Paper Number
PO120
Session
Poster Session
Title
Super absorbent polymers for internally cured, high performance concrete: Rheopecticity and rheological properties
Presentation Date and Time
October 12, 2022 (Wednesday) 6:30
Track / Room
Poster Session / Riverwalk A
Authors
- Seshadri, Akul N. (Purdue Univeristy, Materials Science and Engineering)
- O'Banion, Ethan E. (Purdue University, Materials Science and Engineering)
- Adams, Caitlin J. (Purdue University, Materials Science and Engineering)
- Corder, Ria D. (Purdue University, School of Materials Engineering)
- Erk, Kendra A. (Purdue University, School of Materials Engineering)
Author and Affiliation Lines
Akul N. Seshadri, Ethan E. O'Banion, Caitlin J. Adams, Ria D. Corder and Kendra A. Erk
School of Materials Engineering, Purdue University, West Lafayette, IN 47907
Speaker / Presenter
Seshadri, Akul N.
Keywords
experimental methods; composite rheology; construction materials; gels; mud rheology; polymer sustainability; soil rheology
Text of Abstract
Hydrogels made from Superabsorbent Polymers (SAPs) are added to cement to act as internal curing agents. The rheology of cement pastes with commercial SAPs of varying size and supplier was investigated. Cement is rheopectic at constant shear and shear thinning with increasing shear rate. The addition of SAP increases the viscosity of cement pastes. SAP chemistry and size affects the resulting rheology of the cement paste. A new method of constructing a flow curve from the minimums of rheopectic viscosity curves is proposed as an alternative to traditional shear rate ramping tests that do not account for the rheopectic behavior of cement pastes. Samples from Supplier A showed a clear trend of increasing viscosity with post-hydration age while SAP samples from Supplier B did not show any correlation between hydration age and viscosity. Samples became less shear thinning with age. The SAP with the smallest average particle size gave the highest viscosity and yield stress and was also the most shear thinning. SAPs from Supplier B had high variability (error) in their rheology. The viscosities of Supplier B samples all converged to a similar value ~10 Pa.s at high shear. The yield stress decreased with age for Supplier B SAP samples while remaining constant for No SAP and Supplier A samples.