Novel electromagnetic induction heat curing process of fly ash geopolymer using waste iron powder as a conductive material

Abstract

Geopolymer (GP) was invented to replace concrete, but its heat curing requirement hinders extensive use in real-world construction. Past studies have tested several methods of heat curing. However, the conventional heat curing process (using an oven) is still required for GP to develop good strength on the laboratory scale. This study introduces a new heat curing method for GP based on an electromagnetic field (EMF)generator and a ferromagnetic material. Waste iron powder (WIP) was used as the ferromagnetic material mixed with the fly ash-based GP to generate heat through induction. The sample was cured at 1.18 kW with 150–200 kHz of EMF generator for 15 min. The results showed that 5% of the WIP mixed sample gained compressive and flexural strength at 28 days more than the control (oven-cured). Compressive and flexural strengths of 76.8 MPa and 11.3 MPa were obtained, respectively. In addition, heat induction enhanced the densification and geopolymerization in the GP matrix following SEM and XRD results. This alternative method of heat curing accelerated the formation of the GP matrix, reduced curing time, and increased strength. Moreover, this EMF curing method can save 99.70% of the energy consumed compared to the conventional heat curing method.

Manufacturing Waste for Sustainable Energy Generation: A Comprehensive Review of Current Methods and Future Trends

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Microstructural Analysis of Thermally Treated Geopolymer Incorporated with Neodymium

“…This substance is recognized for its eco-friendliness and is a notable alternative to conventional cement materials. Natural clay, waste, and by-products are widely used as alternative aluminosilicate materials for the synthesis of geopolymers; the use of these products, in addition to obtaining environmentally friendly material, also reduces construction costs [ 5 ]. According to their composition, geopolymers are a class of amorphous materials consisting of cross-linked [AlO 4 ] − and [SiO 4 ] tetrahedra units, and the negative charge aluminum in fourfold coordination is balanced by alkali metal or alkaline earth metal cation, such as Na + , K + , Mg 2+ , and Ca 2+ [ 6 , 7 , 8 , 9 ].…”