Rheology and impact of power ultrasound on mixtures of cement and limestone fillers

Supervisor
F. Toussaint
 (
HIC
)
CoSupervisors
S. Manneville
 (
CNRS
)
J. Royer
 (
UEDIN
)

Objectives: Cement is responsible for more than 5% of the total anthropogenic CO2 emissions. A solution to reduce the carbon footprint of cement-based materialsi s to substitute cement with other types of particles, such as limestone filler. Another solution is to reduce the amount of concrete through 3D Printing. In both cases, admixtures are used to target a required rheological behavior, either to fluidify or to structure the cement paste.  First, the HIC DC will perform an in - depth study of the rheological properties of cement/limestone filler rheological properties at an early stage with various concentrations of superplasticizer to understand their flow properties. Second, the DC will determine the impact of power ultrasound on these dispersions (including in the presence of non-Brownian particles mimicking sand of larger aggregates present in concrete-related applications) and assess how such external perturbation could replace the use of polymer to control (e.g., fluidify or structure) the rheological response ofthe mixtures. Tools will include rheometry and combination rheometry with power ultrasound in collaboration with UEDIN (Royer) and CNRS (Manneville). Finally, the long-term (> 28 days) mechanical properties (e.g., hardness, Young modulus,etc.) of the hydrated mixtures investigated will be performed at HIC.

Academic secondment: The DC will be at CNRS (15M/M16 - M30) to study the rheology of the cement-based paste exposed to power ultrasound.