Strength Characteristics Research Articles

Characterising mechanical properties and failure criteria of steel slag aggregate concrete under multiaxial stress states

To advance the application of steel slag aggregate concrete (SAC) in civil engineering, this study introduces a comprehensive experimental program to explore the failure mode, strength, deformation, and failure criteria of SAC under multiaxial stress conditions. In this investigation, SAC specimens containing 50% stabilised steel slag as a coarse aggregate were examined for mechanical behaviour (e.g. stress–strain relationships) under diverse loading scenarios, including uniaxial tensile and compressive loadings, biaxial compression, and true triaxial compression loadings. Subsequently, three distinct failure criteria (i.e. the Ottosen criterion [1], William–Warnke criterion [2], and Guo criterion [3]) for SAC were formulated and authenticated based on the experimental outcomes. The results showed varied failure modes in the SAC, such as prism type, splitting tensile, sheet-like tensile, and oblique shear, which depended on the stress state of the specimen during failure. A significant elevation in the ultimate strength and deformation of SAC specimens was observed, with an increment in the first-to-third principal stress ratio (σ1/σ3). Furthermore, the failure criterion introduced by Guo was validated as adept at reproducing all geometric characteristics of the concrete failure surface and precisely forecasting SAC’s ultimate strength of the SAC. Overall, this investigation proposed a reliable failure criterion based on true triaxial test data that can not only describe the multiaxial strength characteristics of SAC but also provide design advice for the applications of SAC in engineering structures.

Tailored nanofiber composites for a flexible piezoelectric nanogenerator: Poly(vinylidene fluoride) with BaTiO3/NiFe2O4

Owing to the depletion of fossil fuel energy and the pollution caused by chemical batteries, as well as the growing number of electronic devices and the Internet of Things (IoT), there is a greater demand for power devices that are lightweight, inexpensive, durable, and sustainable. An excellent alternative is a self-sufficient, adaptable piezoelectric energy harvester, easily integrated with small electronics to generate real-time, sustained energy. This study develops a piezoelectric nanogenerator (PENG) by uniformly drawing spun membranes containing 2 wt% of barium titanate (BaTiO3) and nickel ferrite (NiFe2O4). The flexible piezoelectric nanogenerator was prepared by electrospinning technique. The electroactive phase content of PVDF is increased by adding nanofillers, and the interfacial polarization between the nanofiller and polymer matrix is significantly enhanced. The obtained electrospun nanofibers were evaluated for mechanical flexibility and piezoelectric responses. The findings demonstrated that, for a given filler composition, the output voltage achieved was more significant than the voltage generated by the pure PVDF. The PVDF/BaTiO3-NiFeO4 electrospun nanofibers demonstrated the highest piezoelectric peak-to-peak output voltage of 4.1 compared to pure PVDF (∼125 mV). From these results, the prepared electrospun polymer nanocomposite fibers may be preferred as the energy-converting devices that can be applied to flexible and wearable electronics. The materials mechanical, breakdown strength and dielectric characteristics align with their potential uses in wearable electronics.

КОМПЬЮТЕРНОЕ МОДЕЛИРОВАНИЕ ЖЕЛЕЗОБЕТОННЫХ БАЛОК С УЧЁТОМ ДЕФЕКТОВ И ПОВРЕЖДЕНИЙ

The article examines the influence of defects and damage on the stress-strain state, strength, crack resistance and rigidity of reinforced concrete beams. Based on computer modeling in the ANSYS and Lira-SAPR software packages, a multifactor numerical experiment was carried out. The following influencing factors are considered: the depth and length of destruction of the protective layer of concrete in the tensile zone, concrete spalling in the compressed zone, a decrease in the area of reinforcement, a local decrease in the strength of concrete, the presence of normal cracks at different percentages of longitudinal reinforcement, delamination of concrete flanges, a change in the class of concrete. The computer model was verified by comparing the results obtained numerically with data from full-scale testing of similar beams. For each factor, the impact on the strength, crack resistance and rigidity of reinforced concrete beams was assessed. It has been established that the rigidity and strength of beams with a lower percentage of reinforcement are more sensitive to initial defects in the form of normal cracks in the middle of the span. The depth and length of destruction of the protective layer of concrete in the tensile zone has practically no effect on the studied parameters. A change in the strength characteristics of concrete to a depth of 20 mm along the perimeter of the section (during concrete corrosion) significantly affects the cracking load, while the strength and rigidity decreases slightly.

A Structural Reliability Analysis Method Considering Multiple Correlation Features

The paper analyzes the correlation features between stress strength, multiple failure mechanisms, and multiple components. It investigates the effects of different correlation features on reliability and proposes a method for structural reliability analysis that considers the joint effects of multiple correlation features. To portray the stress–strength correlation structure, the Copula function is utilized and the influence of the correlation degree parameter on reliability is clarified. The text describes the introduction of time-varying characteristics of structural strength and correlation parameters. A time-varying Copula is then constructed to calculate the structural reliability under the stress–strength correlation characteristics. Additionally, a time-varying hybrid Copula is constructed to characterize the intricate and correlation features of multiple failure mechanisms and components. The article proposes the variational adaptive sparrow search algorithm (VASSA) to obtain optimal parameters for the time-varying hybrid Copula. The effectiveness and accuracy of the proposed method are verified through actual cases. The results indicate that multiple correlation features significantly influence structural reliability. Incorporating multiple correlation features into the solution of structural reliability yields safer results that align with engineering practice.

Geotechnical interpolation methodology for determining intermediate values of soil properties

The article considers the application of geotechnical interpolation using ArcGIS software to determine the intermediate geotechnical properties of soils at a construction site in a residential complex in Astana, Esil district. The study is based on data from 8 boreholes drilled to a depth of 26 meters, and the purpose of the work is to use the kriging interpolation method to determine intermediate soil properties. The raw data include the results of analyzing the physical and mechanical properties of the soils from the boreholes, which served as a basis for interpolation and mapping. The results of the study are presented in the form of maps showing the intermediate mechanical properties of the soil at depths of 5, 10 and 15 m. The maps allow obtaining more accurate intermediate values. The proposed methodology not only facilitates the work of designers, but also provides data for realistic scenarios of soil strength and deformation characteristics, which significantly influences the selection of optimal types and sizes of foundations.

STUDY ON STRENGTH CHARACTERISTICS OF SELF CURING CONCRETE BY PARTIAL REPLACEMENT OF CEMENT WITH ALCCOFINE

STUDY ON STRENGTH CHARACTERISTICS OF SELF CURING CONCRETE BY PARTIAL REPLACEMENT OF CEMENT WITH ALCCOFINE

Effect of Precursor Blending Ratio and Rotation Speed of Mechanically Activated Fly Ash on Properties of Geopolymer Foam Concrete

This research used fly ash and slag to create geopolymer foam concrete. They were activated with an alkali, resulting in a chemical reaction that produced a gel that strengthened the concrete’s structural integrity. The experimental approach involved varying the fly ash content in the precursors at incremental percentages (10%, 30%, 50%, 70% and 90%) and subjecting the fly ash to mechanical activation through a planetary ball mill at distinct rotational speeds (380, 400, 420 and 440 rpm). The investigation discerned that the fly ash content and particle structure exert a discernible influence on macroscopic properties, including flowability, air generation height, compressive strength, dry density and microstructural characteristics such as pore distribution and hydration product arrangement in the geopolymer foam concrete. Employing analytical techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM), it was deduced that diminishing the fly ash content correlates with an enhancement in compressive strength. Furthermore, the specific strength of the geopolymer foam concrete reached a peak of 0.041 when the activated fly ash in the planetary ball mill rotated at 420 rpm, manifesting a lightweight and high-strength outcome.

Analysis of the manufacturing of concrete paving blocks with by-products from thermoelectric power plant

The key factor in constructing urban roads applying interlocking concrete block pavement (ICBP) is to employ an appropriate design method for better effectiveness. Concrete paving blocks (CPB) can also be manufactured using industrial by-products. Then, this paper aims to analyze CPB with coal bottom ash (CBA) from a Thermoelectric Power Plant through mechanical characterization and design methods for ICBP. To this end, tests, such as void index, water absorption, compressive strength, and elasticity modulus, were done on CPB for each mixture. Furthermore, empirical and mechanistic-empirical design methods for ICBP were applied. Then, four dry concrete mixtures (two with CBA and two without CBA) were designed with two water/cement ratios (0.63 and 0.73) to produce rectangular CPB measuring 20 cm × 10 cm × 8 cm (length × width × thickness) by a vibro-press machine. Furthermore, ICBP sections were designed, applying six simulations from empirical and mechanistic-empirical design methods. The results showed that the mixtures A73 and B73 with more water, i.e., water/cement ratio of 0.73, presented higher characteristic compressive strength at 28 days (25.34 MPa and 15.88 MPa, respectively) than the other mixes A63 and B63 with less water, i.e., water/cement ratio of 0.63 (these two mixes showed 15.85 MPa). Furthermore, the CPB application for bike paths or parking areas was allowed according to the Australian specification of 15 MPa for compressive strength test. Also, all ICBP sections from the mechanistic-empirical design required approximately 24.9% fewer materials for the sub-base layer than the empirical process. Finally, the CPB application is possible for areas with light traffic, and the ICBP technology was more feasible with the mechanistic-empirical design method.

Modified Mechanical Strength, Thermal Decomposition, and Combustion Characteristics of Nitroguanidine Propellant with Graphene Nanosheets as Reinforcement

Modified Mechanical Strength, Thermal Decomposition, and Combustion Characteristics of Nitroguanidine Propellant with Graphene Nanosheets as Reinforcement

EXPERIMENTAL INVESTIGATION AND INTELLIGENT PREDICTION OF MECHANICAL STRENGTH OF PERVIOUS CONCRETE

This study determines the mechanical strength characteristics of pervious concrete using fuzzy logic. During construction, the process of determining the quality of concrete produced takes about 28 days before testing, training the fuzzy logic model through the research data gotten from the laboratory experiments in order to intelligently predict the mechanical strength of pervious concrete. Crushed granite was used in this experiment to ensure the pervious concrete has a little degree of fine aggregates and the maximum size of coarse aggregate used was 20 mm. Compressive, flexural and split tensile strength tests were carried out on pervious concrete of mixing ratios 1:4, 1:5 and 1:6 with each of the mixing ratios having varying water to cement ratios of 0.4, 0.5, 0.6 and 0.7. The developed fuzzy logic model was applied to predict the mechanical strengths of the concrete by using data obtained from experimental results, with input parameters of water content, crushing value, weight and density and the mechanical strengths as the output parameters employing the triangular membership function. The model was calibrated using the error measures of the root mean square error (RMSE), mean absolute percentage error (MAPE) and R squared were computed for the model. In this study, it was observed that higher water to cement ratio slightly reduces the mechanical strength of PC but increases the workability compared to increase in cement to granite ratio which notably increases the strength and reduced the workability, alternatively, higher water to cement ratio causes a notable decrease in permeability of the pervious concrete. The correlation between the experimental and predicted values was excellent. This shows that fuzzy logic can be used to predict the mechanical properties of pervious concrete, and fuzzy logic can also be used to appropriately deduce missing values in the mechanical properties of PC subject to further research

Study on large scale direct shear test on soil-rock mixture with multiple grain grades in high fill slope engineering

Soil-rock mixtures are multiphase natural geological materials composed of mineral particles of multiple grain sizes, and have significant natural characteristics of multiscale material groups. In order to investigate the shear strength characteristics and deformation failure characteristics of soil-rock mixtures with multiple grain sizes under in-situ conditions in fill engineering, samples of soil-rock mixtures with multiple grain sizes under in-situ conditions were prepared, and large-scale in-situ direct shear tests were conducted under natural and water-soaked conditions. The test results showed that the shear strength of soil-rock mixtures is relatively high, and after saturated by water immersion, its shear strength decreases significantly, mainly manifested in the decrease of internal friction angle while the cohesion remains basically unchanged. The cohesion of soil-rock mixtures with multiple grain sizes is mainly provided by the shear-breaking cohesion of coarse particles such as gravel in the soil-rock mixture, and its degree of exertion is controlled by the grading characteristics and particle morphology of the soil-rock mixture and affected by constraints. The reason for the significant decrease in shear strength of soil-rock mixtures with multiple grain sizes after water-soaked saturation can be explained as follows: the clay film covering the surface of coarse particles becomes soft after water immersion, resulting in a significant decrease in the sliding friction resistance between coarse particles and the clay film, as well as the occlusion friction resistance generated by the rotation transfer between coarse particles through the clay film interface.

Strength Characteristics and Rheological Behavior of a High Level of Fly Ash in the Production of Concrete.

This study investigates the valorization of coal fly ash (FA-C) generated by the Jerada thermal power plant, aiming to address the pressing need for sustainable construction practices and reduced greenhouse gas emissions in the concrete industry. It is widely used as a pozzolanic material. The key objective is to harness the potential of FA-C as a supplementary material in concrete production, which not only reduces costs but also contributes to environmental sustainability. To achieve this objective, various concrete mixtures were formulated, with FA-C serving as a partial substitute for cement at percentages ranging from 15 to 50%. According to ASTM standards, compressive strength tests were conducted on standard-sized cylinders at 7 and 28 days. The results revealed that the blend containing 15% FA-C exhibited the highest compressive strength, indicating its effectiveness as a concrete additive. Furthermore, this study delves into the rheological properties of concrete mixes, an essential aspect of successful concrete processing. It was observed that a higher replacement level of FA-C significantly improved the rheology, leading to reduced water demand and a linear decrease in plastic viscosity over time. The rheological parameters stabilized after a certain period, demonstrating the controllability of concrete flow behavior with FA-C. The investigation also employed three analytical methods-Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM)-to comprehensively analyze both raw materials and processed samples. FTIR analysis highlighted the minimal impact of FA particles on hydration product formation, emphasizing the role of FA-C in enhancing the concrete's strength. XRD analysis confirmed the presence of an amorphous phase crucial for FA's reactivity. SEM observations revealed that concrete with 15% FA-C exhibited a more uniform microstructure with aluminosilicate gel, while 50% FA-C mixes showed increased porosity and nonhomogeneity due to unreacted FA particles.

PCCP Mortar Protection Layer Research Progress

Prestressed steel cylinder concrete pipe (PCCP) has the characteristics of high strength, excellent impermeability, strong sealing and easy installation, and has become an irreplaceable first choice pipe in China's long-distance water diversion project. However, in the process of using PCCP, there will be pipe bursts and other phenomena, most of which are caused by the broken wire of the prestressed steel wire, and the most important function of the protective layer of PCCP mortar is to protect the prestressed steel wire. In this paper, the research progress of PCCP by scholars at home and abroad is reviewed from five aspects: PCCP working environment, mortar mechanical properties, mortar durability, mortar thickness and mortar curing. as well as testing the durability of the mortar through different solution environments; The research prospect of the production of PCCP mortar protective layer, the detection of PCCP mortar protective layer, and the monitoring of PCCP mortar protective layer were carried out, which provided reference enlightenment for the development of PCCP mortar protective layer.

Implementation of Large-Format 3D Façade Components Using Glass Fibre Reinforced Concrete:ČSOB Hradec Králové, C&A Zürich, Illuster Uster

Glassfibre reinforced concrete (GRC) is a close-grained concrete material reinforced with glass fibres that allows architects complete freedom in designing rear-ventilated façades. It can be shaped, coloured, surface-treated or otherwise tailored to the specific needs of their projects without significant limitations. The main properties of GRC material include its long life-time and sustainability. The results are visually appealing façade panels that can withstand adverse weather conditions for decades. The characteristic high strength and durability is achieved by dispersing glass fibres within the base mixture of Portland cement, sand, water and further refining additives. Fine-grained particles in the composite structure ensure low water absorbency and high frost resistance. This article is an overview of the technical solution and process of GRC façade design. It deals with the design possibilities for anchoring large-format and 3D shaped façade panels. The article further presents all of the above-mentioned characteristics and process details as they are used on three specific structures. The first presented project is the ČSOB Central Office in Hradec Králové, with its typical distinct ledges combined with glazed surfaces. The cascading entrance portal is a significant element of its façade. The next implementation chosen is the renovation of the C&A department store building in Zürich, Switzerland. This building’s façade is comprised of structured large-area panels with distinctive frames. The article concludes with the creatively implemented renovation of the Illuster shopping centre in Switzerland, with its kaleidoscopic façade made up of glassfibre reinforced concrete panels.

Investigating the impact of alkaline activator on the sustainability potential of geopolymer and alternative hybrid materials

Geopolymer binders are considered highly sustainable due to their utilization of industrial wastes. However, previous studies highlight the limited industrial-scale applications of geopolymers. Therefore, this study critically investigates the strength, cost, and environmental impact of geopolymers and alternative hybrid cement mixes to provide a complete picture for the sustainability analysis. Geopolymers and hybrid cement mixes are designed with varying proportions of alkaline activator (sodium hydroxide 5–25 wt%) and ordinary Portland cement (OPC) (15–35 wt%) respectively for the comparative analysis. The strength characteristics of designed mixes have been assessed by analyzing their compressive strength and microstructure. A comparative economic assessment has been made by contemplating the manufacturing and production costs of different materials used in geopolymer and hybrid cement mixes. ReCiPe Midpoint Life cycle assessment (LCA) has been performed to examine the environmental performance by considering the manufacturing and production processes of various binder and aggregate materials used in geopolymer and hybrid cement mixes. Mechanical and microstructural analysis shows that hybrid cement mix with 35 wt% of OPC yields the highest strength due to the formation of excess calcium aluminum silicate hydrate (C-A-S-H) and calcium silicate hydrate (C–S–H) gels than geopolymer mix containing 25 wt% of NaOH. Economic and life cycle assessment reveals that the geopolymer mix with 5 wt% NaOH offers the lowest cost and environmental impact as compared to others containing higher proportions of alkaline activator and OPC. Owing to the conflicting nature of the results, multi-criteria decision making approach has been used which presents the hybrid cement mix (with 35 wt% OPC) as the optimal and sustainable solution for the construction applications. The study's findings offer a sustainable direction for the construction industry by suggesting the application of hybrid concretes.

Evolution Characteristics of the Strength and Dilation Parameters of Gas Hydrate-Bearing Sediments and a Modeling Study

Gas hydrate has gradually become a new potential energy resource. However, some engineering and environmental problems related to the mechanical properties of gas hydrate-bearing sediments (GHBS) during gas recovery may occur. Many studies have been carried out on the basic mechanical properties of GHBS samples based on laboratory tests, but their evolution characteristics and suitable models require further research. Based on a series of data analyses of published laboratory experimental results on GHBS samples with different hydrate saturations under various confining pressures, the evolution characteristics of strength and dilation parameters were investigated. It was found that cohesion (c) increases quickly to a peak value and then decreases gradually to a residual value with an increasing plastic shear strain, and the samples with higher hydrate saturations have higher initial values, peak values, and residual values of cohesion (c). The internal friction angle (φ) increases quickly with increasing plastic shear strain and then becomes stable at a residual value for all the samples with different hydrate saturations. The dilation angle (ψ) increases from negative to positive values with increasing plastic shear strain and then becomes stable at a residual value. These characteristics are likely to be related to the compaction occurring at the early stage of compression before expansion due to dilation. In this paper, a non-linearly fitted model is proposed considering the evolution of the mechanical parameters, and the verification tests show that the proposed model can simulate the stress–strain behaviors of the GHBS samples well. This model is also adopted in the stability analysis of submarine slopes containing hydrate reservoirs. The analytical approach is developed, accompanied by the strength reduction method.

Three-dimensional numerical simulation of dynamic strength and failure mode of a rock mass with cross joints

To study the dynamic mechanical properties and failure characteristics of intersecting jointed rock masses with different joint distributions under confining pressure, considering the cross angle α and joint persistence ratio η, a numerical model of the biaxial Hopkinson bar test system was established using the finite element method–discrete-element model coupling method. The validity of the model was verified by comparing and analyzing it in conjunction with laboratory test results. Dynamics-static combined impact tests were conducted on specimens under various conditions to investigate the strength characteristics and patterns of crack initiation and expansion. The study revealed the predominant factors influencing intersecting joints with different angles and penetrations under impact loading. The results show that the peak stress of the specimens decreases first and then increases with the increase of the cross angle. When α < 60°, regardless of the value of η, the dynamic stress of the specimens is controlled by the main joint. When α ≥ 60°, the peak stress borne by the specimens decreases with increasing η. When α < 60°, the initiation and propagation of cracks in the cross-jointed specimens are mainly controlled by the main joint, and the final failure surface of the specimens is composed of the main joint and wing cracks. When α ≥ 60° or η ≥ 0.67, the secondary joint guides the expansion of the wing cracks, and multiple failure surfaces composed of main and secondary joints, wing cracks, and co-planar cracks are formed. Increasing lateral confinement significantly increases the dynamic peak stress able to be borne by the specimens. Under triaxial conditions, the degree of failure of the intersecting jointed specimens is much lower than that under uniaxial and biaxial conditions.

Strength Characteristics, Ultrasonic Wave Velocity, and the Correlation between Them in Clay Bricks under Dry and Saturated Conditions.

One of the methods used to discover the development of deterioration in bricks used as a construction material in a building is the monitoring of the bricks' strength characteristics over time. However, measuring the strength characteristics of bricks used in a building requires sampling for performing laboratory tests, which is not possible in some cases. As an alternative, ultrasonic wave velocity can be a useful, nondestructive tool for the indirect assessment of the strength characteristics of the bricks. In the present study, six different samples of clay bricks before utilization as construction materials in buildings located in Khorramabad City (Lorestan Province, western Iran) were collected. The mineralogical composition of the samples was studied using X-ray diffraction (XRD) analysis. As one common physical characteristic of the construction materials, the porosity (n) of the samples was measured. Next, the strength characteristics, including uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), and P-wave velocity (Vp), of the samples under dry and saturated conditions were determined. It was found that after the saturation of the samples, considerable decreases in the UCS and BTS and increases in the Vp occurred, respectively. By comparing the values of the UCS, BTS, and Vp of the samples under dry and saturated conditions, we found that the integrity loss for the UCS and BTS was higher than for the Vp. Results showed that the integrity loss of the UCS, BTS, and Vp was significantly affected by the n and clay mineral (CM) content of the samples. Considering the dry or saturated condition of the samples, there are good correlations with acceptable accuracy levels between the Vp and the UCS and BTS, with coefficients of determination (R2) varying from 0.95 to 0.98. Consequently, our findings showed that establishing UCS and BTS predictive equations for bricks before their use as a construction material can be a worthy, practical tool for monitoring the deterioration of bricks over time after their utilization in a building.

Strength Characteristics of Carbon Fiber Reinforced Plastic in Shear and Cyclic Extension-Compression after 7 Years of Climate Exposure

The results of studies of carbon fiber reinforced plastic (CFRP) for aviation purposes based on the Cycom 977-2 epoxy binder and Tenax® IMS carbon fibers after 7 years of exposure under a canopy and on an open atmospheric stand in the warm humid climate of Sochi are presented. The influence of climatic aging is determined by the change in strength parameters during interlaminar shear and cyclic tension – compression. After exposure under a canopy, the strength characteristics during interlaminar shear and cyclic tension–compression increase by 7–13 %. If the plate is under the direct influence of solar radiation, then the strength characteristics of the material are slightly reduced, but remain at the level of the original values. The kinetic concept of fracture was used to interpret the results. The thermal activation analysis showed that the characteristics of the inelasticity of the plate specimens, both in terms of the relaxation and hysteresis parts of energy absorption, correspond to their strength characteristics.

Изучение эволюции микроструктуры и механических свойств в алюминиевом сплаве 1570 с добавкой 0,5 % гафния

Introduction. Aluminum alloys are in high demand with the aerospace industry. From the viewpoint of various performance characteristic combinations, high-magnesium aluminum alloys with the addition of transition metals, such as Zr and Sc, are among the most future-oriented alloys. Alloy 1570 is one of the most popular in this group. Recent studies demonstrated the positive effect of 0.5 % hafnium addition on as-cast structure. Study objective is to study the effect of the addition of 0.5% hafnium on the structure and properties of aluminum alloy 1570 during thermomechanical treatment. The study addresses the effect of cold rolling, homogenization, and recrystallization annealing on mechanical properties and microstructure of the specimens from alloy 1570 and similar alloy with 0.5 wt. % hafnium addition. Study methodology: for the study, ingots were cast from alloy 1570 with and without additions of 0.5 wt. % of hafnium. The resulting ingots were homogenized for 4 h at 440 °С, followed first by hot rolling and then cold rolling. Cold-rolled specimens were annealed at temperatures 340 °С to 530 °С with a holding time of 3 hours. The homogenized, cold-rolled, and annealed specimens were examined using transmission and light microscopy. In addition, homogenized and cold-rolled specimens were subjected to uniaxial tensile tests to determine the mechanical properties of the studied alloy. Results and discussion. It is revealed that in an alloy containing hafnium, after homogenization annealing, there is a slight decrease in the average particle size and an increase in its total proportion in comparison with alloy 1570. In general, 0.5 % hafnium addition does not significantly affect the mechanical properties. The number of nanoparticles in both alloys increases, as does the yield strength compared to the as-cast state. When heated, both alloys demonstrate an increase in plasticity and a decrease in strength characteristics. Studies of the annealing effect on the grain structure of the studied alloys showed that hafnium increases the tendency of alloy 1570 to recrystallize. However, additional research is required to determine the reasons for this phenomenon.