Search

The escalating quantity of industrial by-products, including oil palm shell (OPS) and palm oil fuel ash (POFA) of palm oil industry which are disposed off as a waste pollutes the environment. Recovering these wastes for product manufacturing would contribute decrease waste discarded at landfill. This research will study the acid resistance of oil palm shell lightweight aggregate concrete containing POFA as partial sand replacement. All concrete mixtures were produced by integrating OPS as coarse aggregate. Unground POFA was used as partial sand replacement up to 20% of fine aggregate. Specimens were immersed in acid solution for certain duration and measured its mass loss as well as compressive strength. Mix containing 10% POFA exhibit the highest resistance towards acid attack. The presence of higher amount of CSH gel and reduction in calcium hydroxide resulted in the lowest deterioration when exposed to an acidic environment. Conclusively, the use of unground fine POFA in concrete manufacturing can be an alternative method for sustainable construction. [ABSTRACT FROM AUTHOR]

Geopolymer Concrete (GPCs) is a novel type of concrete that uses an inorganic alumina silicate binder system rather than the hydrated calcium silicate binder system, which is activated by alkaline liquids. Fly ash is the primary ingredient used to activate the geopolymerization process, as well as to substitute traditional Portland cement. The sole difference between this concrete and standard Portland cement concrete is the binding agent. Sodium hydroxide and sodium silicate solutions were used to activate the substance in fly ash. The geopolymer has the advantages of rapid strength increase, no need for water curing, excellent mechanical and durability features, and is an environmentally safe and sustainable alternative to OPC-based concrete. The manufacture of Portland cement, in particular, results in the release of air pollutants, resulting in environmental pollution in the construction industry. It cuts CO2 emissions by 80-90 percent. This research is to consolidate on the study on characterization and strength of fly ash based geopolymer rigid pavement through compressive strength, water absorption and density. From the results, it is concluded that when the solid to liquid ratio increased, compressive strength and the density will be increased due to the characteristics and properties of the geopolymer concrete however decrease in water absorption. [ABSTRACT FROM AUTHOR]

The need for concrete is growing rapidly every day and cement is utilized to satisfy the requirement for development of infrastructure. The manufacturing of cement products generates a massive concentration of carbon dioxide (CO2) that impacts the ecosystem and surroundings, creates pollution as well as hazardous to human beings. In an effort to minimize the demand for cement and CO2 emission, in this study, alternating cementitious ingredients such as Ground granulated blast furnace slag (GGBFS) and silica fume (SF) were utilized. In this study, NaOH and Na2SiO3 were used to generate ground granulated blast furnace slag based geopolymer concretes that contained various proportions of silica fume, which were then cured at room temperature. Rheological, hardened, and durability properties were investigated. NaOH (14M) and Na2SiO3 were utilized as alkaline solutions to activate the geopolymerization. The findings indicate that the incorporation of SF increased the compressive, splitting tensile and flexural strength of geopolymer concrete. The geopolymer concrete has been observed highly reliable in the existence of 2 percent of sulphuric acid, 5 percent of sodium sulphate and 5 percent of sodium chloride. [ABSTRACT FROM AUTHOR]

The innovation and developments in concrete technology requires the concrete technologist to tailor the mix design of concrete to suit the strength and durability requirements. Modification of concrete is the age-old practice as the normal concrete exhibits drawbacks in terms of durability and flow ability. Several materials are being used for repairs of concrete however; epoxy is used for bonding concrete and also as a repair material confidentially by engineers undisputedly. The addition of epoxy resin to the concrete improves strength, adhesion, and chemical resistance of concrete. Literature and factual figures indicate that even high-performance concrete exhibited distress and deterioration well before reaching their designed service life due to aggressive exposure conditions. Hence there has been a continues technological investigations from 1960 to bring phenomenal changes in normal concrete with the addition of polymeric materials so as to modify ordinary concrete to modern concrete with improved performance in terms of strength and durability. Micro concrete is being used confidently as a repair material by engineers with partial modification by adding flyash, GGBS, polymers and epoxy along with micro aggregate and cement, specially wherever there is a problem of curing and penetration of mortar in inaccessible areas in case of damaged concrete structure. This paper presents a critical review of the development in epoxy modified concrete and micro concretes as value added material in concrete technology. [ABSTRACT FROM AUTHOR]

The study aims to produce concrete using various percentages of hypo-sludge ash (HAS) in place of cement. The waste paper sludge ash is composed of magnesium oxide and calcium oxide. Therefore, it can be tested as an innovative cement replacement, providing a solution for traditional concrete. For this study, the various proportions of ash used are 5%, 10%, and 15% by weight of cement. The mixed design carried out was as per the Indian standard code. The ingredients used for concrete making are cement, aggregates, hypo sludge ash (HSA), superplasticizer, and water. A test mix was carried out to check the behaviour of a concrete mix, and its physical and hardening properties were checked. Cube samples were cured for 3, 7, 14, and 28 days to check hardening properties. Experimental analysis shows that by replacing 5% cement with HSA, the strength results obtained are close to the reference concrete. [ABSTRACT FROM AUTHOR]

There are several methods to raise the asphalt concrete's quality. In this article, the topic of adding surface-active additives to asphalt concrete to strengthen its physical and mechanical qualities is covered (SAA). The employed addition enhances the asphalt concrete's physical, mechanical, and serviceability characteristics. [ABSTRACT FROM AUTHOR]

The article presents the results on the effect of silica-containing fillers on the structure formation of a composite cement binder. Obtaining the results makes it possible to use, the use of active fillers in cement sources makes it possible to reduce the part of the binder without loss of density, which is the result of using the resource of energy-saving research technology in the field of building material. [ABSTRACT FROM AUTHOR]

High strength concrete is currently a very important part in construction, namely construction that has very high strength. The strength of concrete depends on the material used and its size. The size of the concrete constituent materials affects the porosity of the resulting concrete because porosity affects the strength of the concrete. For this reason, efforts are made to use concrete constituent materials that can reduce porosity in concrete. Various materials can be used as additives to give concrete high strength. Among these materials are fly ash and silica fume. Fly ash is a product of coal combustion and functions as a substitute for pozzolanic materials in cement as much as 0, 5, 7.5, 10, 12.5, 15, and 17.5% because it has a very fine grain size < 350 mesh and silica fume ash, which functions as a substitute for fine aggregate 0, 10, 15, 20, 25, 30, and 35% which comes from the ashes of burning refined palm shells with a size < 350 mesh. Materials were prepared, namely: cement, fine aggregate, coarse aggregate, fly ash, silica fume, and weighing water. All the ingredients were stirred until homogeneous and put into a cube-shaped mold measuring 150 x 150 x 150 mm while compaction was carried out using an iron stick, then the mold was left for 24 hours, removed from the mold then soaked in water and soaked in water for 28 days. The compressive strength test and characterization of XRF and XRD and SEM were carried out. Based on the research as outlined in the graph, the maximum compressive strength of substitution of 12.5% fly ash into cement is 45.20 MPa, while the substitution of silica smoke from boiler slag into fine aggregate has a maximum compressive strength of 25% of 50.84 MPa. The results of the XRF characterization of high strength concrete showed that the dominant compounds were 54.60% CaO, and 32.50% SiO2, followed by other compounds. The results of the XRD test showed that the phases formed were calcite (Ca), quartz (SiO2), and anorthite (CaAl2Si2O8) and the distribution of C-S-H was fairly even in the concrete. Thus, fly ash and burning ash of palm shells can affect the compressive strength of concrete for the better, namely the strength increases higher than normal concrete. [ABSTRACT FROM AUTHOR]

Geopolymer concrete is produced without cement, the main material used is fly ash. The alkaline activator solutions used are sodium hydroxide (NaOH) and sodium silicate Na2SiO3. To make geopolymer concrete having a compressive strength according to the plan, one thing that needs to be done is curing. This study examines the effect of the curing method on fly ash-based geopolymer concrete. Three curing methods, namely conventional, heat curing, and steam curing, were used to determine the effect of temperature differences on the compressive strength of geopolymer concrete. Cylindrical specimens used 12 M NaOH, Na2SiO3, water, and fly ash in a ratio of 3:1:6:25. The compressive strength of the concrete was tested on the specimens after 28 days. The results showed that there was an increase in the compressive strength of concrete in heat curing and steam curing at temperatures of 50°, 60°, and 70°C by 8-21% for heat curing and 2-4% for steam curing. [ABSTRACT FROM AUTHOR]

Concrete is the most accepted material in construction as it has better durability than other materials in construction. However, some aggressive substances can reduce their durabilities, such as sulfate attack and chloride ingression. As porosity becomes the main property to improve concrete durability, the utilization of fly ash will be beneficial to reduce concrete porosity. This paper presents the experimental study on durability of high-volume fly ash concretevariationsion of 5%,10%, and 15% of calcium oxide by weight of fly ash were used as addition fly ash content. The testing program consists of compressive strength, elastic modulus test, and rapid chloride penetration test (RCPT) for durability test performance. This study reveals that adding calcium oxide to high-volume fly ash concrete can accelerate setting timebenefitstly, improving concrete compressive strength, modulus of elasticity, and resistance to chloride-ion penetration at a calcium oxide addition of 5%. [ABSTRACT FROM AUTHOR]

The materials which are widely used for construction of the building industry are concrete. But the production of cement releases numerous amounts of greenhouse gases (CO2) that leads to increase in global warming. So, an alternative to cement has to be identified. The current research focuses on the use of mineral admixtures such as fly ash, rice husk ash, and silica fume in place of cement in concrete with the addition of coir fibre. The mechanical properties of the specimens were studied with percentage replacement of cement with various mineral admixtures. With the optimum results flexural behaviour of reinforced concrete were studied. Reinforced concrete beams with percentage replacement of silica fume offered better load carrying capacity. [ABSTRACT FROM AUTHOR]

Impact resistance was the primary goal of preparing a review; thus, it is recommended to do an extensive study to improve the concrete properties, especially from industrial waste materials such as polyethylene terephthalate (PET) fibers. It has shown that nanomaterials have already an ability to treat and strengthen the bond traction between fibers and cement paste by accelerating the hydration reactions at an early age, then consuming the calcium hydrate (CH) and increased the calcium silicate hydrate (C-S-H) which it represents the responsible about the bonding and bridging action. One of the essential qualities of concrete is its impact resistance. Furthermore, combining Nanomaterials and fibers demonstrates how to effect tangible characteristics change. The current state of Nano-materials and Fiber in Concrete is summarized in this brief review. It has been reviewed all studies from 2010-2022. [ABSTRACT FROM AUTHOR]

In this study, lightweight geopolymer concrete was produced based on slag as a binder and using two types of lightweight aggregates (the first type is pumice aggregate resulting from pumice stone crushing, and the second type is bentonite aggregate resulting from converting bentonite clay into aggregate through several stages). This concrete can be considered more environmentally friendly because of its use of slag as a binder and slag as it is known to all that slag is an industrial waste. After pouring the samples and completing the curing period, the compressive strength test was performed and two non-destructive tests (the ultrasonic pulse velocity test and the rebound number test), and then a relationship was found between the compressive strength on the one hand and the non-destructive tests on the other hand, and this relationship is considered very important to estimate the compressive strength of a structure or wall forming of the same type of concrete that has been subjected to certain conditions or dilapidated building through non-destructive tests. As for the best lightweight concrete mix, it is LBB, which contains fine aggregates of bentonite and coarse aggregates of bentonite with a grade (5-25), as it gave a compressive strength of 26.4 MPa. [ABSTRACT FROM AUTHOR]

The feasibility of coloring geopolymer concrete that uses slag as a binder was investigated in this work by employing inorganic pigments and examining the influence of the pigment on certain geopolymer concrete parameters. In geopolymer concrete, tests were carried out with the addition of two pigment types (cobalt blue and iron oxide red), at percent of 0, 2, 4, 6 and 0, 1, 2, 3 %, respectively, of the slag's weight. Values of slump, compressive strength, flexural strength, indirect tensile (splitting) test, permeability test and Fourier transform infrared spectroscopy (FTIR) test were obtained. It was found through the above tests that the optimum percentage of adding pigments is 1% for the red pigment and 2% for the blue pigment. It was concluded through the FTIR test that both pigments that were used in this research did not interact with the other components of the mixtures and did not affect the interaction of the components among themselves. [ABSTRACT FROM AUTHOR]

Geopolymer concrete is green concrete that uses fly ash and alkali activator substituting Portland cement. The use of Fly Ash from different sources produces different concrete characteristics. This study used three different fly ashes obtained from three different coal-fired power plants in Aceh and North Sumatera: Nagan Raya, Labuhan Angin, and Pangkalan Susu, as geopolymer concrete material. The 10 Molar and 12 Molar Sodium Hydroxide (NaOH) solutions were used as a variable in this study. Then, the concrete was tested with a compressive strength test, splitting tensile strength test, flexural tensile strength test, and elasticity modulus test. The specimen for the compressive strength test was 100×100×100 mm cube which was tested at 7, 14, and 28 days. The splitting tensile strength test and modulus elasticity test specimen was 150×300 mm cylinder tested at 28 days. The specimen for the flexure test was 100×100×500 mm beam tested at 28 days. Based on the result, it was found that geopolymer concrete using Pangkalan Susu fly ash and 12 M of NaOH had higher performance than geopolymer concrete using Nagan Raya and mixed fly ashes. Geopolymer concrete made from fly ash is promising to be applied as a construction material for both structural and non-structural elements. [ABSTRACT FROM AUTHOR]

Recent studies show sugarcane bagasse ash and marble waste are used as fillers in concrete mixtures to produce more environmentally friendly construction material. The characteristics of these inputs become the basis for their utilization. Marbles are known to contain silicon-dioxide/silica (SiO2), calcium oxide (CaO), and magnesium oxide (MgO) as the primary chemical components. Meanwhile, the bagasse possesses similar content as the main constituents of Portland cement, including silica (SiO2) and ferrite (Fe2O3) believed to increase the compressive strength of concrete. The aim of this study, therefore, was to determine the effects of the quality of marble waste and bagasse ash on the compressive strength of concrete. This paper applied SNI 03-2834-2000 standard with compressive strength of 30 MPa, cube specimen with 15cm side measurement, and test age of 14 and 28 days. Also, the composition of the mixture was varied at 12% marble waste, 6% bagasse ash, and 12% marble waste mixture+6% bagasse ash. The results showed the 12% marble waste mixture expressed the highest compressive strength of 39.93 MPa or an increase of 25.37% against normal concrete, while the 6% bagasse ash decreased to 26.68 MPa or an estimated -13.25%. This decline is due to corrosion observed in the bagasse and therefore tends to alter the quality of the concrete mixture. Furthermore, 12% of marble waste demonstrated useful workability and is suitable for enhancing compressive strength. [ABSTRACT FROM AUTHOR]

Pervious concrete (PC) is a term refers to a concrete that has a near zero slope and is open-graded. It is normally composed of Portland cement, coarse aggregate (C.A.), less quantity of fine aggregate (F.A.), additives and water. When these components are integrated, a hardened material is formed with interconnected pores that permits easy passage of water. With the growth of construction industry demand of aggregate has also increased and also the construction demolition of structures waste gets deposited more and more per day. As we have a limited source of natural aggregate (N.A.), use of Recycled aggregate (R.A.) would be the easy and sustainable solution. In this work an attempt was made to developing PC with R.A. replacing N.A. with specific proportions. W/c ratio 0.4 and a/c ratio were kept constant for the mix design of PC. Additives such as Fly-ash(F-ash) and styrene butadiene rubber latex were (SBR) were to improve the properties such as compressive strength(c.s.), void ratio(v.r.) and density. A noticeable increment was found in c.s. using SBR up to10% of usage. [ABSTRACT FROM AUTHOR]

The degradation of reinforced concrete (RC) in aggressive environments is caused by a combination of factors ranging from force loading to weathering, to various chemical agents. Reinforcement corrosion in RC structures caused by excessive chloride ion diffusion is then one of the highly critical factors related to the potential destruction of this construction. Considering these facts, it is highly desirable to investigate the behaviour of concretes under a combination of force and chemical loading. The present study thus provides the basic results of an experiment in which laboratory concrete specimens were first subjected to partial loading in a press machine, then immersed in a fully saturated salt solution, and in the last step the compressive strength was determined. The loaded specimens were compared with specimens without the first loading and also with specimens immersed in normal water. This makes it possible to evaluate the combined effect. The results were evaluated also with respect to the strength increase under maturation of concrete in time. The results showed that concrete immersed in water after initial partial loading has a lower ultimate strength. Then, concrete without preloading force but immersed in chloride solution showed lower values and concrete preloaded and immersed in chloride for 90 days had the worst residual strength result. [ABSTRACT FROM AUTHOR]

Concerning about the problem of climate change has motivated many scientists to look for ways to solve it. A lot of research work is devoted to the creation of "green" building materials due to the large contribution of building materials industry to the acceleration of warming processes. Glass concrete is an excellent example of a decorative material that uses recycled resources. But its long-term life can be threatened by the development of an alkali-silica reaction. The paper uses a theoretical method to study the possibility of the appearance of this reaction in concrete. Thermodynamic calculations showed that there is an exothermic process at the temperatures of 243K, 283K, 295K, and at 353 an endothermic one. [ABSTRACT FROM AUTHOR]

The objective of this research is to examine the impact of plastic waste (PW) as a replacement for sand on the fresh properties of self-compacting concrete (SCC). To achieve this, various SCC mixes were prepared with a constant water-to-powder ratio of 0.46 and a powder content of 530 kg/m3. As a supplementary cementitious material, Class C fly ash (FA) was used (30 percent by weight of cement). The shredded plastic waste is used at 0, 2.5, 5, 7.5, and 10% in this experiment. The fresh properties of SCC can be found by slump flow, T50 slump flow (SF) time, V-funnel, J-ring height, L-box height ratio and U-box height tests. The obtained results are compared statically with each other. From these results it is stated that addition of 5% of PW in SCC, there is an ideal value in every test conducted. The criteria of self-compacting concrete is accepted up to 5% of plastic waste in it but if the addition of PW exceeds 5% then there is either an increase or decrease in the values which are not accepted by the criteria of SCC. Hence the plastic waste can be partially replaced with fine aggregate up to 5%. [ABSTRACT FROM AUTHOR]

Corrosion of steel reinforcements in concrete constructions is a big topic for the building industry. Polymeric materials are a possible alternative due to their ability to withstand corrosion. To replace steel reinforcements, fibers with high mechanical properties and a good bonding ability between fiber and concrete are needed. Today different approaches for concrete reinforcement by polymer fibers have been investigated. The bonding ability of the fibers can be increased by mechanical anchoring, e.g. crimped or embossed fibers, as well as by a chemical bonding between concrete and fiber surface. To realize the requirements of high mechanical properties and a good bonding behavior, a fiber that is drawn from a co-extruded filament shall be produced and tested. The filament owns an innovative core-shell-structure. The core maintains the fiber-stiffness and the tensile strength while the shell allows using another material to affect the bonding behavior of the fiber. This study shows the usage of fibers with differing shell materials to examine their influence on the mechanical properties of the fiber in total and the adhesion abilities to concrete. As core material, an unfilled polypropylene (PP) is used. The shell materials are varied using different polymers e.g. polypropylene or ethylene acrylic acid copolymer, as well as two PP based compounds filled with wood particles and calcium carbonate blended with a maleic anhydride based coupling agent. The mechanical properties of the fibers are tested by fiber tensile tests to compare the younǵs modulus and the tensile strength. The influence of the shell phase on the bonding ability to concrete is evaluated by the interfacial shear strength calculated from single fiber pull-out tests. Microscopy is used to interpret changes before and after pull-out. The results depict incredible positive effects and allow new insights in possible materials for fiber reinforced concrete constructions. [ABSTRACT FROM AUTHOR]

The article presents the results of testing models of rigid pavements for agricultural airfields from hexagonal slabs in laboratory conditions. Models of slabs were made of concrete on the basis of Portland slag cement grade 300. The optimal composition of concrete was chosen. For this, samples were made, having the shape of a cube, with dimensions of 10 x 10 x 10 cm. They were tested for compressive strength at ages 1; 3; 7 and 28 days. The results of three series of experiments with three groups of samples are presented. The first group was made from concrete without the introduction of plasticizing additives into it, the second-from concrete with the addition of calcium chloride (CaCI2), and the third with the addition of the superplasticizer naphthalene-formaldehyde type (C-3). It was found that the highest compressive strength have samples in which additives of superplasticizer C-3 were introduced. Models of slabs were made of concrete with this additive. Relations between the parameters of a hexagonal plate and the parameters of its model are established on the basis of existing modeling methods. The results of tests of five models of plates are presented. Two of them were loaded with a central load, and the other three with a load applied in a corner. The analysis of the nature of the destruction of models under different loading methods is carried out. It has been established when the plate model is loaded with a central load, radial cracks first appear in it. However, they did not lead to the loss of the bearing capacity of the model, and the load could be increased further. With a further increase in the load, the formation of ring cracks occurred. This led to the complete destruction of the plate model. When testing plate models for an angular load, only ring cracks appeared on their upper surface. As a destructive load, such a load was taken at which the first hairline crack appears on the surface of the model. It is concluded the destruction of the centrally loaded model of the slab occurs at a load exceeding on average 1.2÷1.3 times the breaking load when loading the corner of the model. [ABSTRACT FROM AUTHOR]

The demand for decorative cements and the requirements for their characteristics are constantly growing. Particularly high demands are made on properties such as color stability under various operating conditions and resistance to efflorescence. In this work, studies of the stability of the properties of colored slag-alkaline concretes and plaster mortars were carried out in order to effectively control their decorative effect. Research is aimed at developing methods for controlling the decorative properties of materials based on these cements, which would be guaranteed to exclude the possibility of efflorescence and discoloration, regardless of their operating conditions. A set of methods was used to determine the tendency of slag-alkaline decorative concretes and plaster mortars to efflorescence and color fastness when exposed to ultraviolet radiation and steaming. The possibility of obtaining fast-hardening decorative slag-alkali cements of the 42.5R class and materials based on them using TiO2, kaolin and CaCO3 in the optimal amount as bleaching additives has been demonstrated. Mineral pigments of different colors and waste from alumina production - red mud - were used for coloring. It is shown that all decorative fine-grained slag-alkali concretes, regardless of the type of bleaching additive and pigment, do not have efflorescence. It is proved that during hardening and operation in indoor and outdoor conditions of atmospheric influences in the autumn-winter-spring period for 6 months, slag-alkaline decorative plaster coatings also had a fairly high resistance to the formation of efflorescence, and the addition of sodium carboxymethyl cellulose in the amount of 0.5% completely eliminates the risk of efflorescence, regardless of the hardening conditions of the plaster coating and operating conditions. Unlike plasters based on clinker decorative cements, which have an uneven shiny glossy surface after curing (which is highly undesirable), slag-alkali plaster coatings have a smooth, uniform matte surface. According to the research results, the color fastness of decorative slag-alkali cements to ultraviolet radiation and steaming is also high, their color after testing has not changed. [ABSTRACT FROM AUTHOR]

For the cementitious nanocomposites which contain carbon nanotubes, a proper dispersion of the nanofiller is an important factor which determines the final properties of the composite. Large, singular concentration of the carbon nanofiller might negate all the additional properties that the carbon nanotubes provide, mainly electrical and thermal conductivity as well as material's strength. The carbon nanotubes are usually added in the form of water suspension; therefore, their uniform dispersion in the aqueous solution is the first and most important step in achieving a proper dispersion in the cementitious matrix. Typically used methods for achieving uniform dispersion of the nanotubes in water utilize the usage of ultrasonication and surfactants. The surfactants are usually specific chemical substances, however, commercially used concrete admixtures can also be used. The paper aims at assessing the usability of commercially available concrete admixtures along with sonication in making homogenous suspension of carbon nanotubes in water. The suspensions have been prepared with a fixed amount of nanotubes and water and examined via visual inspection. The results show that the ability to create a homogenous suspension of carbon nanotubes is largely connected with the basic chemical composition of the admixture. Depending on the chemical composition of the admixture, the suspensions showed different levels of flocculation from almost uniform dispersion up to large, easily observed flocs. This kind of behavior excludes those admixtures from usage in cementitious composites as it will not allow for uniform placement of carbon nanotubes in the cementitious matrix, therefore not creating homogenous properties within the composite. [ABSTRACT FROM AUTHOR]

Concrete is the world's most versatile, durable and reliable construction material and also concrete is proper mix proportions of cement, fine and coarse aggregate and water. Concrete is stronger on compression and weaker in tension. Next to water, concrete is the most used material, which required large quantities of Portland Cement. Ordinary Portland Cement manufacture is the second-largest source of carbon dioxide in the atmosphere, trailing only the automobile. In addition to that large amount energy was also consumed for the cement production. Fly Ash, a by-product of coal used in thermal power plants, is widely available around the world. Fly ash is abundant in silica, and when alumina reacts with an alkaline solution, an alumina silicate gel forms, which serves as the concrete's binding element. It's a great alternative to the traditional plain cement concrete in construction. Geopolymer concrete shall be produced without using any amount of ordinary Portland cement. Geopolymer concrete is an innovative and environmentally friendly building material and an option for Portland concrete. Geopolymer concrete is manufactured from the consumption of bi product materials such as fly ash, GGBS, rice husk ash etc, and alkaline liquid such as sodium silicate, sodium hydroxide etc. The zeolites are three-dimensional, microporous, crystalline solids from beginning to end a dissimilar structure so as to contain aluminium, silicon, in adding to oxygen in their normal structure; together cat ions and water are originated in the pores. The silicon plus aluminium atoms are tetrahedral and coordinated crosswise in cooperation of joint oxygen atoms. In conditions of composition, zeolites are approximately clay minerals. Specifically, and mutually are alumina silicates, on the other hand, they are dissimilar in their crystal structure. The literature review was carried out for various parameters in geopolymer concrete and found that many researchers have worked on usage of geopolymer concrete with mineral admixtures such as fly ash and GGBS, but limited literature is available on usage of Zeolite. Therefore this paper presents the results on effect of Zeolite on strength and workability. From the previous results it is observed that Zeolite enhances strength and workability slightly comparing to the geopolymer without zeolite. [ABSTRACT FROM AUTHOR]

The current concern for the concrete industry is to make concrete more sustainable and more environmentally friendly. So, the objective of this study is to determine the optimum amount of Attapulgite clay to cement in concrete with an optimum percentage of silica fume replacement to provide the most durable concrete while enhancing its mechanical characteristics. Different percentages of attapulgite were used, including 0%, 4%, 8%, 12%, and 16%, which were prepared for testing the compressive strength and flexural strength. Other properties of mortar concrete were measured, such as absorption and density, to investigate the effect of attapulgite clay on these properties. The findings indicate that using attapulgite clay in replacement of cement content results in sustainable concrete with enhanced mechanical properties for percentages of 4% the compressive strength increased by 9% in comparison with the control sample. While for flexural strength the 8% percentage was the highest with only 3% reduction from the reference sample. In general all concrete mortar mixes that were prepared with different attapulgite percentages results in acceptable mechanical properties. [ABSTRACT FROM AUTHOR]

The current concrete industry is closely related on the massive use of various chemical admixtures, which significantly modify the properties of fresh and hardened concrete. The plasticizers have crucial sense for the production of concrete structures. This paper is dealing with the study of rheology properties of Portland cement paste with an increasing dosage of naphthalene plasticizer. The experimental study was focused on the systematic description of the rheology properties in terms of shear stress and viscosity. The data obtained were expressed by a pseudoplastic model, which exhibited the best fit. The results confirmed essential influence of the studied plasticizer on the rheology properties of fresh pastes. Both studied parameters, thus consistency coefficient and power index, increased with a rising dosage of the studied plasticizer. [ABSTRACT FROM AUTHOR]

Concrete with pores may function less well when challenged to significant shrinkage and settlement rates. The goal of this research was to employ Metakaolin and rock sand to improve performance by decreasing voids in concrete. Metakaolin proven to be a suitable addition to cement concrete as a supplementary cementitious agent. The properties of concrete with metakaolin are the most often used additives in concrete. Metakaolin use in cement concrete may provide economic advantages due to its vast accessibility in our nation. By weight of cement, a substitution percentage of metakaolin of 5%, 10%, 15%, 20% and 25% was to be employed. Cubes and cylinders are cast to determine the durability and strength of concrete. It was seen that an increase in compressive strength of 47.55%, 27.88%, and 47.52% were observed in 15% MK based concrete during 7, 28, and 90 days respectively [ABSTRACT FROM AUTHOR]

Geopolymer concrete could be an alternative of the conventional concrete due their quality and performance in different conditions. In this study, to investigate the effect of river sand replacement to the stone-dust on the mechanical properties of the geopolymer concrete specimens. Slump, density, compressive strength, splitting tensile, flexural strength, poison's ratio, elastic modulus, rebound strength, and ultrasonic pulse velocity tests were performed on the specimens after they had been cured in the oven for 24 hours at 60°C. After the experimental investigation, it is concluded that the compressive strength, splitting tensile, and flexural strength increases with the replacement of river sand to stone dust in the mix design. The elastic modulus of river sand used specimens and stone-dust used specimens are 23.2GPa and 23.4GPa, respectively, after 28 days test. The rebound strength graph follows the same pattern as the specimens' compressive strength. The UPV of stone-dust specimens is slightly higher than river sand used specimens. The ultrasonic pulse velocity of stone-dust used specimens and river sand used specimens are 4.22km/sec and 4.16km/sec, respectively, after 56 days test. [ABSTRACT FROM AUTHOR]

Mix trials have been conducted in order to develop an effective GPC that provides maximal strength. By-products from industries such as calcined clay and GGBS (Ground Granulated Blast-Furnace Slag) can be used to substitute with cement for lowering carbon di-oxide (CO2) emissions and thereby reducing greenhouse gas emissions. Using the mentioned items reduces water demand in concrete and has practically nothing long-term impacts in concrete; therefore, these by-products may be efficiently employed in concrete manufacturing. GGBS and calcined clay were offered as substitutes for cement in the production of M30 geopolymer concrete. The Alkali concentrations of sodium hydroxide and sodium silicate were substituted with water for improved adhesion and mixing. The GGBS and Calcined geopolymer was made paste in this work using 10M sodium hydroxide solution. Bacterial concentration (105 CFU) of bacillus sphaericus bacteria was used during the mixing of concrete paste. Bacterial solution improved the mechanical properties of the geopolymer concrete. [ABSTRACT FROM AUTHOR]

The Indian construction industry has a major challenge to execute projects using environmentally eco-friendly materials at low cost. The current study demonstrates that stone dust can be used as a fine aggregate material in the concrete due to its high strength and durability. The stone dust has been collected from a stone cutting plant which situated at Bharatpur (Rajasthan), near the Achnera cold storage. In our present study a comparison studied in terms of strength and cost point of view has been made to replace the sand by using stone dust in concrete. The compressive strength of a cubic block prepared by river sand is 26.66 N/mm2, while the compressive strength of a cubic block prepared by stone dust is 30.22 N/mm2. It has been studied that percentage increment of concrete using stone dust for 28 days is 13.5% compare to river sand whereasfor 7 days increment is 46.66%. This research will contribute to the objectives of economic construction also developing high strength concrete. [ABSTRACT FROM AUTHOR]

Besides high mechanical properties requirements, Ultra-high-performance concrete UHPC is intended by the application requirements to exhibit exceptional durability characteristics, especially the resistance to ions ingresses such as chlorides and sulfates. In this study, small cement replacements of up to 4% of Nano-Silica Ns were investigated as a potential enhancer of compressive strength and concrete durability. The effects of other mixture-determining variables such as sand to binder s/b and water to binder W/B ratios were also investigated. Results showed that adding 4% Ns dosage by the binder mass significantly improved compressive strength by 38%. While 0% Ns mixtures with the lowest binder content used (s/b=1.2) did not attain 150 MPa of 56 days compressive strength, 4% addition of Ns was found effective in securing this threshold level. With Ns-incorporated UHPC, a considerably higher level of durability was also attainable in terms of less water absorption characteristics including water absorption and volume of permeable voids. The addition of Ns is therefore expected to improve UHPC resistance to the external attacks of chlorides and sulfates. [ABSTRACT FROM AUTHOR]

In this work, the properties of concrete containing titanium dioxide microparticles and concrete samples whose surface was treated with a photocatalyst were investigated. An economical and effective method of applying the TiO2 photocatalyst to the concrete surface is proposed. The application of the photocatalyst was carried out using a mold for the manufacture of concrete. It was found that when using 2% TiO2 in the mixture, the flexural and compressive strength decreases by 9 and 5%, respectively. The strength of the samples with a photocatalyst on the concrete surface was not reduced. [ABSTRACT FROM AUTHOR]

Reactive Powder Concrete (RPC) is a cement-based substance that's considered as one of the ultrahigh performance concrete types. In fact, it is an ultrahigh strength concrete with excellent toughness. It can somewhat be referred to as a mortar than a real concrete mix due to the substitution of fine and coarse aggregate in conventional concrete by extremely fine sand having a particle size within the range (150-400 µm). In this investigational work, the compressive as well as the flexural strength of control mixture ((RPC) and (RPC) with three different nano alumina contents (1.5, 3 and 5%) replaced from the weight of silica fume was obtained, and the outcomes were compared. An experimental work was conducted on these four groups of mixtures, consisting of 12 cubes of (50×50×50) mm and 12 prisms of (50×50×300) mm. The microstructural analysis was performed using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The results manifested that the ultimate compressive strength is 140.32 MPa, and the maximum flexural strength is 30 MPa in mixes with 3% nano alumina. Mixes with 1.5% and 5% nano alumina also enhanced the compressive and flexural strength compared with the plain concrete mix. The XRD and SEM results elucidated that the nano alumina addition enhanced the microstructural bonding and augmented the hydration of the cement, which led to improving RPC mechanical properties. [ABSTRACT FROM AUTHOR]

In the Philippines, plastic laminates are seen everywhere because most of the products consumed are sold in sachet packets. These packets are composed of multiple layers of polymers, making them very difficult to recycle. Numerous studies concerning plastic waste as an additive to concrete and asphalt have shown increase in strength, decrease in deflection, and decrease in the overall construction cost. In this research, shredded plastic laminates were used as a partial substitute to bitumen (pen. 60/70). Volume replacement of plastic laminates to bitumen was performed from 0% to 100% with increments of 10%. The samples were tested for softening, penetration, and ductility. Results of the tests showed that as the replacement percentage increased, the penetration and ductility of the mastic decreased, while the softening point increased. This indicates that the mastic becomes tougher and brittle with the addition of plastic laminates. Both the penetration and softening point for the samples passed the standards provided by the Department of Public Works and Highways, which indicate that should the modified asphalt mastics be used in asphalt concrete, it would be less likely to deform under repeated loading, it would also be less susceptible to temperature changes. Meanwhile, the ductility measured for the modified asphalt mixtures did not pass the standards provided by Department Order 152. This may indicate an increase in the asphalt pavement's tendency to crack under repeated loading. Despite the significant improvement in the physical properties of the binder even at 10% replacement with the plastic laminates, the presence of foil may have contributed to the loss in ductility. Further studies should be conducted considering a smaller replacement range between 2-10% [ABSTRACT FROM AUTHOR]

Blended cements get by various minerals admixtures of fly ash, silica fumes.this cements are higher quality than conventional cements. Its experiment is performance of concrete made by PSC compare than OPC and GGBS. We will select the cement content of 300,320,340,380 kg/m3. Its test carries on 3days, 7days, 28 and 90 days. Compare than test carry on one set of PSC Concrete and one set of OPC with GGBS. [ABSTRACT FROM AUTHOR]

The self compacting concrete is a binding composite which involves formworks without need of vibration and high resistance. However construction waste such as bricks is used as recycled coarse aggregate in order to improve the sustainability demands of structures. While introducing of RBC in SCC Will generate better improvement in construction sectors. In order to increasing of workability we introduce Super plasticizer in concretes. In order to enhanced the durability properties of SCC Crimped steel fiber are added as additive in the concrete mix. Crimped steel fiber develop good bonding properties with the recycled aggregate. [ABSTRACT FROM AUTHOR]

In this fast-moving construction world, the main problem of the conventional concrete is the formation of carbon-di-oxide (CO2). This is due to emission of CO2 during the production of cement. As a solution for this, Geopolymer (GPC) was invented it has the capability of produce nil carbon-di-oxide emissions. In addition to this, in our modern world everyone wished to complete a project within a short span of time but conventional concrete takes more time for setting and curing. This disadvantage can also be eradicated by using Geopolymer concrete as it has the tendency of setting within less duration of time. In this article used fly ash, GGBS as the replacing cement with GPC which can be also bring down the cost. In this research article gives the GPC properties are with different percentage for AAS, FA, GGBS. [ABSTRACT FROM AUTHOR]

Global warming has risen to prominence as a major environmental concern in the modern era. The amount of greenhouse gases discharge into the environment increases year after year. Carbon dioxide remains the most powerful greenhouse gas, considerably contributing to global warming. CO2 emissions account for roughly 82% of all greenhouse gas emissions. The cement industry contributes significantly to CO2 emissions. India is the globally second largest cement maker, trailing only China, and is attempting to diminish the cement amount used in concrete mix. The viability of totally substituting fly ash for cement and partially substituting quarry sand (QS) for natural river sand (RS) in geopolymer concrete was studied in this research. Utilizing this form of concrete can will make reduction in cement use and CO2 emissions. This project work utilizes the industrial waste product into the concrete production. M30 grade of concrete is adopted for this study. [ABSTRACT FROM AUTHOR]

To counteract the environmental problem, industrial waste materials is used in the field of construction which is also economical. Ground granulated blast furnace slag (GGBS) and fly ashes are examples of industrial by-products that can be used to partly substitute cement in concrete and are environmentally friendly. This paper describes an experiment that was conducted to explore the properties of polymer concrete with waste materials. Highly desirable mechanical is mostly on the out performs of polymer concrete. The compressive strength, tensile strength, curing period, these materials improve impact resistance, chemical resistance, and freeze-thaw toughness. To make polymer concrete, two types of resins (unsaturated polyester and epoxy resin) were mixed with fly ash, GGBS, and sand. The aim of this study is to use M20 grade concrete to investigate the flexural behaviour of beams containing GGBS and FA. Polymer concrete specimens by using industrial wastes with monomers are prepared with various proportions like 30 and 35% GGBS and 35 and 40% Fly ash. To determine the optimal waste dosage of materials, these test results were compared to ordinary concrete specimens. [ABSTRACT FROM AUTHOR]

The paper presents some results of research on increase of frost resistance and impermeability of concrete links of culverts with colmatating compositions. Concrete with Calmatron additives, showed a frost-resistance grade of F300 without fixation of any signs of destruction, and the water resistance corresponded to W8. The results were obtained by the author as part of the research work on the preparation of the standard organization "Increasing the frost resistance of concrete of transport facilities on regional and inter-municipal roads in Khabarovsk Territory", conducted by the Test Center for Construction Materials of Pacific State University. The results obtained made it possible to give recommendations on ensuring the required frost resistance of road pipe links at the stage of their operation in the conditions of the Khabarovsk Territory: it is necessary to ensure the implementation of engineering methods for protecting concrete of pipes with colmatating compositions. It is recommended to use Calmatron (CALMATRON®) - TU 5116-001-33575922-99 as colmatating materials. Recommendations are included in the standard of the organization RSBI "Khabarovsk Highway Administration" "Increase of frost resistance of concrete of transport facilities on regional and intermunicipal automobile roads of Khabarovsk Territory". [ABSTRACT FROM AUTHOR]

The article presents the results of using a complex modified additive to improve the physical and mechanical properties of concrete. The complex additive includes industrial production wastes: metallurgical slag and alcohol production wastes (post-alcohol bard). To stabilize the hydrogen index the alkali KON is included in the composition of the additive. To assess the effect of the additive on the properties of concrete, a set of laboratory studies on measuring the strength, absorption, and frost resistance of test specimens was carried out. Comparison of physical and mechanical properties was made for samples of different concentrations of slag. The range of slag component in relation to cement was from 5 to 25 % by the total mass of the binder, a multiple of 5 %. The optimal composition of the mixture, with maximum strength values, corresponds to the percentage of slag 15%, post-alcohol bard 22.5 liters, alkali 150 grams. In general, the results obtained data points of the compared parameters showed consistent results with minimal variation in the data. The results obtained are of practical value related to the reduction of the cost of production of structural concrete with an increase in its strength indicators. [ABSTRACT FROM AUTHOR]

The purpose of this work is to demonstrate the possibility of obtaining lightweight concrete based on granulated foamed zeolite (GFZ) and composite binder using natural zeolite. Earlier scientific studies have revealed a high potential for the development of concrete technology with the use of aluminosilicate raw materials capable of forming stable compounds and creating a strong structural framework, while replacing a certain percentage of the cement. Yakutia possesses huge deposits of natural zeolites. The balance of just Khonguruu reserves alone comes to the amount of 11272 thousand tons, the efficient application of which in the composition of light concretes would have pushed the development of the construction industry of Yakutia towards higher efficiency of the production processes, as well as towards the sustainable development. Thus, the paper presents the results of research on the effect and interaction of composite binder and porous aggregate based on natural zeolite in lightweight concrete. To obtain information about a possible role of porous aggregates in the formation of strength characteristics of a cement framework a number of tests were carried out, which revealed a low activity of GFZ in relation to CaO. However, there was an increase in the weight of GFZ after its interaction with cement mortar was noted, which is probably associated with new formations on its surface that gave grounds for continuing research. Further, the composition of lightweight concrete was chosen in accordance with interstate standards and rules of composition selection with the use of superplasticizer; As a result, maximum compressive strength of concrete is achieved with the use of superplasticizer in the amount of 1 per cent by mass and 15 per cent of natural zeolite. At the same time, variation of natural zeolite within the range of 0-30 percent showed that the difference in strength values varies within only 0.06 MPa. This indicates that the replacement of 15 percent of cement in the composition of the binder can majorly reduce the cost of production of lightweight concrete with an insignificant effect on the strength. [ABSTRACT FROM AUTHOR]

Geopolymer concrete concept has attracted attentions during the last two decades due to its superior properties, that has made it good and a potential alternative to ordinary Portland cement. The current study therefore, aimed to study the effect of acid on silica and aluminum content of geopolymer concrete and its optimum study. This was achieved by using experimental design tool by adopting central composite design (CCD) technique resulting in a total number of 13 experimental runs for optimum acid concentration effects on the geopolymer concrete mix. Water and acid concentrations were variable parameters used to study their effects on concrete mix, with boundaries of 2-5 ml and 5-10 ml for acid and water concentrations respectively. These two variables were selected to optimize the chosen key factors such as the silicate (SiO2) and alumina (Al2O3) contents of the mix. These were inputted on the design of experiment interface, studied the effects as responses and simulated for ANOVA analysis and optimization. The mass to volume variation trends recorded for SiO2 and Al2O3 were 23.1 to 20.3 kg/m3 and 6.1 to 5.1 kg/m³ respectively. The silica to alumina ratio and silica to magnesium ratio of the geopolymer concrete contents were established to be 3.7 and 5.5 respectively which were within the specifications range. It is concluded that, the optimum acid treatment was established as evidence from the R²-values of both silica and alumina which were close to 1 and the error difference between the predicted and validated values of 2.9 and 3.0 % respectively. The models therefore, are significant as their probability greater than F-value are less than 0.05 in each case. [ABSTRACT FROM AUTHOR]

The application of alkali-activated slag cement concrete (hereinafter AASC concrete) is relevant for building constructions which are exploited in aggressive environments with exposed class XF4. It is due to increased freeze-thaw resistance of AASC concrete in water solutions of salts if compared with portland cement concrete. The aim of this work was to investigate the effects of technological factors on porous structure and freeze-thaw resistance of plasticized AASC concrete in NaCl solution. It was shown that increasing of fresh concrete consistency from class S1 up to class S4 due to plasticization by complex admixture "polyorganohydrosiloxane - sodium lignosufonate - polyethylene glycol" as well as application of alkaline component in dry form, in contrast to liquid form, ensures negative changes in porous structure of AASC concrete. These changes cause decreasing of freeze-thaw resistance from mark F500 down to F200. It was revealed that hardening of plasticized AASC concrete under normal conditions (t = 20±2 °С, RH = 95±5%), compared with hardening in water or under steam curing (t = 85±5 °С), ensures more effective porous structure which causes maintained freeze-thaw resistance of F300 in contrast to F200 and F250 agreeable. Effective technological decisions for advanced freeze-thaw resistant of AASC concrete were determined. [ABSTRACT FROM AUTHOR]

In modern conditions, self-compacting concretes have become widely used to ensure high standards in monolithic construction; they are also used in the production of complex densely reinforced or long structures. Such concretes have several advantages: they can densely fill the form or formwork and penetrate hard-to-reach places. Such properties are achieved as a result of the correct selection of the concrete mixture composition using fine fractions of the aggregate, and the use of appropriate plasticizing additives. Obligatory is also the use inorganic materials with a high specific surface that mixtures which allows to regulate technological increase of water-retaining properties of concrete mixtures. Now the issue of obtaining high-movable and concrete mixtures is relevant for at the monolithic concreting and production of the reinforced concrete with the retention of properties with time which allows them to be piped by concrete pumps. Every year modern construction raises stricter requirements to concrete mixtures for the special building and constructions with improved operating properties. [ABSTRACT FROM AUTHOR]

The increase in commercial vehicles and the increase in air temperature which increases the pavement temperature results in a decrease of the performance (decrease) of the pavement. One alternative treatment is the use of polymer modified asphalt. The use of polymer modified asphalt (PMA) produces a mixture with a higher polymer at high pavement temperatures. This study aims to determine the effect of modified asphalt polymers on marshall characteristics and the resistance of asphalt-concrete mixtures (AC-WC) compared to conventional asphalt, namely Pertamina Pen 60/70 asphalt. This study uses a quantitative approach, experimental methods, and research and development (R&D) techniques with several stages, ranging from material preparation, material inspection, mix planning, to marshall test and wheel tracking machine test. The results showed that the asphalt-concrete mix - used track (AC - WC) using modified asphalt polymer (JAP 57) had a high value and high resistance, so that the mixture was stiffer than conventional asphalt (Pen 60/70). Dynamic stability was obtained with a mixture of AC – WC using modified polymer asphalt (JAP 57) of 875 passes/mm while conventional asphalt (Pen 60/70) was 1067.8 passes/mm. Likewise, the speed of deformation obtained with a mixture of AC – WC using modified polymer asphalt (JAP 57) is 0.0480 mm/minute, while conventional asphalt (Pen 60/70) is 0.0393 mm/minute. So when compared between modified asphalt polymer (JAP 57) and conventional asphalt (Pen 60/70), modified asphalt polymer (JAP 57) is better than conventional asphalt (Pen 60/70). 0480 mm/minute, while conventional asphalt (Pen 60/70) is 0.0393 mm/minute. So when compared between modified asphalt polymer (JAP 57) and conventional asphalt (Pen 60/70), modified asphalt polymer (JAP 57) is better than conventional asphalt (Pen 60/70). 0480 mm/minute, while conventional asphalt (Pen 60/70) is 0.0393 mm/minute. The results of this study are expected to provide an overview of the benefits for the development and consideration of making hot asphalt mixtures, especially in areas that have hot temperatures and heavy traffic loads. [ABSTRACT FROM AUTHOR]

Graphene oxide is a nanomaterial that has a hydrocarbon bond. Graphene oxide (GO) can be in the form of one layer, powder or dispersed. Graphene oxide is widely used in biomedical applications, composite materials, and energy storage. Graphene oxide has a hexagon-shaped hydrocarbon bond. Strong bonds are owned by graphene oxide which is the reason in this study. Graphene oxide functions as an admixture to increase the compressive strength of concrete. Several variations in this study will be compared with normal concrete. Graphene oxide used is dispersed graphene oxide which has a concentration of 1 mg / mL with variations of 20 mL, 30 mL and 50 mL. The cylinder to be used measuring 15 cm in diameter and 30 cm high. [ABSTRACT FROM AUTHOR]

Low strength of aggregates reduces the strength of lightweight concrete, and its fragility prevents the ductile behavior of structures exposed to seismic loads. The use of reinforcing materials and fibers to compensate for the effect of reducing the strength caused using lightweight aggregate and preventing the sudden failure of concrete, can lead to the strength of lightweight concrete. The performance of the materials used is an effective parameter in determining the behavior of structural members. Therefore, to predict the behavior of structural members in computational finite element analysis, accurate behavioral models of materials are needed. In this study, the tensile behavior of lightweight structural concrete including steel fibers (with a volume percentage of 1%) and nano silica reinforcing pozzolans (with a weight percentage of 1% and 3%), respectively, and the effective parameters including tensile strength and the strain corresponding to the maximum stress is presented. The results show that the combined presence of steel fibers and nano silica has the greatest effect on improving the tensile behavior of lightweight concrete. With the addition of 3% nano silica and 1% steel fibers, the direct tensile strength of lightweight concrete has increased by 74%. Also, in all samples, the indirect tensile strength is slightly higher than the direct tensile strength. [ABSTRACT FROM AUTHOR]

Currently, the high-strength modified concrete with mineral additives with compressive strength of 80 MPa and above are developed, introduced and produced on an industrial scale. In this paper, the research was carried out for the high-strength fine-grained modified "powdery" concrete (HSFPC), which is a relatively new construction material. The purpose of the study is to determine the basic physical and mechanical properties and crack resistance characteristics of high-strength fine-grained concrete, to simulate their destruction under various loading conditions, to experimentally refine the hypothesis of the process of fracture of high-strength and ultra-high-strength concrete. According to the results of the study, the experimental values of the physicomechanical characteristics of fine-grained high-strength concrete (aged 7, 14, 28, 60 days) were determined: cubic strength, concrete tensile strength at bending, concrete tensile strength, axial cracking, concrete axial class compression, elastic modulus. The parameters of fracture mechanics: critical factor of stress intensity, critical rate of energy release are also determined. The results obtained are the basis for development of the theory of strength of high-performance concrete using the methods of fracture mechanics, and also for creating a regulatory framework for the design of engineering structures made of high-strength concrete. [ABSTRACT FROM AUTHOR]