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The opportunity of application of natural aluminosilicate – perlite – as reactive mineral admixture and as individual binding component when production of construction materials.

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the efficiency of traditional raw materials using as well as expanding of potential uses for non-conventional and alternative raw materials with different origin is the tasks exiting interest among material scientists and manufacture stuff. Investigation of the above is oriented on solution of such scientific problem as more deep understanding of structure and features of material. The results obtained also allow solution of some technological, technical and economical tasks. Greatly, it is actual when using of new types of raw materials as well as when synthesis of new composites. Concerning the construction material science field, the classic problem is the looking for ways to study the reactivity of raw components under different conditions, its control and, generally, its increasing to produce higher performance materials. Among the popular and widely-used construction materials are alkali-activated binders and relevant composites. In this study the results of granulometric analysis of suspension based on alkali-activated aluminosilicate with different crystallinity degree are presented. It was found, when treatment of aluminosilicate grain by alkali activator leads to the grain solubilizing (but differently depending on crystallinity degree of aluminosilicate) and formation of alkali-aluminosilicate gel that reacts with unreacted part of the grain according to structure affinity principle. It was also determined the crystallinity degree of aluminosilicate component is inversely proportional to its solubility in highly-alkali environment. The model of structure formation for geopolymer system under alkali effect is offered.

A large amount of research publications and analytical data, concerning gypsum-bearing wastes (GSW) gives an understanding of their huge volumes in many countries, as well as the urgent need to find solutions and opportunities that open up in the development and implementation of effective technologies for the disposal of GSW in various areas of the construction industry. In this paper, the review of actual technological approaches for recycling of GSW in the framework of such field of utilization as a gypsum binder production. It was found, that application of traditional technologies of synthesis of binders, containing natural raw materials is not reasonable for GSW-bearing binders due to variation in component composition, high concentration of impurities, and high dispersion. For this reason, the most advanced technologies proposed by various researchers provide for measures to correct these shortcomings or involve the synthesis of the final product - a high-quality gypsum binder, which is based on different principles - growing crystals of the desired geometry and properties in salt and acid solutions. These technologies are characterized by complexity, a negative impact on equipment, and personnel. In addition, they lead to the formation of secondary waste, which reduces the attractiveness of their practical implementation. Synthesis of GSW-bearing binders using the method of calcining is the simplest technologically and organizationally, but the binders are characterized by unsatisfactory physical and mechanical properties. The desired way to increase their profitability and investment attractiveness is the possibility of providing comprehensive processing of raw materials, where the final product will be not only binders but also other conditioned products, taking into account the minimum formation of secondary waste. The development of such technology of GSW recycling and its implementation on a commercial scale will allow increasing the volume of GSW recycling as well as to solve the ecological aspects and to expand the raw materials source base in regions where this problem is actual

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This research focuses on an evaluation of mineral phase and structure transformations in Class F fly ash-based geopolymer systems. The research also studies the strength response of geopolymers when exposed to temperatures between 25 and 800 °C. The purpose of this research is to understand the processes that occur in alkali-activated systems within a wide range of high-working temperatures. The XRD, SEM, and DTA/TG analyses performed for the alkali-activated compositions after exposure to different temperatures confirmed a direct correlation of structural transformations with strength performance. The detrimental effect of sodium hydrocarbonate Na3(HCO3)(CO3) 2H2O or trona contained in one of the fly ash products was observed for the corresponding alkali-activated composite under high-temperature exposure between 600 and 800 °C. It was also detected that a high-temperature interval of 400–800 °C created favorable conditions that helped to form nanosized nepheline crystals and an additional vitreous substance that also contributed to a denser alkali-activated matrix.

Nowadays geopolymer is promising and relevant material that can be effectively used in wide range of application areas. It is possible because of there are a lot of potential sources of raw materials for geopolymer synthesis. Raw components are the one of the key parameters that effect on geopolymer performance. On the other hands, the technological stages of geopolymer synthesis is no less important factor. The purpose of this study was to determine effect of technological parameters of geopolymer synthesis such as component composition of solid state phase, alkaline activator preparation and its introduction onto geopolymer paste as well as curing temperature on performance characteristics of geopolymer. Fly-ash based geopolymer samples were prepared with adding of different mineral components: Portland cement (PC), kaolin, metakaolin; different curing temperature conditions: ambient temperature and temperature treatment at 70 °C in oven during 24 hours; different methods of preparation and application of alkaline activator: using of fresh alkaline solution and using alkaline solution after 24 hours of cooling. The results show that efficiency of curing temperature conditions strongly depend on component composition of geopolymer paste. Samples, containing PC and metakaolin demonstrate better characteristics after curing under ambient temperature. Samples, containing kaolin and reference composition (fly ash only) the temperature treatment in oven is the best curing method (increasing in compressive strength up to 13 times). Using alkaline solution of NaOH after 24 hours of cooling gives a good effect on geopolymerization process and provides increasing in compressive strength value from 13 to 84 % for all experimental geopolymer pastes. However, average density for all compositions is varied slightly.