Cement Setting Research Articles

Effect of using sugar and gypsum as a retarder on concrete properties in Omani weather

This study deals with the retardation of cement setting time and workability in hot weather such as in Sultanate of Oman. Combination of sugar and gypsum was used as retarders. The aim of this study was to investigate the effect of retarders on consistency, setting time of ordinary Portland cement (OPC) paste and compressive strength of concrete cubes after 7 days of curing. OPC paste with a water cement ratio 0.4 to 0.5 was prepared by mixing 500 grams of ordinary Portland cement, a fixed amount of sugar of 0.02% by weight of cement with a combination of different gypsum of 1, 2, 3, 4, and 5% by weight cement and water. Sugar has a strong retarding effect, and this effect, controlled by Gypsum, can shorten the long setting time caused by sugar. The setting time of cement paste was reduced from 5.5 hours to 3 hours with an increase in Gypsum at a fixed amount of sugar. At a constant sugar content, increasing the gypsum content reduced the compressive strength from 31.5 MPa to 30.92 MPa.

Long-Term Hindrance Effects of Algal Biomatter on the Hydration Reactions of Ordinary Portland Cement

The incorporation of carbon-fixing materials such as photosynthetic algae in concrete formulations offers a promising strategy toward mitigating the concerningly high carbon footprint of cement. Prior literature suggests that the introduction of up to 0.5 wt % chlorella biological matter (biomatter) in ordinary Portland cement induces a retardation of the composite cement’s strength evolution while enabling a long-term compressive strength comparable to pure cement at a lower carbon footprint. In this work, we provide insights into the fundamental mechanisms governing this retardation effect and reveal a concentration threshold above which the presence of biomatter completely hinders the hydration reactions. We incorporate Chlorella or Spirulina, two algal species with different morphology and composition, in ordinary Portland cement at concentrations ranging between 0.5 and 15 wt % and study the evolution of mechanical properties of the resulting biocomposites over a period of 91 days. The compressive strength in both sets of biocomposites exhibits a concentration-dependent long-term drastic reduction, which plateaus at 5 wt % biomatter content. At and above 5 wt %, all biocomposites show a strength reduction of more than 80% after 91 days of curing compared to pure cement, indicating a permanent hindrance effect on hardening. Characterization of the hydration kinetics and the cured materials shows that both algal biomatters hinder the hydration reactions of calcium silicates, preventing the formation of calcium hydroxide and calcium silicate hydrate, while the secondary reactions of tricalcium aluminate that form ettringite are not affected. We propose that the alkaline conditions during cement hydration lead to the formation of charged glucose-based carbohydrates, which subsequently create a hydrogen bonding network that ultimately encapsulates calcium silicates. This encapsulation prevents the formation of primary hydrate products and thus blocks the hardening of cement. Furthermore, we observe new hydration products with composition and micromorphology deviating from the expected hardened cement compounds. Our analysis provides fundamental insights into the mechanisms that govern the introduction of two carbon-negative algal species as fillers in cement, which are crucial for enabling strategies to overcome the detrimental effects that those fillers have on the mechanical properties of cement.

Mechanistic study of the effect of potassium ferrate and straw fiber on the enhancement of strength in cement-based solidified municipal sludge

The high content of organic matter in sludge is the primary reason for the poor solidifying effect and excessive dosage of the cement base. In this study, potassium ferrate and straw fiber are utilized to synergistically enhance the solidifying effect of the cement and elaborate the strength mechanisms. Among them, potassium ferrate was selected to oxidize and crack the structure of organic matter in sludge and consume part of organic matter; straw fiber was used as an adsorption material to absorb some of the organic material and reduce its interference with the cement hydration reaction; the skeleton function of straw fiber in solidified sludge was used to improve the final solidified sludge strength. It is shown that the presence of these two additives significantly improved the cement solidification strength and reduced the moisture content of the solidified body. Moreover, the moisture content and strength followed an obvious linear relationship (adjusted R2 = 0.92), with the strength increasing as the moisture content decreased. After pretreatment with potassium ferrate, the free water content in the dewatered sludge increased by 4.5%, which was conducive to the adequate hydration reaction with cement. The analysis using X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), and mercury intrusion porosimetry (MIP) revealed potassium ferrate synergizes with straw fibers to promote the production of hemihydrate gypsum and gismondine. However, hemihydrate gypsum, calcium carbonate, and gismondine resulted in structural swelling, which was confirmed by the microscopic morphology and pore structure analysis. However, the adverse effects due to swelling were offset by the increase in strength brought by the above crystalline substances.

Multiscale Enhancement Mechanisms of EVA on EPS-Cement Composites

Ethylene-vinyl acetate (EVA) lotion can significantly improve the interface problems caused by the physical and chemical differences between expanded polystyrene (EPS) beads and cement, which is one of the reasons why EPS cement composites are widely used in the construction field. However, the research on its problems is often limited to phenomenological engineering methods, ignoring the potential interaction mechanism in atomic structure. Therefore, in this study, the strengthening mechanism of EVA on EPS particle–cement slurry interface was systematically studied from the aspects of macromechanical properties, microstructure characteristics, chemical composition, and molecular structure. In terms of physical test, it was found that the compressive strength and flexural strength of EPS-cement-based materials containing EVA are increased by 19% and 31%, respectively, at 28 days when the content of EPS particles is the same. It was observed through an electron microscope snapshot that EVA makes a uniform and dense interface structure between EPS particles and cement. For chemical tests, EPS particle surface hardening cement was ground into powder and tested by X-ray diffraction and Fourier transform infrared spectrometer. It was comprehensively analyzed that EVA reduced the hydration product Ca(OH)2 and increased calcium silicate hydrate (C-S-H) at the interface. In terms of numerical simulation, through molecular simulation modeling and calculation, it was found that the introduction of EVA can produce more stable hydrogen and ion bonds at the EPS–C-S-H interface, which plays a vital role in reducing the interface effect and increasing the interface binding energy.

Studies Quantify Cement Sealing Performance Under Downhole Conditions

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 212542, “Quantifying the Sealing Performance of Plug and Abandonment Cement Systems Under Downhole Conditions,” by Roel F.H. Roijmans, SPE, Timotheus K.T. Wolterbeek, and Erik K. Cornelissen, Shell, et al. The paper has not been peer reviewed. _ Reliable evaluation of cement-plug sealing performance requires testing under elevated temperature and pressure conditions representative of downhole conditions. In the complete paper, two laboratory setups designed for this purpose are described. In both setups, plugs are cured and tested under downhole conditions inside sections of steel pipe. Using this equipment, a strong positive correlation was found between the amount of interfacial stress buildup and the sealing performance of the set cement plug against gas flow. This demonstrates that cement systems that expand effectively under downhole conditions can reduce seepage risk after plugging and abandonment (P&A). Importance of Cement Testing Under Representative Downhole Conditions The authors devote the first part of the paper to making a case for including cement expansion additives (CEAs) in P&A cement slurry and explain the need for verifying the expanding properties of slurry design under elevated pressure and temperature conditions representative of downhole conditions. Cement-testing equipment currently used by the industry to determine shrinkage and expansion of cement systems includes the ring-mold test and the membrane test. However, these tests do not represent downhole conditions in terms of water access, confinement, pressure, and geometry, although test outcomes in terms of cement expansion can be influenced significantly by these factors (Table 1 of the complete paper lists factors that influence the CEA in creating interfacial stress). Two laboratory setups were designed to evaluate expanding cement slurry behavior under representative downhole conditions, namely small-scale tests on 2-in. plugs and large-scale tests on 8-in. plugs. Multiple cement slurries with varying amounts of CEA were cured and analyzed for sealing performance at representative downhole conditions, and the functionality of multiple CEAs was investigated by exposing them to heated tap water. The complete paper provides a discussion of experimental methodologies and setups for measuring CEA reactivity and for 2-in. and 8-in. cement-plug sealing-performance-evaluation setups. It also describes a modified ultrasonic cement analyzer (UCA) vessel. Results and Discussion Reactivity of CEAs. The reactivity in tap water of two commercially available calcium oxide (CaO) and magnesium oxide (MgO)-based CEAs was determined. The low-temperature CEA was analyzed at 35 and 70°C. The high-temperature CEA was analyzed only at 70°C. For the thermogravimetric analyses, the CEA was submerged in water (as opposed to cement slurry). As a result, ample water was always available with which the CEA could react. Inside a slurry, on the other hand, the reaction speed was slower because of a reduced amount of water.

Utilization of tartaric acid and 5-sulfosalicylic acid for tailoring the performance of aluminum sulfate alkali-free accelerator

The organic components used in the alkali-free accelerator have a significant influence on the performance of the accelerator. The effects of two distinct types of organic acids, tartaric acid (TA) and 5-sulfosalicylic acid (SSA), on the performance of alkali-free accelerator, mainly on the setting time of cement paste and the early strength of mortar were investigated in this work. The mechanism of effects was studied by the isothermal calorimetry, SEM, XRD, and FT-IR analysis. The results demonstrate that both TA and SSA can extend the setting of cement; TA can diminish the early strength of mortar, while SSA has little influence. The –COOH in TA can be complexed with Ca2+ to form calcium tartrate, which accelerates the dissolution of gypsum and hydration of C3A; The calcium tartrate and R-OH in TA can be adsorbed on the surface of C3S, prolonging the induction period and inhibiting the hydration of C3S. The Ar-OH in SSA can react with Al3+ to form a stable chelate, inhibit the hydration of C3A and extend the setting of cement. The Ar-OH adsorbed on the surface of C3S can also prolong the induction period, but the Ar-OH is more active than R-OH, resulting in unstable adsorption reaction and poor effect on extending the induction period.

Performance assessment of hemispherical solar distillers integrated with the red bricks filled with cement as natural thermal storage materials

AbstractThis manuscript aims to augment the production rate of drink water from the hemispherical solar distillers using red bricks filled with cement as natural low‐cost reasonable storage materials. To obtain the optimal height and optimal gap distance of the red brick tiles filled with cement that achieves the highest productivity of hemispherical distillers. Three different heights of the red brick (1, 2, and 3 cm) with two different gap distances of (4 and 6 cm) were experimentally studied. Therefore, three hemispherical distillers were constructed and operated under the same climate conditions. The first is the traditional hemispherical solar distiller (THSD) which represents the reference distiller. The second is a hemispherical distiller with red brick tiles filled with cement set at a gap distance of 6 cm. The third is a hemispherical distiller with red brick tiles filled with cement set at a gap distance of 4 cm. The results presented that, the utilization of red brick tiles filled with cement with a height of 2 cm and a gap distance of 4 cm represents a good choice that achieves the highest performance of hemispherical distillers. The results showed that the utilization of red bricks filled with cement will be improved the accumulative yield from 4.3 L/m2/day (THSD) to 6.55 L/m2/day with an improvement of 52.3%. Also, using the red bricks filled with cement improved the thermal and exergy efficiencies by 51.24% and 435.5%, respectively compared to THSD.

Mining waste and coconut fibers as an eco-friendly reinforcement for the production of concrete blocks

Using mineral and agro-industrial wastes associated with the cement matrix can add value and guarantee suitable properties for reinforced composites. This research aimed to evaluate the effect of the incorporation of quartzite and coconut fibers on masonry blocks' physical, mechanical, and thermal properties. Quartzite was evaluated replacing 0%, 25%, 50%, 75%, and 100% of the sand, whereas the coconut fibers were added in a proportion of 2.5% of the volume of gravel. Quartzite residues were analyzed regarding their granulometry, chemical composition, and pozzolanicity. The block initial formulation (control) was: 8.2% cement, 45.9% sand, and 45.9% gravel. The cement was cured at room temperature for 28days. Subsequently, the blocks were subjected to the characterization of physical, mechanical, and thermal properties. Coconut fibers presented a low percentage of extractives, with a low inhibition index (1.93%), reducing their effect on cement hardening. The increase in the content of quartzite incorporated provided a reduction in bulk density and an increase in porosity (from 11.7 to 16.0%) and water absorption after 24h (from 7.0 to 8.5%). The compressive strength was reduced from 50% with the insertion of the quartzite. The quartzite and coconut fibers reduced the concrete's thermal conductivity, providing essential reflections for the performance of the blocks in terms of thermal comfort in built environments. Further, incorporating these materials provided the potential to obtain blocks with characteristics of resistance and offering possible thermal comfort, besides contributing as an option for a destination for these mineral and agro-industrial wastes.

Preparation of sustained-release-type citric-acid-intercalated hydrotalcite and its application in oil-well cement

To address the problems of poor thermal stability and over-retarding of cement slurry by retarders, as well as the sensitivity to citric acid (CA) dosage and poor early strength of cement treated with hydroxycarboxylic acid retarders, CA-intercalated magnesium aluminium hydrotalcite (Mg/Al-CA-LDH, henceforth called CAIH) with a sustained-release effect was prepared by an anion exchange reaction between CA and magnesium aluminium carbonate layered double hydroxide (Mg/Al-CO3-LDH). The prepared CAIH exhibited good crystallinity and high thermal stability, and 39.92% CA could be inserted in the composite. Evaluation of the thickening and compressive strength of oil-well cement showed that the addition of CAIH effectively maintained the fluidity of the cement slurry and improved its early compressive strength. Furthermore, because of the seed effect of hydrotalcite and the microrelease of CA in CAIH, the synergistic effect of hydrotalcite and CAIH can promote the setting of oil-well cement: the effect was stable and the thickening curve was stable, indicating right-angle thickening.

A Casing Deformation Prediction Model Considering the Properties of Cement

A large amount of casing deformation has occurred in shale gas wells during the complex fracturing process, which affects the fracturing construction and single well production. Based on the statistical analysis of casing deformation wells and caliper logging interpretation, the main mechanism of casing deformation of shale gas wells is revealed as formation slip. By comprehensively considering the rotating speed under casing running condition, the cement solidification heat release under cementing condition, and the fracturing fluid temperature drop under fracturing condition, the safe service margin of the casing is large. Moreover, simply increasing the casing steel grade and wall thickness has no obvious effect on casing deformation prevention, so full wellbore casing deformation prevention measures should be considered. By using the method of unconventional oil and gas well casing string simulation test and numerical simulation, the mechanical response of wellbore and the mechanism of bridge plug resistance are analyzed. By analyzing the influence of elastic modulus and wall thickness of cement on the casing minimum drift diameter after shear deformation, an analytical model of the minimum drift diameter of shale gas casing under the effect of fracture slip is established and verified, which provides technical support for parameter selection of cement and measures to prevent casing deformation.

Effects of Using Aluminum Sulfate as an Accelerator and Acrylic Acid, Aluminum Fluoride, or Alkanolamine as a Regulator in Early Cement Setting.

Aluminum sulfate was employed as the main accelerator in order to explore new non-chloride and alkali-free cement accelerators. Acrylic acid, aluminum fluoride, or alkanolamine were used as regulators to further accelerate cement setting. The setting time, compressive, and flexural strengths in cement early strength progress were detected, and both the cement (raw material) and hydrated mortar were fully characterized. The cement setting experiments revealed that only loading acrylic acid as the regulator would decrease the setting time of cement and increase the compressive and flexural strengths of mortar, but further introduction of aluminum fluoride or alkanolamine improved this process drastically. In the meantime, structural characterizations indicated that the raw material (cement) used in this work was composed of C3S (alite), while hydrated mortar consisted of quartz and C3A (tricalcium aluminate). During this transformation, the coordination polyhedron of Al3+ was changed from a tetrahedron to octahedron. This work puts forward a significant strategy for promoting the activity of aluminum sulfate in cement setting and would contribute to the future design of new non-chloride and alkali-free cement accelerators.

Strength, Porosity and Permeability Properties of Porous Concrete Made from Recycled Concrete Aggregates

Due to expansion in infrastructure and increased development of urbanization in Ethiopia, most of the places are covered either by impermeable cement concrete or bitumen that blocks the percolation of water from rainfall. A porous concrete made of zero fine aggregates, creating a pore that permits the concrete to be water permeable, is highly desirable. Similarly, the demand for natural coarse aggregates remains high, while natural resources are being depleted. Therefore, this study aims to investigate the properties of porous concrete using recycled concrete aggregate as a partial replacement for natural coarse aggregate. Experimental tests were conducted on cement setting time, workability of concrete, compressive, split tensile, porosity, and permeability of porous concrete. The properties of porous concrete at different ratios—0, 15, 30, 45 and 60%—revealed that RCA is suitable for use as coarse aggregate. The optimum replacement percentage of recycled aggregate for porous concrete in terms of strength is 30%, with 28th-day compressive strength of 17.37 MPa. However, slight increments were observed in porosity and permeability coefficient. Therefore, the concrete produced in this study is structural concrete, which is suitable for walkways and other concrete flat works, whereby heavy vehicle traffic loads do not exist.

Study of the Genetic Formation of New Formations during the Hardening of Pozzolanic Cement with a High Content of Ash and Slag Waste of Dry Selection

Study of the Genetic Formation of New Formations during the Hardening of Pozzolanic Cement with a High Content of Ash and Slag Waste of Dry Selection

Https://doi.org/10.47191/ijcsrr/V6-i2-09

The results of physical and chemical studies of the processes of hydration and structure formation during hardening of pozzolanic cements containing dry–selection ash and slag waste from the Angren TPP as an active mineral additive are presented. It has been established that, despite the replacement of up to 50% of the clinker part, the experimental cements acquire high hydraulic activity, which ensures their grade 400–500, which is facilitated by the presence of active silica, alumina and low–basic calcium silicates in the composition of the additive, which in the process of chemical interaction with hydration products clinker minerals are involved in the formation of a dense microstructure of the cement composite.

EFFECTS OF TRANSPORT AND STORAGE CONDITIONS IN A TROPICAL CLIMATE ON CEMENT SETTING TIMES

Multiple studies have established an inverse relationship between ambient theatre temperatures and polymethyl methacrylate (PMMA) cement setting times. It is also known that allowing cement to equilibrate to ambient theatre temperatures restores expected setting characteristics. One overlooked entity is the transport and storage conditions of cement. This is important in tropical regions, where extreme temperature and humidity may cause rapid cement setting times, resulting in potentially significant intra-operative complications.This study investigated the relationship between extreme transport and storage conditions of Antibiotic Simplex cement (Stryker), and the effect on setting times at Cairns Hospital, Far North Queensland, Australia.Fifty units of cement were divided evenly into a control arm and four experimental arms. The experimental arms were designed to mimic potential transport and storage conditions. They included seven days of storage in a medication fridge, on the hospital loading dock, in a cane shed, and in a Toyota Landcruiser parked outdoors during January 2022. Humidity and temperature readings were recorded.The samples in each group were evenly distributed to equilibrate to theatre conditions for 1 hour and 24 hours. Setting time was recorded when a no. 15 scalpel blade was unable to mark the surface.All three ‘hot’ exposures setting times were significantly faster for both 1 hour (ρ=0.001) and 24 hours (ρ=0.024) equilibration times. The difference in setting times for the ‘cold’ exposure was not significant for either equilibration times (ρ=1).To our knowledge, this is the first study investigating cement setting times in tropical climates. Further studies are required to address the effect of these conditions on biomechanical strength of PMMA cement. We conclude that extreme heat and humidity during transport and storage have a statistically significant effect on cement setting times.

Effect of alkali sulfates in clinker on hydration and hardening properties of cement incorporating SCMs

Fly ash and slag are widely used in cement production. The effect of alkali sulfates in clinker on hydration and hardening of cement blended with fly ash and slag is studied. The results of hydration heat evolution, hydrates analysis and mechanical properties indicate arcanite (K2SO4), thenardite (Na2SO4), aphthitalite (3K2SO4·Na2SO4, K3NS4) and Ca-langbeinite (K2SO4·2CaSO4, KC2S3) in clinker could activate the pozzolanic activity of fly ash and slag, facilitating the appearance of the second hydration peak in the initial hydration period, and promote the hydration and hardening properties of blended cement. The adverse effects of alkali sulfates in clinker are alleviated with the addition of fly ash and slag; this can be attributed to the dilution and filler effects of supplementary cementitious materials (SCMs), as well as the effect of the alkali sulfates activating fly ash and slag. Arcanite, thenardite and aphthitalite (K3NS4) provide a better activating effect on mortar with slag than fly ash mortar to increase compressive strength and reduce drying shrinkage when the content of alkali sulfates is less than 0.6% sodium oxide equivalent (Na2Oeq).

Fast-Setting Calcium Silicate-Based Pulp Capping Cements-Integrated Antibacterial, Irritation and Cytocompatibility Assessment.

Calcium silicate-based cements (CSCs) are endodontic materials widely used in vital pulp-capping approaches. Concerning the clinical application, the reduced set time and pre-mixed formulations are relevant characteristics during the operative management of pulpal exposure, aiming to optimise the work time and improve cross-infection/asepsis control. Additionally, clinical success seems to be greatly dependent on the biological performance of the materials that directly contact the living pulp. As such, this work approaches an integrative biological characterisation (i.e., antibacterial, irritation, and cytocompatibility assays) of three fast-setting CSCs-BiodentineTM, TotalFill® BC RRM™ Fast Putty, and Theracal LC®. These cements, after setting for 24 h, presented the expected topography and elemental composition (assessed by scanning electron microscopy, coupled with EDS analysis), in accordance with the information of the manufacturer. The set cements displayed a significant and similar antibiofilm activity against S. mutans, in a direct contact assay. Twenty-four-hour eluates were not irritant in the standardised CAM assay, but elicited distinct dose- and time-dependent cytotoxicity profiles on fibroblastic cells-i.e., Biodentine was devoid of toxicity, TotalFill presented a slight dose-dependent initial toxicity that was easily overcome, and Theracal LC was deleterious at high concentrations. When compared to long-setting ProRoot MTA cement, which highlighted the pursued integrative approach, Biodentine presented a similar profile, but TotalFill and Theracal LC displayed a poorer performance regarding antibiofilm activity/cytocompatibility features, and Theracal LC suggested eventual safety concerns.

Optimization of an Injectable, Resorbable, Bioactive Cement Able to Release the Anti-Osteoclastogenic Biomolecule ICOS-Fc for the Treatment of Osteoporotic Vertebral Compression Fractures.

Vertebral compression fractures are typical of osteoporosis and their treatment can require the injection of a cement through a minimally invasive procedure to restore vertebral body height. This study reports the development of an injectable calcium sulphate-based composite cement able to stimulate bone regeneration while inhibiting osteoclast bone resorption. To this aim, different types of strontium-containing mesoporous glass particles (Sr-MBG) were added to calcium sulphate powder to impart a pro-osteogenic effect, and the influence of their size and textural features on the cement properties was investigated. Anti-osteoclastogenic properties were conferred by incorporating into poly(lactic-co-glycolic)acid (PLGA) nanoparticles, a recombinant protein able to inhibit osteoclast activity (i.e., ICOS-Fc). Radiopaque zirconia nanoparticles (ZrO2) were also added to the formulation to visualize the cement injection under fluoroscopy. The measured cement setting times were suitable for the clinical practice, and static mechanical testing determined a compressive strength of ca. 8 MPa, comparable to that of human vertebral bodies. In vitro release experiments indicated a sustained release of ICOS-Fc and Sr2+ ions up to 28 days. Overall, the developed cement is promising for the treatment of vertebral compression fractures and has the potential to stimulate bone regeneration while releasing a biomolecule able to limit bone resorption.

About the processes of hydration and hardening of cement

The paper deals with some poorly studied issues of cement hydration and hardening. It is shown that the interaction of cement with water begins with the attack of oxygen atoms of clinker minerals by water protons. In this case, the process of structure formation of a cement stone can be represented as a process of inversion of the dispersed cement – water system, when the dispersion medium (water) in the initial periods turns into a dispersed phase at the later stages of hardening. Conversely, the dispersed medium (cement) becomes the dispersion medium. Attention is drawn to the relevance, but insufficient knowledge of information interactions in the cement – water system, as well as the influence of a hydrated electron on the reactivity of the system under consideration.

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.