Concrete Production Research Articles

Three-dimensional meso-scale modeling of asphalt concrete

An efficient method to address the three-dimensional modeling of the visco-elasto-plastic material behavior, specifically of bituminous conglomerates used in asphalt concrete production, is proposed. The method resorts to one of the most recent formulations for asphalt creep modeling, represented by the modified Huet-Sayegh fractional rheological model. The Grünwald-Letnikov representation of the fractional operator is adopted to treat the operator numerically in an efficient manner. Further, a coupling scheme between the creep model and elasto-plasticity is proposed by adopting the additive decomposition of the total strain tensor. This enables the numerical assessment of the mechanical behavior for bituminous materials under short- to long-term loading. In this context, both constant strain rate tests, and creep recovery tests are numerically simulated.Numerical analyses are conducted at the meso-scale with the aim to evaluate the development of inelastic strains in the binder during creep, due to the local interaction between the different material components.

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.

Performance, cost, and ecological assessment of fiber-reinforced high-performance mortar incorporating pumice powder and ground granulated blast furnace slag as partial cement replacement

The production of cement and concrete is a significant source of greenhouse gas emissions. Hence, recent governmental regulations have brought the attention of industry and academia to the environmental impact of these materials. Recognizing the pressing need to address the environmental footprint of the widely used construction materials, there is a growing focus on strategic initiatives that involve incorporating alternative waste materials to partially substitute ordinary Portland cement (OPC). It is also noteworthy that high-performance concrete and mortar emits significantly less CO2 per unit of strength. Therefore, this study aims to develop high-strength mortar mixes incorporating pumice powder (PP) and ground granulated blast-furnace slag (GGBS) as substitutes for OPC. To this end, nine different mixes, with varying levels of OPC replacement ranging from 0% to 60%, were produced. These mixes underwent a comprehensive experimental evaluation to assess their physical, mechanical, and durability properties. Scanning electron microscopy analyses were conducted to examine the microstructural characteristics of the mixes as well. Furthermore, the embodied energy, embodied carbon, and cost of the prepared mixes were calculated. The experimental findings suggest that high-strength mortar, with a compressive strength varying between 64 and 82 MPa at 28 days of curing, can be successfully produced with reduced embodied carbon and embodied energy compared to conventional mortar mix while maintaining a comparable cost.

Challenges of a Circular Economy: The Example of Raw Recycled Tyre Steel Fibres Added to Concrete.

This research was conducted to analyse the possibility of using raw, untreated recycled tyre fibres as an effective concrete reinforcement according to circular economy principles. The aim of the article was also to develop a method for dispensing tire fibres on a real scale. Additional treatment and homogenisation of recycled steel fibres entail higher energy consumption, emissions of greenhouse gases, and increased costs. However, obtaining durable and safe concrete effectively reinforced with steel fibres is critical. Finding a balance between environmental friendliness and product durability is a circular economic challenge. Reference concrete with commercial steel fibres (15 kg/m3) and two concretes containing various quantities of non-treated, raw tyre recycled fibres (25 kg/m3 and 45 kg/m3) were industrially produced. Tests were carried out on the properties of the concrete mixture and hardened concrete, such as compressive strength, flexural strength, splitting strength, modulus of elasticity, residual flexural tensile strength, and fibre distribution in concrete. Tests revealed that increasing the amount of raw tyre fibres disturbs the structure and causes air entrainment and the formation of fibre clusters. Smaller quantities of raw tyre fibres turn out an effective concrete reinforcement. The use of non-treated tyre fibres as concrete reinforcement is possible but requires more stringent control of the concrete parameters. Implementation tests on an industrial scale are a novelty in this study, presenting an analysis of the possible dispensing of tyre fibres in a ready-mixed concrete production plant and testing the characteristics of manufactured concrete.

A different approach for green concrete production: Determination of the effect of e-waste and waste rubber powder on durability properties of concrete

A different approach for green concrete production: Determination of the effect of e-waste and waste rubber powder on durability properties of concrete

Peningkatan Kompetensi dan Pembuatan Teknologi Terbaru Beton Porous di Jurusan Teknik Konstruksi dan Perumahan SMKN 1 Balikpapan

The city of Balikpapan has many flood points every year,.Flood events are a priority issue for the Balikpapan City Government, in 2017 there was an increase in flood events by 89 incidents. To solve this problem is to apply the construction with the latest environmentally friendly technology, namely porous concrete so that surface water can seep into the ground and can become a groundwater reserve. Porous concrete is the latest type of concrete technology with high porosity which is applied as a concrete plate which allows rainwater and water from other sources to pass through. Limited facilities and infrastructure, lack of teaching staff relevant to the Construction and Housing Study Program at SMKN 1 Balikpapan School so that they cannot carry out concrete manufacturing and testing because this is a basic competency that every student must have. The activity began by formulating a program that was relevant to the knowledge and research of the PkM team of the Civil Engineering Department of the Balikpapan State Polytechnic and the problems that exist around Balikpanan City. SMKN 1 Balikpapan to carry out follow-up activities or programs to be implemented, activity planning, activity schedules and activity output. The activities were carried out for 2 days which included socialization and practice of making porous concret.

Proposal for formulation of blocks to guarantee the sustainability of buildings in the Abidjan real estate park

A recurring fall of buildings in recent years (2013-2023) in the city of Abidjan has caused enormous material and human damage. This study was initiated in order to propose a formulation for the development of concrete blocks to guarantee the sustainability of buildings in the Abidjan real estate. The raw materials used are aggregates composed of sand, granite powder and a hydraulic binder (portland cement) then water for mixing. The aggregates were characterized before being used for the manufacture of the various FSB, FPS and FPG concrete blocks. The materials were subjected to physical and mechanical tests. The results showed that the sand and granite powder aggregates have a granular class of 0/1 and 0/2 respectively. Concerning concrete blocks, the density increases with the maturation time, namely 28 days maximum and when they are composed of both sand and granite powder (FPS). This significantly reduces the number of pores in the material. The compressive strength test showed that at 28 days of maturation, the FPS are more resistant than the FPG and FSB with respective values of 6.50 MPa; 5.31 MPa and 3.10 MPa. It appears that the addition of granite powder to the composition of the concrete blocks improves the density, porosity and compressive strength of the latter. The promotion of this formulation among concrete block manufacturers would make it possible to improve real estate construction, guarantee the durability of buildings in the Abidjan real estate park and thus avoid the possible fall of buildings.

A comparative assessment of uncrushed-river concrete mix of Hari-River, and Kamar-Kalaq: the two widely used concrete mix in Herat, Afghanistan

Concrete, as a cornerstone of modern construction, heavily relies on the quality of its constituent materials, particularly aggregates. Among the critical factors contributing to high-quality concrete are proper gradation, absence of clay particles, and angular shape of aggregates. Adhering to these standards typically results in concrete with superior strength. However, aggregates sourced from riverbeds often possess a natural gradation, contain clay particles, and have rounded shapes. This study delves into a comparative analysis of aggregates sourced from two widely utilized riverbed regions, namely Hari-River and Kamar-Kalaq, situated within Herat province, Afghanistan. Given that over 90% of concrete in Herat province is sourced from these two riverbeds, the findings of this study carry immense significance. The research meticulously examines key parameters, including clay content, gradation, aggregate shape, and compressive strength, to determine the optimal choice for concrete production. Methodologically, samples were acquired following ASTM standards, and rigorous testing procedures were conducted, encompassing clay particle analysis, sieve analysis, and strength testing. The results reveal significant disparities between the two regions, with Hari-River demonstrating superior characteristics across various metrics. Particularly noteworthy is Hari-River’s lower clay content of 2.7% compared to Kamar-Kalaq’s 3.7%. The gradation of Hari-River for both coarse and fine aggregates is superior to that of Kamar-Kalaq when compared to size 67 aggregate range. Additionally, the average 28 days concrete compressive strength of Hari-River aggregates is 27.8 MPa, while that of Kamar-Kalaq is 23.4 MPa.

Effect of Granite Fly Ash on Mechanical Properties of Basalt and Glass Fiber Reinforced Polymer Composite

The granite processing industry generates a substantial volume of residual granite waste daily. This residue is collected through a filtration process during the drying and heating stages of concrete mixture production. Utilizing this residue, known as granite fly ash (GD), offers a promising avenue for mitigating adverse effects due to this waste material. The present study undertakes an experimental investigation into the potential utilization of granite fly ash as a filler to enhance the mechanical properties of basalt/glass composites (BFRC/GFRC). The research focuses on assessing the density and tensile characteristics of the developed fibre-reinforced polymer (FRP) composites. Composite samples were fabricated by incorporating GD at varying loadings, i.e., 1 wt.%, 3 wt.%, and 5 wt.%. The FRP laminates were produced using hand lay-up and vacuum silicon mold curing techniques. The outcomes show a slight increase in density, in which a maximum of 7% increment at 5 wt% of GD in BFRC. Meanwhile, tensile properties displayedsignificant enhancements, especially FRP with 3 wt.% GD content, for both BFRC and GFRC. Notably, the addition of 1 wt.% GD resulted in a 9% increase in tensile strength and a substantial 27% increase in modulus for the BFRC composite. In summary, the study underscores the advantageous influence of GD incorporation, particularly within the 1 wt.%, 3 wt.%, and 5 wt.%, on the mechanical properties of both BFRC and GFRC composites.

Utilization of Tunnel Waste Slag for Cement-Stabilized Base Layers in Highway Engineering.

The rapid expansion of highway infrastructure in the mountainous regions of China has led to a significant increase in tunnel construction, generating substantial amounts of tunnel waste slag. Concurrently, the development of transportation infrastructure has created a critical shortage of natural aggregates, necessitating the exploration of alternative sustainable sources. This study aimed to conduct a comprehensive evaluation of the physical and mechanical properties of tunnel waste slag and explore its potential for utilization in cement-stabilized base courses for highway engineering applications. The uniaxial compressive strength of the parent rock (tunnel waste slag) ranged from 81 MPa to 89 MPa in the desiccated state, indicating its suitability for use as a construction material. This study also determined the maximum dry density (2.432 g/cm3) and optimal moisture content (5.4%) of cement-stabilized mixtures incorporating recycled aggregates derived from tunnel waste slag. The splitting tensile strength of these mixtures at 28 days varied from 0.48 MPa to 0.73 MPa, demonstrating robust mechanical performance. Moreover, the unconfined compressive strength of these mixtures escalated from 7.0 MPa at 7 days to 11.0 MPa at 90 days, signifying a substantial enhancement in strength over time. These results validate the viability of utilizing tunnel waste slag in highway engineering and furnish valuable insights for designers, concrete manufacturers, and construction firms engaged in the development of cement-stabilized aggregate base courses.

Calcined Clays as Concrete Additive in Structural Concrete: Workability, Mechanical Properties, Durability, and Sustainability Performance.

Calcined clays (CCs) as supplementary cementitious materials (SCMs) can be a promising option to reduce clinker content and CO2 emissions in eco-friendly concretes. Although CCs as components of composite cements in combination with Ordinary Portland Cement (OPC) and limestone powder (LSP) have attracted industry interest, their use as concrete additives is limited. This study investigates the effects of the addition of CCs on the fresh and hardened properties of industry-standard ready-mixed concretes. Four concrete mix designs, each with three superplasticizer dosages, were tested, resulting in 12 variations. The CCs used, which are typical of 2:1 bentonite clays with low metakaolin content, reflect the clays available in Germany. The results showed that CCs significantly influenced the workability, which could be controlled with a high superplasticizer dosage. Increased CC contents reduced bleeding tendencies, which was beneficial for certain structural applications. Early age strength decreased with CCs, but the 28-day strength exceeded that of pure OPC concretes up to 30 wt% CCs. Resistance to CO2-induced carbonation decreased with higher levels of CCs but was comparable up to 15 wt%. Freeze-thaw damage decreased, and chloride migration resistance improved due to a denser microstructure. The global warming potential (GWP) of the concretes tested is in line with that reported in the literature for concretes made from highly blended cements, suggesting that CCs can improve the sustainability of concrete production.

Use of Biomass Bottom Ash as an Alternative Solution to Natural Aggregates in Concrete Applications: A Review.

Biomass bottom ash (BBA) is a by-product of the energy industry and is produced from biomass-fired thermal power plants. They represent the coarsest fraction of the recovered ash and are mostly landfilled. Several researchers have investigated the feasibility of the use of BBA as a replacement for natural aggregates in cementitious material. The utilisation of BBA in the manufacturing of concrete provides an economic and ecological way to upcycle it. At the same time, its use conserves natural resources and promotes sustainability. This review article first presents the chemical, mineralogical and physical properties of BBA, to highlight the possible effects on cementitious materials and the interest in valorising them as a building material. Secondly, the focus is on the utilisation of BBA incorporated in place of natural aggregates used in the manufacturing of concrete. This review investigates the multi-physical properties of concrete manufactured with the partial incorporation of BBA. This substitution leads to decreased workability, which can be limited by the use of admixtures. In the hardened state, a reduction in the mechanical properties is shown with BBA replacement. However, many experimental works show that BBA can be used in appropriate proportions to maintain the specified properties of the concrete.

Composite Building Materials Prepared from Bioresources: Use of Rice Husk for Autoclaved Lightweight Concrete Production

Composite Building Materials Prepared from Bioresources: Use of Rice Husk for Autoclaved Lightweight Concrete Production

Effect of plantain peel ash as an admixture on concrete properties

This study investigates the effect of plantain peel ash as an admixture on concrete properties, which is a sustainable alternative to conventional concrete production. The aim is to optimize the mix design of concrete required for improved performance, investigate the effect of the plantain peel ash on the compressive strength of the concrete, and examine the effects of plantain peel ash as a supplementary material on the durability and service life of concrete. The use of plantain peel ash as an admixture for cement in concrete has gained increasing popularity due to its ability to reduce the environmental impact of concrete production. This study contributes to the understanding of the durability and performance of plantain peel ash in concrete which is crucial for sustainable construction practices. The methodology involves mix design according to IS 10262:2009 for M15 grade of concrete with 5%, 10%, 15% and 20% plantain peel ash replacement, testing of compressive strength and durability of the concrete samples and also the optimal dosage required, in comparison with conventional concrete. The result of this study shows that the addition of 5% plantain peel ash increases the compressive strength of the concrete with obtained value of 27.30 N/mm2 and also has the standard workability for a normal concrete at 45 mm for the control and 60 mm for 5% PPA. The 10%, 15% and 20% shows a decrease in their compressive strength compared to the control mix (0%) with a value of 18.42 N/mm2 for 28 days curing. Overall, it can be said that 5% plantain peel ash has provided a strong basis for the use of plantain peel ash in concrete mixtures. The 5% is equivalent to 0.72 kg PPA.

Towards sustainable construction: Strength and microstructural assessment of Dillenia suffruticosa and Acacia auriculiformis leaf ash as novel supplementary cementitious materials

Researchers are exploring local, recycled, and waste materials for construction to address environmental concerns. Concrete heavily depends on cement, contributing to energy consumption and greenhouse gas emissions. Substituting cement with alternatives like recycled materials can cut energy use and minimize the environmental impact on concrete production. This research represents the first investigation into using Dillenia Suffruticosa (DS) and Acacia Auriculiformis (AA) leaf ash as sustainable alternatives to cement in producing eco-friendly mortar, an area that other researchers have not previously explored. The study aims to investigate using DS and AA leaf ash as sustainable alternatives to cement in mortar production. In this study, the incorporation of DS and AA leaf ash as a partial replacement for cement was systematically varied in increments of 5 %, ranging from 5 % to 40 % of the total mortar volume. The ash was systematically incorporated into the mortar in increments of 5 %, ranging from 5 % to 40 % of the total mortar volume. The study further conducted a comprehensive investigation into the physical properties of the mortar, including consistency, bulk density, dry density, water absorption, and flow characteristics, alongside an analysis of its compressive strength. Microstructural behaviour was assessed using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy and thermogravimetric analysis to provide a comprehensive analysis. Results indicate that the enhancement in compressive strength of DS ash specimens, relative to AA ash, ranged from 1.32 % to 24.49 % at 7 days, 5.81 %–16.86 % at 14 days, and 1.87 %–11.91 % at 28 days. Furthermore, the highest enhancement in compressive strength is observed with a composition containing 10 % DS ash and 5 % AA ash content, underscoring the superior performance of DS ash compared to AA ash. The mineralogical characteristics of DS and AA leaf ashes illustrate their effectiveness as supplementary cementitious materials in sustainable construction. The significant advantages of using DS and AA leaf ash as a cement substitute are environmental sustainability, innovative materials use, and contribution to sustainable construction.

Economic and environmental impact analysis of cellulose nanofiber-reinforced concrete mixture production

Incorporating cellulose nanofibers into concrete has a positive impact on its strength. This study evaluated how cellulose nanofiber-reinforced concrete affected the economic and environmental performance compared to conventional concrete. The estimated minimum selling price per unit mass (m3) per unit compressive strength (MPa) of cellulose nanofiber-reinforced concrete mixture is 12 % lower ($2.52/m3/MPa) compared to the minimum selling price of conventional concrete mixture ($2.87/m3/MPa). However, when comparing the minimum selling price on a mass basis, the cellulose nanofiber-reinforced concrete mixture showed a 3.33 % higher minimum selling price ($150/m3) than the conventional concrete mixture ($145/m3). Similarly, the estimated global warming impact of cellulose nanofiber-reinforced concrete mixture was higher by 0.59 % when evaluated on a mass basis (509.88 kg CO2 eq/m3) but 14.5 % lower when evaluated on per m3 per unit compressive strength basis (8.57 kg CO2 eq/m3/MPa), compared to conventional concrete mixture (506.88 kg CO2 eq/m3 or 10.02 kg CO2 eq/m3/MPa).

Durability fragility curves for service life prediction of concrete with various supplementary cementitious materials subjected to natural carbonation

This study estimates the service life of concretes containing supplementary cementitious materials (SCM) subjected to carbonation from a probabilistic and reliability-based perspective. The aim is to enhance understanding of the risks associated with degradation and to propose an alternative approach for estimating the durability of reinforced concrete (RC) structures. The inclusion of supplementary cementitious materials (SCMs) is crucial for making concrete more sustainable, as these materials can reduce the carbon footprint of concrete production and improve its durability. Using available natural carbonation data from the literature on samples containing SCM, computational codes were developed for reliability analyses via the Monte Carlo Simulation method. The results indicated that all concrete samples exhibited a 100% probability of failure for coverages of 20 mm and 25 mm at an age of 100 years. For a coverage of 30 mm, all samples maintained a failure probability of over 98% within the same period. Notably, concretes incorporating metakaolin showed a substantial reduction in failure probability across all evaluated time periods, indicating superior durability compared to other samples. These findings significantly contribute to a deeper understanding of concrete degradation processes and provide valuable insights for the design and maintenance of RC structures, particularly in the context of using SCM. By adopting a probabilistic approach, the study underscores the importance of considering variability and uncertainties in predicting concrete durability, ultimately aiding in the development of more resilient and long-lasting infrastructure.

High-strength fiber reinforced concrete production with incorporating volcanic pumice powder and steel fiber: sustainability, strength and machine learning technique

High-strength fiber reinforced concrete production with incorporating volcanic pumice powder and steel fiber: sustainability, strength and machine learning technique

EXAMINING THE USE OF MARBLE WASTE AS A SUBSTITUTE OF CONVENTIONAL MATERIALS IN CONCRETE: A BRIEF REVIEW

For decades studies have investigated using marble waste as a partial replacement for conventional materials in concrete. This review examines the findings on substituting marble waste for coarse aggregate, fine aggregate, and cement. The studies accessed suggest that replacing up to 50% of coarse aggregate with marble waste can improve the concrete's mechanical properties and durability. Using marble waste for up to 20% of fine aggregate in concrete, mortars, and self-compacting concrete improves workability, compressive strength, and sustainability. Additionally, substituting up to 10% of cement with marble dust helps reduce cement consumption and the environmental impact of concrete production. The benefits of using marble waste include better mechanical properties, cost savings, and a smaller ecological footprint. Despite the numerous benefits, gaps in research persist, particularly in long-term performance studies, standardized testing methods, and comprehensive life cycle assessments. This review highlights the potential of marble waste as a valuable resource in the concrete industry and underscores the need for further research to optimize its use and fully realize its benefits in sustainable construction practices.

Improvement of crushed returned concrete aggregates by wet carbonation

A considerable quantity of pre-mixed concrete is returned from construction sites which is usually dumped directly into pits. While this concrete may possess lower quality attributes due to inadequate compaction and curing, the crushed hardened concrete can be potentially used to produce recycled aggregates. Carbonation is regarded as a significant way of improvement of recycled concrete aggregates. This study investigated the effectiveness of wet carbonation method for the improvement of crushed returned concrete aggregates (CRCA) to reuse in concrete productions. Recycled concrete aggregate (RCA) obtained from crushing of old conventionally cast concrete was also subjected to the same treatment, and its properties were compared with those of CRCA to understand the improvement in each type of recycled aggregate. The effectiveness of wet carbonation was evaluated by the aqueous chemistry during carbonation, development of microstructure, depth of calcium carbonate deposition, the mineralogy, water absorption, and compressive strength for both treated and untreated CRCA and RCA for different carbonation durations. The results showed that, although the water absorptions of both uncarbonated and carbonated CRCA were higher than those of RCA, the rate of reduction of water absorption of CRCA after carbonation was higher than that in RCA. Due to the long exposure to open environment, CRCA showed less initial alkalinity and conductivity than RCA but at the end of carbonation, both pH and conductivity were almost same as those of RCA. Wet carbonation successfully produced well shaped calcite in both CRCA and RCA where the deposition depth of calcite was higher in CRCA than in RCA. Mineralogical analysis showed higher calcium carbonate formation in CRCA indicating its potential of sequestrating more CO2 than by RCA. The improvement of concrete compressive strength was more pronounced for CRCA, with a 28 % enhancement observed after 2 hours of carbonation, compared to an 18 % enhancement for RCA. These findings demonstrated that wet carbonation can be regarded as an effective strategy for enhancing CRCA.