, cut, or shredded into short fibers or loose particles, and an alkaline NaOH activating solution of 12 M to 14 M. The waste ceramic wool both adds Si and Al components to the geopolymerization reaction and acts as a reinforcing fiber phase. The process includes the steps of preparing unburned mud, processing the ceramic wool, dry mixing, wet mixing with the alkaline solution, pelletizing, recirculation through the press, low-temperature curing under conditions that limit water evaporation, and further curing in air.The invention allows the use of unburned dredged mud in significant quantities while still producing aggregates that meet the necessary physical and mechanical properties; in the preferred application scheme, this aggregate is used to completely replace natural stone aggregates in Portland cement concrete.

Images