Mix Design-Driven Control of Carbonation and Hydration in CO<sub>2</sub>-Mixed Cement Pastes: Effects of Water, Slag, and Surfactant
This study systematically investigates the influence of mix proportion on and the early-age properties and CO<sub>2</sub> uptake of CO<sub>2</sub>-mixed cement paste, focusing on variations in the water-to-binder (w/b) ratio, slag content, and air-entraining agent (AEA) dosag...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-06-01
|
| Series: | Buildings |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-5309/15/12/2116 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1839654549579628544 |
|---|---|
| author | Jingliang Xia Chunjin Li Haoyuan Ma Qiang Ren |
| author_facet | Jingliang Xia Chunjin Li Haoyuan Ma Qiang Ren |
| author_sort | Jingliang Xia |
| collection | DOAJ |
| description | This study systematically investigates the influence of mix proportion on and the early-age properties and CO<sub>2</sub> uptake of CO<sub>2</sub>-mixed cement paste, focusing on variations in the water-to-binder (w/b) ratio, slag content, and air-entraining agent (AEA) dosage. Mineralogical characteristics were analyzed using X-ray diffraction (XRD) and thermogravimetric analysis (TGA), while pore structures were assessed via nitrogen adsorption. CO<sub>2</sub> uptake was quantified immediately after mixing. Results indicate that a low w/b ratio limits CO<sub>2</sub> dissolution and transport, favors hydration over carbonation, and leads to a coarser pore structure. At moderate w/b ratios, excess free water facilitates concurrent carbonation and hydration; however, thinner water films ultimately hinder CaCO<sub>3</sub> precipitation and C-S-H nucleation. Slag contents up to 30% slightly suppress early carbonation and hydration, while higher dosages significantly delay both reactions and increase capillary porosity. An increasing AEA dosage stabilizes CO<sub>2</sub> bubbles, suppressing immediate CO<sub>2</sub> dissolution and reducing the early formation of carbonation and hydration products; excessive AEAs promotes bubble coalescence and results in an interconnected pore network. An optimized mix design, moderate water content, slag below 30%, and limited AEA dosage enhance the synergy between carbonation and hydration, improving early pore refinement and reaction kinetics. |
| format | Article |
| id | doaj-art-6e4d85f6739b4deaae6240b44e09aa2f |
| institution | Matheson Library |
| issn | 2075-5309 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Buildings |
| spelling | doaj-art-6e4d85f6739b4deaae6240b44e09aa2f2025-06-25T13:36:15ZengMDPI AGBuildings2075-53092025-06-011512211610.3390/buildings15122116Mix Design-Driven Control of Carbonation and Hydration in CO<sub>2</sub>-Mixed Cement Pastes: Effects of Water, Slag, and SurfactantJingliang Xia0Chunjin Li1Haoyuan Ma2Qiang Ren3State Key Laboratory of Building Safety and Built Environment, National Engineering Research Center of Building Technology, Beijing 100013, ChinaKey Laboratory of Advanced Civil Engineering Materials of Ministry of Education, School of Materials Science and Engineering, Tongji University, 4800 Cao’an Road, Shanghai 201804, ChinaKey Laboratory of Advanced Civil Engineering Materials of Ministry of Education, School of Materials Science and Engineering, Tongji University, 4800 Cao’an Road, Shanghai 201804, ChinaState Key Laboratory of Building Safety and Built Environment, National Engineering Research Center of Building Technology, Beijing 100013, ChinaThis study systematically investigates the influence of mix proportion on and the early-age properties and CO<sub>2</sub> uptake of CO<sub>2</sub>-mixed cement paste, focusing on variations in the water-to-binder (w/b) ratio, slag content, and air-entraining agent (AEA) dosage. Mineralogical characteristics were analyzed using X-ray diffraction (XRD) and thermogravimetric analysis (TGA), while pore structures were assessed via nitrogen adsorption. CO<sub>2</sub> uptake was quantified immediately after mixing. Results indicate that a low w/b ratio limits CO<sub>2</sub> dissolution and transport, favors hydration over carbonation, and leads to a coarser pore structure. At moderate w/b ratios, excess free water facilitates concurrent carbonation and hydration; however, thinner water films ultimately hinder CaCO<sub>3</sub> precipitation and C-S-H nucleation. Slag contents up to 30% slightly suppress early carbonation and hydration, while higher dosages significantly delay both reactions and increase capillary porosity. An increasing AEA dosage stabilizes CO<sub>2</sub> bubbles, suppressing immediate CO<sub>2</sub> dissolution and reducing the early formation of carbonation and hydration products; excessive AEAs promotes bubble coalescence and results in an interconnected pore network. An optimized mix design, moderate water content, slag below 30%, and limited AEA dosage enhance the synergy between carbonation and hydration, improving early pore refinement and reaction kinetics.https://www.mdpi.com/2075-5309/15/12/2116CO<sub>2</sub> mixingCO<sub>2</sub> sequestrationmix proportioncarbonationproperties |
| spellingShingle | Jingliang Xia Chunjin Li Haoyuan Ma Qiang Ren Mix Design-Driven Control of Carbonation and Hydration in CO<sub>2</sub>-Mixed Cement Pastes: Effects of Water, Slag, and Surfactant Buildings CO<sub>2</sub> mixing CO<sub>2</sub> sequestration mix proportion carbonation properties |
| title | Mix Design-Driven Control of Carbonation and Hydration in CO<sub>2</sub>-Mixed Cement Pastes: Effects of Water, Slag, and Surfactant |
| title_full | Mix Design-Driven Control of Carbonation and Hydration in CO<sub>2</sub>-Mixed Cement Pastes: Effects of Water, Slag, and Surfactant |
| title_fullStr | Mix Design-Driven Control of Carbonation and Hydration in CO<sub>2</sub>-Mixed Cement Pastes: Effects of Water, Slag, and Surfactant |
| title_full_unstemmed | Mix Design-Driven Control of Carbonation and Hydration in CO<sub>2</sub>-Mixed Cement Pastes: Effects of Water, Slag, and Surfactant |
| title_short | Mix Design-Driven Control of Carbonation and Hydration in CO<sub>2</sub>-Mixed Cement Pastes: Effects of Water, Slag, and Surfactant |
| title_sort | mix design driven control of carbonation and hydration in co sub 2 sub mixed cement pastes effects of water slag and surfactant |
| topic | CO<sub>2</sub> mixing CO<sub>2</sub> sequestration mix proportion carbonation properties |
| url | https://www.mdpi.com/2075-5309/15/12/2116 |
| work_keys_str_mv | AT jingliangxia mixdesigndrivencontrolofcarbonationandhydrationincosub2submixedcementpasteseffectsofwaterslagandsurfactant AT chunjinli mixdesigndrivencontrolofcarbonationandhydrationincosub2submixedcementpasteseffectsofwaterslagandsurfactant AT haoyuanma mixdesigndrivencontrolofcarbonationandhydrationincosub2submixedcementpasteseffectsofwaterslagandsurfactant AT qiangren mixdesigndrivencontrolofcarbonationandhydrationincosub2submixedcementpasteseffectsofwaterslagandsurfactant |