Evaluation of Eco-Efficient Concretes Produced with Fly Ash and Uncarbonated Recycled Aggregates
The fabrication of conventional concrete, as well as remains from demolition, has a high environmental impact. This paper assessed the eco-efficiency of concrete made with uncarbonated recycled concrete aggregates (RCA) and fly ash (FA). Two concrete series were produced with an effective water/ceme...
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MDPI AG
2021-12-01
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| Online Access: | https://www.mdpi.com/1996-1944/14/24/7499 |
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| author | Miren Etxeberria |
| author_facet | Miren Etxeberria |
| author_sort | Miren Etxeberria |
| collection | DOAJ |
| description | The fabrication of conventional concrete, as well as remains from demolition, has a high environmental impact. This paper assessed the eco-efficiency of concrete made with uncarbonated recycled concrete aggregates (RCA) and fly ash (FA). Two concrete series were produced with an effective water/cement ratio of 0.50 (Series 1) and 0.40 (Series 2). In both series, concretes were produced using 0% and 50% of RCA with 0%, 25% and 50% FA. After analysing the compressive strength, and carbonation and chloride resistance of those concretes, their eco-efficiency based on the binder intensity and CO<sub>2</sub>-eq intensity was assessed. We found that the use of 50% uncarbonated RCA improved the properties of concretes produced with FA with respect to using natural aggregates. The concrete made of 25% FA plus RCA was considered the most eco-efficient based on the tests of compressive, carbonation and chloride properties with the values of 4.1 kg CO<sub>2</sub> m<sup>−3</sup> MPa<sup>−1</sup>, 76.3 kg CO<sub>2</sub> m<sup>−3</sup> mm<sup>−1</sup> year<sup>0.5</sup> and 0.079 kg CO<sub>2</sub> m<sup>−3</sup> C<sup>−1</sup>, respectively. The uncarbonated RCA improved carbonation resistance, and FA improved chloride resistance. It can be concluded that the use of 50% un-carbonated RCA combined with FA considerably enhanced the properties of hardened concrete and their eco-efficiency with respect to concretes produced with natural aggregates. |
| first_indexed | 2024-03-10T03:41:09Z |
| format | Article |
| id | doaj.art-84493f43d6cd4762a3ae444d14305d1e |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T03:41:09Z |
| publishDate | 2021-12-01 |
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| spelling | doaj.art-84493f43d6cd4762a3ae444d14305d1e2023-11-23T09:18:48ZengMDPI AGMaterials1996-19442021-12-011424749910.3390/ma14247499Evaluation of Eco-Efficient Concretes Produced with Fly Ash and Uncarbonated Recycled AggregatesMiren Etxeberria0Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya·BarcelonaTECH, Campus Nord, 08034 Barcelona, SpainThe fabrication of conventional concrete, as well as remains from demolition, has a high environmental impact. This paper assessed the eco-efficiency of concrete made with uncarbonated recycled concrete aggregates (RCA) and fly ash (FA). Two concrete series were produced with an effective water/cement ratio of 0.50 (Series 1) and 0.40 (Series 2). In both series, concretes were produced using 0% and 50% of RCA with 0%, 25% and 50% FA. After analysing the compressive strength, and carbonation and chloride resistance of those concretes, their eco-efficiency based on the binder intensity and CO<sub>2</sub>-eq intensity was assessed. We found that the use of 50% uncarbonated RCA improved the properties of concretes produced with FA with respect to using natural aggregates. The concrete made of 25% FA plus RCA was considered the most eco-efficient based on the tests of compressive, carbonation and chloride properties with the values of 4.1 kg CO<sub>2</sub> m<sup>−3</sup> MPa<sup>−1</sup>, 76.3 kg CO<sub>2</sub> m<sup>−3</sup> mm<sup>−1</sup> year<sup>0.5</sup> and 0.079 kg CO<sub>2</sub> m<sup>−3</sup> C<sup>−1</sup>, respectively. The uncarbonated RCA improved carbonation resistance, and FA improved chloride resistance. It can be concluded that the use of 50% un-carbonated RCA combined with FA considerably enhanced the properties of hardened concrete and their eco-efficiency with respect to concretes produced with natural aggregates.https://www.mdpi.com/1996-1944/14/24/7499eco-efficiencyrecycled aggregate concretefly ashmechanical propertiescarbonationchloride resistance |
| spellingShingle | Miren Etxeberria Evaluation of Eco-Efficient Concretes Produced with Fly Ash and Uncarbonated Recycled Aggregates Materials eco-efficiency recycled aggregate concrete fly ash mechanical properties carbonation chloride resistance |
| title | Evaluation of Eco-Efficient Concretes Produced with Fly Ash and Uncarbonated Recycled Aggregates |
| title_full | Evaluation of Eco-Efficient Concretes Produced with Fly Ash and Uncarbonated Recycled Aggregates |
| title_fullStr | Evaluation of Eco-Efficient Concretes Produced with Fly Ash and Uncarbonated Recycled Aggregates |
| title_full_unstemmed | Evaluation of Eco-Efficient Concretes Produced with Fly Ash and Uncarbonated Recycled Aggregates |
| title_short | Evaluation of Eco-Efficient Concretes Produced with Fly Ash and Uncarbonated Recycled Aggregates |
| title_sort | evaluation of eco efficient concretes produced with fly ash and uncarbonated recycled aggregates |
| topic | eco-efficiency recycled aggregate concrete fly ash mechanical properties carbonation chloride resistance |
| url | https://www.mdpi.com/1996-1944/14/24/7499 |
| work_keys_str_mv | AT mirenetxeberria evaluationofecoefficientconcretesproducedwithflyashanduncarbonatedrecycledaggregates |