Research

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14 pages, 1941 KiB

Open AccessArticle

Embodied CO₂ Reduction Effects of Free-Form Concrete Panel Production Using Rod-Type Molds with 3D Plastering Technique

by Seunghyun Son, Dongjoo Lee, Jinhyuk Oh and Sunkuk Kim

Sustainability 2021, 13(18), 10280; https://0-doi-org.brum.beds.ac.uk/10.3390/su131810280 - 14 Sep 2021

Cited by 1 | Viewed by 1812

When using concrete to produce exterior finishing panels of free-form building structures, different panel shapes make it difficult to reuse the forms. This results in increased formwork cost as well as a significant amount of embodied CO₂ (ECO₂) generation. Through [...] Read more.

When using concrete to produce exterior finishing panels of free-form building structures, different panel shapes make it difficult to reuse the forms. This results in increased formwork cost as well as a significant amount of embodied CO₂ (ECO₂) generation. Through years of research, we have developed a free-form panel (FCP) production technique engaging the 3D plastering technique (3DPT) without using conventional plywood forms. When 3DPT becomes available for free-form building projects, a great deal of ECO₂ reduction effects is expected in addition to reduced time and cost in FCP production. The purpose of this study is to prove this by analyzing ECO₂ reduction effects achieved through sustainable FCP production using 3DPT. The study involved project case selection, calculation of resources consumed for conventional plywood forms, and analysis of the reduction effects. As a result, it was demonstrated from the case project that 1196 tons of CO₂ were reduced using 3DPT, accounting for approximately 99% of the amount produced from conventional plywood forms (CPF). The study findings will be used as a basic reference for sustainable production of FCPs ensuring speed and precision in production as well as innovative ECO₂ reduction effects. Full article

(This article belongs to the Special Issue Sustainable Construction and Innovative Building Materials)

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19 pages, 12620 KiB

Open AccessArticle

Autogenous Self-Healing Capacity of Early-Age Ultra-High-Performance Fiber-Reinforced Concrete

by Estefania Cuenca and Pedro Serna

Sustainability 2021, 13(6), 3061; https://0-doi-org.brum.beds.ac.uk/10.3390/su13063061 - 11 Mar 2021

Cited by 17 | Viewed by 2091

Abstract

This paper analyzes the autogenous self-healing capacity of early-age Ultra-High-Performance Fiber-Reinforced concretes (UHPFRCs) by measuring the crack closure and the possible mechanical recovery on healed specimens. The main parameters considered in this research were the healing exposure conditions (humidity chamber, immersion in tap [...] Read more.

This paper analyzes the autogenous self-healing capacity of early-age Ultra-High-Performance Fiber-Reinforced concretes (UHPFRCs) by measuring the crack closure and the possible mechanical recovery on healed specimens. The main parameters considered in this research were the healing exposure conditions (humidity chamber, immersion in tap water, immersion in seawater and heat curing) and the precracking levels (microcracks and macrocracks). For the microcrack level, four-point bending tests were performed on prismatic specimens (100 × 100 × 500 mm³) obtaining a multiple cracking pattern characterized by crack widths ranged from 10 to 20 µm. Whereas for the macrocrack level (behavior after crack localization), splitting tests were carried out on notched cubic specimens (100 × 100 × 100 mm³) obtaining crack widths of up to 0.4 mm. For both precracking levels, specimens were precracked at two days and were cured for one month in the mentioned exposure conditions. Healing products were analyzed on the specimen surface and also inside the cracks; to this purpose, their microstructure was analyzed by means of SEM and EDS analyses. The results have shown that the highest crack closure values were obtained for the heat-cured specimens and for the specimens immersed in water (tap water and seawater) whereas the less efficient condition was the humidity chamber. Full article

(This article belongs to the Special Issue Sustainable Construction and Innovative Building Materials)

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28 pages, 4559 KiB

Open AccessArticle

Use of Iron and Steel Slags in Concrete: State of the Art and Future Perspectives

by Alan Piemonti, Antonio Conforti, Luca Cominoli, Sabrina Sorlini, Antonella Luciano and Giovanni Plizzari

Sustainability 2021, 13(2), 556; https://0-doi-org.brum.beds.ac.uk/10.3390/su13020556 - 08 Jan 2021

Cited by 25 | Viewed by 6564

Abstract

In the two last decades, world production of pig iron and steel has undergone a significant increase. In 2018, 1252.87 and 1806.46 million tons of pig iron and steel, respectively, were produced as compared to the 575.78 and 809.94 million tons of 2000. [...] Read more.

In the two last decades, world production of pig iron and steel has undergone a significant increase. In 2018, 1252.87 and 1806.46 million tons of pig iron and steel, respectively, were produced as compared to the 575.78 and 809.94 million tons of 2000. Consequently, the amount of the different types of slags deriving from these production processes has also increased considerably. In relation to the principles of sustainability and circular economy, the available literature suggests several possible reuses for these slags (bituminous conglomerates, hydraulic engineering, metallurgy, fertilizers, etc.). This paper aims to provide an overview of the iron and steel slags production and their reuse in concrete (for example as replacement of cement, fine or coarse aggregates). The characteristics of slags are analyzed in terms of chemical, physical, and mechanical properties. Mechanical and durability tests (both from material and structures point of view) carried out in the different studies and research are shown as well. Particular attention was devoted to electric arc furnace slags (EAF) since they are the most produced in Italy. Based on this deep literature review, the gaps that still require further studies have been identified and discussed. Full article

(This article belongs to the Special Issue Sustainable Construction and Innovative Building Materials)

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13 pages, 1719 KiB

Open AccessArticle

Sustainable Recycling of Electric Arc Furnace Steel Slag as Aggregate in Concrete: Effects on the Environmental and Technical Performance

by Alessandra Diotti, Luca Cominoli, Adela Perèz Galvin, Sabrina Sorlini and Giovanni Plizzari

Sustainability 2021, 13(2), 521; https://0-doi-org.brum.beds.ac.uk/10.3390/su13020521 - 07 Jan 2021

Cited by 11 | Viewed by 2858

Abstract

The aim of this research work was the evaluation of the feasibility to utilize industrial by-products, such as electric arc furnace steel slags, for sustainable concrete production. The paper evaluated the environmental and mechanical properties of steel slags and concrete, respectively. Specifically, the [...] Read more.

The aim of this research work was the evaluation of the feasibility to utilize industrial by-products, such as electric arc furnace steel slags, for sustainable concrete production. The paper evaluated the environmental and mechanical properties of steel slags and concrete, respectively. Specifically, the release of contaminants from steel slags was investigated by leaching test and the properties of fresh and hardened concrete were evaluated for a concrete mixture designed with a partial substitution (30%) of natural coarse aggregates with electric arc furnace steel slags. The results show that the concentrations of pollutants were lower than the legal limits imposed by the Ministerial Decree 186/2006 and the addition of steel slag can enhance the mechanical performance of concrete. The compressive strength of cubic specimens was also measured after different cycles of alternate wetting–drying. The steel slag incorporation results in a stiffness comparable to that of a traditional concrete. Overall, the mechanical and leaching characterization has shown that the reuse of electric arc furnace steel slags for sustainable concrete production is feasible and reliable. Full article

(This article belongs to the Special Issue Sustainable Construction and Innovative Building Materials)

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18 pages, 8406 KiB

Open AccessArticle

Thermal Performance Assessment of Walls Made of Three Types of Sustainable Concrete Blocks by Means of FEM and Validated through an Extensive Measurement Campaign

by Jesús M. Blanco, Yokasta García Frómeta, Maggi Madrid and Jesús Cuadrado

Sustainability 2021, 13(1), 386; https://0-doi-org.brum.beds.ac.uk/10.3390/su13010386 - 04 Jan 2021

Cited by 9 | Viewed by 2372

Abstract

The thermal behavior of three different walls, made with and without by-products, is assessed by means of the Finite Element Method, aiming to evaluate its performance in terms of the sustainable construction of the blocks. Results were compared to those obtained from an [...] Read more.

The thermal behavior of three different walls, made with and without by-products, is assessed by means of the Finite Element Method, aiming to evaluate its performance in terms of the sustainable construction of the blocks. Results were compared to those obtained from an experimental campaign, aiming at validation of the model. The by-products used for the blocks were “lime sludge” and “sawdust”, whose performance was compared against the traditional blocks made of concrete as a reference, aiming to demonstrate its sustainability, showing decreases of the thermal transmittance up to 10.5%. Additionally, following the same methodology, the thermal behavior of these above-mentioned blocks but now with added internal insulation made of “recycled cellulose” was assessed, showing higher decreases up to 25.5%, increasing sustainability by addressing an additional reduction in waste, so the right combination of using by-products and the insulating filler in their cavities has been revealed as a promising way of optimizing the walls, offering a relevant improvement in energy savings. Finally, when comparing the U-values of the blocks made of concrete without insulation versus those made of by-products, with insulation, improvements up to 33.3% were reached. The adaptation of the procedure through a moisture correction factor was also incorporated. Full article

(This article belongs to the Special Issue Sustainable Construction and Innovative Building Materials)

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14 pages, 8452 KiB

Open AccessArticle

Sustainable Soil-Compacted Blocks Containing Blast Furnace Slag (BFS) Activated with Olive Stone BIOMASS Ash (OBA)

by Jordi Payá, José Monzó, Josefa Roselló, María Victoria Borrachero, Alba Font and Lourdes Soriano

Sustainability 2020, 12(23), 9824; https://0-doi-org.brum.beds.ac.uk/10.3390/su12239824 - 24 Nov 2020

Cited by 5 | Viewed by 1755

Abstract

Soil stabilization using cementing materials is a well-known procedure for earth-based building blocks preparation. For the selected binding materials, innovation usually focuses on low carbon systems, many of which are based on alkaline activation. In the present paper, blast furnace slag (BFS) is [...] Read more.

Soil stabilization using cementing materials is a well-known procedure for earth-based building blocks preparation. For the selected binding materials, innovation usually focuses on low carbon systems, many of which are based on alkaline activation. In the present paper, blast furnace slag (BFS) is used as a mineral precursor, and the innovative alkali activator was olive stone biomass ash (OBA). This means that the most important component in CO₂ emissions terms, which is the alkali activator, has been replaced with a greener alternative: OBA. The OBA/BFS mixture was used to prepare compacted dolomitic soil blocks. These specimens were mechanically characterized by compression, and water strength coefficient and water absorption were assessed. The microstructure of blocks and the formation of cementing hydrates were analyzed by field emission scanning electron microscopy and thermogravimetry, respectively. The final compressive strength of the 120-day cured blocks was 27.8 MPa. It was concluded that OBA is a sustainable alkali activator alternative for producing BFS-stabilized soil-compacted blocks: CO₂ emissions were 3.3 kgCO₂/ton of stabilized soil, which is 96% less than that for ordinary Portland cement (OPC) stabilization. Full article

(This article belongs to the Special Issue Sustainable Construction and Innovative Building Materials)

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Review

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21 pages, 5332 KiB

Open AccessReview

Mechanical Properties of Cement-Based Materials with Recycled Plastic: A Review

by Jun Kil Park and Min Ook Kim

Sustainability 2020, 12(21), 9060; https://0-doi-org.brum.beds.ac.uk/10.3390/su12219060 - 30 Oct 2020

Cited by 9 | Viewed by 4294

Abstract

This study summarizes existing studies on plastic recycling to determine whether ocean plastics with high pollution degrees could be used for cement-based materials. In particular, the methods to recycle plastic waste, the effects of recycled plastic on the physical and mechanical properties of [...] Read more.

This study summarizes existing studies on plastic recycling to determine whether ocean plastics with high pollution degrees could be used for cement-based materials. In particular, the methods to recycle plastic waste, the effects of recycled plastic on the physical and mechanical properties of cement-based materials, and their effective usage were investigated. Workability, density, compressive strength, split tensile strength, and flexural strength of cement-based materials with recycled plastics were reviewed and divided into recycled aggregates and fibers. Based on the previous investigation, the direction of research necessary to recycle marine plastics is suggested. As the amount of recycled plastic aggregate increased, the mechanical strength of cement-based materials decreased. The recycled plastic aggregate lowered the density and increased porosity of the cement-based material. Meanwhile, recycled plastic fibers reduced the compressive strength but improved the tensile strength; to effectively improve tensile strength, a volume content of less than 1.5% should be added to prevent balling fibers. Furthermore, an appropriate aspect ratio should be determined based on the type of plastic to be used. Full article

(This article belongs to the Special Issue Sustainable Construction and Innovative Building Materials)

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35 pages, 1686 KiB

Open AccessFeature PaperReview

Utilization of By-Products and Wastes as Supplementary Cementitious Materials in Structural Mortar for Sustainable Construction

by Shamir Sakir, Sudharshan N. Raman, Md. Safiuddin, A. B. M. Amrul Kaish and Azrul A. Mutalib

Sustainability 2020, 12(9), 3888; https://0-doi-org.brum.beds.ac.uk/10.3390/su12093888 - 09 May 2020

Cited by 70 | Viewed by 5779

Abstract

Rapid growth in industrial development has raised the concern of proper disposal of the by-products generated in industries. Many of them may cause serious pollution to the air, land, and water if dumped in open landfills. Agricultural and municipal wastes also cause environmental [...] Read more.

Rapid growth in industrial development has raised the concern of proper disposal of the by-products generated in industries. Many of them may cause serious pollution to the air, land, and water if dumped in open landfills. Agricultural and municipal wastes also cause environmental issues if not managed properly. Besides, minimizing the carbon footprint has become a priority in every industry to slow down global warming and climate change effects. The use of supplementary cementitious materials (SCMs) obtained from agricultural, industrial, municipal, and natural sources can decrease a significant amount of fossil fuel burning by reducing cement production and contribute to proper waste management. Also, SCMs can enhance desirable material properties like flowability, strength, and durability. Such materials may play a big role to meet the need of modern time for resilient construction. The effective application of SCMs in cement-based materials requires a clear understanding of their physical and chemical characteristics. Researchers studied how the flowability, strength, and durability properties of structural mortar change with the replacement of cement with different SCMs. Various experiments were conducted to examine the behavior of structural mortar in extreme conditions (e.g., high temperature). Many scholars have attempted to improve its performance with various treatment techniques. This article is an attempt to bring all the major findings of the recent relevant studies together, identify research gaps in the current state of knowledge on the utilization of SCMs in structural mortar, and give several recommendations for further study. The available results from recent studies have been reviewed, analyzed, and summarized in this article. A collection of the updated experimental findings will encourage and ease the use of various by-products and wastes as SCMs in structural mortar for sustainable construction. Full article

(This article belongs to the Special Issue Sustainable Construction and Innovative Building Materials)

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