Accelerated carbonation of cement pastes in situ monitored by neutron diffraction

Publicación versión impresa: diciembre de 2008
In-situ monitoring of the changes that take place in the phase composition of cement pastes during accelerated carbonation (100% CO2) for different binders, has been carried out, by taking Neutron Diffraction patterns in parallel with the carbonation experiments. The variation of the intensity of chosen reflections for each phase along the experiment has been used to monitor concentration changes and has supplied data, in real time, for fractional conversion of different phases (Portlandite, Ettringite and CSH gel) of the hydrated cement pastes. Fitting of these results has allowed to make a qualitative approach to the kinetics of the carbonation of the different phases and extracting conclusions on the microstructural changes that takes place during the carbonation of cement pastes.
The experiments reported here were done thanks to the beamtime (Exp 5-25-50) granted by the Institute Max von Laue- Paul Langevin (ILL). The authors are especially grateful to the staff of D20. The authors also acknowledge the funding provided by the Spanish MMA through the project n° 005/2006/2-3.1.