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.

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The clay is the basic raw material used in the production of a wide range of ceramic products. However, global guidelines encourage limiting the consumption of natural resources in the production process. For this reason, research is being conducted in developing technologies that enable the production of full-value products by using post-process materials. The article presents the properties of post-production clay sourced from the Jurassic limestone Raciszyn II deposit. In this study, the results of mineralogical (X-ray diffraction) and chemical (X-ray fluorescence) analysis of post-production raw material will be presented. In addition, the leachability in water and the natural radioactivity of the material were established, which determines the possibility of using the raw material in building applications. It was found that, because of the presence of minerals from the kaolinite group in the post-production raw material from Raciszyn II deposit, it is suitable for the production of alkaline-activated materials. However, it was necessary to determine the temperature range of its thermal treatment. The processes occurring in the post-production raw material during its heating were characterised by means of thermogravimetry, differential thermal analysis and mass spectroscopy thermal analysis-coupled techniques. The compressive strength properties of alkali-activated materials, produced from the post-process material from Raciszyn, analysed after 14 and 28 days of curing, were also presented.

The paper presents the results of the study of geopolymer composites reinforced with carbon and aramid fibers. Geopolymers were made on the basis of fly ash activated with 10 mole sodium hydroxide solution with an addition of aqueous sodium silicate solution. The fibers were introduced in the form of a roving. Carbon fibers 800 tex and aramid fibers 805 tex were used. Additionally, to compare the influence of the number of fibers on the properties of geopolymer composites for carbon fiber, 1600 tex fiber was also used. The flexural strength of composites made with the fibers was tested. Fiber reinforced geopolymer composites showed a higher value of flexural strength than unreinforced ones. The higher value was noted for carbon fiber reinforced composites (800 tex) compared to aramid fiber roving composites (805 tex). The study also showed that the application of higher fiber mass in the case of carbon fiber roving does not bring the expected increase in mechanical properties of the composites. The use of carbon fiber roving (1600 tex) resulted in a lower flexural strength than in the case of 800 tex roving. Double increase of fiber mass in the composite caused a decrease in strength parameters.

The main objective of this study is to develop the advanced composites for civil engineering applications as material for the building industry, especially for an insulation purpose. The research processes include several steps. Firstly, the prototype elements, such as bricks and elevation elements were performed from eco-friendly composite -flax fiber reinforced geopolymer. The elements were designed to take into consideration for environment. Geopolymers are environmentally friendly, sustainable, and resource efficient, including energy demand. Next, the wall was built from these elements and exposed during the three months in a relevant environment. The main conclusion of the research is that the kind of fibers is important for the mechanical properties of the composite, including the fact that for those different fibers could be more beneficial for different raw materials, giving higher strength properties. The significant influence on the mechanical properties of the composites has the adhesion between fiber and material used as a matrix. The adhesion depends among others on the previous treatment of the fibers.

The paper presents the results of the study concerning the possibility of immobilization of secondary waste from municipal waste incineration plants in geopolymers. The study was conducted for 2 different sources of ash from Poland and Lithuania. Three different types of waste were tested. Geopolymers were made with 70% added waste from incineration plants. The samples were made in many variants: geopolymers were made on the basis of fly ash and metakoline and waste was added untreated and after washing with water in a ratio of 1:5 (solid/liquid). Compressive strength and water leaching tests were carried out. As a result of the study, geopolymers as a material for immobilization of secondary waste from waste incineration plants were found to be useful. Water leaching tests proved that all the tested wastes stabilized in geopolymers are characterized by very low leachability values of metals suchas: copper, zinc, lead, etc.

The main motivation of research work is connected with environmental issues. The production of the most important building material of the 20th century - Portland cement technology is associated with significant environmental pollution. The process requires very high temperature and it is energy consuming. During the manufacturing also takes place emission of significant amounts of carbon dioxide and highly toxic nitrogen oxides into the atmosphere These factors show that new solution in this area is required. The most promising alternative is inorganic polymer (geopolymer) technology. The main objective of the presented research work was to design a new composite for practical applications, especially in construction industry. The paper presents the results of research of geopolymer composites based on geopolymer binders made of metakaolin and fly ash with the addition of titanium oxide and aluminum-calcium cements (including mainly calcium monoglinate) in amount of 4 and 6% by weight. Research methods applied: tests for mechanical properties (compressive strength tests), scanning microscopy investigations (SEM) and X-Ray Diffraction (XRD). The results show that the addition of aluminum-calcium cements (including calcium monoglinate) significantly increases the compressive strength of geopolymers. Geopolymers based on fly ash with the addition of 6% calcium-aluminum cement with a calcium monoglinate content above 69% are characterized by compressive strength above 50 MPa, while geopolymers from metakaolin with the same additive were characterized by compressive strength above 80 MPa.

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