Seminar: Dr. Xiaodan Li
Computationally Implemented Modeling of the Creep and Relaxation of Hydrating Cement Paste
3:30 pm –
4:30 pm
Scott Engineering Center Link
Room: N105 / PKI 207
Additional Info: SLNK
Abstract:
Cement paste exhibits viscoelastic/viscoplastic effects in addition to the instantaneous elastic effects; such time-dependent creep and relaxation have a significant impact on the stress and strain fields in cementitious materials. Inside the hydrating cement composite, when load-bearing phases dissolve while the material is under load, the stress being transmitted by those phases is handed off to neighboring phases. This leads to potentially additional deformation and creep of cement paste. To experimentally determine this creep is challenging.
A novel, fully coupled thermodynamic, Mechanical, and Microstructural model and computational methodology was developed in order to predict the evolution of the viscoelastic/viscoplastic properties of reacting cement paste. The model was utilized to test the hypothesis that solid phase dissolution within loaded hydrating cement paste leads to significant creep and relaxation. The simulations suggest that inherent viscoelastic deformation caused by calcium silicate hydrate is not necessarily the primary mechanism leading to the overall viscoelastic/viscoplastic behavior of cement paste. The effect of time-dependent dissolution of solids is substantial and should be considered as a significant mechanism for creep and relaxation. Results of the simulation were compared to experimental measurements (via X-ray CT).
Bio:
Xiaodan (Sonia) Li holds the B.S. degree from Hong Kong University of Science and Technology in 2009, and M.S. and Ph. D. degree from Texas A&M University in 2012 and 2017, all in Civil and Environmental engineering. She is currently a Postdoctoral Research Associate working at Oklahoma State University, OK. USA.
Her research focuses on studying the early age hydration of cement and predicting the properties of fresh concrete through computational modeling and multi-scale experimentation work. She has developed various computational models to predict the mechanical properties and long term durability of many cementitious materials, such as Portland cement, fly ash, and Calcium Sulfate Aluminate cement. She has also utilized fast micro and nano X-ray tomography to directly in-situ observe and analyze the early age hydration of cement.
She has published six first-author high impact journals (Cement & Concrete Composites, Journal of the American Ceramic Society, etc.), one book chapter and given nine presentations and lecturers at national and international conferences (ACerS, ACI, etc.). Many of her papers have been awarded as one of “best papers” from the Journal of the American Ceramic Society and Materials and Structures. Over the past few years, she has worked as a major contributor for a few research projects sponsored by NSF, FHWA and DOE. She has also contributed to writing and reviewing research proposals submitted to EPRI, FHWA and Tran-SET. She is a member of ACerS and ACI. She served as secretory for ACI Texas A&M student Chapter in 2015.
Cement paste exhibits viscoelastic/viscoplastic effects in addition to the instantaneous elastic effects; such time-dependent creep and relaxation have a significant impact on the stress and strain fields in cementitious materials. Inside the hydrating cement composite, when load-bearing phases dissolve while the material is under load, the stress being transmitted by those phases is handed off to neighboring phases. This leads to potentially additional deformation and creep of cement paste. To experimentally determine this creep is challenging.
A novel, fully coupled thermodynamic, Mechanical, and Microstructural model and computational methodology was developed in order to predict the evolution of the viscoelastic/viscoplastic properties of reacting cement paste. The model was utilized to test the hypothesis that solid phase dissolution within loaded hydrating cement paste leads to significant creep and relaxation. The simulations suggest that inherent viscoelastic deformation caused by calcium silicate hydrate is not necessarily the primary mechanism leading to the overall viscoelastic/viscoplastic behavior of cement paste. The effect of time-dependent dissolution of solids is substantial and should be considered as a significant mechanism for creep and relaxation. Results of the simulation were compared to experimental measurements (via X-ray CT).
Bio:
Xiaodan (Sonia) Li holds the B.S. degree from Hong Kong University of Science and Technology in 2009, and M.S. and Ph. D. degree from Texas A&M University in 2012 and 2017, all in Civil and Environmental engineering. She is currently a Postdoctoral Research Associate working at Oklahoma State University, OK. USA.
Her research focuses on studying the early age hydration of cement and predicting the properties of fresh concrete through computational modeling and multi-scale experimentation work. She has developed various computational models to predict the mechanical properties and long term durability of many cementitious materials, such as Portland cement, fly ash, and Calcium Sulfate Aluminate cement. She has also utilized fast micro and nano X-ray tomography to directly in-situ observe and analyze the early age hydration of cement.
She has published six first-author high impact journals (Cement & Concrete Composites, Journal of the American Ceramic Society, etc.), one book chapter and given nine presentations and lecturers at national and international conferences (ACerS, ACI, etc.). Many of her papers have been awarded as one of “best papers” from the Journal of the American Ceramic Society and Materials and Structures. Over the past few years, she has worked as a major contributor for a few research projects sponsored by NSF, FHWA and DOE. She has also contributed to writing and reviewing research proposals submitted to EPRI, FHWA and Tran-SET. She is a member of ACerS and ACI. She served as secretory for ACI Texas A&M student Chapter in 2015.