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Preparation of C/M−S−H cementitious materials from phosphate tailings and their dehydration and hydration mechanism
Graphical abstract Display Omitted
Highlights The waste phosphorus tailings are used to obtain the 100% content of C/M-S-H cementitious material. The thermal activation of C/M-S-H cementitious material can increase the early strength of cement concrete by 48%. It reveals that the effect mechanisms of thermal activation temperature on the phase evolution and rehydration behavior of C/M-S-H.
Abstract Aiming to reduce the CO2 emission of the cement materials preparation, a novel strategy to fabricate C/M-S-H cementitious materials from phosphate tailings has been proposed. To reveal the dehydration and hydration behavior of C/M-S-H, an experimental program combining TG, XRD, SEM, and corresponding strength evaluation was performed. The agglomerate-shaped C-S-H and flake-shaped M-S-H were synthesized from phosphate tailings. The experimental results showed that the rehydration capacity of C-S-H increased and then decreased with the rise in temperature (200–600 °C). The basic structural framework of M-S-H was maintained below 400 °C and disrupted at 600 °C, where the rehydration capacity decreased sharply. The dehydrated M-S-H showed a structural recovery after rehydration. However, dehydrated C-S-H formed dense C-S-H particles on the surface after rehydration, increasing the accumulation volume in this region and improving early strength. Ultimately, appropriate dehydration temperatures and additions could increase early hydration reactivity, thereby enhancing the concrete.
Preparation of C/M−S−H cementitious materials from phosphate tailings and their dehydration and hydration mechanism
Graphical abstract Display Omitted
Highlights The waste phosphorus tailings are used to obtain the 100% content of C/M-S-H cementitious material. The thermal activation of C/M-S-H cementitious material can increase the early strength of cement concrete by 48%. It reveals that the effect mechanisms of thermal activation temperature on the phase evolution and rehydration behavior of C/M-S-H.
Abstract Aiming to reduce the CO2 emission of the cement materials preparation, a novel strategy to fabricate C/M-S-H cementitious materials from phosphate tailings has been proposed. To reveal the dehydration and hydration behavior of C/M-S-H, an experimental program combining TG, XRD, SEM, and corresponding strength evaluation was performed. The agglomerate-shaped C-S-H and flake-shaped M-S-H were synthesized from phosphate tailings. The experimental results showed that the rehydration capacity of C-S-H increased and then decreased with the rise in temperature (200–600 °C). The basic structural framework of M-S-H was maintained below 400 °C and disrupted at 600 °C, where the rehydration capacity decreased sharply. The dehydrated M-S-H showed a structural recovery after rehydration. However, dehydrated C-S-H formed dense C-S-H particles on the surface after rehydration, increasing the accumulation volume in this region and improving early strength. Ultimately, appropriate dehydration temperatures and additions could increase early hydration reactivity, thereby enhancing the concrete.
Preparation of C/M−S−H cementitious materials from phosphate tailings and their dehydration and hydration mechanism
Jia, Jinpeng (author) / Hu, Nanyan (author) / Ye, Yicheng (author) / Yao, Nan (author) / Huang, Yang (author) / Fu, Fanghui (author)
2023-08-02
Article (Journal)
Electronic Resource
English
Hydration Reaction of Cementitious Materials Prepared with Molybdenum Tailings
| DOAJ | 2018