Events Calendar

Astani Civil and Environmental Engineering Ph.D. Seminar

Speaker: Dr. Shiho Kawashima, Columbia University

Talk Title: Thixotropy of Fresh Cement-Based Systems

Abstract: Over its lifetime, cement-based materials transition from behaving as a near-Newtonian fluid to a viscoelastic fluid-solid to eventually a rock-like solid. And although the first two phases are fleeting compared to the third phase, this earlier life period is intimately tied to materials processing.
Therefore the corresponding properties are critical in determining the efficiency of the placement process during construction, as well as the eventual performance of the structure in place. This requires that the rheological properties of the material be well characterized and controlled. During placement the material undergoes a wide range of deformations -“ very large during processes such as pouring and pumping, but then diminishingly small after placement when it is essentially at rest. This talk will cover studies that investigate the specific rheological aspect of thixotropy in cement paste and mortar systems that incorporate highly-purified attapulgite clay through static shear and dynamic rheological protocols that span wide timescales and magnitudes of deformations and rates.



Biography:
Shiho Kawashima is an Assistant Professor of Civil Engineering and Engineering Mechanics at Columbia University. Her work is in experimental cement and concrete research, which aims to tie nano-microstructural behavior to macroscale structural response. She specializes in cement rheology, particularly in the development of innovative measurement techniques to further the understanding of the structural and temporal evolution of the fresh-state microstructure of cementitious systems. She is also interested in the design of nanocomposites and sustainable infrastructural materials. She received her B.S. in Civil Engineering and Engineering Mechanics at Columbia University, and her M.S. and Ph.D. in Civil Engineering at Northwestern University.


Host: Dr. Erik Johnson

Location: Biegler Hall of Engineering (BHE) - 122

Audiences: Everyone Is Invited

Contact: Evangeline Reyes