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Influence of Mechanical Screened Recycled Coarse Aggregates on Properties of Self-Compacting Concrete

The use of recycled coarse aggregates (RA) in concrete is a sustainable alternative to non-renewable natural aggregate (NA) to fabricate concrete products using in concrete structures. However, the adhered mortar on the surface of RA would considerably impact the qualities of concrete products. As a...

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Autores principales: Tang, Waiching, Khavarian, Mehrnoush, Yousefi, Ali, Landenberger, Bill, Cui, Hongzhi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9965383/
https://www.ncbi.nlm.nih.gov/pubmed/36837113
http://dx.doi.org/10.3390/ma16041483
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author Tang, Waiching
Khavarian, Mehrnoush
Yousefi, Ali
Landenberger, Bill
Cui, Hongzhi
author_facet Tang, Waiching
Khavarian, Mehrnoush
Yousefi, Ali
Landenberger, Bill
Cui, Hongzhi
author_sort Tang, Waiching
collection PubMed
description The use of recycled coarse aggregates (RA) in concrete is a sustainable alternative to non-renewable natural aggregate (NA) to fabricate concrete products using in concrete structures. However, the adhered mortar on the surface of RA would considerably impact the qualities of concrete products. As a practical treatment procedure, mechanical screening can remove the adhered mortar. This research aims to study the influence of mechanical screening on the fundamental properties of RA and the resulting self-compacting concrete (SCC). The RA were mechanically screened up to four times, and their physical properties including particle size distribution, water absorption, and crushing value were investigated. The properties of RA-SCC including workability, density, compressive and tensile strengths, modulus of elasticity, and microstructure were also examined. The results demonstrated that screening reduced the water absorption of RA from 6.26% to 5.33% and consequently enhanced the workability of RA-SCC. Furthermore, it was shown that increasing the screening up to twice improved the mechanical properties of concrete. In particular, screening increased the compressive strength of concrete by 15–35% compared to the concrete with unscreened RA. Similar improvements were found in tensile strength as well as the elastic modulus results. The microstructure of screened RA-SCC was comparable to that of the control concrete, showing minimal porosity and cracks along the interfacial transition zone. In conclusion, once or twice screening is recommended to the recycling facility plant to remove adequate amount of adhered mortar and fines while preventing damages to the RA. Improving the quality of RA via mechanical screening is one of the promising approaches to increase their potential for use in concrete, thereby reducing extraction of natural resources and promoting a circular economy.
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spelling pubmed-99653832023-02-26 Influence of Mechanical Screened Recycled Coarse Aggregates on Properties of Self-Compacting Concrete Tang, Waiching Khavarian, Mehrnoush Yousefi, Ali Landenberger, Bill Cui, Hongzhi Materials (Basel) Article The use of recycled coarse aggregates (RA) in concrete is a sustainable alternative to non-renewable natural aggregate (NA) to fabricate concrete products using in concrete structures. However, the adhered mortar on the surface of RA would considerably impact the qualities of concrete products. As a practical treatment procedure, mechanical screening can remove the adhered mortar. This research aims to study the influence of mechanical screening on the fundamental properties of RA and the resulting self-compacting concrete (SCC). The RA were mechanically screened up to four times, and their physical properties including particle size distribution, water absorption, and crushing value were investigated. The properties of RA-SCC including workability, density, compressive and tensile strengths, modulus of elasticity, and microstructure were also examined. The results demonstrated that screening reduced the water absorption of RA from 6.26% to 5.33% and consequently enhanced the workability of RA-SCC. Furthermore, it was shown that increasing the screening up to twice improved the mechanical properties of concrete. In particular, screening increased the compressive strength of concrete by 15–35% compared to the concrete with unscreened RA. Similar improvements were found in tensile strength as well as the elastic modulus results. The microstructure of screened RA-SCC was comparable to that of the control concrete, showing minimal porosity and cracks along the interfacial transition zone. In conclusion, once or twice screening is recommended to the recycling facility plant to remove adequate amount of adhered mortar and fines while preventing damages to the RA. Improving the quality of RA via mechanical screening is one of the promising approaches to increase their potential for use in concrete, thereby reducing extraction of natural resources and promoting a circular economy. MDPI 2023-02-10 /pmc/articles/PMC9965383/ /pubmed/36837113 http://dx.doi.org/10.3390/ma16041483 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Tang, Waiching
Khavarian, Mehrnoush
Yousefi, Ali
Landenberger, Bill
Cui, Hongzhi
Influence of Mechanical Screened Recycled Coarse Aggregates on Properties of Self-Compacting Concrete
title Influence of Mechanical Screened Recycled Coarse Aggregates on Properties of Self-Compacting Concrete
title_full Influence of Mechanical Screened Recycled Coarse Aggregates on Properties of Self-Compacting Concrete
title_fullStr Influence of Mechanical Screened Recycled Coarse Aggregates on Properties of Self-Compacting Concrete
title_full_unstemmed Influence of Mechanical Screened Recycled Coarse Aggregates on Properties of Self-Compacting Concrete
title_short Influence of Mechanical Screened Recycled Coarse Aggregates on Properties of Self-Compacting Concrete
title_sort influence of mechanical screened recycled coarse aggregates on properties of self-compacting concrete
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9965383/
https://www.ncbi.nlm.nih.gov/pubmed/36837113
http://dx.doi.org/10.3390/ma16041483
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