Glass powder and high-calcium fly ash based binders - Long term examinations

Fly ash and glass cullet - two materials, which are produced in quite large amounts. This paper presents the new way the high calcium fly ash (HCA) and the industrial glass waste powder (GP) disposal in building materials technology as main components of binders. Samples were examined over the period up to 6 years of maturity. There were used only two kinds of waste materials (GP + HCA) and water to produce pastes. Fine grinded glass was used as alkaline activator. The HCA was used to induce alkaline activation and dissolution of the glass powder in HCA - GP mixtures. Materials were mixed in three different proportions to prepare the samples. The mechanical strength, microstructure, phase composition and expansion were examined. Results showed that the HCA in connection with GP gave a good alkali activated binding materials for some special applications. In addition to that, the GP + HCA mixtures could be prepared with neither Portland cement nor any additional activator using exclusively waste materials. This is important for the perspective of reducing the CO2 emission. Presented materials were prepared. This is the first work which presents the usage of GP as an alkali activator. (C) 2019 Elsevier Ltd. All rights reserved.