Composition Of Concrete Mixture Research Articles

TECHNOLOGICALITY OF FORM SYSTEMS AT DIFFERENT METHODS OF CONCRETE PREPARATION

It is shown that many scientific publications and researches in the field of monolithic house-building aredevoted to increase of efficiency of use of formwork systems as the most labor and economically expensive area. It isnoted that up to 50 % of the costs are for formwork, including the cost of renting or purchasing, its installation,maintenance, storage and remuneration. It is presented that with the development of formwork systems their technologyis improved, in particular the regulatory framework is improved to reduce the complexity of the work, adjustments aremade to the size of the formwork, it becomes more uniform, reduces the number of connections, increases the turnoverof formwork systems, which also reduces costs.It is shown that a very important issue, inseparable from monolithichousing is the improvement of design with the composition of concrete and concrete mixtures. One of the promisingУкраїнський журнал будівництва та архітектури, № 4 (004), 2021, ISSN (Print) 2710-0367, ISSN (Online) 2710-0375 17 areas of technology improvement is to reduce the time of the set of design strength. The question of the accelerated setof durability by concrete at hardening is very actual in the conditions of the market and high cost of rent of a timbering.Predicting the accelerated growth of concrete strength, respectively, will establish the morning timing of removal offormwork systems. The graph of dependence of time of a set of durability by concrete, for example at activation ofcement suspension in an electromagnetic field in comparison with standard data of hardening is specified. The reductionof the term (days) of keeping concrete in the formwork is shown, it improves the manufacturability of its use,accordingly it causes a reduction of all costs, incl. reduction of construction time and, accordingly, acceleratedmovement of funds and economic profit due to the earlier commissioning of facilities.The area of perspectiveresearches on establishment of interrelation of indicators of efficiency from parameters of object and technology isformulated. This gives a theoretical justification for further computational experiments. The object of research is theproduction processes with the use of collapsible formwork systems for frame-monolithic construction. The subject ofthe study are indicators of manufacturability of the use of formwork systems. The purpose of scientific and appliedresearch is the ability to show the increase of manufacturability of construction by ensuring the normative turnover offormwork by intensifying the hardening of concrete in frame-monolithic construction with a reduction in the duration ofthe strength of concrete. As a result of research the following tasks were defined: the area of further researches isformulated, ways of reduction of the basic technical and economic indicators are offered, the expedient theoreticalsubstantiation of the further computational experiments is proved.

Recovery of Residues of Surface and Emulsion Waste Water Treatment at a Bearing Factory

The directions of utilization of production wastes of the second level, namely, residues of surface and emulsion waste waters treatment of a bearing factory, are given. The results of studies of a new composition of asphalt concrete mixture obtained on the basis of foam, sludge from the treatment of surface water and oily sludge from the treatment of emulsion wastewater from a bearing factory are presented. A technological scheme for the reuse of waste water from surface and emulsion wastewater treatment at a bearing factory has been developed.

An investigation of the effect of thermoplastic additives in asphalt concrete mixtures on the properties of different types of asphalt concrete

The effect of modification of asphalt concrete mixtures of different grain sizes with “Ric-Polycell” (Ukraine) and “Duroflex®-SMA” thermoplastic polymers (Germany), which were added directly to the asphalt mixer during their preparation, on the properties of asphalt concrete was studied. It is confirmed that it is more expedient to use stone mastic asphalt concretes with a larger size of mineral crushed stone grains on high-traffic roads, as they are more rutting-resistant compared to asphalt concretes with smaller size and content of crushed stone grains. The effect of the temperature of preparation and thermostating of asphalt concrete mixtures modified with the investigated thermoplastics on the compressive strength of asphalt concrete at a temperature of 50 °С, which were made of the studied mixtures, was investigated. It was found that the maximum possible temperatures of preparation and thermostating of asphalt concrete mixes provide a more complete modification. The effect of the content of thermoplastic polymers in the composition of asphalt concrete mixtures on the properties and rutting resistance of fine-grained asphalt concrete, as well as stone mastic asphalt concrete, was studied. It was found that adding the “Ric-Polycell” polymer in the amount of 1.5 % and 3 % by weight of bitumen in the composition of the studied asphalt mixtures in the asphalt mixer during their preparation increases the rutting resistance of asphalt concrete under the studied conditions by 2.52–3.86 times. Modification of asphalt concrete mixtures with the “Duroflex®-SMA” additive in the amount of 0.3 % and 0.6 % by weight of the aggregate by a similar technology also allows increasing the rutting resistance of the obtained asphalt concrete by 1.86–3.16 times. Using these modifiers in the future will have a positive effect on the service life of the entire pavement structure

АНАЛІЗ ЕКСПЕРИМЕНТАЛЬНИХ ДОСЛІДЖЕНЬ ФІЗИКО-МЕХАНІЧНИХ ВЛАСТИВОСТЕЙ ЕПОКСИАСФАЛЬТОБЕТОНУ ДЛЯ ЙОГО ЗАСТОСУВАННЯ У ЯКОСТІ МОСТОВОГО ПОКРИТТЯ НА АВТОМОБІЛЬНИХ ДОРОГАХ

Introduction. This paper considers the issue of improving the quality of coatings on road reinforced concrete, reinforced concrete bridges or metal bridges with orthotropic slab. The constructive decisions of increase of working capacity and fatigue durability of asphalt concrete coverings are offered. The results of the analysis of experimental researches of physical and mechanical properties of epoxy asphalt concrete are given. The efficiency of epoxy components in asphalt concrete mixtures, which significantly improve the physical and mechanical properties of bitumen, is shown. According to the results of experimental laboratory tests, a comparative analysis of the properties of epoxy asphalt concrete and source asphalt concrete on viscous and rarefied bitumen is given. Also, the influence of the duration and temperature of curing of epoxy components on the properties of epoxy asphalt concrete was analyzed. Problem statement. In today’s conditions of high-speed intensive traffic, high traffic loads and adverse weather and climatic factors that occur in our country, increasing the durability of pavements on bridges to increase service life and reduce costs associated with maintenance, requires special attention. One of the effective ways to improve the quality and durability of asphalt pavements on road bridges is the modification of bitumen by using as the main material thermosetting polymer additives, in our case – epoxy components (epoxy resin and its hardener). Objective. The purpose of the analysis of experimental studies of physical and mechanical properties of epoxy asphalt concrete is to study the possibility of its use as a pavement on highways. As well as confirmation of efficiency in solving the problem of achieving increased fatigue life of such coatings at different load frequencies by increasing track resistance, strength, crack resistance and at the same time solving no less important issue to minimize the cost of repair and construction work during bridge operation. Materials and methods. Asphalt concrete coverings on orthotropic or reinforced concrete slab of the carriageway of the bridge with improved physical and mechanical properties due to the use of thermosetting polymer additives as a bitumen modifier. Results. The analysis of experimental researches of physical and mechanical properties of epoxy asphalt concrete is carried out and efficiency of its application for improvement of quality of coverings on road bridges and increase of their durability is defined. A set of studies was conducted to compare the properties of epoxy asphalt concrete and source asphalt concrete on viscous and rarefied bitumen. Conclusions. To increase the fatigue life of asphalt pavements on road bridges in modern conditions of high traffic intensity in our region with a wide range of operating temperatures, it is necessary to develop new solutions for the use of building materials. That is why the study of physical and mechanical properties of asphalt concretes improved by thermosetting polymer additives in order to determine their true effectiveness in improving track resistance, strength and crack resistance of coatings based on them is an urgent issue today. The use of epoxy-asphalt concrete coating on orthotropic or reinforced concrete slab of the carriageway of the bridge requires special attention in establishing the optimal duration and curing temperature of epoxy components, which can dramatically affect its physical and mechanical properties and determine the cooking technology. Keywords: epoxy asphalt concrete, epoxy asphalt concrete mixture, physical and mechanical properties of epoxy asphalt concrete, composition of epoxy asphalt concrete mixtures, epoxy resin, road bitumen, modification of bitumen, properties of bitumen, durability of paving.

Dependence of Physical and Mechanical Characteristics on the Specific Surface of Mineral Particles in Asphalt Concrete

The ever-increasing intensity of traffic and axial loads from motor vehicles is forcing material scientists and road-building organizations to develop and use asphalt concrete with higher physical, mechanical and operational characteristics. An integral part, when creating new compositions of asphalt concrete mixtures, is the study of the processes going on at the phase boundary “surface of mineral particles - organic binder”.In the presented studies, mineral materials with different specific surfaces were considered. To study the effect of the specific surface on the physical and mechanical properties of asphalt concrete, the following were used: natural sand, quartz sand, and waste foundry sand. To obtain an objective result of the study, all materials were selected with the same size modulus. The first stage of laboratory research was aimed at studying the structure and surface shape of the particles of stone materials. The second stage consisted of molding asphalt concrete samples and determining their physical and mechanical characteristics. Three compositions of asphalt concrete have been studied.The presented studies confirm the theory put forward earlier by the authors about the mechanism of interaction of the surface of mineral particles with an organic binder. An increase in the specific surface of stone materials increases the adhesion force of bitumen to the surface of stone materials. It has been established that a well-developed, rough surface of particles of mineral aggregate in asphalt concrete can act as an effective modifying element. An increase or decrease in the specific surface area of the particles of mineral aggregate, with the same modulus of fineness, it is possible to achieve a proportional change in the strength characteristics of asphalt concrete using bitumen. With an increase in the specific surface of the particles of mineral aggregate in the asphalt mix, it is possible to create asphalt concrete capable of resisting increasing loads from the rolling stock.

Influence of a new dispersant additive amount on the structural and rheological properties of chamotte concrete and samples from it

The use of dispersing additives in the composition of concrete mixtures helps to reduce water demand, increase flow, increase strength after hardening in air. The effect of a new dispersant additive amount on a polycarbonate base in comparison with the currently used phosphate-containing additive on the structural and rheological properties of chamotte concrete from a mixture of the “SSHBD” grade and samples from it has been investigated. The optimal amount of new dispersant additive on the polycarbonate base has been established and it has been shown that, in its effect on the structural and rheological properties of concrete from a mixture of the “SSHBD” grade and the properties of samples from it, it is similar to the phosphate-containing additive used at present. The change nature of the concrete flowability is practically the same. "Vitality" (i.e. the time period during which the concrete mass is suitable for performing high-quality lining by vibrocasting) of the compared concretes is ~ 4 hours; cold crushing strength of concrete samples with additives after hardening in air for 7 days and heat treatment at a temperature of 110 °C, as well as cold crushing strength of samples after firing at a temperature of 1350 °C are practically the same. The use of new polycarbonate-based dispersant can be recommended for the preparation of chamotte concrete as an alternative phosphate-containing additive.

Changes in the Fracture Toughness under Mode II Loading of Low Calcium Fly Ash (LCFA) Concrete Depending on Ages.

This study investigated the influence of the curing time on the fracture toughness of concrete produced with different content of low calcium fly ash (LCFA). During the study, the amounts of 20% and 30% of pozzolanic additive were used. In order to observe the effect of the applied pozzolanic additive on the analyzed concrete properties, the obtained results were compared with the values obtained for the reference concrete. Compressive strength—fcm and fracture toughness, by using mode II loading—KIIc (shearing), were determined between the 3rd and 365th days of curing. In the course of experiments, changes in the development of cracks in individual series of concrete were also analyzed. In addition, the microstructures of all composites and the nature of macroscopic crack propagation in mature concretes were assessed. It was observed that the greatest increase in fracture toughness at shear was in the case of reference concrete during the first 28 days, whereas, in the case of concretes containing LCFA, in the period of time above 4 weeks. Furthermore, concrete without the LCFA additives were characterized by a brittle fracture. In contrast to it, concretes with LCFA additives are mainly characterized by a quasi-plastic process of failure. Moreover, most of the samples showed a typical pattern of the destruction that occurs as a result of shearing. The presented test results may be helpful in selecting the composition of concrete mixtures containing LCFA to be used in concrete and reinforced concrete structures subjected to shear loads.

Algorithm formulation for adjusting the estimated composition of concrete mixture taking into account relevant properties of the raw materials

This article deals with the research dedicated to the formulation and testing algorithm of water amount adjustment tempering while producing concrete mixtures depending on raw material characteristics. The algorithm is intended for an automated quality control system of concrete mixtures of raw components, providing continuous data collection in real time. The article provides the necessity of automatic quality control implementation and adjusting the calculated compositions of concrete mixtures based on them. There is the discussion of factors discouraging the formulation and implementation of the given systems at the existing production of reinforced concrete products. There were formulated the ways of solving the problems, the scientific significance of the proposed projects was proved. There was revealed the main parameter of the concrete mixture, which provides the concrete quality obtained on its basis and factors influencing it associated with the physicochemical characteristics of raw materials are shown.

Construction Materials with Tailings of Quartzite Enrichment

The composition and properties of the tailings of quartzite enrichment of “Gora Karaul’naya” deposit, the possibility of its using as an aggregate in the composition of heavy and fine-aggregate concrete and dry construction mixture were determined. The introduction of quartzite tailings increases the water demand of the mixture, reduces the compressive strength of concrete and mortar, increases the bending strength compared to quartz sand.

Influence of quality indicators of the surface of mineral particles on the properties of asphalt concrete

Increasing traffic loads are driving the demand for durable asphalt concrete. The creation of new compositions of asphalt concrete mixtures is possible by studying the structure-forming processes at the interface between the phases “surface of mineral particles-organic bindef”. The presented study makes it possible to assess the degree of influence of the specific surface area on the physical and mechanical properties of asphalt concrete. Were considered fine mineral materials with different specific surface (natural sand, quartz sand, waste molding sand). They were matched with the same size modulus. At the first stage, the structure and shape of the surfaces of the particles of mineral materials were determined. At the second stage, the physical and mechanical characteristics of three asphalt concrete compositions were determined. It has been established that a well-developed, rough surface of mineral aggregate particles in asphalt concrete can act as an effective modifying element in the composition of asphalt concrete and achieve the desired physical and mechanical characteristics. An increase in the specific surface area of the mineral aggregate particles, with the same size modulus, makes it possible to proportionally increase the strength characteristics of asphalt concrete.

THE EFFECT OF COMPLEX MULTI-PURPOSE ADDITIVE ON OPERATING PROPERTIES OF HYDRATED CEMENT AND CONCRETE

The research developments in materials science in the construction field concerning the formulation and production process of fine-grain concrete are aimed at the formation of structure and properties that provide the appropriate performance characteristics. The literature review and experimental data on the concrete treatment made show that the required quality of concrete can be achieved by changing the concrete mixture composition, activation of aggregate and mixing water, introduction of multi-purpose modifying additives, different approaches, etc. The paper presents the development of the effective multi-purpose additive consisting of such industrial wastes as marble-microcalcite, nano silicon dioxide, microsilica, and peat hermally modified at 600 °C. The influence of this additive on hydrated cement and concrete properties is studied herein. It is shown that the introduction of the multi-purpose additive in an amount of 5 % with a decrease in the cement consumption, improves the compressive strength of hydrated cement stone up to 69 %. The chemical composition of new formations of modified hydrated cement is determined by the physicochemical analysis.

OPTIMIZING THE USE OF ROCK ASH AS FINE AGGREGATES WITH THE ADDITION OF ADDITIVES TO THE CONCRETE MIXTURE WITH A COMPRESSIVE STRENGTH OF 350 Kg/cm2


 
 
 
 Stone dust nowadays is a side product of the stone crushing industry, the quality of which is quite a lot that it becomes a waste that needs to be handled. This study is intended to find out the composition of stone dust by adding some additive substance type D and type F to reach a compressive strength of 350 kg/cm2. The variation of percentage of stone dust on the composition of concrete mixture is 0%, 20%, 40%, 60%, 80%, 100%. The design of concrete mixture composition refers to the procedure of making preparation of the normal concrete mixture. SNI 03-2384-1993. The size of the cylinder test object is 15 cm in diameter and 30 cm in height.
 The result of this research shows that the mixture using stone dust has quite an effect on the compressive strength of concrete. From the result of the experiment, it is shown that for compressive strength of 350 kg/cm2, we can use 100% of stone dust with a resulted compressive strength of 445 kg/cm2.
 
 
 

Встановлення складу епоксиасфальтобетоних сумішей для їх застосування в якості тонкошарового покриття на автомобільних дорогах та мостах

Встановлення складу епоксиасфальтобетоних сумішей для їх застосування в якості тонкошарового покриття на автомобільних дорогах та мостах

Reactivity Index and Strength Development of High Strength Concrete with GGBFS Cement

The slag cement industry in Indonesia is growing in tandem with the smelter industry as a supplier of slag material. The use of slag cement instead of ordinary cement can reduce CO2 emissions. This research aimed to design the mixture composition of slag cement and ordinary cement for high-strength concrete. Standard concrete cylinders and concrete beams were tested to gain the compressive, tensile and flexural strength. The testing results indicate that generally, the concrete mixture compositions of low GGBFS (25%) gained their optimum strength at the age of 28 days while concrete with high composition of GGBFS (55%) achievedsimilar strength at the age of 90 days.A mixture using higher percentage replacement of GGBFS might attain its optimum strength at the longer ages. The use of Silica Fume (SF) in high-strength concrete mixtures with GGBFS found ineffective to increasethe concrete strength as the results indicate that concretes with SF have lower strength compared with non-SF concrete mixtures.

Problems and prospects of self-compacting concrete mixes for high-strength concrete

The prospects and problems of multilevel optimization of the dispersed composition of self-compacting concrete are considered with the aim of significantly increasing its construction and technical properties, with a minimum content of binder. Theoretical and practical principles have been developed for designing the rational composition of concrete with an increased concentration of solid phase per unit volume and operational properties with a complex organomineral additive based on the optimal ratio of finely dispersed mineral and chemical components that optimize its dispersed composition and structure. It is shown that it is advisable to use particles of the clinker phase of several geometric sizes. To study the properties and structure of concrete, we used two fractions of fine aggregate, granite-gab rubble FR. 5-10 mm, Portland cement of class CEM I 42.5N, finely dispersed granulated blast furnace slag, metakaolin, silica fume, highly dispersed cement fraction, Glenium 430 superplasticizer and highly valent hardening accelerator. Research methods: the shape and size of the dispersed particles of the components were determined by a laser analyzer, the mobility of the concrete mix in accordance with GOST 10181-2014, the compressive strength of concrete in accordance with GOST 10180-2012. The structure of the cement stone was studied using scanning electron microscopy, thermographic and X-ray phase analysis methods. The strength of concrete with an optimized dispersed composition, superplasticizer and a highly valent hardening accelerator prepared using self-compacting concrete mixtures, aged 1 day after hardening under normal conditions (NU) was 58; 67; 77, and in 28 days - 150; 186; 219 MPa with cement consumption of 650, 710, 770 kg/m3, respectively. Multilevel dispersion-granulometric analysis in combination with chemical modification of the composition of self-compacting concrete mixtures ensures the synthesis of high-strength concrete with a minimum consumption of Portland cement and high physical and mechanical properties. It is advisable to use several structural levels of particles of the clinker component.

Machine learning prediction of mechanical properties of concrete: Critical review

Accurate prediction of the mechanical properties of concrete has been a concern since these properties are often required by design codes. The emergence of new concrete mixtures and applications has motivated researchers to pursue reliable models for predicting mechanical strength. Empirical and statistical models, such as linear and nonlinear regression, have been widely used. However, these models require laborious experimental work to develop, and can provide inaccurate results when the relationships between concrete properties and mixture composition and curing conditions are complex. To overcome such drawbacks, several Machine Learning (ML) models have been proposed as an alternative approach for predicting the mechanical strength of concrete. The present study examines ML models for forecasting the mechanical properties of concrete, including artificial neural networks, support vector machine, decision trees, and evolutionary algorithms. The application of each model and its performance are critically discussed and analyzed, thus identifying practical recommendations, current knowledge gaps, and needed future research.

ИЗУЧЕНИЕ ФИЗИКО-МЕХАНИЧЕСКИХ СВОЙСТВ АСФАЛЬТОБЕТОННЫХ ОБРАЗЦОВ НА АКТИВИРОВАННЫХ МИНЕРАЛЬНЫХ ПОРОШКАХ РАЗЛИЧНЫХ СОСТАВОВ

the article presents the results of testing asphalt samples based on activated mineral powder from silica-containing raw materials. Activated filler was obtained by joint grinding of waste wet magnetic separation (WMS) of ferruginous quartzites of the Kursk Magnetic Anomaly in a spherical planetary mill in the presence of surfactants (stearic acid, adhesive additive Amdor-10) and bitumen. First of all, it should be noted that the use of activated mineral powder in the composition of asphalt concrete mixture led to an increase in the packing density of the composite. This was reflected not only in the technological process, but also contributed to the decrease in the porosity of the mineral core. It was found that the use of surfactants in the process of grinding mineral powder made it possible to increase the strength of asphalt concrete samples. However, the change in the crack resistance and shear resistance of asphalt concrete specimens, determined from the ratio of the corresponding compressive strengths, did not occur (table). This is due to the fact that there has been a proportional change in all the strength characteristics at different temperatures. Analysis of the physical-mechanical characteristics of the properties of asphalt concrete led to the conclusion that it was possible to use activated mineral powder from waste WMS as a component of asphalt concrete mixtures.

АНАЛИЗ ВЛИЯНИЯ КАЧЕСТВЕННОГО СОСТАВА АСФАЛЬТОБЕТОННОЙ СМЕСИ НА ОСНОВНЫЕ ПОКАЗАТЕЛИ ХАРАКТЕРИСТИК АСФАЛЬТОБЕТОНА В ПОКРЫТИИ

the paper presents an analysis of information quality assurance of production of asphalt concrete mixtures, as well as the study of the relationship of the qualitative composition of asphalt concrete mixtures and physical and mechanical characteristics of asphalt concrete pavement. The study of the main characteristics was carried out on the example of asphalt concrete type B and grade I and crushed-mastic asphalt concrete – SchMA-20. It is established that the deviation of asphalt mixtures in composition from the required values leads to their under-compaction in the pavement. It is also established that increasing the number of inconsistencies in the asphalt concrete mixture leads to an increase of physical-mechanical characteristics that differ from the requirements of GOST 9128-2013 and GOST 31015-2002 respectively. As an information base for the assessment of the influence of granulometry of the mineral part of asphalt concrete, as well as the amount of bitumen on the main characteristics of asphalt concrete, the data of the current ACP of Belgorod region were used. Analysis of the particle size distribution was carried out using a laser analyzer of asphalt ABA7/35B. The obtained data became the basis for a further study of the influence of various parameters on the properties of asphalt mixes, as well as improving the efficiency of the asphalt mix production management system.

Comparative assessment of the technological properties of mastic and sulfur-mastic asphalt concrete mixtures

The technological properties of mastic and sulfur-mastic asphalt concrete mixtures have been evaluated. The hypothesis has been confirmed that the compositions of mastic asphalt concrete mixtures with crystallization-coagulation structure have increased fracture resistance. Optimal technological modes of producing and paving are recommended.

ФОТОКАТАЛИТИЧЕСКИ АКТИВНЫЕ САМООЧИЩАЮЩИЕСЯ МАТЕРИАЛЫ НА ОСНОВЕ ЦЕМЕНТА. СОСТАВЫ, СВОЙСТВА, ПРИМЕНЕНИЕ

The paper reviews the available technologies for producing photocatalytic active self-cleaning materials based on cement, including concretes and dry building mixtures. Used photocatalytic additives and their influence on the cement system are considered. The applied methods for assessing the photocatalytic activity of self-cleaning cement materials are presented. The compositions of concrete mixtures, their properties, areas and prospects of application are analyzed. The main problems of development, production and application of photocatalytic active self-cleaning materials based on cement are presented. The main directions to increase the self-cleaning ability of photocatalytic active materials based on cement are: optimization of the microstructure of the photocatalyst and the composite with its use in the direction of creating a developed surface of the photocatalyst - hierarchical microstructure; it intensifies the diffusion processes of photocatalytic reaction reagents and increases the contact area photocatalyst with a pollutant; it absorbs and accumulates ultraviolet radiation waves; optimization of the phase composition of titanium dioxide - search for the ratio of the anatase and rutile phases, at which the maximum photocatalytic activity is achieved; choosing of economically feasible method for periodical updating of the surface of concrete products carbonized during operation in order to restore self-cleaning ability.