Long-term creep deformations in colloidal calcium-silicate-hydrate gels by accelerated aging simulations

Han Liu; Shiqi Dong; Longwen Tang; N M Anoop Krishnan; Enrico Masoero; Gaurav Sant; Mathieu Bauchy

doi:10.1016/j.jcis.2019.02.022

Long-term creep deformations in colloidal calcium-silicate-hydrate gels by accelerated aging simulations

J Colloid Interface Sci. 2019 Apr 15:542:339-346. doi: 10.1016/j.jcis.2019.02.022. Epub 2019 Feb 7.

Authors

Han Liu¹, Shiqi Dong², Longwen Tang³, N M Anoop Krishnan⁴, Enrico Masoero⁵, Gaurav Sant⁶, Mathieu Bauchy⁷

Affiliations

¹ Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA.
² Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA; Laboratory for the Chemistry of Construction Materials (LC(2)), Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA.
³ Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China.
⁴ Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA; Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
⁵ School of Engineering, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK.
⁶ Laboratory for the Chemistry of Construction Materials (LC(2)), Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA; California Nanosystems Institute (CNSI), University of California, Los Angeles, CA 90095, USA.
⁷ Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA. Electronic address: bauchy@ucla.edu.

PMID: 30769256
DOI: 10.1016/j.jcis.2019.02.022

Abstract

When subjected to a sustained load, jammed colloidal gels can feature some delayed viscoplastic creep deformations. However, due to the long timescale of creep (up to several years), its modeling and, thereby, prediction has remained challenging. Here, based on mesoscale simulations of calcium-silicate-hydrate gels (CSH, the binding phase of concrete), we present an accelerated simulation method-based on stress perturbations and overaging-to model creep deformations in CSH. Our simulations yield a very good agreement with nanoindentation creep tests, which suggests that concrete creep occurs through the reorganization of CSH grains at the mesoscale. We show that the creep of CSH exhibits a logarithmic dependence on time-in agreement with the free-volume theory of granular physics. Further, we demonstrate the existence of a linear regime, i.e., wherein creep linearly depends on the applied load-which establishes the creep modulus as a material constant. These results could offer a new physics-based basis for nanoengineering colloidal gels featuring minimal creep.

Keywords: Accelerated dynamics; Calcium–silicate–hydrate; Colloidal gel; Creep.