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This paper focused on investigating the problems associated with the expansion joints in Al Murtadha Bridge that may cause significant damage to its structural components. In addition, the considerable expenses associated with the ongoing maintenance of these expansions were also taken into account. An examination was conducted to determine potential strategies for addressing these challenges, with structural analysis carried out using a CSI bridge software program according to AASHTO LRFD 2017. A potential solution was proposed to reduce issues related to expansion joints on bridges and enhance bridge durability, subsequently leading to an improvement in the service life of the bridges. A link slab was designed to connect the two adjacent spans instead of the expansion joint. Two options were suggested the first one uses Conventional Concrete CC in a link slab and the other uses Ultra High Performance Concrete UHPC as another one. [ABSTRACT FROM AUTHOR]

Concrete is the most generally and extensively used building material. Curing is a crucial step to ensure that concrete attains its desired strength. Internal curing is a process where the concrete is internally cured from inside the concrete. The objective of this research is to evaluate the potential of vermiculite as an internal curing agent. The vermiculite is partially replacing the fine aggregate by 10, 30, and 50% by volume. Mechanical and durability properties tests on the specimens were conducted. The results show that internally cured concrete with a 10% vermiculite replacement has superior mechanical and durability properties. From the findings, it is concluded that vermiculite has the potential to be used as an internal curing agent in concrete. [ABSTRACT FROM AUTHOR]

A wide range of sectors are seeing the increasing importance of NFRC (Natural Fiber-Reinforced Composites), which are the subject of this extensive review. A more sustainable and environmentally friendly alternative to conventional synthetic composites is NFRC composites, which are mixtures of natural fibres with different matrices. The different methods of synthesis, mechanical characteristics, durability, and uses of NFRC composites explored by previous researches, are all thoroughly investigated in this paper. It also delves into how different processing factors, such as the ways in which fibres are treated and the matrices used, might improve the mechanical and thermal characteristics of NFRCs. [ABSTRACT FROM AUTHOR]

This work is aimed to study the self-healing on self-compacting concrete with special bacteria. In SCC high flow ability is present and doesn't need vibrators for filling ability compared to conventional concrete. Self-compacting concrete is homogeneous concrete that flows under its own weight and doesn't need any external vibration for compacting. It has a high flow rate and a moderate viscosity, which has changed the way concrete is placed. So that the structure works well and lasts for a long time, this kind of concrete should have a low yield value and not bleed. It should also stay the same during transport, placement, and curing. The apparatus that we are using in this SCC includes slump-cone test, L-box test, U-tube test, V-flow test for workability test. Apart from this strength of durability test are conducted in a hardened state of concrete, which is cured for 28 days with bacteria. [ABSTRACT FROM AUTHOR]

For many civil engineering projects in developing nations, concrete is the go-to "manmade" material. In fields where environmental consciousness is growing, the value of concrete's eco-friendliness is rising. The mortar-aggregate interface is the source of the microcracks that make concrete so brittle. Concrete with fibre reinforcement has been developed to combat the underlying problems. Due to their discontinuous nature, fibres are typically added to concrete in a manner that ensures they are blend in seamlessly and boost the concrete's properties in all directions. One such attempt to employ only fibres is presented here. Compressive testing was conducted on cube and cylinder specimens with dimensions of 150mm x150mm x 150mm using a method that provided the full compressive strength. The durability and strength of concrete mixed with different mix types are compared to those of standard concrete. In the current project work, Fiber reinforced composites are fabricated using carbon fibres at volume fractions of 1, 1.5, 2, 2.5, and 3% and polypropylene (PP) fibre at volume fractions of 0.5, 1%, 1.5%, 2.5%, and 3%. The data demonstrates that the material's tensile strength has improved and that it is more resistant to cracking. Proposed sample has 7, 21, and 28 days of curing time. The proof of the FRC's effectiveness under extreme loads will be in how well it confines the structure. [ABSTRACT FROM AUTHOR]

High performance concrete to improve efficiency over the course of its lifetime without sacrificing its quality. (HPC). In this project, a mix ratio for high-graded concrete is calculated and the optimal percentage of silica fume (SF) is added as a pozzolanic reactor. For filling voids in concrete, nano silica (nS) is an appropriate cementitious material that can be added in different amounts to increase density and impermeability (2). In order to meet the workability requirements of recent concrete, super plasticizer (Conplast SP430) is favored over the addition of nano silica and silica fume. HPC with varying levels of nS had its mechanical properties (compressive and split tensile strength) and durability properties (acid resistance and water absorption test) investigated. The findings of the pertinent tests are taken into account to determine the ideal level of nS in HPC. Based on the test findings, the reinforced high performance concrete beams' performance was evaluated, and the load deflection curve indicates that the member's behavior has improved. [ABSTRACT FROM AUTHOR]

Construction cementitious materials or construction-based materials, such as cement paste, mortar, and concrete, are one of the most utilized materials in building construction today. This material's advantages include its high compressive strength, durability, lower labor costs, and applicability to a wide range of building applications. In its use, this material is susceptible to shrinkage, which produces a decrease in the material's volume because of reduced moisture content and loss of water during the hardening process. In a mixture of cement-based construction materials with a low water-cement ratio, superabsorbent polymer (SAP) is known to be one of the materials with "healing agent" capabilities. In addition, the usage of this material can automatically cover cracks. This study aims to examine the use of superabsorbent polymer in improving the durability of cement-based construction materials, as well as the problems that could occur if this material is applied in Indonesia. Several techniques, including data collection techniques, data reduction, data analysis, data presentation, and drawing conclusions, are used to conduct a literature review. The result of this research is a literature review on the definition of SAP, its durability, and its challenges in Indonesia. [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]

Low-density wood is often produced from fast-growing tree species and has lower quality in terms of physical, mechanical, and durability properties. Hence, wood modification techniques were introduced in the 1900s to improve these inherent properties. In this study, heat treatment and densification were applied to the laminas of Paraserianthes falcataria. The objective of this study was to obtain the result of colour changes after heat treatment and densification. Laminas were heat treated inside the laboratory oven at three different temperatures (100℃, 120℃, and 140℃) for 60 minutes before being densified at three stages. The result indicated that the colour of heat-treated laminas becomes darker as the temperatures increased to 140℃, as well as the densification process. Overall, these treatments (heat and densification) altered the physical properties of laminas. [ABSTRACT FROM AUTHOR]

Various studies devoted to the issues of quality assurance, reliability and durability of sealing units used in various machines and mechanisms have considered. The results of a study of the process of completing parts that form a sealing joint are presented. The connection of the primary shaft of the gearbox of the YaMZ-239 engine with a cuff was chosen as the object of study. A technique has been developed and tested for completing the parts of the «shaft-seal» joints, including the calculation of the number of groups and the appointment of shaft repair dimensions and the selection of cuffs according to the criterion of maintaining the least tightness in the joint. The technique is applicable for restoring all joints of the «shaft-seal» type, if a standard reinforced rubber cuff according to GOST 8752-79 is used as a seal. Before calculating the repair dimensions, it is necessary to analyze the wear values of the shafts. [ABSTRACT FROM AUTHOR]

The role of fluorine chemistry in modern technology with its extreme operating conditions can hardly be overestimated: fluorine-containing materials have solved many problems facing space, jet and aviation technology. Areas of application of surfactants are extremely diverse. One of the methods for increasing the wear resistance of friction pairs is the method of treating the surfaces of friction pairs with fluorotensides. Fluorotensides are multicomponent systems that include fluoroorganic surfactants in various solvents and control additives. Freons, alcohols, and some other liquids can be used as base media. Currently, a wide range of epilams is used in world practice. With metal surfaces, f-surfactant forms a chemisorption bond. They are applied to solid surfaces from a solution by immersing the product in it or introduced into lubricating oil or grease. The latter play the role of f-surfactant transport, which at the initial stage is adsorbed on solid surfaces and then chemisorptionally binds to them. In lubricating oils, f-surfactants are easily emulsified, giving stable emulsions. [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]

This research is focused on selecting a hot asphalt mixture test method for water and temperature applied in Indonesia. The study was carried out based on the literature study of various tests that existed so far. The search results are known to the existing test method are Immersion Compression, Original Lottman, Modified Lottman, Root-Tunnicliff, Duriez, Hamburg Wheel Tracking Device, Saturation Ageing Tensile Stiffness, Highways, Indonesian National Standard (SNI), Moisture Induced Stress Tester (MIST), and Boil Test. Based on the investigation, it can be inferred that water and temperature are contributing factors to the formation of a hot asphalt mixture, as the adhesion and cohesion connections are damaged. Adhesion damage is identified using a soaking and emphasizing procedure, whereas cohesion damage is identified by modeling vehicle stresses on the sample to be examined. Apart from the potential for damage to the asphalt mixed bond, the technique selection procedure is influenced by the test duration, mechanical evaluation, climate compatibility, and tool availability. The selection process begins with making a scoring scale for each parameter, then scoring each test method, and finally adding up the scores of the five parameters. The factors can be categorized into five categories, except duration and climate adaptability. Only two types of damage are classified based on their influence on adhesion or the combination of adhesion and cohesion. The mechanical evaluation contains only three grading categories: 1, 3, and 5, with no point for tool availability. The testing process can take as little as one day or as long as four days. Based on the results of the sum of the scores for each method, it can be seen that SNI 6753-2015 is the most appropriate asphalt durability test technique for usage in Indonesia, scoring 22 points overall, followed by MIST (21 points) and Bina Marga (20 points). [ABSTRACT FROM AUTHOR]

Organic soils have low shear strength and high compressibility, which make these soils unsuitable for some engineering applications. The resistance of soil stabilizers to wetting-drying cycles is important to maintain the long-term stability and strength of the stabilized soils. Using waste products such as fly ash (FA), is a convenient and sustainable procedure for many soil improvement methods. In this study, FA-based geopolymer was used to increase the shear strength and durability of an organic soil. Different ratios of alkali solutions (sodium hydroxide and sodium silicate) were used to produce the geopolymer. The specimens were initially cured at (45, and 65°C)and then cured for 28 days at room temperature. The FA-stabilized specimens had poor performance during the wetting-drying cycle, as they collapsed during the first cycle. The geopolymer-stabilized specimens passed 12 cycles of wetting-drying with less than 4% loss in weight and without any observed volume change. Furthermore, the increase in the Unconfined compressive strength values was as high as 56%. FA-based geopolymer is considered an effective additive to improve organic soils due to the high strength and long-term stability of the geopolymer bonds. [ABSTRACT FROM AUTHOR]

The interest in recycling waste materials increasing globally. The use of recycled asphalt pavement (RAP) could be more efficient with geopolymer materials. Fly ash (FA) and kaolinite (Kao) materials are known as geopolymer raw materials. This study investigates the effect of wetting–drying (w–d) cycles on the durability as well as the microstructure of the RAP-geopolymer in the subgrade material. In addition, the strength characteristics were determined by the unconfined compressive strength (UCS) test. A sandy silt soil with a plasticity index of 11% was used in this study. Various soil-RAP-geopolymer mixtures were activated by an alkaline solution consisting of the NaOH at 8 molarity and NaOH: Na2SiO3 liquid. Soil-cement mixture was prepared and tested as a reference mix. The results showed a great improvement in the strength of the soil in terms of the UCS. The stabilized FA-based geopolymer, and RAP-FA-based geopolymer passed the durability test by a weight loss less than 10% and a volume change less than 2% as per ASTM standards. Specimens stabilized by the RAP-Kao-based geopolymer passed the wetting and drying cycles without remarkable weight loss or volume change while the Kao-based geopolymer did not pass. The microstructural analysis by scanning electronic microscope (SEM) images proved the formation of the geopolymer binder irrespective of the raw material of the geopolymer. The overall performance of the fly ash-based geopolymer and RAP mixtures was much better than the kaolinite-based geopolymer in terms of the strength and the durability. The fly ash geopolymer can be considered as an effective method to stabilize the fine-grained soil to use in the subgrade layer material. [ABSTRACT FROM AUTHOR]

In recent years, using waste reclaimed or recycled asphalt pavement (RAP) has been an important problem in each country, especially those that own less natural materials resources. Sustainability has gained widespread acceptance in many spheres of society, including the pavement concrete industry. Cost savings, protection of the environment, and emission reduction. This work aims to improve the asphalt mixtures properties by using RAP. In this work, two proportions of RAP are used replacement from a total mix, considering the percent of asphalt in the RAP. Percentage of RAP replacement were included (i.e., 15% RAP and 40% RAP with a softening agent). One type of softening agent (vacuum residue liquid asphalt) is used. The testing procedure included the following experiments for characterizing the prepared mixture: Marshall Stability (MS), and flow tests, indirect tensile strength (ITS) tests, Resilient Modulus Test, moisture susceptibility, and aging (long term). The outcomes indicated that adding RAP significantly enhanced mechanical properties, workability, and durability. [ABSTRACT FROM AUTHOR]

In the present study, the influence of visible rock textures on the durability and strength characteristics of different rocks viz. shale, slate, phyllite, gneisses, granites, schists, metabasics, dolostone and quartzites were investigated. A total twenty seven rock blocks with distinct and visible textural features collected from the Himalayan terrain were studied for the purpose. The minerological and textural features of rocks were studied under optical microscope. The slake durability index (Id) and unconfined compressive strength (UCS) through indirect test i.e. point load test for each group of rock types were determined in the laboratory using standard ISRM suggested methods. It has been observed that rocks located near the major geological thrusts and faults have undergone deformation because of the tectonic activity around these faults and thrusts, and thus resulted either in reduction in grain sizes or mylonitization and exhibits exceptionally higher UCS in rocks like granite and dolomite contrast to rocks located away from the thrust and fault whereas in amphibolites, the lower UCS is due to development of schistosity in amphibolites near fault/thrust. The rocks with higher mica or clay contents disintegrate faster and having lower strength values. It has been observed that the mineral contents of the rock influence their durability rather than textures. [ABSTRACT FROM AUTHOR]

The article presents theoretical and experimental studies of the electrical strength of the polymer bracket KPVLT-p BOREL manufactured by LLC NPPELEKTROMASH in Yekaterinburg, designed to support and isolate the overhead power transmission line wires of signalling, centralization and blocking devices (STsB) and the longitudinal power supply line (PE) with a voltage of 6-10 kV. [ABSTRACT FROM AUTHOR]

The present study uses the results of experimental investigations of the electrical resistivity of four types of concrete mixtures for numerical analysis of the durability of concrete exposed to an aggressive environment. Two concretes are reference concretes (one without and one with chemical additives for air entrainment), and the other two concretes contain metallurgical sludge waste (MSW) as a partial replacement of fine aggregate. With the derived diffusion coefficient and maturation factor, numerical models were used to estimate the durability of an exemplary reinforced concrete structure exposed to chloride ions. The elementary model was used to estimate the corrosion initiation time of reinforcement. The model allows a general specification of the structure and material properties. The results show the effect of chemical admixtures and MSW on the structure's durability in an aggressive environment and the differences with respect to other concretes. The study extends the portfolio of numerical calculations of the durability of unconventional concretes. [ABSTRACT FROM AUTHOR]

There are many different types and methods of experimental tests that mimic the different types of loads of lacquered surfaces used. The main indicators of the quality of lacquered surfaces of wooden floors are adhesion, elasticity, impact resistance, wear resistance and resistance to various liquids, mechanical damage, abrasion, etc. During the test of wooden coatings for wear resistance, laboratory tests should simulate the operating conditions of wooden floors. However, mainly all methods of experimental tests are standardized, but some of them do not allow to determine the minimum requirements or control values of certain technical properties of different paint surfaces. Which in turn creates a dilemma for technologists or even consumers, who are expected to determine the quality requirements of certain products. The article presents the results of experimental research to determine the coefficient of abrasion of the surface layer of the parquet board and to establish the class of its resistance to abrasion according to the results of the Taber test. They can serve as information for the relevant properties of wooden floor surfaces and be aimed at better knowledge of information on experimental tests of floor coverings for wear resistance. [ABSTRACT FROM AUTHOR]

The article is a continuation of the research started earlier with the aim to create a technology for modification of composite materials to give them increased strength and durability by filling the porous space of the matrix with a permeable compound based on epoxy resin, which hardens in the pores of the matrix. The article analyzes the existing methods of decreasing the viscosity of the compound and investigates the decrease of viscosity under the influence of ultrasonic vibrations. A physicochemical model of the process of filling the porous space of the body, which leaks out, has been developed and grounded. The physical and chemical processes of solidifying surface during formation of the polymerizing structure are considered. Also, the physical and mechanical indicators of the quality of concrete soaked with epoxy compound under the influence of ultrasonic vibrations and overpressure are presented. [ABSTRACT FROM AUTHOR]

Urban runoff management and treatment are necessary, especially in areas that encounter heavy rains during the year. Pervious concrete (PC) is a plausible material that can be used in light traffic areas and green spaces to mitigate stormwateras well as make a good contribution to treating them. In this regard, anthracite is known as an excellent filter media for water purification. However, no attempt was made to utilize the anthracite in PC. Therefore, the use of anthracite as a rawmaterial in the production of PC was investigated in this paper aiming to improve the stormwater management system. Theeffects of adding anthracite in different proportions (10, 20, and 30% w/w of coarse aggregates) on compressive strength, flexural strength, tensile strength, porosity, and permeability coefficient of PC were pursued. After evaluating these parameters, the chemical oxygen demand (COD) of the runoff samples after passing through different PC specimens was measured. Results show the improvement in strength with increasing anthracite proportions, but it affects the permeabilityand porosity negatively. Unsurprisingly, all PC specimens containing anthracite performed better in COD reduction. [ABSTRACT FROM AUTHOR]

Clay shale is a type of soil susceptible to the influence of water. This soil type is dominated by silt, with montmorillonite as the main mineralogy. The montmorillonite content causes the soil to have high shrinkage and low shear strength. Chemical stabilization by mixing additives can improve the properties and strength of clay shale. As a waste of burning coal in PLTU, fly ash can be used for soil stabilization. It is similar to Portland cement, fly ash contains silica and alumina. This study aims to obtain unconfined compressive strength and slake durability are related. The proportions of clay shale and geopolymer were 75:25. Sixty-five percent fly ash and 35 percent alkali activator were used in the geopolymer. The alkali activator was made composed of sodium hydroxide and sodium silicate. The sodium hydroxide concentration utilized in this experiment was 12M. The alkali activator ratio was 1.5 and 2, with 7, 14, and 28 days of curing. The results showed that increasing the compressive strength increased the durability index. The addition of geopolymer can increase the compressive strength of the soil. An increase of 339%, 453%, and 528% occurs in samples 7, 14, and 28 days. In addition, geopolymer resulted in the soil's increasing void ratio but decreasing moisture content. [ABSTRACT FROM AUTHOR]

The present paper aims to find the strength and durability properties of hybrid fiber reinforced concrete under marine conditions, and to investigate the effect of hybridization of fibres on properties of concrete. where the fibers to be used are steel fiber and polypropylene fiber and to find the proper corrosion less hybrid fiber reinforced concrete by adding the chemical admixture i.e CHYRSCO OPTIMA 9313 and MICRO SILICA to produce a moderate water reduction, better flow and retention of HYRC. Water to cement ratio increases there is a chance of high extend of having concrete permiablity, so in this investigation water to cement ratio is about 0.38 % only. The literature study reveals that there is very little literature on the durability aspects of marine conditions on hybrid fibers reinforced concrete hence lot of research is to be done. Present experimental investigation is done up to M40 grade concrete mix design. The compressive strength is one of the most important features of concrete,Compressive strength was investigated, the mix design also affected the water-cement ratio The planned technique allows the designer to estimate characteristics such as compressive strength and workability of the concrete [ABSTRACT FROM AUTHOR]

Geopolymer concrete made by reacting ingredients containing silicate and aluminate with a caustic activator. Ware products such as "GGBS, flyash,& slag" from the metal and iron industries are frequently employed. Recent research has included the addition of novel ingredients such as "Alccofne", which enhance the characteristics of geopolymer concrete even at room temperature. This study gives a comprehensive review of the literature on the durability of geopolymer concrete. Various study literatures on durability of geopolymer concrete with the inclusion of various extra Cementous materials are evaluated, as their use is becoming more common as a result of persistent ingredients previous research from literature surveys revealed that substituting chemical and mineral admixtures for cement improved the strength and durability of concrete. Microstructutres,morphological structures discovered using SEM, decreased shrinkage, Stronger mechanical strengths, superior durability, and environmental sustainability are all observed. Increased polymerisation reaction, which is responsible for the growth of strength, was discovered in XRD tests. GPC controls elevated temperatures and surface degradation better than OPC. Under comparison to ordinary concrete, geopolymer concrete provides increased chemical resistance and water absorption for specimens. Sorptivity and porosity have a strong impact on the durability attributes in ambient curing circumstances. [ABSTRACT FROM AUTHOR]

The durability characteristics of treated recycled coarse aggregate concrete are presented in this paper. When recycled coarse aggregate is reused in concrete, the old cement mortar connected to its surface is removed, causing the concrete to perform poorly in terms of strength and durability. So, before being used in concrete, recycled coarse aggregate is treated in a variety of ways to improve its strength and durability. In this paper various physical, chemical, mechanical and durability properties of recycled aggregate concrete are discussed. When comparing the qualities of concrete formed with 20-30% recycled coarse particles to those of normal concrete, there is no notable difference. Concretes with 50% to 100% recycled aggregates show a lower increase in compression strength from 7 to 28 days than conventional concrete containing solely raw materials. The HCl acid soaking treatment eliminated a considerable amount of mortar content, resulting in a significant increase in the characteristics of treated recycled coarse aggregate (TRCA). [ABSTRACT FROM AUTHOR]

In the present scenario of leading technological development in concrete, the practice of high-performanceconcrete (HPC) has expanded all over the world due to its fame in the construction field. Usually, HPC requires huge amounts of cementitious content as well as a lower water to cement ratio. HPC can't always be accomplished on a regular basis using conventional ingredients and normal mixing, laying, and curing procedures. With the increase in the demand for HPC in the construction industry, there is a need for supplementary cementitious materials (SCMs) with mineral as well as chemical admixtures that can be used to improve the performance of concrete. These materialslike Alccofine 1203 provides some incredibly unique properties to the concrete that cannot be met when using ordinary Portland cement (OPC). The major purpose of this study is to assess the strength and durability properties of Alccofine 1203 concrete. The literature of several scholars who have studied the durability of HPC with Alccofine 1203 is examined in this work. The low calcium silicate content of Alccofine 1203 improves the pH of the concrete to guard against corrosion, allows for faster shuttering removal, greater pumping ability, and increased concrete durability. [ABSTRACT FROM AUTHOR]

This research is an experiment study that provides a full investigation of the rubber influence on various self-compact concrete (SCC) characteristics as well as production self-compacting rubberized concrete, SCRC. The purpose of this study is to exam and evaluate the durability, mechanical characteristics and rheological characteristic of fresh concrete of composite self-compacting rubberised concrete exposed to normal and severe salty environmental conditions. This study also encourages to employ crumb rubber tire in production of concrete so as to reduce the impact solid waste (tyre waste) and its effect on environment. Experimentally, crumb rubber tyre was partially replaced fine aggregate. These percentages of replacement ranged (0%, 4%, 8%, 12%, and 16%) by mass of fine aggregate. The results of this study designated to decrease in fresh properties indicators, slump flow-box, sieve segregation, as the crumb rubber tire content increases in SCC mixes. Also, the hardened properties of SCC, compressive, flexural and splitting strength test were considered the using crumb rubber tyre percentage in these mixes has a detrimental impact on these properties. While, the durability properties of SCRC, surface absorption, chloride migration and chloride penetration depth improved these properties with using the crumb rubber tyre in SCC mixes. [ABSTRACT FROM AUTHOR]

Concrete is one of a brittle material which has low strain and strength capacity when load applied. In order to make the concrete strong in tension, they are supplemented with reinforcement. Both materials are structural in levels; fibers used in this project can improve the strength level, load carrying capacity and ductility of concrete by changing the percentage and aspect ratio in fibers. When a large portion of short fibers are mixed they control micro-cracks. This concept has been used for hybrid fiber reinforcement. Supplementary Cementations Material (SCM) like Silica Fume (SF), Rice Husk Ash (RHA) are generally in use as cement replacement materials which present a possible solution for sustainable development united with multiple benefits of savings in cost as well as energy. The different types of fibers ware used in this project study are Polypropylene fibers (PEF). The mixture of these fibers in suitable proportion give desired properties. This project is concerned with the strength, durability and flexure investigation of a new innovative concrete named as Fiber Reinforced Blended Concrete (FRBC) in M20, M25 grade of concrete. FRBC is a concrete made up of PEF in mono form and in hybrid form gained thorugh partial replacement of SF and RHA as binary and ternary blend. To enhance the material properties numerous test such as cube compressive strength, cylindrical split tensile strength, modulus of elastic and impact strength. [ABSTRACT FROM AUTHOR]

In the present era of concrete innovations, natural fibres hold an important role due to their abundance in tropical countries like India and their eco-friendly nature. They out-shadow the synthetic or steels fibre with its cost-effectiveness, environmental friendliness, unhazardous production, nil heat generation to medium, and many property-oriented benefits. Amongst natural fibres, coir fibres dominate the local availability and have better mechanical and durability properties, hence the comparative analysis on former parameters of coir fibre reinforced cement composite (CFRCC), along with the general failure of natural fibre and countermeasures are reported in this paper. CFRCC with high compressive, tensile, and bond strengths and also least water absorption of cement medium at saturation made to take over the rest of local coastal natural fibre reinforced concrete. CFRCC was found to possess a predominant strength under impact loadings due to the hard nature and appreciable setup of constituent materials in the coir fibre. Here, is an overview of the mechanism behind attaining corresponding strength studied on the elementary level. Further, the predominant terminologies and models of mechanical behaviour for understanding material performance without mathematical details are discussed. Additionally, the general failure mechanism of natural fibre with specific improvement based on coir fibre was dealt with in the work. References from the authors of various time scales included as a means of comparing durability enhancement methods are discussed in this work. CFRCC held the appreciable improvement of the properties amongst the other modified natural fibre reinforced cement composite, including the durability aspects. [ABSTRACT FROM AUTHOR]

Concentration of loads in structural elements, as well as in machine parts, is created by geometrical concentrators, i.e. local changes in the size and shape of the form from the overturning along the stress line (laps, stiffeners, welded and bolted connections). Concentration of loads is one of the main factors of decrease of support of stiffness of both machine parts and structural elements. The load increase in the concentrator area can be characterized by the theoretical concentration coefficient, but there is no clear methodology for its determination. The operating load of structural elements is always non-stationary, and all normative characteristics are set for stationary loads. That is why one of the problems of forecasting the support of the second frame is the estimation of the shock absorption at the rotor, which occurs at the non-stationary process of the load and its replacement by the stationary equivalent in its shock absorption. In a thin-walled girder, the non-planar chord loses its cylindrical shape when loaded. The areas of the belt between the walls try to straighten the angles and increase the radius of curvature under tension, while under compression, on the contrary, their curvature decreases. This leads to a decrease in the longitudinal stiffness of the belt and redistribution of stresses. The article examines the factors that affect the operation of the crane girders of the overhead crane. [ABSTRACT FROM AUTHOR]

Engineered cementitious composite (ECC) is unique in terms of promising ductility and its value of durability. Research on ECC have covered wide range of structural applications based on the design function of ECC. Recently, green ECC is gaining attentions from scientists and practitioners due to increasing environmental concerns and sustainability considerations. This paper summarize review on the constituents in making green ECC and feasibility of various green or recycled materials in developing green ECC while still able to maintain its superior characteristics. Mechanical strengths of green ECC specifically in terms of compressive, tensile, flexural as well as tensile strain capacity from existing research are compared and discussed. Durability tests on green ECC from previous work are reported and gaps of research are identified. Finally, future directions on research of green ECC are suggested. [ABSTRACT FROM AUTHOR]

The article describes a method for predicting the contact-fatigue durability of rails. The method is based on the data on the relative damageability of the rail running surface when the wheel is rolling with different values of the wheel load. Relative damageability is calculated in the software program "Fatigue" by importing data on the stress tensor that occurs on the rail surface when the wheel is rolling. The parameters of the strain S-N curves are determined based on the modified Roessle – Fatemi hardness method. The method takes into account the sinuous movement of wheel sets and the degradation of mechanical properties of the rail running surface due to the passed tonnage. Calculations are performed taking into account the probability of the distribution of vertical forces from the daily bunch of trains running along the section under consideration. Using the proposed method for section Zilovo – Zudyra of the Trans-Baikal Railway, the rail durability for shares of freight trains formed from wagons with an axial load of 250 kN, 9 and 64 % in the daily bunch of trains was calculated. It was calculated that an increase in the share of trains formed from wagons with axial loads of 250 kN from 9 to 64 % leads to thr decrease in the durability of rails due to contact fatigue defects from 572 to 522 million tons gross, or by 8.7 %. [ABSTRACT FROM AUTHOR]

The classification of rolling surface defects of wheelsets of high-speed electric trains was given. It was revealed that in practice there were more than 60 types of defects of solid-rolled wheelsets that arise under the influence of various factors that directly or indirectly affect traffic safety. The reasons affecting the wear of the rolling surface of wheelsets of high-speed electric trains were considered. Positions of authors dealing with issues of studying the processes of friction and wear expressing different opinions about the nature of the wear of the wheel-rail set friction were presented. We developed a research methodology allowing to identify the degree of impact of proposed methods on the durability of the rolling surface of wheelsets based on a model of multidimensional analysis of the choice of the most effective methods, as well as to identify the needs of a specific locomotive depot when applying each of the methods. We proposed a method to increase the resource of wheelsets by changing the design of the rail joint. Since the disadvantage of the existing butt device was the dynamic effect of the wheel on the upper edge of the rail head. the article presented a variant of using rails with a bevel of joints at an angle of 45 degrees on railways. Their use would increase the durability of the rail track and, as a result, the durability of the wheel-rail set friction. [ABSTRACT FROM AUTHOR]

Calculation of coefficient of margin of safety of a wheel with a conic disk was made. The calculation allowed to specify the size of an average limit of endurance on disk amplitude in a settlement zone. The stated algorithm of calculation implemented in the MathCad program can form a basis for assessing the durability of wheels with various configurations of disks and a level of residual technological and operational tension. The made program code in MathCad at data exchange on tension, calculated in certainly - an element SolidWorks/Simulation package, allowed to automate the calculation of durability of a wheel. [ABSTRACT FROM AUTHOR]

Mango-aloe vera juice is the potential to be a functional fruit beverage. The critical point in the fruit beverage development is appropriate proportions, and the process should preserve their physicochemical properties and provide durability without reducing the specific properties of food. This research aims to optimize mango-aloe vera juice in proportion to mango-aloe vera and process mixing (the temperature and time mixing) using a D-optimal combined design methodology to obtain the color difference and pH oBrix, and IC50 of the product. Mango puree and aloe vera puree were selected as the mixture design factors from 80% to 100% and 0 to 20%. The temperature mixing ranged from 60-80°C, and time mixing (D) ranged from 10–20 min were selected as processing factors. Our result showed mango-aloe vera ratio significantly affects color differences, pH, °Brix, and IC50. The optimum amount of mango puree, aloe vera puree, mixing temperature, and mixing time was 84.38%, 15.62%, 80°C, and 20 min. [ABSTRACT FROM AUTHOR]

The need of weak and weathered rock recognition and characterization should be emphasized to forecast the stability of rock slope. Engineering geologists and geological engineers might encounter the difficulties in practicing for the weak and weathered rock field due to the historical geological processes. Disintegration behavior of weak rock such as mudstone is observed via Slake Durability Test while strength behavior is observed via Uniaxial Compression Test in this study. Both strength and durability behaviors then been investigated further with the effect of mineralogical content using X-Ray Diffraction Test in all samples. Selected weathered sedimentary outcrop of Semanggol Formation from Bukit Kukus Kedah were characterized for disintegration, strength, and mineral properties. The result shows that the increasing of weathering grade has decreased the results on strength and durability of all samples. Furthermore, the mineralogical composition had impacted the higher values on slake durability index and compressive strength with the increasing of quartz content and decreasing of clay minerals. [ABSTRACT FROM AUTHOR]

Earthen blocks refer to blocks made out of earth (calculated percentage of clay, silt, sand and gravel). The earth is compressed at high pressure with the help of either manual or automatic/ semi-automatic press. Since the blocks are unfired, it is stabilised with either lime or cement. Studies on performance of the unfired earthen block in comparison with the conventional blocks is gaining momentum. This study aims at investigating the strength and durability properties of the earthen blocks reinforced with jute fibres. The jute fibres were mixed at a ratio of 0.25%, 0.5%, 0.75% and 1 % with the earth (Gravel + sand = 45%, Clay + Silt = 45%). The mix was stabilized with 10% of lime. Test was conducted on strength parameters (compression & tensile) and durability parameters (water absorption, erosion & wearing, shrinkage & drying time). It was found that with the inclusion of jute fibers, the tensile strength and compressive strength of the block showed an increase of 30 – 40 %. The optimum percentage of fibre was found to be 0.5% as higher percentage of fibre increases the water content and voids in the blocks. The erosion and the wearing resistance of the block increased with inclusion of jute fibres. Since jute is a natural fibre, its natural decomposition is a challenge that needs to be addressed in the future studies. Studies on fibre treatment and its orientation can be future work. [ABSTRACT FROM AUTHOR]

Results of industrial research are presented aimed at increasing durability of press stamps during hot forging operations due to effective environmentally friendly water-based graphite technological lubricants and heat-resistant stamp steel grades developed by authors of this paper. In particular, the durability of press stamps with usage of widely used oil-graphitetechnological lubricants such as 'industrial oil and 25% of silver graphite' and 'Ukrinol-7' was investigated. In addition, results of studies of stamps durability when using water-graphite lubricant 'B1' during hot extrusion operations of steel forgings are presented. It has been established that lubricant 'B1' makes it possible to increase the durability of press stamps by 20% in comparison with factory oil-graphite lubricant and to obtain similar durability in comparison with lubricant 'Ukrinol-7'. Results of testing heat-resistant stamp steel grades 4X4Nl2BFC (Di-22) and 30X6MAFL are presented. Comparison of stamps durabilitymade of above given steel grades and steel grade 5XHM showed that usage of steel grade Di-22 makes it possible to increase durability of stamps by more than 2 times and usage of steel grade 30X6MAFL makes it possible to increase durability of stamps by more than 4 times. [ABSTRACT FROM AUTHOR]

The paper studies the problem of the structural durability of unique buildings, reinforced concrete bridges, and cement concrete pavements of automobile and service roads affected by the environmental factors. First of all, these are carbon emissions, which have a destructive effect on construction materials and products. The paper studies the causes of destruction and air carbonization of construction materials and suggests the ways to reduce these effects. It is shown that cement hydration products transfer to denser states, which is accompanied by the concrete volume decrease and shrinking deformation that disturb the structural integrity of the materials and even lead to their fracture. It is found that the negative effect from shrinking deformation and carbonization on constructional materials and products can be reduced by the addition of calcareous rocks to the cement composition or lime-sand binding materials, for example, limestone or dolomite. [ABSTRACT FROM AUTHOR]

Within the framework of the refined variational formulations of inverse problems of forecasting the determining characteristics of composites under the influence of extreme environmental factors, the influence of the errors in measuring the residual resource in the retrospection interval on the accuracy of the forecast is studied.. Functional analytical relations, have been developed that allow us to assess the influence of the level of measurements errors of the residual resource in the retrospection interval on the accuracy of the forecast of the residual resource of the composite. [ABSTRACT FROM AUTHOR]

To ensure the physical durability of machines and their equipment, the methodology of calculation for metal structures should be based on the study of degradation processes in materials. The model of cyclic degradation of materials based on the experiments providing full stress-strain curves (FSSCs) is generalized to the case of random stress. A Python-based software was developed to help implement a method of calculating structural durability in the case of quasi-random stress using randomization. At the same time, a linear sum calculation of damage is performed. The initial data for the calculation of durability in the target zone of the metal structure are given based on the basic model experiments, estimation of the stress field and data on the fatigue strength of the weld assemblies. This methodology of calculation can be used as an alternative approach to calculating the service life of load-bearing metal structures of machines and their equipment under the stress of high-cycle fatigue. The example durability estimation of the longitudinal beam of the grab crane established that calculation according to the provided methodology gives a conservative durability estimate. [ABSTRACT FROM AUTHOR]

This paper presents the outcomes on an exploratory program conveyed to investigate the chance of fly ash and alccofine as complete substitution of cement in Geopolymer concrete. GPC mixes were designed in such a way that flyash and alccofine proportions are taken as M1 F100A0, M2 F90A10, M3 F80 A20, M4 F70 A30, M5 F60 A40, M6 F50A50, for which M3 F80A20 is taken as optimum mix based on economic conditions. Experimental programme developed to check the durability properties like Acid attack test (H2SO4), Chloride attack test (HCL), Nitrate attack test (HNO3), Sulphate attack test (Na2SO4), and water absorption test. The compressive strength of Geopolymer concrete and change in mass percentages were indicated by the tests results. [ABSTRACT FROM AUTHOR]

Based on concepts and principles of physical mesomechanics, a multiscale process of fatigue crack origination and propagation is considered. Universal diagrams are proposed to describe a multi-stage crack propagation process and a multiscale level process characterizing the durability based on the criterion of σ–1/σ0.2, where σ−1 is the "so-called" fatigue limit of the material and σ0.2 is the yield stress. The conditions for the transition from the mesoscale level (high-cycle fatigue) to the micro-scale level (low-cycle fatigue) of damage accumulation are discussed. [ABSTRACT FROM AUTHOR]

Anti-reflective coatings are employed on both sides of the glass envelope tube of evacuated parabolic trough receiver tubes to minimize reflectance losses. This paper reports the measured initial transmittance values of seven different receiver tube manufacturers as well as the degradation rates after accelerated aging, outdoor exposure and in- service testing. The presented data represents a summary of measurements carried out in the OPAC laboratory at Plataforma Solar de Almería in the period between 2013 and 2019. [ABSTRACT FROM AUTHOR]

In Central Receiver Systems, the receiver coating absorbs the concentrated sunlight from the heliostat field and needs to withstand high thermal stresses in harsh desert climates. Coating degradation is associated to high repair and down-time costs and therefore several research activities have been conducted in the past years to increase the service lifetime of receiver coatings. This paper presents the durability test results of six novel receiver coatings developed for operation temperatures of 600°C. The coatings were deposited on ferritic-martensitic steel coupons made of T91 and VM12-SHC. The testing program involved a sequential accelerated aging test: on-sun testing with an average flux level of 300 kW/m2 was combined with isothermal furnace testing and humidity testing at low temperature to mimic condensation on the receiver during night-time. In addition, climate chamber tests have been carried out. This paper summarizes test results and identifies the most promising coating developments. [ABSTRACT FROM AUTHOR]

The paper deals with the study of fatigue durability of SLM Ti-6Al-4V specimens after post-build combined Ultrasonic Impact– EelectroPhysical Treatment (UIEPT). It is shown that the highest fatigue performance was characteristic for SLM Ti-6Al-4V specimens treated by the mode 1 (with lower pulse frequency and duration). It was revealed that the conducted combined ultrasonic impact – electrophysical treatment slightly changed the internal structure and microhardness. The modification mostly took place in the surface layers while but the straing and pulsed electric current exposure together gave rise to certain heating as well as variation of bulk material properties. It is suggested that the post-build treatment by the selected rational parameters due to favorable combination of mechanical and electro- physical impacts made it possible to reduce residual stresses. It was shown that the post-build treatment at higher values of electric current pulse frequency and duration did not provide efficient increase of fatigue durability. It suggests that increased energy input during the post-build treatment increased the brittleness and induced excess defects and stresses. [ABSTRACT FROM AUTHOR]

Graphene and its composites are now reinforced with asphalt a pavement material to increase durability of roads. The present review paper focuses on improved performance of asphalt material when mixed with graphene, reduced graphene oxide and graphene nanoplatelets. Graphene is the world's versatile wonder two-dimensional material with countless multifunctional applications in electrical, physical, biomedical, chemical and in mechanical fields. High economical expenditure in roads maintenance in all climatic conditions, high traffic loads, resistance to wear and tear are the challenges for construction engineers. The objective of the paper is to bring awareness and understanding of increased performance of asphalt when reinforced with graphene. Various parameters like aging resistance, marshall stabilityand high temperature stability were reviewed in the present study. [ABSTRACT FROM AUTHOR]

Fiber Reinforced Plastics (FRP) are widely used in marine, aeronautical, automotive, space applications due to their corrosive resistance and low cost to performance. The main aim of this research was to examine the impact of alkali absorption and durability in the Carbon/Epoxy, Carbon/Vinylester, and Carbon/Isopolyester composites immersed in 13.59 pH alkaline solutions for a maximum of 25 days at 27°C (room temperature) and 65°C. Epoxy, vinyl-ester and Isoployester resin are selected as a matrix material and Poly-acrylonitrile-based Carbon fiber of 200 gsm fabrics is chosen as reinforcement and hand lay-up process is used for fabrication in the ratio of 35: 65 respectively and cured at room temperature with applied pressure using hydraulic press for 24 hrs. Solution of alkali was prepared and specimens were subjected to alkali solution. The moisture absorption was calculated on the basis of rate of moisture for every 5days interval and rate of diffusion coefficient (m2/sec) were calculated. Similarly durability studies (UTS, ILSS and FS) are conducted at 27°C and 65°C. Characterization of the fractured area was done using a scanning microscope. The obtained result rate of moisture absorption in case of neat casting and CFRP specimen shows the maximum alkali absorption in Iso-polyester / carbon whereas the minimum absorption was shown in vinyl ester/carbon specimens at RT and at 65°C over a period of 25days. At room temperature and 65°C the diffusion coefficient (D) was found and identified higher value for Iso-polyester/carbon and low for vinyl ester/carbon this is because Iso-polyester are distributed along the main chain, which makes easily available for reaction but in vinylesters the ester functional groups acts as a shield by methyl groups which restrict the easy absorption. Reduce in percentage in mechanical properties is due to Alkali absorption in terms of reduced degradation values in UTS, Flexural Strength and ILSS samples, carbon / epoxy showed supremacy over vinylester / carbon and iso-polyester / carbon. Scanning electron microscopy images show the embrittlement and micro-cracks on surface due to exposure to the alkali environments, matrix bonded to fiber are hardly identified as the temperature increases. [ABSTRACT FROM AUTHOR]