Eco-friendly Concrete Research Articles

Shear strength of eco-friendly self-compacting concrete beams containing ground granulated blast furnace slag and fly ash as cement replacement

It is becoming essential to find solutions to preserve the environment from emissions related to cement manufacture. One of the most effective solutions and techniques is using supplementary cementitious materials (SCMs) as cement substitutes to produce eco-friendly concrete. This experimental work primarily aimed to investigate the impact of ground granulated blast furnace slag (GGBFS) and fly ash (FA) as cement substitutes on the shear behavior of SCC beams. Six SCC mixtures with binary and ternary binders based on cement, FA, and GGBFS were manufactured. Twelve SCC beams (two beams for each mixture) with and without shear reinforcement were cast and tested under simply supported four-point loading conditions. Test variables were different substitute levels of GGBFS and FA (0 %, 25 %, and 50 %) of the total weight of cement and shear reinforcement ratio. The findings indicated that the addition of GGBFS and FA had a negative impact on the mechanical characteristics of SCC. The stiffness, ultimate shear strength, and toughness of SCC beams decrease with the increase of GGBFS and FA contents. The ultimate shear strength of tested beams without stirrups comprising GGBFS and FA up to 50 % was reduced by about 12.1 % and 19.3 %, respectively. The ultimate shear strength, shear ductility, and stiffness of tested beams comprising up to 50 % GGBFS were reduced by about 10.5 %, 36.4 %, and 9.1 %, respectively. Based on the experimental results, from both an environmental and engineering perspective, a combination of ternary binders based on 50 % cement, 25 % FA and 25 % GGBFS can be considered the optimum substitute ratios that can be used on the SCC mixture. Whereas it contains a high level of SCMs causing a minimal impact on shear strength with the improvement of the ductility of SCC beam. Lastly, the experimental ultimate shear strength of test specimens was compared with those predicted from different international design codes.

Review of alternative ash aggregates in concrete-solution towards waste management and environmental protection.

Owing to the depletion of natural resources, new alternative materials are emerging in construction industry. Especially, development of alternative binders and aggregates using industrial by-products paves way for the development of eco-friendly concrete. As aggregates occupy about 60-70% of the volume of concrete, new alternative materials developed as a substitute for aggregates are considered as need of the day for achieving sustainability in concrete industry. In the past few decades, many industrial by-products are researched as an alternative for natural aggregates. Ash being the largely produced by-products from different industries, it has huge potential in the development of artificial aggregates. Nevertheless, ashes produced from different sources such as coal, municipal solid waste and biomass have different characteristics and affect the properties of aggregates made out of them. The volume of research works reported on development of ash aggregates all over the globe shows that there is a faster growth rate in the development of alternative aggregates and its utilization in concrete. In this context, the current study aims to review the literature reported on mortar/concrete made of ash aggregates from various sources such as thermal power stations, biomass and municipal solid waste incinerator. The characteristics of different types of ash, development of aggregate and its properties in mortar/concrete are reviewed. Based on the review, future recommendations and directions are provided to utilize more of ash aggregates in the place of natural aggregates to prevent depletion of natural resources.

Performance Assessment of Concrete Using Discarded Membrane Filter Materials

Currently, membrane filters, which need to be replaced regularly as they get worn, are used in filtration facilities globally. The old membrane filters and housings become continuous industrial waste and are currently 100% incinerated. To solve this environmental problem, this study proposes the development of an eco-friendly concrete by mixing waste membrane resources with concrete. Through this, the environmental pollution and wastage of resources due to incineration, and the enormous amount of carbon dioxide generated during cement production, can be decreased by reducing the cement required when mixing concrete. To this end, the membrane module outer surface (acrylic butadiene styrene, ABS) and inner membrane (poly vinylidene fluoride, PVDF) were extracted from the waste membrane system and pulverized. Different mix ratios of 1%, 3%, and 5% for replacing cement were used when mixing concrete. The test specimens were then tested and compared with the reference concrete (ordinary Portland cement) specimen. It was confirmed that the compressive strength was high after 28 days in all the specimens to which ABS was added at 1%, 3%, and 5% mix ratios. Therefore, the possibility of technological development of eco-friendly concrete using waste resources from membrane filtration facilities was verified.

Mineralogical and microtextural characterization of eco-friendly concrete for marine infrastructures: Methodologies for the MARINEFF Project

The European cross-border Project MARINEFF explores the use of eco-friendly concrete materials in the construction of marine structures (oyster bed modules, dykes, boat moorings and rockpools). The structures and materials are designed to protect and improve the local biodiversity of the marine environment of the Channel / La Manche. This paper focuses on the mineralogical and microtextural characterization of the concrete materials. The aim is to introduce how advanced analytical methods have been employed to gain an understanding of the evolution of the materials, in particular their response to immersion into the sea. Our methods include the traditional techniques for examining concrete materials (optical microscopy, scanning electron microscopy, X-ray diffraction), but also introduces the benefits of mineralogical methods that go beyond the current “state-of-the-art” (automated scanning electron microscopy by QEMSCAN®, electron-probe microanalysis). Our results offer detailed insight into the controls on the compositional and structural evolution of the materials.

Application of Multivariate Adaptive Regression Splines (MARS) approach in prediction of compressive strength of eco-friendly concrete

Concrete is the most often used material in the building sector. The use of ground-granulated blast-furnace slag (GGBFS) and recycled concrete aggregates (RCA) in concrete reduces its negative environmental impact. However, increasing the number of ingredients in concrete complicates the prediction of its compressive strength. This research aims to develop a machine learning model for predicting the compressive strength of eco-friendly concrete using Multivariate Adaptive Regression Splines (MARS). MARS is a well-known technique for creating predictive modeling equations using experimental data. A data set of 161 concrete specimens was obtained to train and evaluate the machine learning algorithms for this work. The findings of the MARS prediction algorithm were compared to those of the Support Vector Machine and the Random Forest regression algorithms (black-box models) using the training set. A hyperparameter tuning procedure was applied to find the optimal MARS, RF, and SVM model parameters. The results of 5-fold cross-validation indicate that the MARS optimal model has the highest coefficient of determination (R2), with a value equal to 0.889, and the lowest Root Mean Squared Error (RMSE) measure, with a value equal to 4.110 MPa. For our case, the performance metrics measures proved the superiority of the MARS model when compared with RF and SVM. The final MARS optimal prediction equations were built using a full training set and were then evaluated using unseen data (testing set). Our model has the potential to help civil engineers in designing durable infrastructures.

Utilization of Recycled Plastic Waste in Fiber Reinforced Concrete for Eco-Friendly Footpath and Pavement Applications

The use of concrete in road construction has grown over the past decade due to the material’s great durability. However, concrete has poor tensile strength, ductility, and energy absorption. This paper aims to investigate the utilization of plastic waste, namely polypropylene (PP), to create a novel fiber to enhance the engineering properties of fiber reinforced concrete (FRC), an eco-friendly concrete that can reduce environmental problems. The 28-day design strengths of 28 and 32 MPa were used in this study because the compressive strength requirements for concrete footpaths and pavement specified by Austroads and the Department of Highways, Thailand, were at least 25 and 32 MPa, respectively. The fiber (F) was a mixture of virgin PP and recycled PP (RPP). The study used F contents of 0.25, 0.50, 0.75, and 1% by weight of cement and PP:RPP ratios of 100:0, 75:25, 50:50, 25:75, and 0:100. The compressive strength, flexural strength, leaching, and CO2 emissions savings of FRC were evaluated. Improvements in the compressive strength, flexural strength, and toughness of the samples with F were observed in comparison to the control concrete samples for all design strengths. All mixtures met the compressive strength requirements for concrete footpaths, except for F contents of 0.75 and 1% and a PP:RPP ratio of 0:100. By contrast, the 32 MPa FRC samples with F contents of 0.25 and 0.5% and all PP:RPP ratios met the requirements for rigid pavement. From an environmental perspective, the heavy metal contaminants of the 32 MPa FRC sample were within the allowable limits for all mixtures. Regarding incineration disposal, the maximum CO2 emissions savings of 28 MPa and 32 MPa FRC with an F content of 0.5% and a PP:RPP ratio of 0:100 were 1.0 and 1.11 kg CO2-e/m3, respectively. This research will enable plastic waste, traditionally destined for incineration and landfill disposal, to be used as a sustainable fiber in the construction industry.

Conservation Environments' Effect on the Compressive Strength Behaviour of Wood-Concrete Composites.

This paper addresses the issues in making wood–concrete composites more resilient to environmental conditions and to improve their compressive strength. Tests were carried out on cubic specimens of 10 × 10 × 10 cm3 composed of ordinary concrete with a 2% redwood- and hardwood-chip dosage. Superficial treatments of cement and lime were applied to the wood chips. All specimens were kept for 28 days in the open air and for 12 months in: the open air, drinking water, seawater, and an oven. Consequently, the compressive strength of ordinary concrete is approximately 37.1 MPa. After 365 days of exposure to the open air, drinking water, seawater, and the oven, a resistance loss of 35.84, 36.06, 42.85, and 52.30% were observed, respectively. In all environments investigated, the untreated wood composite concrete’s resistance decreased significantly, while the cement/lime treatment of the wood enhanced them. However, only 15.5 MPa and 14.6 MPa were attained after the first 28 days in the cases of the redwood and the hardwood treated with lime. These findings indicate that the resistance of wood–concrete composites depends on the type of wood used. Treating wood chips with cement is a potential method for making these materials resistant in conservation situations determined by the cement’s chemical composition. The current study has implications for researchers and practitioners for further understanding the impact of these eco-friendly concretes in the construction industry.

The Influence of Industrial Steel Waste on Slump Test and Compressive Strength in Eco-Friendly Concrete Fabrication

This study evaluated the suitable percentage of replacing natural coarse aggregate (crushed granite) with wasted Zinc Aluminum (Zincalume) generated from metal roofing fabrication industry to produce G35 grade eco–friendly concrete. Design mix for the wasted Zincalume substitution with crushed granite was prepared at 10%, 15% and 20% where the control mix specimen used as reference for mechanical strengths comparison. The mechanical strengths were observed with the increasing of curing age, but the strengths reduced with the increment of wasted Zincalume in the mixture. An amount of 10% of Zincalume substitution gave the optimum mechanical strength values. Acid – base reaction between cement and Zincalume coating in the concrete mixture, generated hydrogen gas, which reduced the compressive strength. The higher percentage of Zincalume in the concrete mixture, the weaker mechanical strengths were obtained. By recycling the steel waste, the eco – friendly concrete encourages to protect environment and enhance the economy growth.

Performance and life-cycle assessment of high-volume fly ash concrete mixes containing steel slag sand

The present study discusses the performance of high-volume fly ash concrete (HVFAC) mixes containing slag sand which is a solid waste obtained from basic oxygen steel making industry. The design of such mixes was optimized to attain sufficient strength for structural purposes and then cement and natural sand in them were replaced with fly ash and slag sand up to 50%. Other than temperature developments, their fresh and hardened properties like slump, air content, compressive and tensile strengths, elastic modulus, strain softening response under uniaxial compression, shrinkage, water permeation, sorption and absorption, chloride ions diffusion and migration, and bulk electrical resistance at different ages were also studied in detail. The impact of fly ash and slag sand on the sustainability of such mixes were assessed and their co-effects on concrete microstructure were discussed with the results of scanning electron microscopy and Mercury intrusion porosimetry. The HVFAC mixes displayed a slower strength increase at early ages, but they were found to be highly workable, durable, and temperature rise in them was comparatively lower. The strength and durability of these mixes at early ages were found to enhance in the presence of slag sand which is generally capable of strengthening the aggregate-paste interface. India is the second largest producer of cement in the world. Both the fly ash and slag sand possess a lower energy requirement and their inclusions led to the production of eco-friendly concrete which is highly desirable for Indian conditions.

Durability of Reinforced Concrete Containing Biochar and Recycled Polymers

In the field of sustainable construction materials, the production of eco-friendly concretes, obtained by the addition of waste products such as biochar and recycled polymer particles, offers interesting alternatives to traditional materials. Biochar is a carbonaceous solid by-product obtained from the thermo-chemical conversion of biomass and its addition into concrete admixtures can offer an eco-friendly carbon sequestration solution, capable to slightly improve concrete properties. Recycled polymer materials can be used to partially replace conventional aggregates with the aim of obtaining lighter concretes that help to face the disposal challenge presented by this non-degradable plastic waste. However, the influence of these waste additions on the corrosion behavior of steel rebars embedded in these “eco-concretes” is still unexplored. Within this context, this work presents some results of an extensive study dealing with the concrete mechanical and physical properties and the rebar corrosion resistance during cyclic exposures to chloride-containing solutions.

Mechanical and durability properties of concrete with recycled polypropylene waste plastic as a partial replacement of coarse aggregate

Reusing non-biodegradable plastic waste materials can be a viable solution for minimizing the consumption of natural resources for construction purposes and reducing environmental hazards. Thus, this study inspects the potentialities of polypropylene (PP) plastic waste as coarse aggregate in concrete. This study aims to evaluate the mechanical and durability properties of PP concrete. It focuses mainly on workability, hardened density, compressive strength, modulus of elasticity (MoE), splitting tensile strength (STS), flexural strength, bond strength, temperature effect on compressive strength, shrinkage properties, and chloride ion penetration. The experimental work includes a varying percentage of PP aggregate as 10% and 20% of the volume of coarse aggregate and the water-cement ratios as 0.35, 0.40, 0.45, and 0.50. The experimental results revealed that the workability of concrete increased with the addition of PP aggregate into the mixture. Almost 5% and 10% reduction in concrete density can be possible while using 10% and 20% PP content, respectively. In terms of compressive strength, MoE, STS, and flexural strength, all the properties were decreased after incorporating PP aggregate into the concrete. At elevated temperatures, compressive strength decreased up to 10.8% and 34% at 100 °C and 200 °C, respectively. Besides, the shrinkage percentage increased with increasing the percentage of PP aggregate. However, the chloride ion penetrability of all PP concrete fell in the moderate category. The 10% PP concrete exhibited better bond strength and a higher slip bearing capacity than the other percentages. Moreover, the PP concrete cylinders exhibited comparatively ductile failure than the brittle failure of the reference concrete. Finally, to produce efficient and eco-friendly concrete, it is suggested to use PP aggregate up to 10% in structural concrete.

Eco-Friendly Concretes with Recycled Plastic Aggregates

Every year, in the world, the produced quantities of plastic amount to approximately 400 million tons. This implies a high level of plastic pollution and a growing decrease of available natural resources. Therefore, seems to be clear that there is a need to act in such a way as to reduce plastic pollution, safeguard natural resources and prevent the disposition of great quantities of waste in landfills or, even worse, the discharging into marine waters. This explains the need to implement processes of recovery and recycling of this plastic waste and their reuse in operable and practical products. Many studies analyzed the chances of employing plastic waste to produce cement and concrete, but the research about the use of polyolefins for the production of lightweight concretes is still limited. This study shows that the use of recycled polyolefins as substitutes of natural aggregates is a viable solution for the production of lightweight concretes by analyzing the influence of this kind of plastic on mechanical, physical and thermal performance, through experimental tests performed on four samples containing different amounts of plastic aggregates.

Geopolymer Concrete A Ecofriendly Concrete

Concrete became most popular material due to its low cost, versatility, availability of ingredients and excellent resistance to water and played significant role in development of the world for last one and half century but cement is the main ingredient for the concrete production. There are different sources of carbon di oxide emission during cement production. The largest source is combustion of fossil fuels to operate rotary kiln and other on is de-carbonation of limestone in the kiln during manufacturing of cement. The raw materials such as lime stone, clay and other minerals are required for the manufacture of cement, but quarrying of these raw materials is also causes environmental degradation. The climate change and environmental pollution is major problem of the world is facing today also responsible to the global warming. Therefore, to preserve the global environment from the impact of cement production then reduced the amount of Portland cement and replacing it with material which has lower manufacturing temperature. Also, to produce environmental friendly concrete, we have to replace the cement with the industrial by products such as fly ash and other geo-based materials. Thus the Geopolymer concrete is a good solution for producing an environmental friendly type of concrete. The geo-polymer concrete is one of the revolutionary developments related to novel materials resulting in low-cost and environmentally friendly material as best alternative to cement concrete. In this work cement is replaced with fly ash by 50%, 75% and 100% and alkaline solution which is the combination of sodium hydroxide and sodium silicate with different proportion i.e. 9M and 12M were used to determine compresive strength for M25 and M30 grade of concrete and compare with the conventional concrete. From the analysis it is observed that the Geopolymer concrete can be used under conditions similar to those suitable for ordinary portland cement concrete also, shows the good alternative to ordinary portland cement concrete.

Comparative study of mechanical properties between irradiated and regular plastic waste as a replacement of cement and fine aggregate for manufacturing of green concrete

Concrete and plastic are a major source of environmental contamination and unsustainability. This study has been employed to come up with the eco-friendly concrete by using the plastic waste to promote the sustainability. Gamma radiations were used to enhance the micro-structure of plastic waste to increase the mechanical properties of resulting concrete. The crystallinity and chemical properties of regular and irradiated plastic were studied using x-ray diffraction (Xrd) and x-ray fluorescence (Xrf), respectively. Enhancement in the crystallinity and chemical properties were observed in the irradiated plastic. Different compositions by weight were opted for replacement of cement and fine aggregate for both regular and irradiated plastic waste with silica fume and superplasticizers. A set of experiments were performed on concrete and the effect of plastic waste on the compressive strength and split tensile strength of concrete was examined. Untreated replacement of plastic waste has shown to decrease the compressive strength and anomalous behavior was observed in case of split tensile strength. Both the mechanical properties were enhanced by replacing the cement and fine aggregates with irradiated plastic waste including silica fume and superplasticizers. This study contributes towards sustainable development of green concrete by lowering the carbon emissions and overcoming the fine aggregate scarcity problem. Moreover, as plastic is ductile and inclusion of plastic in concrete lowers the overall weight of the structure; impact of an earthquake is reduced.

An Innovative Approach on Pet Bottles Compiled with Waste Materials to Produce Eco-friendly Concrete

PET bottles, such as water bottles, cool drink bottles, and oil storage bottles, are becoming increasingly popular in India. Bottles used to package water take over 1,000 years to biodegrade and, if incinerated, contain poisonous gases. Recycling these PET bottles requires more attention however, this was also among the most famous effective ways to minimize waste. Only PET bottles, however, it’s recyclable; all other bottles must be discarded. In fact, only 1 out of 5 containers are able to be sent to the recycle bin. The strength criteria was studied in PET bottles by filled up with different waste materials such as M-sand, Quarry dust, Fly ash, River sand and Construction debris. These filled bottles are inserted in concrete cube mould for minimising the concrete quantity and strength parameters were studied. Based on the experimental work, it was identified that, PET bottles having good compression resistance and also act as a filler material in concrete.

INCREASE IN STRENGTH OF CONCRETE BY USING BAGASSE ASH AS PARTIAL REPLACEMENT OF CEMENT

Bagasse ash, one of the waste , is used in this study .The reason to choose the Bagasse ash to develop a novel method to transfer it to valuable product and to solve the problem of dumping the tons of bagasse waste. The importance of this alternatively stone replacement to reduce bagasse waste that is hard to lapse and in addition to reducing the pollution of nature, it also saves cost and apply the concept of Reduce, Reuse and Recycle. Concrete is most widely used construction material in the world. To solve environmental issue like deposition of waste product, recycling or reuse of waste product, I am using Bagasse ashto make eco-friendly concrete. Due to growing environmental awareness, the world is increasingly turning to researching properties of waste and finding solution on using its valuable components parts so that those might be used as secondary raw material in other branches. Green building is an increasingly important global concern and a critical way to conserve natural resources and reduce the amount of materials going to our landfillS

THE USE OF FIBROUS PLANTS IN THE PRODUCTION OF BUILDING MATERIALS

Concrete development has gone so far since the revolution of human kind. Climate change, energy conservation, and life cycle examination problems are majors that have accorded to the quick augmentation of plant-based materials for buildings, which can be entitled as environmental and eco friendly, enduring and efficient multidisciplinary materials. Recently, several approaches are in action in order to develop concrete materials that are environmentally friendly. The aim of this work is to estimate the suitability of Hemp, Nettle, Artemisia vulgaris and Sida hermaphrodite plants for production of building materials. The tasks of this research are to calculate density, compressive and bending strength and insulation of the concrete with Hemp, Nettle, and Artemisia vulgaris and Sida hermaphrodite fibres. The main objective of this research is to check the possibility of replacing the concrete that has been in use till date now with the major focus on decreasing the emission of the carbon dioxide and developing environmental friendly concrete for future. The results of the research carve the path for further research in future. Artemisia vulgaris concrete is strongest but not enough for structural material. Further research on these plants is highly essential as they can be the base for the replacement of cement concrete and making world a better place by developing the eco-friendly concrete.

Post-fire residual fracture characteristics and brittleness of self-compacting concrete containing waste PET flakes: Experimental and theoretical investigation

Correct understanding of the fracture mechanism of self-compacting concrete (SCC) after tolerating elevated temperatures plays a big role in the design of SCC mixes and helps better understand the behavior of SCC structures during a fire incident. Besides, to obtain eco-friendly concretes incorporating wastes and be able to employ them in concrete structures, knowing their mechanical characteristics is essential. Therefore, in this research, the three-point bending test was conducted on 240 notched beams to determine the effect of the partial substitution of polyethylene terephthalate (PET) flakes for fine aggregates at volume percentages of 0, 5, 10, and 15% on the fracture characteristics and ductility of SCC in two states: without heat treatment and after the application of 200, 400, and 600 °C. For this purpose, the two methods of size effect method (SEM) and work of fracture method (WFM) were used to analyze and interpret fracture parameters. The analysis of the obtained results demonstrated in the specimens without PET, after the heat treatment, fracture energy values obtained from WFM and SEM, as well as the fracture toughness (KIC) obtained from SEM, declined. Moreover, the results obtained for the effective size of the process zone (cf) parameter in SEM and characteristic length (lch) parameter in WFM demonstrated that the concrete without PET became more brittle and less ductile. On the contrary, in concretes incorporating PET, as the temperature increased, the fracture energy and toughness levels of the SCC declined, but its ductility increased. Moreover, considering the size effect design, the behavior of the SCC approached the linear elastic fracture mechanics (LEFM) criterion as the temperature increased and the substitution percentage of PET for fine aggregate decreased. On average, in all the specimens, the fracture energy values obtained from WFM were 2.35 times those obtained from SEM. Finally, based on the obtained mechanical characteristics and test variables, multivariate models were presented to predict the fracture parameters of SCC incorporating PET after tolerating elevated temperatures and compared with the experimental results of the present research and literature. A proper accuracy was observed for the models.

Development of Prediction Model to Predict the Compressive Strength of Eco-Friendly Concrete Using Multivariate Polynomial Regression Combined with Stepwise Method

Concrete is the most widely used building material, but it is also a recognized pollutant, causing significant issues for sustainability in terms of resource depletion, energy use, and greenhouse gas emissions. As a result, efforts should be concentrated on reducing concrete’s environmental consequences in order to increase its long-term viability. In order to design environmentally friendly concrete mixtures, this research intended to create a prediction model for the compressive strength of those mixtures. The concrete mixtures that were used in this study to build our proposed prediction model are concrete mixtures that contain both recycled aggregate concrete (RAC) and ground granulated blast-furnace slag (GGBFS). A white-box machine learning model known as multivariate polynomial regression (MPR) was developed to predict the compressive strength of eco-friendly concrete. The model was compared with the other two machine learning models, where one is also a white-box machine learning model, namely linear regression (LR), and the other is the black-box machine learning model, which is a support vector machine (SVM). The newly suggested model shows robust estimation capabilities and outperforms the other two models in terms of R2 (coefficient of determination) and RMSE (root mean absolute error) measurements.

Durability of high-performance self-compacted concrete using electric arc furnace slag aggregate and cupola slag powder

The current trend in the development of self-compacting concrete with sustainable construction materials has served as a guide to design a novel self-compacting concrete, with siderurgical by-products (steel slag aggregates and cupola slag powder as supplementary cementing material) that also meets the demands of high-performance concrete. This research sets out to clarify the unknown behavior of slag concrete, its durability, which is the ability to withstand any process that tends to deteriorate it. In order to assess the durability of this eco-friendly concrete, three control mixes were manufactured with the same high-quality coarse aggregate (diabase) and three different fines, limestone filler, fly ash and cupola slag powder. All the mixtures were subjected to the same tests, the results demonstrate that steel slag concrete shows an excellent response against carbonation, a slightly lower response against thermal shock cycles, similar drying shrinkage and a superior response against the action of freezing-thawing cycles and abrasion wear in comparison to the control mixes.