Foaming and Physico-Mechanical Properties of Geopolymer Pastes Manufactured from Post-Metallurgical Recycled Slag

• Published in: Materials Vol. 17; no. 6; p. 1449
• Main Authors: Sitarz, Mateusz, Zdeb, Tomasz, Mróz, Katarzyna, Hager, Izabela, Setlak, Kinga
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 21-03-2024; MDPI
• Subjects: Aluminum; Analysis; Chemicals; Composite materials; Compressive strength; Construction industry; Decomposition; Equipment and supplies; Foaming agents; Gases; Geopolymers; Hydrogen peroxide; Image analysis; Image processing; Industrial wastes; Mechanical properties; Parameters; Particle size; Pastes; Physical properties; Porosity; Powders; Production methods; Reagents; Slag; Sodium; Viscosity; Zinc; Netherlands; foamed geopolymer; pore size distribution; industry waste; stereology; porous materials; paste; work of damage
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma17061449

This paper presents a research program aimed towards developing a method of producing lightweight, porous geopolymer composites for the construction industry based on industrial wastes. A direct method involving the addition of chemicals is currently most commonly used to produce the porous mineral structure of a geopolymer matrix. This relies on a reaction in a highly alkaline environment of the geopolymer to produce a gas (usually hydrogen or oxygen) that forms vesicles and creates a network of pores. This paper demonstrates the feasibility of producing a slag-based geopolymer paste foamed with aluminum powder, taking into account different parameters of fresh paste production: the mixing duration, its speed and the timing of foaming agent addition. The foaming process of the fresh paste in terms of the volumetric changes and temperature development of the fresh paste during the curing of the material are observed. After hardening, the physical properties (density and porosity) as well as the mechanical parameters (compressive strength and work of damage) are determined for the nine manufactured foamed pastes. Image analysis software was used to assess the porosity distribution of the material across the cross-section of the samples. The results enabled the design of the mixing procedure to be adopted during the manufacture of such composites.