| 摘要: |
| 对经CO2矿化后的再生骨料（RA）吸水率和表观密度的影响因素进行分析.结果表明：CO2矿化处理能有效改善再生骨料的物理性能，且随着固碳率的增加，RA的物理性能改善愈发显著；当RA含水率为1.3%时，在环境温度和相对湿度分别为50 ℃和98%，CO2体积分数、压力、碳化时间分别为99%、0.15 MPa、24 h条件下，RA的碳化强化效果最佳，与未经碳化处理的RA相比，其固碳率为1.77%，吸水率降低33.47%，表观密度增加2.06%.经CO2矿化处理后，RA中的Ca（OH）2和水化硅酸钙（C-S-H）凝胶与CO2发生碳化反应，在孔隙中生成方解石晶型的CaCO3，使得界面过渡区变得致密，孔隙率由22.07%降至12.78%，实现了RA对CO2的封存，改善了RA的物理性能. |
| 关键词: 再生骨料 CO2矿化 性能提升 微观分析 |
| DOI：10.3969/j.issn.1007-9629.2024.10.004 |
| 分类号:TU502 |
| 基金项目:中国建材集团关键核心技术“揭榜挂帅”项目（2021HX0506）；“十四五”国家重点研发计划项目（2022YFB2602604） |
|
| Influencing Factors of Physical Properties of CO2 Mineralized Recycled Aggregate and Its Mechanism |
|
YUAN Qiang1,2, ZHANG Jiaoling1,2, ZHANG Suhui1,2, DING Rensheng3
|
|
1.School of Civil Engineering， Central South University， Changsha 410075， China;2.National Engineering Research Center of High-Speed Railway Construction Technology， Central South University， Changsha 410075， China;3.Shanghai-Hangzhou Railway Passenger Dedicated Line Co.， Ltd.， Shanghai 200237， China
|
| Abstract: |
| The influencing factors affecting the water absorption and apparent density of recycled aggregate（RA） after CO2 mineralization were analyzed. Results show that the physical properties of RA improved significantly after CO2 mineralization. And as the carbon sequestration increases， the physical properties of RA improve more significantly. The strengthening effect of RA after carbonation is the best， when the water content of RA is 1.3%， the temperature and relative humidity of 50 ℃ and 98%， CO2 concentration of 99%， pressure of 0.15 MPa and carbonation time of 24 h. At these conditions， compared with untreated recycled aggregete， the CO2 uptake of recycled aggregate is 1.77%， the water absorption of RA is reduced by 33.47%， the apparent density of RA is increased by 2.06%. After CO2 mineralization， Ca（OH）2 and calcium silicate hydrated （C-S-H） gel converted to calcite in the pore makes the interface transition zone dense and the porosity decrease （from 22.07% to 12.78%）， which realized the storage of CO2 by recycled aggregate and the physical properties of RA are improved. |
| Key words: recycled aggregate（RA） CO2 mineralization performance improvement microstructural analysis |
