MSE Colloquium: Sriramya Nair, Cement-based Magneto-rheological Fluids for Well Cementing and 3D Printing of Concrete

Dr. Sriramya Nair
Assistant Professor,
School of Civil and Environmental Engineering,
Cornell University
https://nair.cee.cornell.edu

Abstract

Rather than focusing solely on the chemical additives that can change the properties of concrete, by incorporating magnetic particles into cement paste and applying a magnetic field, the rheological properties of the cement paste can be controlled in real time. Such fluids are called cement-based magnetorheological fluids. By varying the particles and intensity of magnetic field, flow-on-demand and set-on-demand properties can be achieved. Two applications that benefit from real time control of rheological properties are well cementing and 3D printing of concrete. In well cementing, achieving complete displacement of cement slurries in the entire cross section is challenging because there is limited control behind a casing, especially thousands of feet underground. Moreover, it is hard to determine if complete displacement has been achieved using logging tools. By using a custom designed electromagnetic wellbore tool and incorporating magnetic particles in the slurry, the well cementing process can be improved. Furthermore, when the intensity of the external magnetic field is increased, the set-on-demand feature enables stiffening of the cement slurry and prevents unwanted flow of hydrocarbons during hydration of the cemented column.

Moving onto 3D printing of concrete, the most common technique, the discrete layer deposition technique, is faced with many challenges particularly in terms of the printable height, uniformity and loss of shape. The talk will discuss the applicability of magneto-rheology to address these challenges. Finally, the talk will also focus on the use of these single crystal magnetic particles for grain by grain analysis using far field high energy diffraction microscopy (ff-HEDM) at the Cornell High Energy Synchrotron Source. Under compressive load, ff-HEDM is used to probe the stress state of each of the crystalline magnetic particles to understand the the micro-mechanical behavior of cementitious materials.

Bio

Dr. Nair is a material scientist focusing on development and characterization of novel cementitious materials. Prior to joining CEE, she worked as a Post-Doctoral Associate at the Cornell High Energy Synchrotron Source (CHESS), investigating the micro-mechanical response of alternate cementitious materials. Previously, she was a Research Associate in the Petroleum Engineering Department at the University of Texas at Austin and worked on improving zonal isolation of oil and gas wells and for decommissioning and permanent abandonment of wells. Dr. Nair received her Ph.D. in Civil Engineering from the University of Texas at Austin and developed a novel set-on-demand concrete based on the principles of magneto-rheology. Her master’s degree is from the University of California, Davis and her undergraduate degree is from Indian Institute of Technology Madras. She is an active member of American Concrete Institute and American Ceramics Society.

Zoom link

https://osu.zoom.us/j/98291108807?pwd=MEt2N3RwSW5YRklOb1FaSy9qTDM4dz09

Zoom password:

768326