Issue |
Matériaux & Techniques
Volume 112, Number 4, 2024
|
|
---|---|---|
Article Number | 403 | |
Number of page(s) | 7 | |
Section | Ecomaterials | |
DOI | https://doi.org/10.1051/mattech/2024023 | |
Published online | 11 October 2024 |
Original article
Study of the influence of the substitution of natural aggregates by hardened cement aggregates in concrete and the exposure of concrete to a medium enriched with carbon dioxide
1
Université Jean Lorougnon Guédé, Daloa, Côte d’ivoire
2
Université Félix Houphouët Boigny, Abidjan, Côte d’ivoire
3
Institut National Polytechnique Houphouët Boigny, Yamoussoukro, Côte d’ivoire
* e-mail: kbraoul@ujlg.edu.ci
Received:
21
December
2023
Accepted:
28
July
2024
The valorization of waste is an excellent way to protect the environment. This study focuses on waste consisting of cement that has hardened before use. The goal of this study is to determine the conditions under which these can be valorized in concrete. These wastes are used as aggregates, referred to as Hardened Cement Aggregates (HCA). First, the density, granulometry, and impact resistance of these aggregates were measured and compared to those of natural aggregates (NTA). The results showed that natural aggregates have a bulk density and specific gravity more than 25% higher than those of HCA. However, this trend reverses when considering mechanical strength. Specifically, the Los Angeles and micro-Deval abrasion coefficients of NA are 10% and 18% lower, respectively, indicating better mechanical resistance than HCA. This difference in performance is attributed to the higher porosity within the structure of HCA. When evaluating the concrete, it was observed that the poor physical and mechanical properties of HCA adversely affected the concrete produced with them (HCAC). Therefore, the subsequent phase of the research aimed to identify conditions that could optimize the properties of HCAC. Samples of HCAC were cured in two different environments: plain water (control) and CO2-enriched water (carbonated environment). The results demonstrated that curing in the carbonated environment significantly improved the mechanical properties of HCAC by over 20%. This increase allowed the concrete to reach a compressive strength of 28 megapascals, which matches the strength of concrete made with natural aggregates (NAC). Consequently, hardened cement aggregates can effectively replace natural aggregates in concrete when used in a carbonated environment.
Key words: hardened cements / aggregates / concretes / carbonation / recycling
Publisher note: The article type "Review" has been changed to "Original article". The article has been corrected on 19 November 2024.
© SCF, 2024
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.