Research Preparation and Properties of Geopolymer-Based Rapid Repair Materials

摘要

Metakaolin (MK)-geopolymer has rapid coagulation at higher curing temperature, excellent durability, and mechanical properties. The aim of this research was to develop rapid repair materials of MK-based geopolymer cured at room temperature. In this study, portland cement was added to MK to prepare geopolymer. The influences of cement on the water requirement of normal consistency, setting time, bulk density, flowability, consistency, mechanical properties, and reaction mechanism of the geopolymer system were studied. The results showed that the consistency, flowability, bulk density, and mechanical properties of geopolymer were improved, and the setting time is prolonged by mixing a proper amount of cement into MK-geopolymer. When the cement content was 40 %, the strength of the geopolymer was the highest. Scanning electron microscopy and Fourier transform infrared analysis showed that the calcium silicate hydrate gel and sodium aluminosilicate hydrate gel structures overlapped each other and formed compact skeleton structure in the modified MK-geopolymer. The appropriate content of cement can give the geopolymer excellent performance under room temperature, which will contribute to the on-site construction of geopolymer.