Document Type
Extended Abstract
Abstract
Given that CO2 chamber and high inner pressure are needed in the traditional carbonation curing, we propose an in-situ internal carbonation by aminated mesoporous silica nanoparticles (MSNs) to tackle the challenge due to its high specific surface area. In this study, phase transformation and nucleation behavior were investigated by in-situ carbonation of alite paste with MSNs-amine absorbing CO2 (MSNs-amine-AC) and MSNs-amine desorbing CO2 (MSNs-amine-DC), separately. C-S-H with low Ca/Si ratio and negative electric potential is formed when MSNs-amine-DC is gradually eroded, wrapped and collapsed, converting to reaction sites chemically. On the contrary, ACC generated in MSNs-amine-AC blocks the mesopores, retard the pozzolanic reaction and maintain the silica skeleton. Thereafter, calcite is crystallized via the dissolved ACC and embedded on C-S-H with positive electric potential, turning to nucleation sites physically. To conclude, the in-situ internal carbonation models of amined MSNs modified alite paste are proposed to exhibit the microstructure evolution.
Keywords
Internal carbonation, Alite, Mesoporous silica nanoparticle, Nucleation, Microstructure evolution.
DOI
10.5703/1288284317952
Microstructure evolution of alite in-situ carbonated by aminated mesoporous silica nanoparticles
Given that CO2 chamber and high inner pressure are needed in the traditional carbonation curing, we propose an in-situ internal carbonation by aminated mesoporous silica nanoparticles (MSNs) to tackle the challenge due to its high specific surface area. In this study, phase transformation and nucleation behavior were investigated by in-situ carbonation of alite paste with MSNs-amine absorbing CO2 (MSNs-amine-AC) and MSNs-amine desorbing CO2 (MSNs-amine-DC), separately. C-S-H with low Ca/Si ratio and negative electric potential is formed when MSNs-amine-DC is gradually eroded, wrapped and collapsed, converting to reaction sites chemically. On the contrary, ACC generated in MSNs-amine-AC blocks the mesopores, retard the pozzolanic reaction and maintain the silica skeleton. Thereafter, calcite is crystallized via the dissolved ACC and embedded on C-S-H with positive electric potential, turning to nucleation sites physically. To conclude, the in-situ internal carbonation models of amined MSNs modified alite paste are proposed to exhibit the microstructure evolution.