The foamed geopolymers are promising alternative to other foamed materials. The article presents the method of its production and the results of the research on such materials produced from fly ash from CHP plant. It provides and analyses the strength and thermal conductivity of the expanded geopolymers. It also determines the relationship between the thermal conductivity and density of foamed geopolymers. The density of the obtained materials ranged from approx. 400kg/m3 to 650kg/m3. The research results confirm that the foamed geopolymers produced from fly ash from CHP plant have reasonable mechanical properties and performance of a construction product

This study was conducted to investigate the influence of various reaction conditions, namely the silica modulus SiO₂/Na₂O, H₂O/Na₂O molar ratio, and liquid/solid ratio on the geopolymerization reaction of the waste fired clay bricks (Grog). The starting raw material and the generated geopolymer specimens produced by different geopolymerization reaction conditions have been characterized using different techniques: X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and thermal analysis. Furthermore, physico–mechanical characterization has been carried out through the determination of bulk density, porosity, water absorption, and compressive strength for each sample at interval curing times of up to 28 days. The results indicated that the geopolymerization system of the waste fired clay bricks is influenced by the investigated reaction conditions at room temperature. The compressive strength of the geopolymer sample produced at optimum conditions increased significantly by up to 37.5 MPa, in comparison with 4.5 MPa for other conditions. Finally, an optimum recommendation and useful conclusions concerning the recycling and utilization of this waste material through the geopolymerization process are made for compatibility with construction applications.

The main objective of this article is to develop ceramic-based materials for additive layer manufacturing (3D printing technology) that are suitable for civil engineering applications. This article is focused on fly ash-based fiber-reinforced geopolymer composites. It is based on experimental research, especially research comparing mechanical properties, such as compressive and flexural strength for designed compositions. The comparison includes various composites (short fiber-reinforced geopolymers and plain samples), different times of curing (investigation after 7 and 28 days), and two technologies of manufacturing (casted and injected samples—simulations of the 3D printing process). The geopolymer matrix is based on class F fly ash. The reinforcements were green tow flax and carbon fibers. The achieved results show that the mechanical properties of the new composites made by injection methods (simulations of 3D technology) are comparable with those of the traditional casting process. This article also discusses the influence of fiber on the mechanical properties of the composites. It shows that the addition of short fibers could have a similar influence on both of the technologies.

Over the last several years, there has been a large increase in interest in geopolymer materials, which are usually produced from waste materials, and their applications. The possibilities of application of geopolymers seem to be unlimited, and they are used in almost all fields of technology. Their use as insulation materials appears promising due to their complete nonflammability and excellent strength. However, one limitation is their complex manufacturing process and lack of stability of the obtained geopolymer foams as well as difficulties in achieving such good insulation properties possessed by polyurethane foams, polystyrene, and wool. Hundreds of studies have already been performed on insulating geopolymer foams and various types of foaming agents, and their authors reported that foamed insulating geopolymers had a density starting from 200 kg/m³ and thermal conductivity from 0.04 W/mK. However, the repeatability of the obtained results on an industrial scale is questionable. It is still a challenge to obtain a geopolymer material with comparable properties as conventional insulation materials and to overcome the barriers associated with the successful implementation of geopolymer material as insulation in buildings and other applications on a mass scale. This paper provides a comprehensive review of the methods used for the production of foamed geopolymers and the best parameters obtained, as well as a summary of the most important information reported in the scientific literature. It also presents the results of a critical analysis of the feasibility of implementing this technology for mass deployment. In addition, the problems and limitations that are most often encountered with the implementation of geopolymer technology are discussed.

Nowadays, one very dynamic development of 3D printing technology is required in the construction industry. However, the full implementation of this technology requires the optimization of the entire process, starting from the design of printing ideas, and ending with the development and implementation of new materials. The article presents, for the first time, the development of hybrid materials based on a geopolymer or ordinary Portland cement matrix that can be used for various 3D concrete-printing methods. Raw materials used in the research were defined by particle size distribution, specific surface area, morphology by scanning electron microscopy, X-ray diffraction, thermal analysis, radioactivity tests, X-ray fluorescence, Fourier transform infrared spectroscopy and leaching. The geopolymers, concrete, and hybrid samples were described according to compressive strength, flexural strength, and abrasion resistance. The study also evaluates the influence of the liquid-to-solid ratio on the properties of geopolymers, based on fly ash (FA) and metakaolin (MK). Printing tests of the analyzed mixtures were also carried out and their suitability for various applications related to 3D printing technology was assessed. Geopolymers and hybrids based on a geopolymer matrix with the addition of 5% cement resulted in the final materials behaving similarly to a non-Newtonian fluid. Without additional treatments, this type of material can be successfully used to fill the molds. The hybrid materials based on cement with a 5% addition of geopolymer, based on both FA and MK, enabled precise detail printing.

This paper concerns the recycling of waste material from wind turbine blades. The aim of the research was to determine the possibility of using ground waste material derived from the exploited structures of wind turbines as a filler in geopolymer composites. In order to determine the potential of such a solution, tests were carried out on three different fractions originating from the ground blades of wind turbines, including an analysis of the morphology and chemical composition of particles using SEM and an EDS detector, the analysis of organic and inorganic matter content and tests for multivariate geopolymer composites with the addition of waste material. The compression and flexural strength, density and absorbability tests, among others, were carried out. The composite material made of the geopolymer matrix contained the filler at the level of 5%, 15% and 30% of dry mass. The addition of the filler showed a tendency to decrease the properties of the obtained geopolymer composite. However, it was possible to obtain materials that did not significantly differ in properties from the re-reference sample for the filler content of 5% and 15% of dry mass. As a result of the research, it was found that waste materials from the utilization of used wind power plants can become fillers in geopolymer composites. It was also found that it is possible to increase the strength of the obtained material by lowering the porosity.