In the article the questions of application of the mining waste: dropout of quartzite sandstone crushing as filler in the fibre concrete production were considered. Composite binders based on cement and dropout of quartzite sandstone crushing were also developed. The effectiveness of composite binders’ usage consisting in improving the physical and mechanical characteristics and reduction of their prime cost compared to the cement with a slight increase in the complexity of their production was proved. The compositions of concrete dispersed reinforced with steel wave fiber and without it were developed. The efficiency of the use of dispersed reinforcement of fine-grained concrete is proved, which consists in improving the performance characteristics.
Manufacturers of building materials strive to optimize the three basic concrete properties—strength, durability, and shrinkage deformation, of which the focus is generally on the durability in the structure when designing and monitoring the poured concrete. Studying concretes’ structural performance and the change in their characteristics over time enables the solution of many important issues associated with the design of reliable, durable, and cost-effective buildings and structures. This article presents studies aimed at improving the physical, technical, and operational characteristics of cement concrete and reducing cement consumption in heavy concretes through the use of complex modifiers and volumetric fiber reinforcement. Four concrete compositions of widely recognized grades were developed, of which samples were molded and tested for compressive and flexural strength, frost resistance, volumetric water absorption, and density. Test results confirmed the possibility of binder (cement) economy up to 18% and increasing frost resistance up to W300 when using microsilica, reduction in volumetric water absorption of up to 40% when using both microsilica and hyperplasticizer, and increasing flexural strength by over 30% when using polymer fiber. The developed compositions passed the industrial tests, and were successfully introduced in the production process of the operating reinforced concrete products’ manufacturer.
Fullerenol-d C 60 (OH) 22−24 was synthesized by the method of direct heterogeneous oxidation of fullerene C 60 , dissolved in o-xylene, by NaOH, dissolved in water, in the presence of interphase catalyst t − (C 4 H 9) 4 N OH. Identification of fullerenol-d was provided by: C-H-N elemental analysis, High performance liquid phase chromatography, IR-and Electronic spectroscopy, Mass-spectrometry. The antioxidant properties of aqueous fullerenol-d solutions were investigated against free radicals, generated by hydrogen peroxide and molecular I 2. Measurement of fullerenol antioxidant activity was based on the potentiometric titration of fullerenol solutions by hydrogen peroxide and molecular I 2 solutions and vice versa with compact Pt as working electrode. As a comparison, the very popular and strong anti-oxidant-ascorbic acid was used. Pourbaix Diagrams (pH − Eh) for hydrogen-oxygen and iodine forms were constructed. Fullerenol-d is a weaker antioxidant than ascorbic acid, but in contrast, fullerenols-d molecules are able to undergo multiply reversible absorption-desorption of some free radicals.
The necessary fiber content in the first place is determined by the requirements of bending strength and resistance to dynamic loads. The fiber content depends on the composition and consistency of concrete, fiber properties and mixing techniques. The most widespread types of fibers, their advantages and disadvantages, possible areas of their application are considered. Fibers whose modulus of elasticity is greater than the modulus of elasticity of a concrete matrix, such as steel fibers or glass fibers, increase the workload on the cracks.
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