Sustainable Concrete Research Articles

Optimizing Waste Glass Powder Content in the Development of Sustainable Concrete for High-Temperature Resistance

Optimizing Waste Glass Powder Content in the Development of Sustainable Concrete for High-Temperature Resistance

THE IMPACT OF GLASS AND CONCRETE SLUDGE AMOUNTS ON THE PROPERTIES OF SUSTAINABLE CONCRETE WITH A CRYSTALLISING ADMIXTURE

THE IMPACT OF GLASS AND CONCRETE SLUDGE AMOUNTS ON THE PROPERTIES OF SUSTAINABLE CONCRETE WITH A CRYSTALLISING ADMIXTURE

Evaluation of technical and gamma radiation shielding properties of sustainable ultra-high performance geopolymer concrete

This study proposed to use barite-enhanced ultra-high performance geopolymer concrete (UHPGC) as the composite matrix to develop high-strength, cement-free, and sustainable radiation shielding materials. The physical properties, γ ray attenuation capacity, microstructure, and environmental and economic impacts of prepared barite-enhanced radiation shielding UHPGC were determined and compared with normal concrete and ultra-high performance concrete (UHPC). The combination of steel fibers and barite aggregate increased the density of UHPGC, thereby enhancing its γ ray attenuation capacity. Multi-scale γ ray shielding simulation results demonstrated that although thickness was the more decisive factor of γ ray attenuation capacity of composites, the enhancement of the shielding capacity of the material helps reduce the floor area and the cost of radiation shielding structure. The micro-analysis results revealed that barite-enhanced UHPGC exhibited compact microstructure and excellent interfacial performance. Furthermore, life cycle assessment results demonstrated that UHPGC was more suitable as a composite matrix than UHPC to develop sustainable and low-cost radiation shielding materials.

The Effects of Polypropylene Wastes on the Compressive Strength of Grade 25 Concrete

The effect of polypropylene waste on the compressive strength of grade 25 concrete was studied. This was due to the increased problem of environmental pollution which may lead to flooding these wastes are causing in our environment. The research used the experimental methods in carried out the study. The polypropylene were pulverized to sand particle sizes and dosed at 5 %, 10 %, 15 % and 20 % by weight as partial replacement of sand in grade 25 concrete, cured for 7 days, 14 days, 21 days and 28 days respectively. The results reveal that polypropylene can be substituted with sand in concrete up to 15% by weight with a negligible decrease of 3.7 % of compressive strength when compared to the control concrete. This depicts that polypropylene can be used in producing sustainable concrete.

The influence of graphene nanoplatelet content on the mechanical properties and microstructure of sustainable concrete

The effects of the content of graphene nanoplatelets (GNPs) on the mechanical properties and microstructure of sustainable concrete were investigated. Aqueous solutions were prepared, using a wet-dispersion technique to disperse GNPs in the mixing water. Concrete batches were prepared using different GNP fractions (0.05, 0.1, 0.25, 0.5, 1 and 2% by weight of cement), and their compressive, flexural and tensile strengths were determined at 28 days. Qualitative microstructural analyses were performed using scanning electron microscopy and energy dispersive X-ray analysis. The results obtained were analysed using analysis of variance (Anova), which demonstrated improvements in all strength properties when using GNP filaments regardless of their weight fraction. The batch containing 0.5% GNPs showed the largest strength improvements, with improvements in compressive, flexural and tensile strength properties of 22.6%, 23.9% and 255.4%, respectively. Microstructural analysis showed a good dispersion of nanofilaments inside the concrete matrix through the dispersion technique used in this study. Finally, Anova revealed statistically significant relationships between the GNP content and the compressive, flexural and tensile strengths of the concrete specimens. The results highlight the importance of the GNP content in influencing the concrete's mechanical properties.

A comprehensive study on engineering and sustainability characteristics with emphasizing on 3R's approach in building construction

The study assesses the mechanical efficiency, long-lasting characteristics, microstructure, and sustainability of sustainable concrete (SC) samples through several optimization methods, emphasizing the significance of the 3Rs (recycle, reuse, reduce) approach in the construction sector. The study uses advanced techniques like the Taguchi method, grey relational analysis (GRA), analysis of variance (ANOVA), and signal-noise ratio (SNR) to optimize parameters affecting the performance of SC. In this study, the properties of SC are assessed by considering various parameters. These parameters include the use of 10 %, 20 %, and 30 % of ground granulated blast furnace slag (GGBFS) as a replacement for fly ash (FA). Additionally, six different binder contents ranging from 300 kg/m3 to 600 kg/m3 are examined. The study also investigates three different molarities of sodium hydroxide (NaOH) (8 M, 12 M, and 16 M), three different ratios of alkaline activators (AA) (1.5, 2.0, and 2.5), three different AA to-binder ratios (0.30, 0.35, and 0.40), and curing temperature (CT) of 30 °C, 60 °C, and 90 °C. The study includes fresh properties such as fresh density (FD) and slump, mechanical properties such as tensile strength (TS), flexural strength (FS), modulus of elasticity (MOE), and compressive strength (CS), and durability studies such as dry density (DD), impact strength, water absorption (WA), and sorptivity. The blended proportions were obtained using the Taguchi method. The study shows that GGBFS accelerates geopolymerization in FA-based concrete, reducing setting time and early-age CS. FA is crucial for setting time, workability, and CS enhancement. GGBFS increases the densities of fresh and hardened concrete, with a highly correlated increase, allowing accurate hardened density prediction with a coefficient of 0.9057. The CS of the cube SC surpassed 40 MPa, irrespective of variables such as the AA ratio, CT, and NaOH molarity. The trail mix with a binder concentration of 600 kg/m3, 30 % GGBFS content, 12 M NaOH molarity, 1.5 AA ratio, 0.35 AA to binder ratio, and 90 °C CT exhibited the greatest strength. Mixtures containing 10 % GGBFS can attain a CS above 30 MPa after 28 days, making them suitable for structural purposes. The T18 mix exhibited a compact Calcium (alumino) silicate hydrate (C-A-S-H) and N-A-S-H gel, whereas the T3 mix displayed a varied and permeable structure. The study used GRA, ANOVA, and SNR methods to analyze properties varying by six variables, finding GGBFS content as the most influencing parameter. The study found that the SC had a lower sustainability score than the OPC mix, but had better energy efficiency.

Mechanical properties, permeability and microstructural characterisation of rice husk ash sustainable concrete with the addition of carbon nanotubes

This study investigated the effects of incorporating carbon nanotubes (CNTs) into rice husk ash (RHA) sustainable concrete on its mechanical properties, permeability and microstructure characterisation. Mechanical test results suggested that the addition of 0.10 % multiwalled CNTs (MWCNTs) yielded optimal results, with increases in the compressive strength, splitting tensile strength, flexural strength, and elastic modulus of the RHA concrete at 28 days of 7 %, 23.81 %, 17.5 %, and 1.0 %, respectively. However, with further addition of MWCNTs, the mechanical properties ultimately deteriorated. Further, the incorporation of CNTs enhanced the long-term performance of RHA sustainable concrete. The addition of 0.1 % MWCNTs and 15 % RHA yielded a 20 %, 14 %, and 66 % decrease in water absorption, porosity, and chloride diffusion coefficient compared to the mixture solely containing 15 % RHA. Scanning electron microscopy of this mixture revealed the filling and bridging effects of MWCNTs between the hydration products have enhanced the performance of RHA sustainable concrete.

Examining the structural viability of recycled fine aggregates in sustainable concrete

Examining the structural viability of recycled fine aggregates in sustainable concrete

Sustainable self-Compacting concrete with marble slurry and fly ash: Statistical modeling, microstructural investigations, and rheological characterization

The escalating generation of marble waste and the substantial carbon footprint associated with cement production pose significant environmental challenges. Thus, by substituting fly ash for supplementary cementitious material and using leftover marble waste for fine aggregate in concrete can reduce cost and carbon emissions that may lead to sustainable development. The presented paper aims to study the effect of partial substitution of marble slurry with natural fine aggregates and fly ash as supplementary cementitious material (SCM) on Self-Compacting Concrete (SCC). Polycarboxylate Ether (PCE) based superplasticizer (SP) was added in the concrete mix, to decrease the demand of higher water to binder (w/b) ratio. After developing SCC, fresh state properties and compressive strength (CS) at the curing age of 7 and 28 days were evaluated. To maximize the utilization of marble slurry and fly ash, mixture optimization was performed using the Box-Behnken Design (BBD), a robust technique within the response surface methodology (RSM) framework. Rheological analysis was performed to analyse the fresh state behaviour of the SCC with the help of the Bingham and Modified Bingham (MB) models. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) studies were also carried out to study the behaviour of the marble slurry and fly ash in the concrete. Carbon emission and cost analysis of SCC was evaluated at different replacement level of the marble slurry and fly ash. It was inferred that marble slurry and fly ash can be used in the certain percentages without compromising any strengthen and flowability properties of the SCC. The rheological behaviour also confirmed that linear and nonlinear behaviour of SCC in the certain mix proportion may results in the formation of the stable SCC. The analysis of cost and carbon emission confirmed that sustainable SCC mixture achieved substantial reductions of 21.44 % in cost and a remarkable 47.71 % decrease in carbon dioxide (CO2) emissions compared to conventional concrete.

Effect of Water Quality on Performance of Concrete: A Study Towards Developing Sustainable Concrete

Effect of Water Quality on Performance of Concrete: A Study Towards Developing Sustainable Concrete

Reviewing the potential of waste paper incorporation in enhancing concrete sustainability

Reviewing the potential of waste paper incorporation in enhancing concrete sustainability

Investigation of the Mechanical Behaviors of Sustainable Green Reactive Powder Concrete Produced Using Ferrochrome Slag and Waste Fiber

Reactive powder concrete (RPC) is a new generation concrete with high strength, used in special structures, and its use is increasing day by day. In this study, instead of using high-strength aggregates typically used in RPC, wastes released in ferrochrome production were used. In addition, the possibility of using fibers obtained from end-of-life automobile tires (ELT), instead of the micro steel fibers typically used in RPC, was investigated. Thus, sustainable green reactive powder concrete (GRPC), the material which is obtained from waste materials except the binder and chemical additive, has been developed. As ferrochrome wastes, olivine, serpentine, rum, slag, and pure waste were used as powder and aggregate in GRPC. Firstly, in GRPC without fiber, the physical and mechanical properties of ferrochrome wastes were examined by using different ratios. Then, the optimum mixture was selected, and different ratios of industrial steel and ELT fiber were added to this mixture. As a result, the compressive strength of GRPC using olivine and pure waste (ferrochrome slag) is close to the reference RPC. However, it is 28% more economical. The flexural strength of the samples with a 4% addition of industrial or ELT fiber increased by 182% and 213%, respectively, compared to the reference sample without fiber. With the use of 4% ELT fiber (by volume) in GRPC, the flexural strength increased by 11% compared to the use of industrial steel fiber. In terms of cost, with the use of ferrochrome waste and ELT fiber, GRPC was 48% more economical. When examined in terms of the flexural and compressive unit strength cost, GRPC was approximately 41% more economical. As a result of this study, high-performance concrete with high mechanical properties that is economical, sustainable, and environmentally friendly has been produced by evaluating the use of waste materials.

Reemplazo del Agregado Fino por Residuo de Ladrillo Refractario en Concreto Expuesto a Elevadas Temperaturas

Refractory brick waste, added to the fires originated in structures, makes it possible to bring together two problems to contribute to sustainable construction and introduce new aggregate alternatives in concrete. The objective of the study was to produce concrete with less fine aggregate and to evaluate a more sustainable concrete, using refractory brick residues (RBR) to replace fine aggregate in five percentages 10 %, 20 %, 30 %, 40 % and 50 % to be exposed to direct fire. The design was based on a water-cement w/c ratio of 0.71 and the production of 144 RBR-based concrete specimens. The fresh samples were subjected to slump and fresh unit weight tests, the cylindrical specimens prepared after 28 days of curing were subjected to compressive strength at room temperature and various temperatures (200 to 1 000 °C) for different times of 15, 30 and 60 minutes. In addition, a Three Factor statistical analysis of variance was performed with respect to the compressive strength at 28 days. The results showed that the RBR influences the concrete mix are less workable and reduce the fresh unit weight at higher substitution percentages. On the other hand, the ideal dosage was with the percentage of 40RBR as opposed to the other dosages subjected to heat, being insignificant at 15-minute exposure, but relevant at 30 and 60 minutes. It is concluded that RBR significantly influences the improvement of its mechanical properties under high heat and the amount of residues is limited to a specific dosage, providing a sustainable constructive approach to direct controlled fire exposures.

Examination of the Physical–Mechanical Properties of Sustainable Self-Curing Concrete Using Crushed Ceramic, Volcanic Powder, and Polyethylene Glycol

This study investigates the properties of sustainable self-curing concrete (SSC) by adding volcanic powder (VP), crushed ceramic (CC), and polyethylene glycol 6000 (PEG). VP and CC are prepared from volcanic ash, as a natural pozzolanic material, and construction waste, respectively. PEG is used as an inner-curing agent. Twenty-six concrete mixtures are prepared using VP at 5%, 10%, 15%, and 20%, CC at 50%, and PEG at 1%, 1.5%, and 2% and tested after 7, 28, and 56 days. Mechanical, workability, and durability characteristics are evaluated using different tests. The bond and cohesion between aggregates and mortar are tested using a scanning electron microscope (SEM). The results show that the optimum replacement mix for enhancing strengths, by producing C-S-H, of the studied SSC is 10% VP and 1.5% PEG. This improved the compressive, tensile, and flexural strengths of SSC by 54.5%, 60.7%, and 34.9%, respectively, compared to a reference mix. Adding CC enhances the compressive strength of SSC by 41.6% and 11.5% and decreases chloride penetration by 10% and 9.1% compared to control mixes. PEG improves the mechanical, workability, and durability characteristics of SSC even with the addition of 1%. The obtained results reveal the possibility of using VP and CC in producing SSC.

Influence on impact strength and chloride permeability of concrete made with cementitious material and artificial sand

The over usage of natural sand and cement has negative social and ecological effects. To address this, by-products of industrial wastes known as pozzolanic materials, including as fly ash, GGBFS, silica fume, and metakaolin, can be utilised with the manufactured sand in place of the natural fine aggregate and cement. As a result, the current research project discussed in this article examines the viability of replacing cement in concrete with pozzolana and crushed sand. Thus, this will address two issues at once: the large-scale use of pozzolanic materials and the preservation of natural sand quarries. The main objective of this experimental investigation is to find out the impact and durability properties of concrete produced by replacing natural sand by manufactured sand in varying percentages like 0, 10, 20, 30, 40, 50, 60 70, 80, 90, 100, and 20% cement replacing with pozzolanic materials. Cylindrical disc 150 mm diameter and 65 mm thick was tested for impact strength and chloride permeability 50 mm thick and 100 mm diameter samples were cast. The 28-day impact strength and chloride permeability of concrete mixed by partially substituting cement with pozzolan and partially substituting natural fine aggregate with artificial sand were tested. For the various concrete mix proportions, the findings for impact strength and chloride permeability were examined and contrasted with standard concrete. The results of this study show that substituting 20% of the cement with silica fume and 60% of the natural fine aggregate with M-sand results in concrete that has a maximum impact strength and a minimum chloride permeability. An ANN Model was developed using the experimental values. For design of model 400 result values where used, 20% results used for testing purpose and 80% results used for ANN model training. Calculated using the product of 25 input data. The ANN model’s results offer a precise elastic prediction of the impact strength and chloride iron pass ability of concrete mixed with substituting industrial cementitious waste for cement and artificial sand with naturally occurring fine aggregate. The findings of this study help to reduce the extraction of non-renewable natural recourses and the environmental impact of industrial waste by preparing more sustainable concrete.

Compressive and tensile strength estimation of sustainable geopolymer concrete using contemporary boosting ensemble techniques

Abstract Geopolymer concrete (GPC) serves as an environmentally conscious alternative to traditional concrete, offering a sustainable solution for construction needs. The ability to make on-site changes is dependent on the concrete’s strength after casting, which must be higher than the target value. To anticipate the concrete’s strength before it is poured is, thus, quite helpful. Three ensemble machine learning (ML) approaches, including gradient boosting, AdaBoost regressor, and extreme gradient boosting, are presented in this work as potential methods for forecasting GPC’s mechanical strength that incorporates corncob ash. To determine which modeling parameters are crucial, sensitivity analysis was employed. When the compressive strength and split-tensile strength of GPC were tested with ensemble ML models, R 2 values of more than 90% were discovered between the predicted and actual results. Statistics and a k-fold analysis based on the error and coefficient of determination were used to verify the developed models. Slag amount, curing age, and fine aggregate quantity were the three mix proportions that had the most impact on GPC’s mechanical strength, as shown in the sensitivity analysis. The results of this study demonstrated that ensemble boosting approaches could reliably estimate GPC mechanical strength. Incorporating such procedures into GPC quality control can yield significant improvements.

Enhancing sustainability in self-compacting concrete by optimizing blended supplementary cementitious materials

Within concrete engineering, the uptake of self-compacting concrete (SCC) represents a notable trend, delivering improved workability and placement efficiency. However, challenges persist, notably in achieving optimal performance while mitigating environmental impacts, particularly in cement consumption. However, simply reducing the cement content in the mix design can directly compromise the structural-concrete requirements. Towards these challenges, global trends emphasize the utilization of appropriate waste materials in blended concrete. This study explored a promising strategy by integrating supplementary cementitious materials (SCMs) to contribute to the United Nations' Sustainable Development Goals (SDGs) in addition to the engineering contributions. It suggests an optimal combination of Metakaolin (MK) and Limestone Powder (LP) to partially substitute cement. The research methodology employs the response surface method (RSM) to systematically explore the ideal ingredient ratios. Through a comprehensive analysis of orthogonal array of 16 mixes, encompassing both mixture and process variables, this study aims to explain the effects of MK and LP addition on the rheological and mechanical properties of SCC with varying cement replacement levels. In terms of mixture constituents, the total composition of cement, MK, and LP was fixed at 100%, while coarse aggregate (CA), fine aggregate (FA), and the water-to-binder ratio were held as process variables. In order to assess the rheological properties of the mix-design, various tests including slump flow, L-box, and sieve segregation were conducted. Additionally, to evaluate mechanical strength, samples were tested for compressive strength at both 7 and 28 days. Findings from the experiments reveal higher concentrations of MK result in reduced workability and hardened properties. Through RSM-based designed experimentation covering both rheological and mechanical aspects, it is observed that the optimal cement replacement level lies between 40 and 55%. The findings of this study contribute to the advancement of sustainable and structurally robust concrete practices, offering insights into the optimal utilization of SCMs to meet both engineering requirements and environmental sustainability goals.

Prediction on partial replacement of cement and coarse aggregate by zeolite powder and steel slag in high-performance concrete

High performance concrete is obtained by the inclusion of mineral admixtures like silica fume and fly ash in the concrete. The research explores the viability and performance of sustainable concrete by introducing zeolite powder as a partial substitute for cement and steel slag as a partial replacement for coarse aggregate in M-70 grade concrete. Zeolite powder, possessing pozzolanic properties, is a natural or synthetic aluminosilicate material, while steel slag is an industrial byproduct with potential as an alternative aggregate source. The main objective is to investigate the impact of zeolite powder and steel slag on the development of High-Performance Concrete (M-70) in accordance with Bureau of Indian standards. The formulation of high-performance concrete involved replacing 12.5%, 15%, and 17.5% of the cement with zeolite powder and varying the proportion of steel slag as a replacement for coarse aggregate (ranging from 30% to 55%). A comprehensive mechanical test was conducted on these specimens and compared with conventional concrete. Among the 19 mixes, the optimal combination was identified, incorporating 15% zeolite powder as a cement replacement and 45% steel slag as a coarse aggregate replacement, resulting in superior performance compared to conventional concrete. This mix was further studied for non-destructive testing, and microstructural analysis. Subsequently, the experimental results were compared with predicted outcomes using the Taguchi method. The close alignment between the values obtained experimentally and those predicted further validates the effectiveness of the optimized mix.

Sustainable Concrete Production: Utilizing Cow Dung Ash and Corn Stalk Ash as Eco-Friendly Alternatives

This study aims to determine whether it is feasible to replace conventional materials used in manufacturing concrete with waste materials, namely cow dung ash and corn stalk ash. This study proposes to assess the possibility of using these agricultural by-products to improve the sustainability of concrete while simultaneously tackling the environmental issues related to the manufacture of conventional concrete. The research aims to assess the mechanical qualities, optimize the mix proportions, and examine the ecological implications of using these substitute materials. This research aims to mitigate environmental challenges like carbon dioxide emissions, resource depletion, and the accumulation of agricultural waste by combining agricultural waste and lowering dependency on traditional cement. The study investigates the use of cow dung ash (CDA) and corn stalk ash (CSA) as alternatives for conventional Portland cement (OPC) in mortar mixes at varying quantities, ranging from 5% to 25% CDA and 2.5% to 10% CSA. Chemical composition reveals that CDA and CSA predominantly comprise O, Mg, Al, Si, P, K, and Ca. The workability, hardened characteristics, and microstructure of CDA and CSA were assessed. Increasing CDA and CSA percentages reduced mortar workability; nevertheless, replacing 8% to 10% CDA and 7.5% CSA maintained compressive, tensile, and flexural strengths comparable to control mixes. However, more significant CDA and CSA proportions resulted in lower mortar strength. For example, 10% CDA-enriched mortar had a compressive strength of 31.77 N/mm2, a tensile strength of 3.42 N/mm2, and a flexural strength of 3.61 N/mm2, whereas 7.5% CSA-enriched mortar had a compressive strength of 28.4 N/mm2, a tensile strength of 3.04 N/mm2, and a flexural strength of 3.7 N/mm2. According to the findings, CDA and CSA can replace OPC by up to 10% and 7.5% in mortar manufacturing, making cementitious material alternatives viable. Doi: 10.28991/CEJ-SP2024-010-02 Full Text: PDF

Image processing and Machine learning in Concrete Cube Crack detection

Concrete cube testing plays a crucial role in various aspects of modern construction. The structural performance of concrete cubes under direct compressive stress can result in failure through concrete cube breakout. Failure modes related to concrete can be classified into two types: acceptable and non-acceptable, with further classification into various modes. However, most of the time 80% to 90% of the cubes are inaccurately selected, leading to lower strength and sustainability of concrete. Moreover, the excessive usage of cement required due to these inaccuracies contributes to global warming and increases costs. To address these issues, this research aims to develop an industry 4.0 solution for the construction and civil engineering fields. The proposed solution will be reliable, efficient, and based on image processing techniques. Convolutional Neural Networks (CNN) is used to detect and analyze cracks in concrete cubes. By examining the crack patterns, the damage area can be determined. By leveraging industry 4.0 technologies and advanced analysis techniques, this research aims to revolutionize the way concrete cube testing is conducted. The proposed solution will provide a reliable and efficient method for evaluating concrete cube quality, mitigating the negative impacts associated with inaccurate cube selection, and improving the performance and environmental sustainability of concrete in construction applications.