Experimental and numerical investigation of accelerated carbonation of recycled fines

• Published in: Construction & building materials 2023-06, Vol.382, p.131286, Article 131286
• Main Authors: Algourdin, N., Larbi, K. Si, Santos, I., Mesticou, Z., Pimienta, P., Pinoteau, N., Larbi, A. Si
• Format: Article
• Language: English
• Subjects: Accelerated carbonation; Chemical kinetics; Diffusion; Engineering Sciences; Experimental tests; Numerical model; Recycled fines
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2023.131286

•RF can uptake between 3 and 21 times more of CO2 compared to recycled sands of 1–4 mm.•Initial RF water content has an important influence on the rate of CO2 uptake.•RF size of 50 µm has a higher degree of carbonation compared with that for a 80 µm.•Rapid CO2 uptake is observed until 17 h. Then, it becomes less pronounced until 24 h.•The carbonation potential of the 80 °C RF is higher than that after the 500 °C heating. The purpose of this study is to perform an experimental and numerical study of accelerated carbonation of recycled fines (RF) to assess its potential and kinetics of CO2 uptake and to estimate its interest in a solicitous field of construction environmental impact. First, a parametric study of accelerated carbonation is carried out on RF, varying the following parameters: water content (1, 7, and 25%), fine size (50 μm and 80 μm), carbonation duration (1, 3, 8, 14, 17, and 24 h), CO2 concentration (18 and 100%), and heating temperature of recycled fine (500 °C). Then, the experimental results are used to calibrate a numerical model to simulate the accelerated carbonation of RF in the second step. The experimental and numerical results show the influence of each parameter on the degree of carbonation of the RF. The optimal water content for CO2 uptake is 7%. The CO2 uptake of the finer RF (50 µm) is faster than that of the larger RF (80 µm).