Structure Of Cement Stone Research Articles

Degradation of Concrete Cement Stone Under the Influence of Aspergillus niger Fungi

The concepts of physical and chemical transformations occurring in cement concrete under conditions of microbiological deterioration can be used to control the processes of the destruction of cement concretes in order to ensure the required durability and to predict the service life of products. The study of changes in the structural and phase composition of cement stone made of Portland cement grade CEM I 42.5N in the process of fungal deterioration for 6 months when moistened, as well as a sample of a concrete wall exposed to fungal microorganisms for 20 years, was carried out. Diffractograms of the studied cement stone samples contain a large number of pronounced narrow peaks and indicate a highly crystalline structure of phases with the presence of an X-ray amorphous phase of calcium hydrosilicates and tobermorite gel in the cement stone. Changes in the structure of cement stone under the influence of fungi are confirmed by the data of a derivatographic analysis. A decrease in the content of calcium hydrosilicates and ettringite, as well as other crystalline phases in cement stone, leads to a decrease in compressive strength by about 15% over 6 months of fungal degradation. Similar changes after 20 years of exposure to microorganisms suggest deterioration in the strength characteristics of concrete.

Developing the composition of fine-grained concrete from the waste of the mining and processing enterprise

The object of this study is fine-grained concrete from the waste of mining and processing plants. These wastes are fine-grained dusty sands of polymineral composition. Their use as an aggregate for concrete is restrained by high water consumption, which does not make it possible to obtain sufficient strength for concrete. Therefore, the problem to be solved was the substantiation of the composition of fine-grained concrete from these wastes with mineral and chemical additives, which would ensure obtaining physical-mechanical and hydrophysical properties reasonable for the production of construction articles. The composition of fine-grained concrete from the waste at the Poltava Mining and Processing Plant and slag Portland cement in a ratio of 3:1 and additives of micro silica (15 % of the cement mass) and polycarboxylate superplasticizer (2 % of the cement mass) with W/C=0.5 was obtained. The compressive strength of this concrete reaches 40 MPa, which exceeds the strength of fine-grained concrete of a similar composition on natural fine-grained sand by 3 times. This is due to a greater degree of cement hydration, a greater number of formed hydration products, the presence of silica and quartz particles, a more uniform alternation of gel, silica particles, and crystal hydrates in the structure of cement stone. As a result, the structure contains a larger number of electro heterogeneous contacts between particles and grains that have negative (quartz, calcium hydro silicates) and positive (crystal hydrates of portlandite, hydro aluminates and calcium hydrosulfoaluminate) surface charges. This is what determines the achieved strength and water resistance of fine-grained concrete. The resulting composition of fine-grained concrete is recommended for the production of construction articles.

Study on the Compatibility of Acrylic Acid-acrylamide-diethyldiallyl Ammonium Chloride Copolymer with Cement Slurry in CO2 Environment.

This paper investigates the structure and aggregation stability of acrylic acid-acrylamide-diethyldiallylammonium chloride (FA367), followed by an investigation into the impact of acidic CO2 environments on the interaction between FA367 and cement slurry. The results showed that FA367 formed stable flocculation in cement slurry filtrate, which was not affected by acid gas CO2. With an FA367 concentration of 0.6%, the fluidity of the cement slurry measures 18.1 cm, but this fluidity is lost upon introducing CO2. At 90 °C, the compressive strength after 1, 3, and 7 days is 10.23, 77.48, and 62.97%, respectively, compared to pure cement. However, with the addition of CO2, the compressive strength increases to 27.03, 99.59, and 75.47%, respectively. The interaction between FA367 and cement slurry impedes cement hydration without altering hydration product composition. Instead, it fosters needle-like aggregations between hydration products, affecting the cement stone's compact structure. Upon CO2 introduction, these needle-like structures diminish, resulting in an overall more intact cement stone structure.

Strength Indicators of Fiber Reinforced Concrete with Carbon Nanomaterials

Concrete composites with low defects, dense and homogeneous, with a high degree of adhesion between the cement matrix and aggregates, as well as a high ratio between static tensile and compressive strengths and plasticity have the best crack resistance characteristics. This ratio increases in the case of the use of fiber-reinforced concrete. Modern research in nanotechnology focuses on the management of matter at the nanoscale level, which makes it possible to create materials with new properties. Due to the high aspect ratio, flexibility, high strength and rigidity, carbon nanotubes (CNTs) exhibit reinforcing properties. Due to their nanoscale features, CNTs interact with a complex network of calcium-silicate-hydrate binder (C – S – H), contribute to a decrease in porosity and compaction of the cement stone structure, increase the shear forces of matrix adhesion in the contact zone. Thus, there are all prerequisites to assert that fiber concrete with a cement matrix modified with carbon nanotubes will have the required high strength characteristics and crack resistance due to multilevel dispersed reinforcement and the efficient operation of fiber in a nanomodified concrete matrix. This article presents the results of testing samples made of cement stone, concrete and fiber concrete with carbon nanotubes. The presence of carbon nanotubes in cement stone contributes to an increase in compressive strength by 11 %, tensile strength during bending by 20 %. The test results of samples made of reinforced fiber concrete modified with nanocarbon materials have shown an increase in tensile strength during bending up to 109 %, tensile strength during splitting up to 82 %, axial tensile strength up to 78 %.

ВЛИЯНИЕ ПЛАСТИФИКАТОРА НА ПРОЦЕССЫ ПЕРЕКРИСТАЛЛИЗАЦИИ ПРИ ТВЕРДЕНИИ ДВЕНАДЦАТИКАЛЬЦИЕВОГО СЕМИАЛЮМИНАТА КАЛЬЦИЯ

The mechanism of structure formation during hydration of duodecalcium semialuminate in the presence of plasticizer is considered. The purpose of the study was to determine the influence of polycarboxylate-based plasticizer on the formation and morphology of the hydrate phases formed. The object of the study was the mineral duodecalcium semialuminate 12CaO-7Al2O3 of stable α-form, having cubic syngony and plasticizer on polycarboxylate basis. The structure of cement stone was studied using X-ray phase and electron microscopic analysis. The mechanism of structure formation during hydration of duodecalcium semialuminate 12CaO∙7Al2O3 in the presence of plasticizer is presented, which consists in the formation of finely dispersed poorly crystallized hexagonal crystals of calcium hydroaluminate. The presence of superplasticizer in the composition of hydrated calcium aluminate slows down the nucleation and growth of crystalline hydrates due to the film formed on the surface of the interface between liquid and solid phases, creating a structural and mechanical barrier, which leads to slower saturation of the liquid phase, but promotes the formation of a greater number of crystallization centers and simultaneous growth of small crystals of both hexagonal and cubic habitus.

ПЕРСПЕКТИВЫ ИСПОЛЬЗОВАНИЯ ОТХОДОВ СТРОИТЕЛЬНОЙ КЕРАМИКИ ПРИ ПРОИЗВОДСТВЕ СТРОИТЕЛЬНЫХ МАТЕРИАЛОВ

The main technological aspects of the production of building ceramics are given. Based on the analysis of literary sources, a comprehensive assessment of the feasibility of using construction ceramic waste as a secondary raw material for the production of new building materials was carried out. Based on the research of modern scientists, it has been established that the waste from the scrap of building ceramics is suitable for use as an aggregate, partial replacement of cement and a reactive additive in concretes and mortars. When using scrap of con-struction ceramics as an aggregate, it is recommended to limit the substitution of natural aggregate at the level of 20-30%, together using various additives: plasticizing and improving rheotechnological and physico-mechanical properties of concrete. Finely ground waste from brick scrap has pozzolan activity and, when used as a reactive additive or partial replacement of cement in concretes and mortars, up to 20-25% can improve the structure of cement stone, increase strength, reduce macroporosity and penetration of chloride ions, and increase sul-fate resistance. This kind of binder is prone to a later set of strength compared to Portland cement. In addition, the waste of building ceramics can be used in the production of alkali-activated cements and slag-alkali binders, as well as s raw materials for the production of new bricks or the construction of road surface bases. It has been revealed that the production of building materials and products based on con-struction ceramics waste is a promising direction for the development of construction production. It is possible not only to obtain materials of equal quality to products based on natural raw materials, but also with improved characteristics.

Features of the Behavior of Highly Frost-Resistant Modified Concretes

One of the main criteria of construction is reliability and durability. Therefore, for the implementation of modern construction projects, especially in harsh operating conditions, cement composites with increased resistance to aggressive external cyclic influences are necessary. For the climatic conditions of the Russian Federation, special attention should be paid to ensuring the frost resistance of concrete. Thus, in accordance with GOST 31384–2017 “Protection of concrete and reinforced concrete structures from corrosion. General technical requirements”, for the lowest temperature and under the condition of alternating freezing and thawing of concrete in a saturated state, the frost resistance mark must be at least F2450. In addition, high mechanical characteristics of the materials used, including the modulus of elasticity, are required, for example, in the construction of infrastructure facilities in the Arctic zone of Russia. To ensure these characteristics, effective modifying additives must be introduced into the concrete mix. However, there is evidence in the literature that water-reducing additives of various genesis, with similar values of water reduction, have different effects on the structure of the formed cement stone. Therefore, in order to ensure high durability of concrete, this article will consider the relationship between the emerging structure of cement stone in concrete and its resistance parameters.

Identifying the influence of basalt fiber reinforcement on the deformation and strength characteristics of cement stone

The object of the research is the quality of cementing oil and gas wells with increasing the strength and deformation capacity of cement stone using basalt fibers. Cement slurry used in cementing oil and gas wells faces the problem of failure under the influence of hydraulic fracturing and perforation procedures. This failure leads to the formation of cracks and may require remedial cementing, which increases operating costs and complicates the process of oil and gas production. Moreover, this problem can lead to premature well water breakthrough and cause serious damage such as oil and gas shows and blowouts, which poses a threat to the environment and safety. To solve the problem of the destruction of cement stone under external influences, the study proposed the approach of reinforcing with basalt fiber. During the study, a cementing material based on Portland cement, reinforced with various concentrations of basalt fibers (0.1 %, 0.5 %, 1 % and 2 %), was developed and tested. Cement strength tests at 2, 7, and 14 days, along with deformation monitoring under load, were performed. The addition of basalt fibers to cement stone significantly improved its strength characteristics. The most successful results were achieved with the addition of 0.5 % basalt fibers, resulting in an 11 % increase in compressive and flexural strength. Basalt fibers complement the structure of cement stone, increasing its ability to deform. One of the key features of the obtained results is the possibility of improving the strength of the cement stone without losing its fluidity as a cement slurry. The results obtained are applicable in the development and production of cement materials based on basalt fibers. This will improve the quality of well cementing and reduce the risks of complications

New insight of solvent-replacement-induced damage to pores of cement stone by comparison with 1H NMR relaxometry, mercury intrusion porosimetry, and nitrogen adsorption

The consensus on the damage to pore structure of cement-based materials caused by solvent-displacement-drying method has yet not been achieved. This work explored the effect of replacing pore water with ethanol, methanol, isopropanol, cyclohexane and acetone on the pore parameters of hardened white cement paste by means of low field NMR, mercury intrusion porosimetry and nitrogen adsorption techniques, with direct-drying (oven-drying and vacuum-drying) as the control. The results show that the degree of damage to the pore structure after secondary-solvent-replacement is close to that of direct- drying in terms of porosity, total pore area, characteristic pore size and pore size distribution. The difference of pore parameters of samples dried by different solvent-displacement is caused by the physical properties of solvents and the reaction with hydration products. Furthermore, thermal analysis results have confirmed the reaction between acetone and hydration products to generate a dark brown substance. If the possible chemical reaction between organic solvents and hydration products is not considered, the pore structure of cement stone can be well protected by replacing pore water with methanol.

Increasing the Speed of Formation of the Structure of Fine-Grained Concrete and its Strength

It was determined that the active component of modern concrete is water. Water has a variable structure, the type of which depends on the temperature at which the water was processed. The use of water in the production of concrete, which has a certain changed structure, allows influencing the rheological properties of concrete mixtures and modifying the structure of cement stone in such a way as to give concrete properties that ensure high operational reliability of structures. However, this method of increasing the strength of concrete has certain disadvantages that prevent its wide application. The purpose of the research is to determine the effect of a mixture of water of different structure on the strength of fine-grained concrete and the speed of its formation.

Optimization of Water Activation Technology for the Production of Fine-Grained Concrete

One of the main active components of modern concrete is water. Water has a variable structure, the type of which depends on the water treatment technology. The use of water in the production of concrete, which has a changed structure as a result of the action of certain substances, allows influencing the rheological properties of concrete mixtures and modifying the structure of cement stone in such a way as to give concrete properties that ensure high operational reliability of structures. However, this method of increasing the strength of concrete has certain disadvantages that prevent its wide application. The purpose of the study is to determine the influence of the type of plasticizers used for water activation on the speed of structure formation and the strength of fine-grained concrete.

Investigation of the Effect of Volumetric Hydrophobization on the Kinetics of Mass Transfer Processes Occurring in Cement Concretes during Corrosion.

The entry of aggressive substances into the pore structure of concrete causes the development of corrosion processes and leads to the destruction of the cement stone structure. Hydrophobic additives provide high density and low permeability and are an effective barrier to the penetration of aggressive substances into the structure of cement stone. To assess the contribution of hydrophobization to the durability of the structure, it is necessary to know how much the processes of corrosive mass transfer slow down. To study the properties, structure and composition of the materials studied in the work (solid and liquid phases) before and after exposure to liquid-aggressive media, experimental studies were carried out using chemical and physicochemical analysis methods: determination of density, water absorption, porosity, water absorption and strength of cement stone; differential thermal analysis; quantitative analysis of calcium cations in liquid medium by complexometric titration. The article presents the results of studies of the effect on the operational characteristics of the introduction of a hydrophobic additive of calcium stearate into the cement mixture at the stage of concrete production. The effectiveness of volumetric hydrophobization was evaluated to prevent the penetration of an aggressive chloride-containing medium into the pore structure of concrete destruction and the leaching of calcium-containing components of cement stone. It was found that the introduction of calcium stearate in an amount of 0.8-1.3% by weight of cement increases the service life of a concrete product during corrosion in liquid chloride-containing media with a high degree of aggressiveness by four times.

Purpose and Justification of Traditional Modes of Heat Treatment of Concrete and Reinforced Concrete Products

The paper presents the comparative characteristics of the most common modes of heat and moisture treatment (HMT), their advantages and disadvantages, as well as proposals for optimizing the HMT stages to obtain the maximum effect of accelerating concrete hardening through the use of thermal energy. Heat and moisture treatment of concrete is one of the most difficult stages in the technology of prefabricated and monolithic concrete. The basis for the durability of structures, their uninterrupted service during the design period of operation is a properly selected HMT mode, which improves the quality of products and reduces material costs in the form of a reduction in energy costs. Therefore, the still practiced simplified methods for selecting the HMT mode are unacceptable. Only under the condition of strict and scientifically substantiated consideration of a complex of factors influencing the ongoing processes of formation of the structure of cement stone and concrete, and the interaction between them, it is possible to obtain concrete with the required characteristics. Depending on the requirements for the finished material, based on knowledge of the mechanism of heat and mass transfer, rational methods and modes of heat treatment of concrete and reinforced concrete products can be calculated. A variety of HMT modes is due to the desire to reduce the possibility of defects in the concrete structure (for example, modes with a stepped or curvilinear temperature increase, which reduces the temperature gradient across the product section), to reduce energy costs (modes with the exclusion of the isothermal holding stage), etc. In the process of HMT of concrete and reinforced concrete products, a number of chemical and physical transformations of the concrete mixture (concrete) occur, as a result of which various defects in the structure of the material may appear, which worsen its properties (strength, permeability, shrinkage, creep and, in general, durability of concrete). Modern technology for the production of concrete and reinforced concrete products and structures provides for the introduction of various chemical additives, their effect on the hardening of concrete at elevated temperatures, unfortunately, is not sufficiently reflected in the specialized literature. For example, the duration of the total cycle of concrete HMT when using chemical additives – hardening accelerators can be reduced by reducing the periods of preliminary exposure, temperature rise and the duration of isothermal exposure; and the use of plasticizers, depending on their type and content, can lead to a lengthening of the cycle. It is necessary to have analytical dependencies for calculating HMT modes and a computer model of the concrete hardening process at elevated temperatures.

Physico-Chemical Substantiation of Obtaining an Effective Cement Composite with Ultrafine GGBS Admixture

To solve a number of problems in construction materials science, composites with nano and ultrafine admixtures were analyzed. Their properties were studied, taking into account the variants of homogenization and stabilization of the system. To characterize the processes of the structure formation of a new material, mathematical methods were also applied. According to the literature review, the aim of the work was formulated. The subject of this research is to conduct physico-chemical studies that characterize the processes occurring during the homogenization and stabilization of the cement system with GGBS components and to establish the effect of the admixture on the properties of the composite. To achieve this goal, an ultrafine admixture based on GGBS was obtained, and the possibility of its introduction into the cement system in the form of a stabilized suspension instead of mixing water was considered. To provide increased characteristics of cement stone modified with the ultrafine admixture, a number of tests were carried out to study homogenization and stabilization of fine slag particles in suspension. The ultrasonic processing parameters were defined to provide uniform distribution of fine slag additive in the suspension: the processing time is 15–20 min, the frequency of ultrasonic vibrations is 44 kHz, the temperature of the dispersed medium is 25 ± 2 °C. To define physical and chemical processes appearing during the introduction of fine slag into water and water-polymer dispersed medium, the mechanism of interaction between fine slag and water was studied. In addition, the mechanism of chemisorption on the surface of fine slag particles and the stabilization mechanism of ultrafine slag particles with a plasticizer was studied to form the concept of aggregate and sedimentation stability of slag particles in suspension. It was found that the stabilization of fine slag particles by a plasticizer is significantly influenced by the hardness of water. The higher the water hardness, the more plasticizer required to stabilize the fine slag particles. At the same time, it was established that the concentration of the plasticizer should not exceed the critical micelle concentration value. If it is exceeded, the plasticizer solution transforms into the micellar colloidal system, and the stabilization of fine slag suspension will not occur. The studies of homogenization and stabilization of the slag suspension allowed the authors to substantiate the possibility of uniform distribution of fine particles in the cement matrix, followed by the formation of a denser and stronger cement stone structure. Cement-sand samples based on Portland cement (OPC) and slag-Portland cement (SPC) with GGBFS admixture showed higher compressive and flexural strength characteristics in the initial hardening periods and at 28 days. It was found that modified samples are more stable in an aggressive medium. On the 90th day of exposure, the resistance coefficient was 0.9 for a modified sample based on OPC and 0.98 for a modified sample based on SPC. The increased sulfate attack resistance of the samples is due to the formation of a dense stone with reduced porosity. It is noted that the porosity of modified OPC samples decreases by 14% and by 18% for SPC-based modified samples compared to the control sample at 28 days. Due to the fact that pores in the cement stone are blocked with hydration products, which make the structure of the cement stone denser, the filtration of aggressive solutions deep into its structure is difficult. Thus, the obtained concrete based on a cement composite with ultrafine slag can be applied as a protective layer of steel reinforcement in a reinforced concrete structure.

On the structure of cement stone with fillers from metallurgical waste

The results of studies of the grinding of metallurgical slags in ball mills and data on the optimization of the grinding process are presented. The results of studies of the influence of the dispersion of the filler and the degree of filling on the formation of the strength of the cement stone are presented.

Development of technology for the preparation of heavy-duty concrete mixtures by processing with an ultrasonic multi-frequency acoustic field

The article presents the results of a study of the use of ultrasonic technologies to increase the strength of cement mortar in the production of building and concrete structures, as well as to improve the rheological parameters of grouting mortar during the construction (drilling) of wells. During the experiment, the concrete mortar was treated for 3 minutes with an ultrasonic multi-frequency acoustic field (frequency 20.0-40.0 kHz, signal power-200-400 W/dm 3) in devices of various geometric shape. Ordinary Portland Cement (OPC) of class G-100 was used in the composition of the solution without plasticizer additives in order to exclude their influence. The ratio of water and cement in the solution was 0.44, the density-1.90 g/cm 3. Typical elements of flow channels were used as volumes where ultrasonic exposure is carried out. The hydrodynamic regime of the processes in the water-cement suspension was modeled at the beginning of the experiments by slow mixing with a paddle agitator (200 Rev./min), and on closing stage, in order to prevent the effect of hydrodynamic cavitation failure, at a speed of 1000 Rev./min. The maximum compression and bending stresses are measured after the mixture solidified in a steam bath (T =60°C, 24 h.) on a hydraulic stand. Conducted experiments have confirmed that ultrasonic exposure using resonant accumulators and flow hoses: has a positive effect on the hydration reaction and the structure of cement stone in the concrete sealing phase; accelerates the intensity of compressive strength. (from 24.3 MPa to 41.5 MPa); uniformity of structure; reduces the influence of temperature on strength gain (reduces energy consumption); increases the reliability of building structures, and in the case of well construction-provides a strong adhesion of the production column with rock. In general, the results of the study allowed: to formulate a technology for the production of heavy-duty concrete mixtures; to develop a set of equipment for the preparation of concrete (grouting mortar) with specified characteristics at production objects. Keywords: ultrasonic multi-frequency acoustic field, high-strength concrete mix, water separation of mortar, cement stone (paste), compressive and bending strength of concrete mix

Comprehensive solution to environmental problems of ceramic production by recycling their waste in cement industry

The paper presents the results of studies to determine the suitability of the dump battle of fired ceramic products based on kaolin clays of the Angren deposit, the positive effect of the addition of fractionated ceramic battle on the formation of the structure and physico-mechanical properties of portland cement stone is established. For use as an additive in cement, the need for fractionation of ceramic production waste with separation of the burnt part of ceramic waste was noted; its chemical and mineralogical compositions and hydraulic activity were determined according to the Student’s criterion, the value of which was t=21.21, which is higher than its regulated value of at least 15 according to GOST (State Standard) 31108-2020. Based on the obtained research results, ceramic waste is recommended as an active mineral additive in cement. The positive effect of the addition of fractionated ceramic waste on the process of origin and evolution of neoplasms in terms of acceleration of hydrolysis, hydration of clinker minerals, and cement hardening with the formation of a low-porous structure of cement stone, which, despite a decrease in the proportion of high-temperature Portland cement clinker up to 20%, is characterized by high hydraulic activity corresponding to the grade of cement PC400-D20.

Modified concrete for irrigation and drainage construction

Within the framework of these studies, issues related to the modification of the composition of heavy concrete based on a polydisperse binder with a complex modifier and its influence on the formation of the structure and properties of cement stone, as well as hardened concrete, are considered. The purpose of the study is to substantiate the possibility of obtaining effective heavy concrete for irrigation and drainage construction with improved indicators of operational properties in terms of strength and hydrophysical characteristics. Object of study: heavy concrete based on a polydisperse binder with a complex modifier reinforced with basalt fiber. Subject of study: the structure and properties of heavy concrete based on a polydisperse cement binder with a high packing density together with a complex modifier and reinforced basalt fiber. The influence of the three-level dispersed composition of the clinker component of cement particles on the reduction of interparticle voidness and the increase in the strength of the cement stone was studied. The resulting modified concrete is characterized by an increase in strength to 77.3 MPa, a stretching of 8.62 MPa and a decrease in water absorption to 1.9%; % in comparison with the control composition.

Change in the strength properties of modified concrete over time

To date, there is no data on the change in the strength of hyper - compacted concrete. The conducted field observations summarize the data of a long-term period and allow us to draw a number of conclusions. As shown by numerous studies, the nature of the development of the strength of concrete over time depends mainly on the type of cement, the composition of the concrete mixture, the temperature and humidity conditions of hardening, and also on many other factors. Obtaining highly efficient building materials is possible by modifying the structure of cement stone and concrete. Consequently, the modification of the concrete structure in this direction is intended to improve the technological properties of the material. By modifying it is possible to change the kinetics of the growth of physical properties and the final values of the strength of concrete. Without considering the physico-analytical mechanism for changing the structure formation of concrete, we note that it is primarily aimed at reducing the amount of water - a mixing agent per unit volume of the material. However, various studies have shown that in the initial period, the structure formation of cement stone develops in the optimal direction only at certain volumetric water content. The limiting reduction in water content complicates the process of hydration of the binder, limiting the final strength properties of the material. At the same time, the final strength properties of the material are improved by reducing the volumetric water content of the mixture in every possible way. In all cases, the modification of concrete assumes its composition to be unchanged from the mixing of the mixture to the final stage of the formation of the concrete structure.

Study of concrete properties based on crushed stone sand mixture and fiber of fly ash of thermal power plants

Abstract The study aims to optimize the composition of the main composite, the components of which, in their joint presence, make it possible to obtain the most significant positive synergistic effect. The authors of this article used the fibers of fly ash from thermal power plants as a finely dispersed component added to the crushed stone sand mixture. The result of the study was a high-strength corrosion-resistant material consisting of a crushed stone sand mixture (CSSM) with the addition of the fibers of fly ash. The authors applied the thermogravimetric and standard methods to study and determine the performance and strength characteristics of the obtained material. The combined effect of a complex organic-mineral modifying additive and the cement with the fibers of fly ash provided a compacted and reinforced structure of cement stone. An optimal binder composition was developed, consisting of cement and fiber of fly ash. The authors of this article examined the physical-mechanical and structural-mechanical properties of a CSSM of fine-grained concrete reinforced with a complex additive of cement, fibers of fly ash, and a superplasticizer. The study also provided technological solutions for manufacturing a functional mixture of fine-grained concrete based on the developed complex organic-mineral additive.