Production Of Concrete Mixes Research Articles

THE IMPACT OF RECYCLED FINE AGGREGATE ON SELECTED PROPERTIES OF CONCRETE

The use of recycled fine aggregate in the production of concrete mixes is one of the elements of a circular economy. However, it is important to ensure that such a modification does not significantly affect the durability of the produced concrete elements. One possible criterion to check whether this condition is met is the practical application of the concept of equivalent concrete properties. The presented studies analyzed the properties of concrete with multi-component cement CEM V/A (S-V) and with recycled fine aggregate. The conducted analyses of the research results showed that with a 15% replacement level of natural sand with recycled sand, it is possible to maintain durability characteristics compared to concrete using only natural sand.

An overview of the constructions of conveyors for moving bulk materials, comparison and study of their parameters

The production of concrete mixes, along with their use in the production of building materials and structures, is one of the key processes in the construction industry during the construction, restoration and repair of buildings and structures. Because of this, the need to create modern concrete mixing plants that will meet the requirements of minimum energy consumption and maximum productivity of concrete mixture production is an urgent task. Not only the main operations, which include the dosing of the components of the mixture and their mixing, but also the maintenance operations, namely operations that ensure the timely movement of the components of the concrete mixture from warehouses to the main technological equipment, affect the set rhythm of the concrete mixture production. Conveyors of various types and designs are used to move bulk materials, such as crushed stone and sand. For the rational selection of such equipment in accordance with the characteristics of the cargo to be transported, knowledge of the types of conveyors, their structures and parameters, understanding of operation issues and methods of parameter calculation are required. In addition, it is worth paying attention to the following parameters: maximum cargo transportation productivity, low energy consumption per unit of moved products, low metal content of the structure. The work reviewed the most common designs of conveyors used to move bulk materials in concrete mixing plants, analyzed the disadvantages and advantages of conveyors, as well as technical parameters. As a result, the predominant directions for the use of belt and plate conveyors at construction enterprises were determined. The advantages of belt conveyors, which contribute to their widespread distribution, are high productivity, simplicity of design, reliability, quiet operation, low specific power consumption. When choosing a conveyor, it is recommended to choose the equipment with the highest productivity and the lowest power of the drive motors, however, the performance should be clearly related to other technological equipment.

Experimental and Statistical Modeling the Influence of Temperature Regimes of Asphalt Concrete Mix Production and Volumes of Supplied Protective Gases on the Process of Thermal Oxidative Aging

Experimental and Statistical Modeling the Influence of Temperature Regimes of Asphalt Concrete Mix Production and Volumes of Supplied Protective Gases on the Process of Thermal Oxidative Aging

Deep learning techniques in concrete powder mix designing

Abstract The water-cement ratio is multiple phases procedure in which we aim to determine the most optimal combination for producing high-performing concrete. In modern literature and business practice, there are various methods for designing concrete mixes, although the Three Equation Method-inspired procedures are by far the most widely used. Concrete compressive strength is one of the fundamental properties that determines its class. Foreseeable compressive strength concrete is necessary to promote the use of concrete structures. The primary feature of its durability and safety is. Deep learning has recently received a lot of attention, and the prospects for this technology are even brighter. Machine learning algorithms have advanced to the point that they can recognize patterns, which are difficult for humans to recognize. This has sparked interest in data mining on enormous datasets. In this research, we aim to utilize cutting-edge developments in machine learning techniques for the production of concrete mixes. To provide the ideal structure of a synthetic neural network that has been chosen, we compiled a comprehensive dataset of concrete mixtures, complete with laboratory destructive test results. A mathematical formula that may be used in practical applications has been developed from the creation of an artificial neural network.

Cement Bypass Dust as an Ecological Binder Substitute in Autoclaved Silica-Lime Products.

The cement industry is one of the most developed industries in the world. However, it consumes excessive amounts of natural resources and can negatively impact the environment through its by-products: carbon dioxide (CO2), cement clinker dust (CKD) and cement bypass dust (CBPD). The amount of dust generated in the cement clinker production process depends largely on the technology used. It typically ranges from 0 to 25% by weight of the clinker, and a single cement plant is capable of producing 1000 tons of CBPD per day. Despite practical applications in many areas, such as soil stabilisation, concrete mix production, chemical processing or ceramic and brick production, the dust is still stored in heaps. This poses an environmental challenge, so new ways of managing it are being sought. Due to the significant content of free lime (>30%) in CBPD, this paper uses cement bypass dust as a binder replacement in autoclaved silica−lime products. Indeed, the basic composition of silicate bricks includes 92% sand, 8% lime and water. The investigation shows that it is possible to completely replace the binder with CBPD dust in the autoclaved products. The obtained results showed that all properties of produced bricks were satisfactory. The study concluded that many benefits could be achieved by using cement bypass dust in the production of bricks, including economic bricks for building, reducing the dependency on natural resources, reducing pollution and reducing negative impacts on the environment.

Study on Laterite Aggregate on Concrete Strength

The research was conducted to collect previous research that talked about the performance of laterite aggregates used in the production of concrete mix with the addition of fly ash. The later aggregate is chosen because it is widely distributed in a tropical country such as Malaysia and Indonesia and the main objectives of this research are to determine the effect of laterite aggregate on the strength of concrete, to determine the comparison of the strength of concrete containing laterite aggregate and granite aggregate. To determine the effectiveness of laterite concrete aggregate using fly ash. Use a compressive strength test. The aggregate will be stronger and more durable when exposed to sunlight and the rain can also replace laterite aggregates in place of the granite aggregate in the future and the descriptive method was used and information was collected to know the performance and effectiveness of concrete in terms of its new properties.

Physical and Chemical Characterization of Coffee Husk Ash Effect on Partial Replacement of Cement in Concrete Production

Today researchers all over the world are focusing on ways of utilizing either industrial or agricultural wastes as a source of raw materials for the construction industry. This is used to minimize the emission of CO2 during the manufacturing of cement. One of the agricultural waste products is coffee husk which is found in large amounts in Ethiopia. This paper aims to characterize the physical and chemical properties of Coffee Husks Ash (CHA) by using X-ray diffraction (XRD), Scanning electron microscope (SEM), and Fourier Transforms Infrared Spectroscopy (FTIR) tests, and also the experiment were conducted to determine the compressive, split tensile and flexural strength of the material and durability tests were determined. The result have shown that, when the replacement percent further increases, the crystalline material increases, silicate concentration decreases, and also the micro pores or air void are increases, which may lead to decreasing the strength of concrete. In the case of mechanical property of concrete, there has been remarkable increment up to 5% CHA replacement and also strongly satisfied up to 10% replacement, furthermore increasing CHA replacement up to 20% are optimum dosage of normal concrete mix production of C-25 concrete. Finally, water absorption and sulfate attack of partially replaced concrete is shown as an improvement in the durability of concrete.

Concrete Compressive Strength under Changing Environmental Conditions during Placement Processes.

The technological process of concrete production consists of several parts, including concrete mix design, concrete mix production, transportation of fresh concrete mix to a construction site, placement in concrete framework, and curing. Proper execution of these steps provides good quality concrete. Some factors can disturb the technological process, mainly temperature and excessive precipitation. Changing daily temperature and rainfall during fabrication, transportation, and placement can shape not only the properties of the concrete mix but also the compressive strength of hardened concrete. In this paper, we tried to answer the question of how temperature and precipitation affect concrete production. The scope of this study was to determine the change of compressive strength of the hardened concrete in a specific period for selected concrete mix recipes, taking into account changing daily temperature and precipitation magnitude. The investigated concrete mixes concrete compressive strength beyond that of the concrete grade, termed “concrete superstrength”. This concrete post limiting behaviour of concrete is also discussed.

Calculation of energy parameters of fixed drum concrete mixer with helicoid-type blades

Currently, one of the most important areas in the construction industry is the production of high-quality concrete and construction mixes used in the manufacture of reinforced concrete products and structures, road, foundation, monolithic works, as well as used in the laying of bricks, blocks, etc. Concrete mixes are able to ensure high quality of the resulting products and structures when solidified. The scope of their use is the most extensive of all building materials, and production volumes are among the largest. The practice of using concrete in world and domestic construction has shown that it is effective, i.e. it has a number of advantages over new types of building materials, provides high productivity during construction work, is universal and easy to obtain. Initial components for the production of concrete are very common, easily accessible and transportable over long distances, which allows for the production of concrete mix in remote locations using mobile plants. To date, the enterprises of building industry is the production of equipment of various designs and principles of operation used for mixing. In the construction industry, a variety of mixing machines with both advantages and disadvantages have been used in the production of concrete mixes.

Analysis and Modeling of Coating Plant Topology and Automatic Control System

At present, road conditions in Russia hinder national economic development. The number of roads at present is insufficient, their quality being unsatisfactory. The creation of a methodological basis for the development of modern hierarchical systems to manage road concrete mix production will contribute to solving not only the tasks of the direct technological process control. It will also help to resolve more complex tasks such as operational management of product quality. The work is based on complex use of methods of automatic control theory, Theory of Probability and Mathematical Statistics, methods of optimal systems, and mathematical modeling. MatLab mathematical package should be used as a more efficient way to make a system analysis and to model production processes. The expected results are modeling the interaction of subsystems of the Automatic Control System (ACS). ACS of cementing materials, as well as ACS of sand and gravel hoppers, will allow estimating the complexity of the interaction of the ACS subsystems. The result of the research is the possible use of the proposed concept and methodological approach to the research and development of optimal ACS structures for the construction industry. The implementation of the research results will allow to make an appropriate assessment of the effectiveness of the solutions proposed for the modernization of ACS coating plants, as well as to assess the range of the tasks they have to solve, and the structure of the proposed ACS of coating plants.

Розвиток методу аналізу ієрархій як механізму вибору інвестиційного проєкту на підприємстві

It is important for companies to choose the optimal project, considering the impact of the most important criteria on the common goal. The article investigates the mechanism of choosing the optimal of the three proposed investment projects at the production enterprise: production of foam blocks, production of paving slabs, production of concrete mix. To solve the problem of choosing the optimal project, the method of hierarchy analysis proposed by T. Saati was used. The method of analysis of hierarchies is considered to be a general theory of measurement, it is used to derive a scale from pairwise comparisons in multilevel hierarchical structures. Comparisons can be made on the basis of real or approximate values. The method is widely used in tasks related to multicriteria decision making, strategic planning, forecasting, etc. The method of hierarchy analysis allows to quantitatively and qualitatively compare alternative projects. The criteria for comparison were: the total amount of investment required for the project, product demand, expected profitability and payback period of the project. A multicriteria matrix model based on the method of hierarchy analysis is constructed. The relationship between the criteria was established and the consistency of results was assessed at all levels of the model. According to the results of the analysis, the optimal project was determined, which has the greatest value of the component of the vector of global priorities - 0.56529 (for the project involving the production of concrete mixtures). For this project, the criteria of "Demand" and "Profit" have the highest priorities of the vector of alternatives. The application of the method of analysis of hierarchies allows to reduce the amount of before the project work and numerically confirm the choice of the project.

Impact of Water Quality on Concrete Mix and Hardened Concrete Parameters

The subject of the present article is the evaluation of the use of different water types in the production of concrete mix and C20/25 class concrete (assuming the same composition). Taking as an example a selected Subcarpathia-based concrete production plant, equipped with a process water management system, the research analysed the quantity-quality parameters of drinking water, sewage water, and groundwater and evaluated them for their accordance with mixing-water quality standards. It should be emphasised that the majority of specifications recommend the use of drinking water for concrete production. The paper presents the results of research which analysed the impact of water quality on selected properties of concrete mix and concrete (consistency; compressive strength after 7, 14, and 28 days; density). The results obtained confirmed the findings of the research on the suitability of recycled water for concrete production.

Local Aggregate in Production of Concrete Mix in Jordan

Concrete properties such as unit weight and compressive strength are highly dependable on the properties of aggregate. Current research aims to study the effect of aggregate properties on concrete considering the resource of aggregate. The properties of aggregate and fine sand were studied (specific gravity, density, absorption, and abrasion). Also, the properties of concrete were studied (density, unit weight, and compressive strength). Samples of coarse and medium aggregates, and fine sand were collected from different areas in Jordan (Ajloun, Amman, Aqaba, Irbid, Jerash, Karak, Ma’an, Madaba, Salt, Zarqa, and Tafila) to be tested and used in concrete mix. Aggregate from South of Jordan has higher values in specific gravity and bulk density (Aqaba, Ma’an, and Karak aggregates). Also, the same aggregate samples have lower values in absorption and abrasion (Ma’an, Aqaba, Karak, and Tafila). For the properties of concrete that include density, unit weight, and compressive strength, all samples have achieved the design properties and strength in the current study. For density and unit weight, samples from South of Jordan have higher values (Ma’an and Aqaba). And for compressive strength, Ma’an, Irbid and Amman concrete samples have the highest values at 7-day, while the 28-day compressive strength comes highest for Zarqa, Ma’an, Irbid and Amman. From the results of the current study, the compressive strength at 7-day and 28-day is related to the density of coarse and medium aggregate, abrasion, and absorption. The higher the density, the higher the compressive strength. And the lower abrasion and absorption, the higher the compressive strength of concrete. Current research will be useful in selecting the source of aggregate to produce a considerable concrete strength.

Mechanical, durability and microstructure properties of concrete containing natural zeolite

Concrete is one of the most widely used construction materials in the world. Producing economical and durable concrete is possible by employing pozzolanic materials. The aim of this study is to underline the possibility of the utilization of natural zeolite in producing concrete and investigate its effects basically on the strength and durability of concrete. In the production of concrete mixes, Portland cement was replaced by the natural zeolite at ratios of 0%, 10%, 15%, and 20% by weight. Concretes were produced with total binder contents of 300 kg/m3 and 400 kg/m3, but with a constant water to cement ratio of 0.60. In addition to compressive and flexural strength measurements, freeze-thaw and high temperature resistance measurements, rapid chloride permeability, and capillary water absorption tests were performed on the concrete mixes. Compared to the rest mixes, concrete mixes containing 10% zeolite yielded in with the highest compressive and flexural strengths. The rapid chloride permeability and the capillary measurements were decreased as the natural zeolite replacement was increased. Freeze-thaw resistance also improved significantly as the replacement ratio of zeolite was increased. Under the effect of elevated temperature, natural zeolite incorporated concretes with lower binder content yielded higher compressive strength. However, the compressive strengths of concretes with higher binder content after elevated temperature effect were found to be lower than the reference concrete.

Energy Efficiency of Binder Application in Concrete

Theoretical calculation of the thermal effect of formation of minerals of binders is carried out. The dependence allowing calculating the thermal effect of formation of minerals of lime, gypsum, slag cement, portland cement, dolomite cement is presented. The formula also takes into account the effect of organic components in the mixture. A comparative analysis of the energy efficiency of different types of binder in concrete is carried out. It is shown that the use of slag cement in the production of concrete mix is twice as effective as portland cement. This is due to the presence in the slag of calcium oxide, which does not need energy to carry out the endothermic decarbonization reaction. Lime in the concrete composition has a rate of energy consumption is five times greater. This means, industrial waste which contains calcium oxide (slag, ash and others) can replace natural materials with high efficiency.

The properties of water from a concrete plant to be used in cement composites

This article presents the requirements for concrete mixing water and evaluates the possibilities of using recycled waste sludge water generated in a concrete plant from rinsing water of the concrete plant agitating centre and agitation trucks. The production of concrete mix requires large amount of water and for this reason, it is necessary to use this resource in an economic way. For further use of these waters, it is vital to know their detailed properties in order to maximize their potential in the design of concrete formulations for the purpose of replacing pure mixing water with recycled sludge water so as to preserve or improve the physical and mechanical properties of fresh concrete mix or hardened concrete. The results of the wastewater tests from the concrete plant confirm compliance with the limit concentrations according to CSN EN 1008. The attention should be paid to the limit of concentration of sulphates.

Transportation matters – Does it? GIS-based comparative environmental assessment of concrete mixes with cement, fly ash, natural and recycled aggregates

The urban world is expanding and densifying fast. This requires and produces huge amounts of new construction materials and construction and demolition waste (CDW) every year. Concrete is not only the most important construction material in terms of sheer amount but also regarding embodied greenhouse gas emissions. Alternative concrete mixes have been developed by introducing supplementary cementitious materials (e.g. fly ash (FA)) and CDW (e.g. recycled aggregates (RA)). So far, environmental assessments focus mostly on the production of concrete mixes without considering the transportation-related impacts. This paper appraises the importance of transportation-related impacts of raw materials for concrete production and proposes a new method combining Life Cycle Assessment and geospatial analysis of road transportation of materials. Environmental impacts (EI) of different mixes are assessed for the specific locations of concrete plants. Traditional and alternative concrete mixes are compared to choose site-specifically the mix with lower impacts. For that purpose, two Portuguese cities were considered as case studies. The new method uncovers if and how location of supply and demand for concrete production is important. The results show that for traditional concrete and for mixes incorporating low FA ratio and/or RA, transportation does not matter. However, it matters when choosing between already drastically improved mixes: then, distances from raw materials suppliers to concrete plants can tip the scales of total EI. In fact, the distances to FA and recycling plants influence the selection of the most environmental friendly concrete mix. The method can be applied to other case studies and materials.

Effects of Varying Dosage Replacement of Cement Content by Animal Bone Powder in Normal Concrete Mix Production

Cement being the main constituent of concrete plays a vital role in concrete production. In Ethiopia, the cement consumption has grown well with a growth rate of about 16.1% per year. Hence, an alternative material to partially replace cement was initiated to reflect the needs of local community in the study area. The waste quantity of animal bones has impacted the environment which are unusual to see in other Non-African countries. The primary aim of the research is to investigate the effects of varying dosage replacement of cement by animal bone powder (ABP) in the normal concrete production. The bone samples collected from Seka Waste Disposal Site of Jimma town, approximately 10km from the bus station where a quantity of waste animal bones can be found. After cleaning and drying, the bone samples burned in the Furnace. The average required energy to burn the animal bone obtained at a temperature of 340°C. The burnt bone was allowed to cool before grinding in a hammer mill and sieving. There were six proportions prepared to start from 0% (as control specimen), 5%, 10%, 15%, 20% and 25% dosage increment by weight of bone powder, and evaluated the normal concrete strengths of C-25 grade concrete. The laboratory test results indicated the chemical analyses of bone powder composed similar compounds of oxide in cement but slightly lesser in content based on ASTM C-150. Likewise, the effects of replacing animal bone on the properties of cement such as consistency and setting time remained within the acceptable limits of the Standard Specifications. On the other hand, the results of compressive, flexural tensile, and the split tensile strengths significantly declined from the control specimen during the dosage increment of the replacement made. Therefore, the optimum dosage of bone powder indicated 10% by weight to replace cement content in normal concrete mix production.

Suitability of Ambo Sandstone Fine Aggregate as an Alternative River Sand Replacement in Normal Concrete Production

Technical experts in construction industries are trying to improve the quality, ease of using materials in different forms, and increasing structure performance. However, in the changing cost of each item, quality of works could be sacrificed. In Ethiopia, the practice of using alternative ingredients to produce materials was observed weak in some scenarios. It was because ignoring the right procedures to perform the required material requirements for construction materials. It is known that Ambo area has a scarcity of natural sand or rivers sand which can be extracted from the river bed. Notably, if available, the quality is not good due to the presence of silt and clay. Once it used, it adversely affects the structural integrity of concrete structures. The primary objective of the research is to evaluate the suitability of Ambo Sandstone Fine Aggregate (ASFA) as an alternative replacement of river sand in normal concrete production. Samples extracted from Senkele and Aleltu quarry sites of Ambo Area. Results showed that fine aggregates from Senkele quarry site indicated 14.28% silt content, while from the Aleltu quarry site indicated 12.28% silt content, all of which exceeded 6% based on Ethiopian Standard Specification. It means the samples must be rejected or appropriately washed before use as a part of a concrete mix. After performing the procedure to remove silt content, it found out that the silt content reduced to 5.3%, less than the allowable maximum of 6%. Hence, Ambo Sandstone Fine Aggregates (ASFA) are suitable for concrete mix production and strength determination. There were nine samples of concrete cubes prepared and tested at 7th, 14th, and 28th days for concrete compressive strength with a mix ratio of 1:2:3 and water to cement ratio of 0.50. Based on the laboratory test results with full replacement of river sand by Ambo Sandstone Fine Aggregate (ASFA), the mean compressive strengths at 7th day was 16.61 MPa, while at the 14th day was 19.62MPa, and at 28th day was 25.59 MPa. It means at 28th day; it satisfied the minimum requirement for C-25 grade concrete. Likewise, the cost of production of the fine aggregate of the Ambo Sandstone quarry site is 140 ETB per cubic meter, while the price of river sand from Legeher Market is 300 ETB-400 ETB per cubic meter. Therefore, Ambo Sandstone Fine Aggregate (ASFA) is cheaper than the river sand. However, it must be given emphasis that the Ambo Sandstone Fine Aggregates must wash thoroughly before use in construction projects.

Utilization of reclaimed asphalt pavement aggregates containing waste from Sugarcane Mill for production of concrete mixes

The present study investigates the potential of waste originating from road sector (RAP) and agricultural industry (Sugarcane Bagasse Ash) for production of concrete mixes. 5 mixes were prepared by partial replacing natural aggregates by coarse RAP (CRAP) and fine RAP (FRAP) in the proportions of 50% and 100%. 3 subsequent mixes were prepared by incorporating 100% RAP aggregates blended with 10% and 15% Bagasse Ash (BGA) as part replacement of cement. It was noted that incorporations of FRAP aggregates decreased the fresh, mechanical and durability properties of concrete significantly compared to CRAP aggregates. Incorporation of 10% BGA was found to enhance the mechanical and durability properties of 100% RAP concrete significantly. Economic analysis of the considered mixes showed that incorporations of RAP aggregates blended with BGA can reduce the total cost of 1 m3 concrete by more than 40% as compared to conventional concrete. From the present study, it is recommended to replace 10% of cement by BGA in RAP concrete as this would not only strengthen the pavement but provides with environmental and economic benefits.